diff --git a/README.md b/README.md
index 844777a86..1c7ec0149 100644
--- a/README.md
+++ b/README.md
@@ -78,15 +78,15 @@ fn main() {
   match io.read_file("settings.json") {
     Ok(content) -> match json.parse(content, Config) {
       Ok(cfg) -> println("loaded: {cfg.name}")
-      Err(e) -> println("parse error: {e.message()}")
+      Err(e) -> println("parse error: {Error.message(e)}")
     }
     Err(io.NotFound(path)) -> println("no config at {path} — run `silt init` first")
-    Err(e) -> println("read error: {e.message()}")
+    Err(e) -> println("read error: {Error.message(e)}")
   }
 }
 ```
 
-Stdlib errors are typed enums — `IoError`, `JsonError`, `HttpError`, and so on — so `match` can fork on specific failures like `NotFound(path)` and still fall back to `.message()` for the long tail.
+Stdlib errors are typed enums — `IoError`, `JsonError`, `HttpError`, and so on — so `match` can fork on specific failures like `NotFound(path)` and still fall back to `Error.message` for the long tail.
 
 ## HTTP
 
@@ -129,9 +129,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> reply(201, todo)
-          Err(e) -> reply(400, #{ "error": e.message() })
+          Err(e) -> reply(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> reply(400, #{ "error": e.message() })
+        Err(e) -> reply(400, #{ "error": Error.message(e) })
       }
       _ -> reply(404, #{ "error": "Not found" })
     }
diff --git a/docs/concurrency.md b/docs/concurrency.md
index 220b2ea5c..c463dbd3d 100644
--- a/docs/concurrency.md
+++ b/docs/concurrency.md
@@ -717,7 +717,7 @@ fn main() {
     Ok(Ok(contents)) -> println(contents)
     Ok(Err(e)) -> println("the read failed: {e}")
     Err(task.Timeout) -> println("the read took too long")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 ```
diff --git a/docs/getting-started.md b/docs/getting-started.md
index 9e32f6160..589798632 100644
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@@ -166,7 +166,7 @@ fn read_head(path) {
 ```
 
 Use `match` to handle the result. Every stdlib error enum (here `IoError`) implements the built-in
-`Error` trait, so you can pattern-match on specific variants and fall back to `.message()` for
+`Error` trait, so you can pattern-match on specific variants and fall back to `Error.message` for
 anything else:
 
 ```silt
@@ -177,7 +177,7 @@ fn main() {
   match io.read_file("app.json") {
     Ok(content) -> println("loaded {string.length(content)} characters")
     Err(io.NotFound(path)) -> println("file does not exist: {path}")
-    Err(e) -> println("error: {e.message()}")
+    Err(e) -> println("error: {Error.message(e)}")
   }
 }
 ```
diff --git a/docs/language/bindings-and-functions.md b/docs/language/bindings-and-functions.md
index 7b7f54b87..7ecca0c78 100644
--- a/docs/language/bindings-and-functions.md
+++ b/docs/language/bindings-and-functions.md
@@ -81,7 +81,7 @@ fn main() {
   let _ = task.spawn { -> println("in the background") }
   match io.write_file("out.txt", "data") {
     Ok(_) -> println("saved")
-    Err(e) -> println("not saved: {e.message()}")
+    Err(e) -> println("not saved: {Error.message(e)}")
   }
 }
 ```
@@ -185,9 +185,9 @@ What a `let`'s value can reach is decided by four rules:
   module's impls give that module's traits (and the builtin traits):
   a `let` that mentions another module's function is initialised after
   every `let` those methods read.
-- **A method call on a value whose type is a bounded type variable
-  (`fn f(x: a) where a: Label { x.label() }`) reaches every impl of the
-  method in the module**, whichever value the call is given.
+- **A call through a trait with a value whose type is a bounded type
+  variable (`fn f(x: a) where a: Label { Label.label(x) }`) reaches every
+  impl of the method in the module**, whichever value the call is given.
 - **A `let` that is a plain value runs nothing.** A plain value is a
   literal, a name, a closure, or a list, tuple, record, map, set or
   variant made of plain values. Such a `let` needs only the top-level
@@ -216,7 +216,7 @@ A closure handed to a function is not a plain value: `let f = wrap({ n
 -> ... f(n - 1) ... })` runs `wrap`, which may call the closure.
 
 - **Showing a value reaches the `Display` impls of its parts.**
-  Interpolation, `println`, `string.from` and `.display()` call the
+  Interpolation, `println` and `string.from` call the
   `Display` impl written for each type the value is made of: its own,
   its fields', its type arguments'. A value of an unknown type (a type
   variable, an associated type such as `Self::Item`) may be of any
diff --git a/docs/language/error-handling.md b/docs/language/error-handling.md
index d0accafb1..63c00cc0c 100644
--- a/docs/language/error-handling.md
+++ b/docs/language/error-handling.md
@@ -36,7 +36,7 @@ catalog is in [`docs/stdlib/errors.md`](../stdlib/errors.md); hovering
 over an error type in your editor shows the same table.
 
 You can either pattern-match on a specific variant, or fall back to
-`.message()` for a rendered string:
+`Error.message` for a rendered string:
 
 ```silt
 import io
@@ -47,15 +47,15 @@ fn main() {
     Ok(content) -> println("loaded {string.length(content)} bytes")
     Err(io.NotFound(path)) -> println("file does not exist: {path}")
     Err(io.PermissionDenied(path)) -> println("denied: {path}")
-    Err(e) -> println("error: {e.message()}")
+    Err(e) -> println("error: {Error.message(e)}")
   }
 }
 ```
 
 Every stdlib error enum implements the built-in `Error` trait, which has
 `Display` as a supertrait and provides `message(self) -> String`. String
-interpolation `"{e}"` and `e.message()` produce the same text — silt routes
-the `Display` impl through `Error::message` for stdlib error enums so the two
+interpolation `"{e}"` and `Error.message(e)` produce the same text — silt routes
+the `Display` impl through `Error.message` for stdlib error enums so the two
 shapes never drift.
 
 ## The `?` Operator
diff --git a/docs/language/generics.md b/docs/language/generics.md
index 695896a5c..331652968 100644
--- a/docs/language/generics.md
+++ b/docs/language/generics.md
@@ -140,13 +140,13 @@ point to.
 Inside the function a type variable stands for a type the function does
 not know: the body must work for every type the caller may choose. It
 cannot treat an `a` as an `Int`, return a `b` where it promised an `a`,
-or call a method no `where` clause promises:
+or ask of it a trait no `where` clause promises:
 
 ```silt
 fn one(x: a) -> a { 1 }                    -- ERROR: expected a, got Int
 fn second(x: a, y: b) -> a { y }           -- ERROR: expected a, got b
-fn show(x: a) -> String { x.display() }    -- ERROR: `a` has no trait bound
-fn show(x: a) -> String where a: Display { x.display() }   -- ok
+fn show(x: a) -> String { "{x}" }          -- ERROR: `a` is not known to implement Display
+fn show(x: a) -> String where a: Display { "{x}" }   -- ok
 ```
 
 An annotation in the body that writes one of the signature's variables
@@ -225,12 +225,12 @@ fn parse(body: String, type a) -> Result(a, DecodeError) where a: Parse {
 }
 
 fn try_from(x: a, type b) -> b where a: Convertible(b) {
-  x.convert()
+  Convertible.convert(x)
 }
 ```
 
 Inside the body, the `type a` parameter doubles as a dispatch target for
-trait methods. `a.default()` invokes the `default` method of whichever
+the trait methods that make a value. `a.default()` invokes the `default` method of whichever
 `Default` impl matches the concrete type passed in — see
 [Trait methods on types](#trait-methods-on-types) below.
 `try_from` shows the companion pattern: a parameterized trait
@@ -381,7 +381,7 @@ import list
 import string
 
 fn shout(items: List(a)) -> List(String) where a: Display {
-  items |> list.map { x -> x.display() |> string.to_upper }
+  items |> list.map { x -> "{x}" |> string.to_upper }
 }
 ```
 
@@ -399,7 +399,7 @@ type Box(a) {
 trait Display for Box(a) where a: Display {
   fn display(self) -> String {
     match self {
-      Box(inner) -> "Box({inner.display()})"
+      Box(inner) -> "Box({inner})"
     }
   }
 }
@@ -442,9 +442,9 @@ trait HashTable(Fn(Int) -> Int) for OtherStore { ... }
 ```
 
 Supertraits can also reference the enclosing trait's params. The args
-flow automatically — a `where x: Child(Int)` constraint makes
-`Parent`'s methods callable on `x` with Parent's own params bound to
-the same `Int`:
+flow automatically — a `where x: Child(Int)` constraint lets `x` be
+given to `Parent`'s methods with Parent's own params bound to the same
+`Int`:
 
 ```silt
 trait Parent(a) {
@@ -456,7 +456,7 @@ trait Child(a): Parent(a) {
 }
 
 fn use_parent(x: b, type a) -> a where b: Child(a) {
-  x.parent_method() -- returns a, bound by Child's arg
+  Parent.parent_method(x) -- returns a, bound by Child's arg
 }
 ```
 
@@ -474,7 +474,7 @@ lowercase type variables bound elsewhere in the signature:
 
 ```silt
 fn try_from(x: a, type b) -> b where a: Convertible(b) {
-  x.convert()
+  Convertible.convert(x)
 }
 ```
 
@@ -494,7 +494,7 @@ supplied arguments when resolving method types at the call site.
 Constraints transitively include supertraits. Given a user-defined
 `Ordered` trait whose declaration names `Equal` as a supertrait
 (hypothetical user-defined trait, not built-in), a `where a: Ordered`
-bound makes methods from `Equal` callable on `a` as well:
+bound gives `a` what `Equal` gives as well:
 
 ```silt
 trait Ordered: Equal {
@@ -502,8 +502,8 @@ trait Ordered: Equal {
 }
 
 fn sorted_unique(xs: List(a)) -> List(a) where a: Ordered {
-  -- Both a.less(b) (from Ordered) and a.equal(b) (from the
-  -- transitively-included Equal supertrait) are callable here.
+  -- Both Ordered.less(a, b) and a == b (from the transitively-
+  -- included Equal supertrait) work here.
   ...
 }
 ```
@@ -532,9 +532,10 @@ error. See [Built-in Traits](traits.md#built-in-traits).
 
 ### Trait methods on types
 
-Some trait methods take no `self` and only return `Self` — constructors
-like `Default::default()` or `Monoid::empty()`. To invoke these without
-an instance, call them on a **type descriptor**: either a bare type
+Some trait methods take no value of the type and only make one —
+constructors like `default()` or `empty()`. A call through the trait
+could not say which impl it means, so these are called on a **type
+descriptor**: either a bare type
 name (`Int.default()`) or a `type a` parameter (`a.default()`):
 
 ```silt
@@ -563,19 +564,21 @@ The rules:
 - **Dispatch is by the descriptor's carried type name.** At runtime the
   descriptor `Int` resolves to the `Default` impl for `Int`; `Todo`
   resolves to `Default for Todo`; etc.
-- **The descriptor is a dispatch key, not an argument.** It doesn't
-  occupy a `self` slot. Method signatures that declare `Self` as a
-  parameter (e.g. `fn combine(a: Self, b: Self)`) receive only the
-  caller's explicit arguments.
+- **The descriptor is a dispatch key, not an argument.** It occupies no
+  parameter of the method: `a.empty()` passes nothing.
+- **A method that takes a value of the type is called through its
+  trait.** `Monoid.combine(x, y)` reaches the impl for the type of its
+  arguments; `a.combine(x, y)` and `Int.combine(1, 2)` are errors whose
+  help names that call.
 - **`where` constraints are required** for the generic path. Writing
   `fn f(type a) -> a { a.default() }` without `where a: Default`
   rejects at the call to `a.default()` — the compiler can't prove an
   impl exists.
-- **A method without `self` is called on a type, never on a value.**
-  `x.default()` on a value `x: a` is an error that names the call to
-  write: `a.default()`, with a `type a` parameter. Nor is it a candidate
-  for a call on a value: with `where a: Foo, a: Bar`, where only `Bar`'s
-  `build` takes `self`, `x.build()` is `Bar`'s.
+- **A method that makes a value is called on a type, never on a value
+  or through its trait.** `x.default()` on a value `x: a` is an error (a
+  dot after a value names a field) whose help names the call to write:
+  `a.default()`, with a `type a` parameter. `Default.default()` is an
+  error that says to call it on a type.
 - **Ambiguity across traits is rejected.** If both `Foo` and `Bar`
   declare a method `build` and `a` is constrained to `Foo + Bar`,
   calling `a.build()` errors with "ambiguous method 'build' on `type a`:
@@ -800,7 +803,7 @@ trait Convert(Int) for String {
 }
 
 fn into(x: a, type b) -> b where a: Convert(b) {
-  x.convert()
+  Convert.convert(x)
 }
 ```
 
diff --git a/docs/language/loops-and-pipes.md b/docs/language/loops-and-pipes.md
index 3113a33b1..51e55c893 100644
--- a/docs/language/loops-and-pipes.md
+++ b/docs/language/loops-and-pipes.md
@@ -16,9 +16,9 @@ let a = list.filter(xs, { x -> x > 0 })
 let b = xs |> list.filter { x -> x > 0 }
 ```
 
-The right side is a call like any other, so the rule is the same when it
-is a method call: the piped value is the first argument the call writes,
-after the receiver. `5 |> acc.add()` is `acc.add(5)`.
+The right side is a call like any other, so the rule is the same for a
+call through a trait: `5 |> Greet.greet` is `Greet.greet(5)`, and
+`5 |> Adder.add(3)` is `Adder.add(5, 3)`.
 
 Without pipes, function composition nests inside-out. With pipes, it reads
 top-to-bottom:
@@ -92,8 +92,7 @@ println("{user.name} is {user.age}") -- field access in interpolation
 String interpolation automatically invokes the `Display` trait. User-defined
 types and the displayable builtins implement `Display` automatically;
 channels and function values are the exception — they do not implement
-`Display`, so interpolating them is a compile error. No need to call
-`.display()` explicitly.
+`Display`, so interpolating them is a compile error.
 
 Escape literal braces with backslash: `"\{not interpolation}"`.
 
diff --git a/docs/language/modules.md b/docs/language/modules.md
index a51b92d11..2524ff12f 100644
--- a/docs/language/modules.md
+++ b/docs/language/modules.md
@@ -169,14 +169,11 @@ module `util`. A type whose name no other type of the program has
 prints bare: `Pt {x: 1}`.
 
 Two modules may also each declare a trait of one name, say `Show` with
-a method `show`, and implement it for one type. A method call means the
-method of the trait its module sees: a trait it declares, imports by
-name, or reaches through a module it imports. A call that sees both
-traits is an error at the call. The builtin traits (`Display`,
-`Compare`, `Equal`, `Hash`, `Error`) are always seen: a trait of the
-program with a method named `display` implemented for `Int` makes
-`5.display()` ambiguous; call it through a `where` bound for the
-trait. The structural traits of a type (`Equal`, `Hash`, `Compare`,
+a method `show`, and implement it for one type. A call names the trait
+it means, as it names any item: `a.Show.show(5)` and `b.Show.show(5)`
+are two calls of two methods. A trait of the program with a method named
+`display` implemented for `Int` is no `Display`: `Pretty.display(5)` calls
+it, and interpolation still shows `5` structurally. The structural traits of a type (`Equal`, `Hash`, `Compare`,
 `Display` without a written impl) go by the builtin traits of its
 fields, whatever trait of the program has a method of the same name.
 
@@ -208,8 +205,8 @@ fn caller() -> Int {
 ```
 
 A builtin module follows the same rule: after `import list`, a binding named
-`list` hides the module inside its scope: `list.map` there is a method call
-on the binding, which a `List` value does not have. No warning is given;
+`list` hides the module inside its scope: `list.map` there is a field of
+the binding, which a `List` value does not have. No warning is given;
 rename the binding, or import the module under another name
 (`import list as l`), to reach both.
 
diff --git a/docs/language/traits.md b/docs/language/traits.md
index 97955a704..22a34bb73 100644
--- a/docs/language/traits.md
+++ b/docs/language/traits.md
@@ -32,10 +32,19 @@ trait Greet for Shape {
 }
 
 fn main() {
-  println(Circle(5.0).greet()) -- hi from a circle of radius 5.0
+  println(Greet.greet(Circle(5.0))) -- hi from a circle of radius 5.0
 }
 ```
 
+A method that takes a value of the implementing type (`self`, or a
+parameter of type `Self`) is called through its trait, as a module's
+function is: `Greet.greet(c)`, `c |> Greet.greet`,
+`list.map(shapes, Greet.greet)`. The call reaches the impl for the type
+of that argument. A trait of another module is named as its other items
+are: `shapes.Area.area(s)` after `import shapes`, or `Area.area(s)` after
+`import shapes.{ Area }`. A dot after a value always names a field (see
+[A dot after a value](#a-dot-after-a-value)).
+
 A trait declares complete signatures: every parameter but `self` has a
 type annotation, and a method declared without a return type returns
 `()`. An impl's method has the types its trait declares, with the impl's
@@ -74,8 +83,8 @@ real built-in `Display` trait look identical and are shown in
 
 An impl gives a record type no method named like one of the record's
 fields, whether the impl writes the method or takes it as the trait's
-default: `job.run(5)` on a record is always a call of the function its
-field `run` holds.
+default: `job.run(5)` calls the function the field `run` holds, and a
+method of that name would read as the same thing.
 
 ```silt
 type Job {
@@ -137,23 +146,23 @@ trait Printable: Display + Hash {
 
 ### Constraint expansion
 
-Inside a `where a: Cmp2` body, methods from `Eq2` (the supertrait)
-are also callable on `a`:
+Inside a `where t: Cmp2` body, a value of type `t` is also given to the
+methods of `Eq2` (the supertrait), each called through its own trait:
 
 ```silt
 fn check(a: t, b: t) -> Bool where t: Cmp2 {
-  -- a.eq2(b) works because Eq2 is a supertrait of Cmp2
-  match a.eq2(b) {
+  -- Eq2.eq2(a, b) works because Eq2 is a supertrait of Cmp2
+  match Eq2.eq2(a, b) {
     true -> true
-    false -> a.lt2(b)
+    false -> Cmp2.lt2(a, b)
   }
 }
 ```
 
 The expansion is transitive: with `trait C: B { ... }` and
-`trait B: A { ... }`, a `where x: C` constraint enables methods from
-`A`, `B`, and `C` on `x`, and implementing `C` on a type requires impls
-of `A`, `B`, and `C`.
+`trait B: A { ... }`, a `where x: C` constraint lets `x` be given to the
+methods of `A`, `B`, and `C`, and implementing `C` on a type requires
+impls of `A`, `B`, and `C`.
 
 ### Errors
 
@@ -214,8 +223,8 @@ trait Show for Item {
 }
 
 fn main() {
-  println(Item { v: 1 }.show()) -- default
-  println(Item { v: 1 }.debug()) -- item-debug
+  println(Show.show(Item { v: 1 })) -- default
+  println(Show.debug(Item { v: 1 })) -- item-debug
 }
 ```
 
@@ -238,8 +247,8 @@ trait Show for Item {
 }
 ```
 
-Default bodies can call other trait methods on `self`, including
-abstract ones the impl is required to provide. Dispatch routes the call
+Default bodies can call other methods of the trait with `self`,
+including abstract ones the impl is required to provide. Dispatch routes the call
 to the impl's version, so the default acts as a template that
 specialises per impl:
 
@@ -249,7 +258,7 @@ trait Describable {
   fn name(self) -> String
   -- the default uses name()
   fn greet(self) -> String {
-    "hi, {self.name()}"
+    "hi, {Describable.name(self)}"
   }
 }
 
@@ -264,12 +273,12 @@ trait Describable for Person {
 }
 
 fn main() {
-  println(Person { who: "alice" }.greet()) -- hi, alice
+  println(Describable.greet(Person { who: "alice" })) -- hi, alice
 }
 ```
 
 Defaults compose with supertraits: a default body may call a supertrait
-method on `self`, and the obligation that the supertrait be implemented
+method with `self`, and the obligation that the supertrait be implemented
 is enforced as usual.
 
 Defaults work on parameterized impl targets too — `trait X for Box(a) { }`
@@ -343,8 +352,8 @@ instantiation only, name it with an alias (`type Ints = List(Int)`,
 
 ### Impl-level where clauses
 
-To call a trait method on an impl-bound type variable, declare the
-constraint on the **impl header** using a `where` clause. The constraint
+To give a value of an impl-bound type variable to a trait's method,
+declare the constraint on the **impl header** using a `where` clause. The constraint
 applies to every method in the impl and is also enforced at every call
 site — passing a `Box(v)` where `v`'s type does not implement the
 required trait is a compile-time error:
@@ -367,18 +376,18 @@ trait Greet for Int {
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
     match self {
-      Box(inner) -> inner.greet()
+      Box(inner) -> Greet.greet(inner)
     }
   }
 }
 
 fn main() {
-  println(Box(5).greet()) -- int-greet
+  println(Greet.greet(Box(5))) -- int-greet
 }
 ```
 
-`Box("hello").greet()` is an error: type 'String' does not implement
-trait 'Greet'.
+`Greet.greet(Box("hello"))` is an error: type 'String' does not
+implement trait 'Greet'.
 
 Multi-trait bounds use `+` (or comma-separated clauses) — identical to
 fn-level `where`:
@@ -386,7 +395,7 @@ fn-level `where`:
 ```silt
 trait Greet for Box(a) where a: Greet + Loud {
   fn greet(self) -> String {
-    match self { Box(inner) -> "{inner.greet()}-{inner.loud()}" }
+    match self { Box(inner) -> "{Greet.greet(inner)}-{Loud.loud(inner)}" }
   }
 }
 
@@ -403,14 +412,14 @@ impl's method has the signature its trait declares, `where` clause
 included: it may restate a bound the trait declares for the method or
 the header declares (or a supertrait of one), with the same trait
 arguments, and may not add one, because a call through the
-trait (`fn f(x: t) where t: Greet { x.greet() }`) knows only the trait's
+trait (`fn f(x: t) where t: Greet { Greet.greet(x) }`) knows only the trait's
 signature and the header:
 
 ```silt
 trait Greet for Box(a) {
   fn greet(self) -> String where a: Greet {
     match self {
-      Box(inner) -> inner.greet()
+      Box(inner) -> Greet.greet(inner)
     }
   }
 }
@@ -437,7 +446,7 @@ trait Peek for Int {
 
 trait Peek for Cell(a) where a: Peek {
   fn peek(self) -> Int {
-    self.value.peek()
+    Peek.peek(self.value)
   }
 }
 ```
@@ -473,12 +482,14 @@ specification — including how trait parameters flow through `where` clauses
 and how multiple impls with different arguments coexist — lives in
 [Generics — Parameterized trait declarations](generics.md#parameterized-trait-declarations).
 
-## Static Trait Methods
+## Methods That Make a Value
 
-Some trait methods take no `self` and only return `Self` — constructors like
-`Default::default()` or `Monoid::empty()`. Invoke these by calling on a
-**type descriptor**: either a bare type name (`Int.empty()`) or a `type a`
-parameter inside a generic function (`a.empty()`):
+Some trait methods take no value of the type and only make one —
+constructors like `default()` or `empty()`. A call through the trait
+could not say which impl it means, so these are called on a **type**:
+either a bare type name (`Int.empty()`) or a `type a` parameter inside a
+generic function (`a.empty()`). A method that takes a value of the type
+is called through its trait (`Monoid.combine(2, 3)`), never on a type:
 
 ```silt
 trait Monoid {
@@ -497,32 +508,34 @@ trait Monoid for Int {
 
 fn main() {
   let zero = Int.empty() -- concrete dispatch
-  let five = Int.combine(2, 3)
+  let five = Monoid.combine(2, 3)
   println("{zero} {five}")
 }
 ```
 
-A method without `self` is called on a type, never on a value:
-`5.empty()` is an error that names the call to write (`Int.empty()`).
-Nor is it ever a candidate for a call on a value, of any trait: where
-another trait gives the type a method of the same name that takes
-`self`, `x.m(..)` calls that one, with no ambiguity; a call on the type
-(`T.m(..)`) has both. An impl writes the parameters its trait declares:
-one that adds or drops `self` (or any other parameter) is an error at
-the impl.
+`5.empty()` is an error: a dot after a value names a field, and the
+help names the call to write (`Int.empty()`). `Int.combine(2, 3)` is an
+error too: `type 'Int' has no method 'combine'`, with the help to call
+it as `Monoid.combine(x, ..)`. Through a type only the methods that make
+a value are candidates: of two traits that give a type a method of one
+name, one that makes a value and one that takes one, `T.m(..)` is the
+first; two that make one are ambiguous. An impl writes the parameters
+its trait declares: one that adds or drops `self` (or any other
+parameter) is an error at the impl.
 
-Dispatch is by the descriptor's carried type name — `Int.empty()` resolves
-to the `Monoid` impl for `Int`. Inside a generic function with
-`type a` and `where a: Monoid`, `a.empty()` dispatches to whichever impl
-matches the concrete type passed in. See
+Dispatch is by the type — `Int.empty()` resolves to the `Monoid` impl
+for `Int`. Inside a generic function with `type a` and
+`where a: Monoid`, `a.empty()` dispatches to whichever impl matches the
+concrete type passed in. See
 [Generics — Trait methods on types](generics.md#trait-methods-on-types) for
 the full rules.
 
 ## Method References
 
-Trait method names are first-class callable values: `TypeName.method` produces
-a function you can pass directly to a higher-order combinator. This avoids
-writing a one-line closure around `x.method()`:
+A method named through its trait is a function value, as a module's
+function is: `Trait.method` can be passed directly to a higher-order
+combinator. Where the type of its argument is known the value is the
+method of that impl; in generic code it finds the impl where it runs.
 
 ```silt
 import list
@@ -531,39 +544,68 @@ type Celsius {
   c: Float,
 }
 
-trait Display for Celsius {
-  fn display(self) -> String {
+trait Describe {
+  fn describe(self) -> String
+}
+
+trait Describe for Celsius {
+  fn describe(self) -> String {
     "{self.c}°C"
   }
 }
 
 fn main() {
   let temps = [Celsius { c: 20.0 }, Celsius { c: 25.5 }]
-  let rendered = list.map(temps, Celsius.display)
+  let rendered = list.map(temps, Describe.describe)
   list.each(rendered) { line -> println(line) }
 }
 ```
 
-`value.method` without a call is not a function: a method is called.
-Write `Type.method`, or a closure, `{ x -> x.method() }`.
+A method that makes a value is taken through its type
+(`list.map(codes, AppError.from)`).
+
+## A dot after a value
+
+A dot after a value names a field, whatever methods traits declare:
+
+- `p.name` is the record's field; `r.f(..)` calls the function the field
+  `f` holds.
+- In a function whose parameter has no annotation, `fn name_of(p) {
+  p.name }` takes any record with a field `name`.
+- A trait's method is called through the trait: `fn g(x) {
+  Greet.greet(x) }` is `fn g(x: a) -> String where a: Greet`, the bound
+  coming from the trait the call names.
+
+A dot that names nothing is an error that says what the value's type
+lacks, with the call to write where the name is a trait's method or a
+function of the type's builtin module:
+
+```silt
+import list
 
-## Calls on a value of unknown type
+trait Greet {
+  fn greet(self) -> String
+}
 
-In a function whose parameter has no annotation, `x.m(..)` and `x.f` are
-decided by what is written, not by which names happen to exist:
+trait Greet for Int {
+  fn greet(self) -> String {
+    "hi"
+  }
+}
 
-- `x.f` is a field: `fn name_of(p) { p.name }` takes any record with a
-  field `name`, whatever methods traits declare.
-- `r.f(..)` on a record with a field `f` calls the function the field
-  holds: a record type has no method named like one of its fields.
-- `x.m(..)` means the one trait in sight that declares a method `m`
-  taking `self`, and bounds `x` by it: `fn g(x) { x.greet() }` is
-  `fn g(x: a) -> String where a: Greet`. If no trait declares `m`, `x` is
-  a record whose field `m` holds a function. If several traits declare
-  an `m` that takes `self`, annotate `x`.
+fn shown(n: Int, xs: List(Int)) {
+  println(n.frobnicate()) -- error: type 'Int' has no field 'frobnicate'
+  println(n.greet())
+  -- error: type 'Int' has no field 'greet'
+  -- help: `greet` is a method of trait `Greet`: call it as `Greet.greet(n)`
+  println(xs.length())
+  -- error: type 'List(Int)' has no field 'length'
+  -- help: `length` is a function of module `list`: call it as `list.length(xs)`
+}
+```
 
 When the type of `x` is decided later in the same definition (a closure's
-parameter by the call it is passed to), the call is checked against that
+parameter by the call it is passed to), the field is checked against that
 type.
 
 ## Built-in Traits
@@ -581,7 +623,7 @@ types arithmetic is on, `Int` and `Float`, and nothing else.
 | `Equal`   | Equality comparison              | by structure | no (an error) |
 | `Hash`    | Hash value for maps/sets         | by structure | no (an error) |
 | `Compare` | Order comparison; includes `Equal` | by structure | no (an error) |
-| `Error`   | Error reporting (`message()`)    | types with an impl | yes |
+| `Error`   | Error reporting (`Error.message(e)`) | types with an impl | yes |
 | `Number`  | `+ - * / %` and unary `-`        | Int and Float only | no |
 
 Operators are these traits: `==` and `!=` need `Equal`, `<` `>` `<=`
@@ -613,8 +655,7 @@ its fields in the order of their names). Write your own
 `Display` impl for a type of another module, or for a built-in type, is
 an error. A type that holds a function has no structural `Display`, and
 may be given a written one. There is one `Display`: `println`, `print`, interpolation,
-`.display()`, `string.from` and a panic's message all show a value the
-same way, and all use the impl you wrote, wherever a value of the type
+`string.from` and a panic's message all show a value the same way, and all use the impl you wrote, wherever a value of the type
 is inside what is shown (`println([t])`, `"{Some(t)}"`, a field of a
 record).
 
@@ -645,8 +686,10 @@ fields in the same order as `println`.
 
 `Equal`, `Hash` and `Compare` are **sealed**: they always come
 from a type's structure (a type gets them when every field
-supports them), and `==`, `<`, `.equal()`, `.compare()`, `.hash()` and
-map keys use exactly that structure. A record is ordered by its fields
+supports them), and `==`, `<`, `Compare.compare`, `Hash.hash` and map
+keys use exactly that structure. `Display`'s `display` and `Equal`'s
+`equal` are not called by a program: interpolation and `string.from`,
+and `==`, do what they would. A record is ordered by its fields
 in the order the type declares them, an enum by its variants in the
 order it declares them and then by their payloads. A
 hand-written `trait Equal for T`, `trait Compare for T` or
@@ -727,14 +770,16 @@ type is the one named first, `Box`.
 
 Two things follow. A type has at most one impl of a trait in a whole
 program, and every module sees the same one: no two modules can each
-write it. And the impl is there wherever it is called: a module that can
-call a method of a trait on a value of a type imports the module of the
-trait and the module of the type (directly, or through the modules it
-imports), and one of those two holds the impl. A value is shown, and a
-method answers, the same way in every module.
+write it. And the impl is there wherever it is called: a call names the
+trait, so its module is in the program, and so is the module of the
+type of a value the call is given; one of those two holds the impl. A
+value is shown, and a method answers, the same way in every module.
 
-A module calls the methods of the traits whose modules it imports,
-directly or through the modules it imports, and of the built-in traits.
+A module calls a trait's methods through the trait's name, which it
+names as any item: a trait it declares, one it imports by name
+(`import shapes.{ Area }`), one of a module it imports
+(`shapes.Area.area(s)`), or a built-in trait (`Compare`, `Hash`,
+`Error`; `json.Encode` after `import json`).
 
 ### In the trait's module
 
@@ -820,12 +865,12 @@ import list
 
 -- CORRECT: 'a' appears in the parameter annotation
 fn print_all(items: List(a)) where a: Display {
-  items |> list.each { item -> println(item.display()) }
+  items |> list.each { item -> println("{item}") }
 }
 
 -- ERROR: 'a' is unbound -- no annotation on x
 fn f(x) where a: Display {
-  println(x.display())
+  println("{x}")
 }
 ```
 
diff --git a/docs/language/types.md b/docs/language/types.md
index 89b30c7c6..095901e40 100644
--- a/docs/language/types.md
+++ b/docs/language/types.md
@@ -175,8 +175,8 @@ println(alice.name) -- Alice
 
 An anonymous record is shown as it is written, without a name, its
 fields in the order of their names: `println(alice)` prints
-`{age: 30, name: Alice}`. A closed one has `==`, `.equal()`, `.hash()`
-and `.display()` when its fields do, and no order (`<`, `.compare()`).
+`{age: 30, name: Alice}`. A closed one has `Equal` (`==`), `Hash` and
+`Display` when its fields do, and no order (`<`, `Compare.compare`).
 
 The type of `alice` is the structural type `{name: String, age: Int}`,
 which can also appear in any annotation:
@@ -289,9 +289,8 @@ let r: {name: String, age: Int} = Person { name: "x", age: 3 }
 `time.Date { ... }`.)
 
 A value whose fields are read is a record, and `p.greet()` on it calls
-a function held in a field `greet`. A method of a declared record is
-not a field: a function that reads `p.name` and calls `p.greet()` needs
-its parameter annotated, `p: Person`, to call the method.
+a function held in a field `greet`. A method of a trait is not a field:
+it is called through its trait, `Greet.greet(p)`.
 
 A row variable stands for the rest of a record's fields, not for a
 type, so the only bounds it takes are the traits a record has when its
diff --git a/docs/proposals/error-from-trait.md b/docs/proposals/error-from-trait.md
index e74a63cf7..2d44befce 100644
--- a/docs/proposals/error-from-trait.md
+++ b/docs/proposals/error-from-trait.md
@@ -228,9 +228,8 @@ trait IntoAppError for json.JsonError {
 }
 
 fn load_config(path: String) -> Result(Config, AppError) {
-  let raw = result.map_err(io.read_file(path), io.IoError.into_app_error)?
-  -- OR using a closure to make the conversion name visible on the value side:
-  let cfg = result.map_err(json.parse(raw, Config)) { e -> e.into_app_error() }?
+  let raw = result.map_err(io.read_file(path), IntoAppError.into_app_error)?
+  let cfg = result.map_err(json.parse(raw, Config), IntoAppError.into_app_error)?
   Ok(cfg)
 }
 ```
@@ -239,9 +238,6 @@ This **works in silt today** because dispatch is by `Self` (each
 source type has one impl, no collision). Drawbacks:
 
 - One `trait IntoX` per target AppError type — doesn't reuse.
-- First-class method reference form (`IoError.into_app_error`) hits
-  the same limits as `AppError.from` when passed as a value, so the
-  closure form may still be needed at some call sites.
 
 Still ugly. But it's the best pattern available without compiler
 work.
@@ -294,7 +290,7 @@ an unknown tail risk of adjacent generic-trait regressions.
 | Unified `SiltError` stdlib type | Loses the module-specific pattern-match granularity the typed errors just shipped. |
 | Polymorphic variants (OCaml-style) | Requires a structural-typing extension to silt's nominal type system. Out of scope. |
 | **One trait per source type** (`trait IntoAppError { fn into_app_error(self) -> AppError }`) | Implementable today. Rejected as the *proposal* design because it doesn't scale — one new trait per target AppError. But it's the right **available-today workaround** and is documented above. |
-| **Inverted `trait IntoErr(target) for Source`** | Dispatches by Self. Works today for multi-source → one-target IF silt supports trait-param inference from target-type ascription (unverified). Rejected because call site becomes `io_err.into_err()` with target inferred from context — i.e. Rust's `.into()` with a different name, the very thing the proposal exists to reject. |
+| **Inverted `trait IntoErr(target) for Source`** | Dispatches by Self. Works today for multi-source → one-target IF silt supports trait-param inference from target-type ascription (unverified). Rejected because call site becomes `IntoErr.into_err(io_err)` with target inferred from context — i.e. Rust's `.into()` with a different name, the very thing the proposal exists to reject. |
 
 ## Non-goals clarified
 
diff --git a/docs/stdlib/bytes.md b/docs/stdlib/bytes.md
index c8246a430..b8a13888c 100644
--- a/docs/stdlib/bytes.md
+++ b/docs/stdlib/bytes.md
@@ -66,7 +66,7 @@ fn main() {
   let greeting = bytes.concat_all([hello, space, world])
   match bytes.to_string(greeting) {
     Ok(s) -> println(s) -- hello world
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 
   -- Slicing (half-open; an index past the end is the end)
@@ -96,7 +96,7 @@ fn main() {
 
 Every fallible `bytes.*` call returns `Result(T, BytesError)`. The enum
 exposes these variants keyed by the structural failure; pattern-match
-for granular handling or fall back to `e.message()`:
+for granular handling or fall back to `Error.message(e)`:
 
 | Variant | Fields | Raised by |
 |---------|--------|-----------|
diff --git a/docs/stdlib/channel-task.md b/docs/stdlib/channel-task.md
index e3c91f92c..c04d242c3 100644
--- a/docs/stdlib/channel-task.md
+++ b/docs/stdlib/channel-task.md
@@ -583,7 +583,7 @@ fn main() {
     Ok(Ok(contents)) -> println(contents)
     Ok(Err(e)) -> println("the read failed: {e}")
     Err(task.Timeout) -> println("the read took too long")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 ```
diff --git a/docs/stdlib/encoding.md b/docs/stdlib/encoding.md
index 2d6cc7931..604098626 100644
--- a/docs/stdlib/encoding.md
+++ b/docs/stdlib/encoding.md
@@ -70,7 +70,7 @@ fn main() {
 ## Errors
 
 The two decoders return `Result(_, EncodingError)`; the encoders are total
-functions. `e.message()` (and `"{e}"`) is the text of the variant.
+functions. `Error.message(e)` (and `"{e}"`) is the text of the variant.
 
 | Variant | Fields | Meaning |
 |---------|--------|---------|
diff --git a/docs/stdlib/errors.md b/docs/stdlib/errors.md
index 99d8fe672..406726941 100644
--- a/docs/stdlib/errors.md
+++ b/docs/stdlib/errors.md
@@ -10,8 +10,8 @@ Every fallible stdlib module declares its own typed error enum. Silt's
 `Result(T, ModuleError)` return shape lets user code pattern-match the
 failure modes directly instead of substring-matching on a `String`
 payload. Each enum implements the built-in `Error` trait, which
-supertypes `Display` and provides a `message()` method so code that
-just wants a rendered error can fall back to `"{e.message()}"`.
+has `Display` as its supertrait and a method `message`, so code that
+just wants a rendered error can fall back to `"{Error.message(e)}"`.
 
 ## Variant naming
 
diff --git a/docs/stdlib/http.md b/docs/stdlib/http.md
index d6bf5a9e7..55a5b3ae1 100644
--- a/docs/stdlib/http.md
+++ b/docs/stdlib/http.md
@@ -58,9 +58,9 @@ fn main() {
   match http.get("http://127.0.0.1:8080/") {
     Ok(resp) -> match bytes.to_string(resp.body) {
       Ok(text) -> println(text)
-      Err(e) -> println("the body is no text: {e.message()}")
+      Err(e) -> println("the body is no text: {Error.message(e)}")
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 ```
@@ -84,7 +84,7 @@ is there (DNS, connection, TLS, a timeout, a head that is no HTTP), and
 one after it: a body that is cut short (`ClosedEarly`), and a body that
 does not unpack or is larger than 10,000,000 bytes (`InvalidResponse`).
 A program for which a status is a failure looks at `resp.status`.
-`HttpError` implements the built-in `Error` trait, so `e.message()`
+`HttpError` implements the built-in `Error` trait, so `Error.message(e)`
 always yields a rendered string.
 
 | Variant | Fields | Meaning |
@@ -144,7 +144,7 @@ fn main() {
   match http.get("https://api.github.com/users/torvalds") {
     Ok(resp) -> println("Status: {resp.status}, body length: {bytes.length(resp.body)}")
     Err(http.Timeout) -> println("timed out; retry later")
-    Err(e) -> println("Network error: {e.message()}")
+    Err(e) -> println("Network error: {Error.message(e)}")
   }
 }
 ```
@@ -425,9 +425,9 @@ fn main() {
             body: bytes.from_string(json.stringify(user)),
             headers: #{ "Content-Type": "application/json" },
           }
-          Err(e) -> reply(400, e.message())
+          Err(e) -> reply(400, Error.message(e))
         }
-        Err(e) -> reply(400, e.message())
+        Err(e) -> reply(400, Error.message(e))
       }
 
       _ -> reply(404, "Not found")
diff --git a/docs/stdlib/int-float.md b/docs/stdlib/int-float.md
index 6eb1c1bec..1575857fb 100644
--- a/docs/stdlib/int-float.md
+++ b/docs/stdlib/int-float.md
@@ -103,7 +103,7 @@ int.parse(s: String) -> Result(Int, IntError)
 Parses a string as an integer. Leading/trailing whitespace is trimmed. Returns
 `Ok(n)` on success, `Err(IntError)` on failure — a typed enum with variants
 `Empty`, `InvalidDigit(offset)`, `Overflow`, `Underflow` and `Other(message)`.
-Match on the variant to handle specific cases, or fall back to `e.message()` for
+Match on the variant to handle specific cases, or fall back to `Error.message(e)` for
 a human-readable default.
 
 ```silt
@@ -112,7 +112,7 @@ import int
 fn main() {
   match int.parse("42") {
     Ok(n) -> println(n)
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
 
   -- Pattern-match on specific failure modes:
@@ -345,7 +345,7 @@ import float
 fn main() {
   match float.parse("3.14") {
     Ok(f) -> println(f)
-    Err(e) -> println("error: {e.message()}")
+    Err(e) -> println("error: {Error.message(e)}")
   }
 }
 ```
diff --git a/docs/stdlib/io-fs.md b/docs/stdlib/io-fs.md
index 54b2835d6..841960057 100644
--- a/docs/stdlib/io-fs.md
+++ b/docs/stdlib/io-fs.md
@@ -34,9 +34,9 @@ Every fallible `io` / `fs` function returns `Result(T, IoError)`.
 | `Other(msg)`             | everything else                            |
 
 `IoError` implements the built-in `Error` trait, so every value exposes
-`.message() -> String` for a human-readable summary. Most call sites
+`Error.message(e) -> String` for a human-readable summary. Most call sites
 destructure specific variants when they need to branch (e.g. "create a
-default when the file does not exist") and fall through to `.message()`
+default when the file does not exist") and fall through to `Error.message`
 otherwise. See [stdlib errors](errors.md) for the shared `Error` trait.
 
 See also [bytes](bytes.md) for reading/writing binary data.
@@ -101,7 +101,7 @@ fn main() {
   match io.read_file("data.txt") {
     Ok(contents) -> println(contents)
     Err(io.NotFound(path)) -> println("no such file: {path}")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -126,7 +126,7 @@ fn main() {
   match io.read_line() {
     Ok(name) -> println("Hello, {name}!")
     Err(io.UnexpectedEof) -> println("(EOF)")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -149,7 +149,7 @@ import io
 fn main() {
   match io.write_file("output.txt", "hello") {
     Ok(_) -> println("written")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -328,7 +328,7 @@ import fs
 fn main() {
   match fs.copy("original.txt", "backup.txt") {
     Ok(_) -> println("copied")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -410,7 +410,7 @@ import list
 fn main() {
   match fs.list_dir(".") {
     Ok(entries) -> list.each(entries) { name -> println(name) }
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -431,7 +431,7 @@ import fs
 fn main() {
   match fs.mkdir("output/reports") {
     Ok(_) -> println("directory created")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -452,7 +452,7 @@ import fs
 fn main() {
   match fs.remove("temp.txt") {
     Ok(_) -> println("removed")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -473,7 +473,7 @@ import fs
 fn main() {
   match fs.rename("old_name.txt", "new_name.txt") {
     Ok(_) -> println("renamed")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -540,7 +540,7 @@ fn main() {
         None -> println("creation time not tracked on this filesystem")
       }
     }
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -584,7 +584,7 @@ import fs
 fn main() {
   match fs.read_link("link") {
     Ok(target) -> println("points at {target}")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -624,7 +624,7 @@ import fs
 fn main() {
   match fs.walk("src") {
     Ok(paths) -> println("{paths}")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -663,7 +663,7 @@ import fs
 fn main() {
   match fs.glob("src/**/*.silt") {
     Ok(files) -> println("{files}")
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
diff --git a/docs/stdlib/json.md b/docs/stdlib/json.md
index 08f322b3c..187dba692 100644
--- a/docs/stdlib/json.md
+++ b/docs/stdlib/json.md
@@ -26,7 +26,7 @@ A document whose shape is not known in advance is read into a
 
 Every fallible `json.*` call returns `Result(T, JsonError)`. The `JsonError`
 enum has four variants you can pattern-match on, or fall back to
-`e.message()` when you just want a rendered string (`trait Error for
+`Error.message(e)` when you just want a rendered string (`trait Error for
 JsonError` is wired in):
 
 | Variant | Fields | Meaning |
@@ -497,10 +497,11 @@ their names, `json.stringify(r)` in the order its type declares them), a
 are used wherever their types are in the value, at the top too: the
 counterpart of [`json.decode`](#jsondecode-1). An impl's `encode` uses it for
 the parts it writes; for its own value (`json.encode(self)`) it would call
-itself without end. In a module that imports json, `x.encode()` is the
-method of the trait: on a value whose type has a written impl it is what
-the impl gives, as it gives it (`json.Float(1.0)` stays a `Float`); on any
-other value it is `json.encode(x)`.
+itself without end. `json.Encode.encode(x)` is the method of the trait,
+called through it in a module that imports json: on a value whose type
+has a written impl it is what the impl gives, as it gives it
+(`json.Float(1.0)` stays a `Float`); on any other value it is
+`json.encode(x)`.
 
 ```silt
 import json
@@ -565,7 +566,7 @@ fn main() {
   let input = """{"name": "Alice", "age": 30}"""
   match json.parse(input, User) {
     Ok(user) -> println(user.name)
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -613,7 +614,7 @@ fn main() {
   let input = """[{"x": 1, "y": 2}, {"x": 3, "y": 4}]"""
   match json.parse_list(input, Point) {
     Ok(points) -> list.each(points) { p -> println("{p.x}, {p.y}") }
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -637,7 +638,7 @@ fn main() {
   let input = """{"x": 10, "y": 20}"""
   match json.parse_map(input, Int) {
     Ok(m) -> println(map.get(m, "x")) -- Some(10)
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
diff --git a/docs/stdlib/list.md b/docs/stdlib/list.md
index c618e68a9..30e23e051 100644
--- a/docs/stdlib/list.md
+++ b/docs/stdlib/list.md
@@ -761,10 +761,10 @@ comes after `b`. The sort is stable: equal elements keep their order.
 import list
 
 fn main() {
-  println(list.sort_with([3, 1, 2]) { a, b -> b.compare(a) }) -- [3, 2, 1]
+  println(list.sort_with([3, 1, 2]) { a, b -> Compare.compare(b, a) }) -- [3, 2, 1]
   -- By the first of each pair only: (1, b) stays before (1, a).
   let pairs = [(2, "c"), (1, "b"), (1, "a")]
-  println(list.sort_with(pairs) { (x, _), (y, _) -> x.compare(y) }) -- [(1, b), (1, a), (2, c)]
+  println(list.sort_with(pairs) { (x, _), (y, _) -> Compare.compare(x, y) }) -- [(1, b), (1, a), (2, c)]
 }
 ```
 
diff --git a/docs/stdlib/postgres.md b/docs/stdlib/postgres.md
index 9908fe4a8..da3427acd 100644
--- a/docs/stdlib/postgres.md
+++ b/docs/stdlib/postgres.md
@@ -153,7 +153,7 @@ the fields once per result, before the statement runs:
   `Err(TypeMismatch(column, field type, column type))`, say
   `TypeMismatch("id", "Int", "float8")`: the column's type decides, not
   its values (an `Int` field is not filled from a `float8` column even
-  where the value is `2.0`). Its `message()` says how to go on:
+  where the value is `2.0`). `Error.message(e)` says how to go on:
   ``postgres type mismatch on column `id`: expected Int, got float8;
   cast it in SQL, for example id::text``. A field that only a json
   document fills (a record, a map, a tuple, a type with a `json.Decode`
@@ -464,11 +464,11 @@ fn main() {
       match users(db) {
         Ok(found) -> println("users: {found}")
         Err(postgres.TxnAborted) -> println("rolled back (transaction aborted, retry)")
-        Err(e) -> println("rolled back: {e.message()}")
+        Err(e) -> println("rolled back: {Error.message(e)}")
       }
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
 ```
@@ -603,5 +603,5 @@ needed) are:
 | `Other(msg)` | `String` | Catch-all for shapes we can't classify |
 
 `PostgresError` implements the stdlib `Error` trait, so if you don't want
-to pattern-match on variants you can always call `err.message()` to
+to pattern-match on variants you can always call `Error.message(err)` to
 get a formatted user-friendly string.
diff --git a/docs/stdlib/regex.md b/docs/stdlib/regex.md
index ddc0f59e2..cd05544ea 100644
--- a/docs/stdlib/regex.md
+++ b/docs/stdlib/regex.md
@@ -20,7 +20,7 @@ fn main() {
   match regex.find("abc 123", "(") {
     Ok(found) -> println(found)
     Err(regex.InvalidPattern(why, at)) -> println("{why} at {at}") -- unclosed group at 0
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 ```
@@ -71,7 +71,7 @@ fn main() {
       println(list.get(groups, 2)) -- Some(host)
     }
     Ok(None) -> println("no match")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 ```
@@ -123,7 +123,7 @@ fn main() {
       println(map.get(groups, "host")) -- Some(example)
     }
     Ok(None) -> println("no match")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 ```
diff --git a/docs/stdlib/result-option.md b/docs/stdlib/result-option.md
index f80dbe6a0..9f52c25d4 100644
--- a/docs/stdlib/result-option.md
+++ b/docs/stdlib/result-option.md
@@ -155,7 +155,7 @@ fn load(path: String) -> Result(String, AppError) {
 fn main() {
   match load("missing.txt") {
     Ok(s) -> println(s)
-    Err(IoWrap(e)) -> println(e.message())
+    Err(IoWrap(e)) -> println(Error.message(e))
   }
 }
 ```
diff --git a/docs/stdlib/tcp.md b/docs/stdlib/tcp.md
index a1afc3b3b..946330645 100644
--- a/docs/stdlib/tcp.md
+++ b/docs/stdlib/tcp.md
@@ -44,7 +44,7 @@ out the OS-specific noise. A variant says what failed:
 | `Timeout` | — | op exceeded its deadline |
 | `Other(msg)` | `String` | unclassified socket failure |
 
-`TcpError` implements the built-in `Error` trait, so `e.message()`
+`TcpError` implements the built-in `Error` trait, so `Error.message(e)`
 renders any variant as a string when you don't want to branch on it.
 
 ## Echo server example
@@ -74,13 +74,13 @@ fn main() {
             loop(())
           }
           Err(e) -> {
-            println("accept error: {e.message()}")
+            println("accept error: {Error.message(e)}")
             loop(())
           }
         }
       }
     }
-    Err(e) -> println("listen error: {e.message()}")
+    Err(e) -> println("listen error: {Error.message(e)}")
   }
 }
 ```
@@ -202,7 +202,7 @@ fn main() {
       let _ = tcp.write(conn, bytes.from_string("hello"))
       tcp.close(conn)
     }
-    Err(e) -> println("connect_tls err: {e.message()}")
+    Err(e) -> println("connect_tls err: {Error.message(e)}")
   }
 }
 ```
@@ -248,7 +248,7 @@ fn serve(conn, cert, key) {
       let _ = tcp.write(tls, bytes.from_string("hello over TLS\n"))
       tcp.close(tls)
     }
-    Ok(Err(e)) -> println("handshake failed: {e.message()}")
+    Ok(Err(e)) -> println("handshake failed: {Error.message(e)}")
     Err(_) -> println("the client took too long")
   }
 }
@@ -271,7 +271,7 @@ fn main() {
         let _ = task.spawn { -> serve(conn, cert, key) }
         loop(())
       }
-      Err(e) -> println("accept failed: {e.message()}")
+      Err(e) -> println("accept failed: {Error.message(e)}")
     }
   }
 }
@@ -325,7 +325,7 @@ fn main() {
       let _ = tcp.write(tls, bytes.from_string("hello, authenticated client"))
       tcp.close(tls)
     }
-    Err(e) -> println("mTLS handshake failed: {e.message()}")
+    Err(e) -> println("mTLS handshake failed: {Error.message(e)}")
   }
 }
 ```
diff --git a/docs/stdlib/time.md b/docs/stdlib/time.md
index 58abed137..9b1e750a4 100644
--- a/docs/stdlib/time.md
+++ b/docs/stdlib/time.md
@@ -71,7 +71,7 @@ pattern that is no format are the structural failure modes:
 | `InvalidFormat(msg)` | `String` | the pattern is at fault, whatever the value or the text: an unknown specifier, or one the type has nothing for (a time of day for a `Date`, a time zone), in a format and in its parse alike; for a parse also fields that are not enough for the value (no time of day for a `DateTime`, no date, an empty pattern) |
 | `Other(msg)` | `String` | unclassified failure |
 
-`TimeError` implements the built-in `Error` trait, so `e.message()`
+`TimeError` implements the built-in `Error` trait, so `Error.message(e)`
 yields a rendered string when variant branching isn't needed.
 
 ## Summary
diff --git a/docs/stdlib/toml.md b/docs/stdlib/toml.md
index 77cd163ee..b097620a4 100644
--- a/docs/stdlib/toml.md
+++ b/docs/stdlib/toml.md
@@ -22,7 +22,7 @@ Parse TOML documents into typed silt values and serialize values to TOML.
 
 Every fallible `toml.*` call returns `Result(T, TomlError)`. The `TomlError`
 enum has four variants you can pattern-match on, or fall back to
-`e.message()` when you just want a rendered string (`trait Error for
+`Error.message(e)` when you just want a rendered string (`trait Error for
 TomlError` is wired in):
 
 | Variant | Fields | Meaning |
@@ -230,7 +230,7 @@ fn main() {
   let input = "name = \"Alice\"\nage = 30\nactive = true\n"
   match toml.parse(input, User) {
     Ok(user) -> println(user.name)
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -264,7 +264,7 @@ fn main() {
   let input = "[[points]]\nx = 1\ny = 2\n\n[[points]]\nx = 3\ny = 4\n"
   match toml.parse_list(input, Point) {
     Ok(points) -> list.each(points) { p -> println("{p.x}, {p.y}") }
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -291,7 +291,7 @@ fn main() {
   let input = "x = 10\ny = 20\n"
   match toml.parse_map(input, Int) {
     Ok(m) -> println(map.get(m, "x")) -- Some(10)
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -336,7 +336,7 @@ fn main() {
   let data = #{ "name": "silt", "version": "1.0" }
   match toml.pretty(data) {
     Ok(s) -> println(s)
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
@@ -389,7 +389,7 @@ fn main() {
   let data = Package { name: "silt", version: "1.0" }
   match toml.stringify(data) {
     Ok(s) -> println(s)
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
diff --git a/docs/stdlib/uuid.md b/docs/stdlib/uuid.md
index e876ed058..87d79d3e9 100644
--- a/docs/stdlib/uuid.md
+++ b/docs/stdlib/uuid.md
@@ -85,7 +85,7 @@ are total. It returns `Result(String, UuidError)`:
 
 | Variant | Fields | Meaning |
 |---------|--------|---------|
-| `Invalid(String)` | why | the input is not a syntactically valid UUID; `e.message()` is `"invalid uuid: ..."` |
+| `Invalid(String)` | why | the input is not a syntactically valid UUID; `Error.message(e)` is `"invalid uuid: ..."` |
 | `Other(String)` | message | unclassified failure |
 
 ## Notes
diff --git a/docs/why-silt.md b/docs/why-silt.md
index f2f0949bc..2dfc915f3 100644
--- a/docs/why-silt.md
+++ b/docs/why-silt.md
@@ -40,7 +40,7 @@ Three design commitments shape everything:
   task running in parallel can see a shared value without a lock.
 - Errors are values of a typed enum, not interface-typed strings. You
   pattern-match on specific variants (`Err(io.NotFound(path)) -> ...`)
-  and fall back to `.message()` for the long tail.
+  and fall back to `Error.message` for the long tail.
 - No `nil`. `Option(a)` is the only way to model absence, and the type
   checker makes you handle the `None` case.
 - You still get CSP with channels and cheap tasks.
diff --git a/examples/birthdays.silt b/examples/birthdays.silt
index 8525bff48..89cbb26ba 100644
--- a/examples/birthdays.silt
+++ b/examples/birthdays.silt
@@ -47,7 +47,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
     |> list.each { p ->
diff --git a/examples/concurrent_processor.silt b/examples/concurrent_processor.silt
index 9854469c9..9c546126b 100644
--- a/examples/concurrent_processor.silt
+++ b/examples/concurrent_processor.silt
@@ -103,7 +103,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/examples/config_parser.silt b/examples/config_parser.silt
index 08f4210ac..a83279981 100644
--- a/examples/config_parser.silt
+++ b/examples/config_parser.silt
@@ -124,7 +124,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/examples/cross_module_errors.silt b/examples/cross_module_errors.silt
index f27606704..d473e355e 100644
--- a/examples/cross_module_errors.silt
+++ b/examples/cross_module_errors.silt
@@ -25,7 +25,7 @@ type Config {
 
 -- Wrapper enum: one variant per module whose errors we want to
 -- surface, plus a Custom for ad-hoc domain errors. Silt's structural
--- Display renders each variant cleanly; `.message()` falls through to
+-- Display renders each variant cleanly; `Error.message` falls through to
 -- the underlying module's trait impl.
 type AppError {
   ConfigRead(io.IoError),
@@ -57,11 +57,11 @@ fn main() {
     Err(e) -> match e {
       -- Granular handling per domain.
       ConfigRead(io.NotFound(path)) -> println("create a config at: {path}")
-      ConfigRead(inner) -> println("config file: {inner.message()}")
-      ConfigParse(inner) -> println("config JSON invalid: {inner.message()}")
+      ConfigRead(inner) -> println("config file: {Error.message(inner)}")
+      ConfigParse(inner) -> println("config JSON invalid: {Error.message(inner)}")
       ApiCall(http.Timeout) -> println("API timed out — retry later")
-      ApiCall(inner) -> println("API call failed: {inner.message()}")
-      ApiResponse(inner) -> println("API response invalid: {inner.message()}")
+      ApiCall(inner) -> println("API call failed: {Error.message(inner)}")
+      ApiResponse(inner) -> println("API response invalid: {Error.message(inner)}")
       Custom(msg) -> println("app: {msg}")
     }
   }
diff --git a/examples/csv_analyzer.silt b/examples/csv_analyzer.silt
index d24cf6b1e..81527b49f 100644
--- a/examples/csv_analyzer.silt
+++ b/examples/csv_analyzer.silt
@@ -89,7 +89,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content |> string.split("\n") |> list.filter { l -> !string.is_empty(l) }
   let data_lines = lines |> list.drop(1)
diff --git a/examples/diff_tool.silt b/examples/diff_tool.silt
index 46c1ba232..c54660145 100644
--- a/examples/diff_tool.silt
+++ b/examples/diff_tool.silt
@@ -86,11 +86,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content |> string.split("\n") |> list.filter { l -> !string.is_empty(l) }
diff --git a/examples/expr_eval.silt b/examples/expr_eval.silt
index b75cd9e9b..0a8d1a403 100644
--- a/examples/expr_eval.silt
+++ b/examples/expr_eval.silt
@@ -20,9 +20,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -203,17 +203,17 @@ fn main() {
   examples
     |> list.each { (label, expr) ->
       println("--- {label} ---")
-      println("  Pretty:     {expr.display()}")
+      println("  Pretty:     {expr}")
       println("  Eval:       {eval(expr)}")
       let s = simplify(expr)
-      println("  Simplified: {s.display()}")
+      println("  Simplified: {s}")
       println("  Eval(simp): {eval(s)}")
       let rpn = to_rpn(expr)
       let rpn_str = string.join(rpn, " ")
       println("  RPN:        {rpn_str}")
       -- Round-trip: from_rpn(to_rpn(expr)) should equal original
       let roundtrip = from_rpn(rpn)
-      println("  Roundtrip:  {roundtrip.display()}")
+      println("  Roundtrip:  {roundtrip}")
       println("  RT eval:    {eval(roundtrip)}")
       println("  Complexity: {complexity(expr)}")
       println("  Depth:      {depth(expr)}")
@@ -223,10 +223,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -244,7 +244,7 @@ fn main() {
   test_exprs
     |> list.each { expr ->
       let cls = complexity(expr)
-      println("  {expr.display()} -> {cls}")
+      println("  {expr} -> {cls}")
     }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -252,7 +252,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -264,7 +264,7 @@ fn main() {
   neg_examples
     |> list.each { (label, expr) ->
       let s = simplify(expr)
-      println("  {label} -> simplified: {s.display()} = {eval(s)}")
+      println("  {label} -> simplified: {s} = {eval(s)}")
     }
   println("\nDone!")
 }
diff --git a/examples/http_client.silt b/examples/http_client.silt
index 293028cf2..dfe27b0f4 100644
--- a/examples/http_client.silt
+++ b/examples/http_client.silt
@@ -16,20 +16,20 @@ type Repo {
 fn fetch_repos(user) {
   -- http.get returns HttpError, bytes.to_string BytesError and
   -- json.parse_list JsonError. Fold them into a single `String` channel
-  -- via `e.message()` so fetch_repos surfaces one uniform error type to
+  -- via `Error.message(e)` so fetch_repos surfaces one uniform error type to
   -- its caller.
   let resp = match http.get("https://api.github.com/users/{user}/repos") {
     Ok(r) -> r
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   -- The body is the bytes that arrived; JSON is text.
   let text = match bytes.to_string(resp.body) {
     Ok(text) -> text
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   match json.parse_list(text, Repo) {
     Ok(repos) -> Ok(repos)
-    Err(e) -> Err(e.message())
+    Err(e) -> Err(Error.message(e))
   }
 }
 
diff --git a/examples/http_server.silt b/examples/http_server.silt
index 615c9fc4d..7f58d8760 100644
--- a/examples/http_server.silt
+++ b/examples/http_server.silt
@@ -47,9 +47,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> json_response(201, todo)
-          Err(e) -> json_response(400, #{ "error": e.message() })
+          Err(e) -> json_response(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> json_response(400, #{ "error": e.message() })
+        Err(e) -> json_response(400, #{ "error": Error.message(e) })
       }
       (http.GET, ["todos", id_str]) -> match int.parse(id_str) {
         Ok(id) -> json_response(200, Todo { id: id, title: "Todo {id}", done: false })
diff --git a/examples/json_time.silt b/examples/json_time.silt
index dee86ea58..dd0005838 100644
--- a/examples/json_time.silt
+++ b/examples/json_time.silt
@@ -22,7 +22,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -34,7 +34,7 @@ fn main() {
     Meeting,
   ) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
@@ -43,7 +43,7 @@ fn main() {
     Schedule,
   ) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -55,7 +55,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
     |> list.each { e ->
@@ -69,6 +69,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/examples/json_transform.silt b/examples/json_transform.silt
index 5cc629200..b94a556f9 100644
--- a/examples/json_transform.silt
+++ b/examples/json_transform.silt
@@ -67,7 +67,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/examples/kvstore.silt b/examples/kvstore.silt
index ac93b3668..0fec3de1f 100644
--- a/examples/kvstore.silt
+++ b/examples/kvstore.silt
@@ -80,7 +80,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -88,7 +88,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -98,7 +98,7 @@ fn handle_load() {
         loaded
       }
       Err(e) -> {
-        println("Error parsing JSON: {e.message()}")
+        println("Error parsing JSON: {Error.message(e)}")
         println("Starting with empty store.")
         #{}
       }
diff --git a/examples/link_checker.silt b/examples/link_checker.silt
index eac2b5461..c6f4ec644 100644
--- a/examples/link_checker.silt
+++ b/examples/link_checker.silt
@@ -23,7 +23,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/examples/pipeline.silt b/examples/pipeline.silt
index b5caf26f9..cfd14fea3 100644
--- a/examples/pipeline.silt
+++ b/examples/pipeline.silt
@@ -137,7 +137,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content |> string.split("\n") |> list.filter { line -> !string.is_empty(line) }
   println("Loaded {list.length(lines)} log lines")
diff --git a/examples/state_machine.silt b/examples/state_machine.silt
index 02f2f742b..c2e5ca757 100644
--- a/examples/state_machine.silt
+++ b/examples/state_machine.silt
@@ -46,13 +46,13 @@ trait Display for Event {
 
 -- Print a labeled displayable value (uses where clause)
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
-  items |> list.each { item -> println("  - {item.display()}") }
+  items |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -154,7 +154,7 @@ fn run_machine(events, initial_state, initial_inventory) {
         _ -> (state2, inventory2)
       }
       let (new_state, message, new_inv) = transition(state3, event, inventory3)
-      let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+      let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
       (new_state, new_inv, step2 + 1, new_log)
     }
   let (_final_state, _final_inv, _step, log) = outcome
@@ -206,7 +206,7 @@ fn main() {
         _ -> "{step}"
       }
       println("[{step_str}] Event: {event_str}")
-      println("     {old_state.display()} -> {new_state.display()}")
+      println("     {old_state} -> {new_state}")
       println("     >> {message}")
       println("")
     }
diff --git a/examples/text_stats.silt b/examples/text_stats.silt
index e26cc9995..4c9426c00 100644
--- a/examples/text_stats.silt
+++ b/examples/text_stats.silt
@@ -97,7 +97,7 @@ fn print_row(label, value) {
 fn main() {
   let filename = get_filename()
   match io.read_file(filename) {
-    Err(e) -> println("Error reading file '{filename}': {e.message()}")
+    Err(e) -> println("Error reading file '{filename}': {Error.message(e)}")
     Ok(content) -> {
       let lines = content |> string.split("\n") |> list.filter { l -> !string.is_empty(l) }
       let line_count = list.length(lines)
diff --git a/examples/time_demo.silt b/examples/time_demo.silt
index b6e10cc0c..18c776cb4 100644
--- a/examples/time_demo.silt
+++ b/examples/time_demo.silt
@@ -6,31 +6,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -42,11 +42,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -57,17 +57,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today |> time.add_days(90)
@@ -77,13 +77,13 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31 |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31 |> time.add_months(-1)
   println("Mar 31 - 1 month = {prev}")
@@ -114,11 +114,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -130,11 +130,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/examples/todo.silt b/examples/todo.silt
index 5ebecb200..c129e55bf 100644
--- a/examples/todo.silt
+++ b/examples/todo.silt
@@ -56,7 +56,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -73,13 +73,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/examples/trait_zoo.silt b/examples/trait_zoo.silt
index 4095f4d4c..a7a0707d8 100644
--- a/examples/trait_zoo.silt
+++ b/examples/trait_zoo.silt
@@ -53,7 +53,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -98,7 +98,7 @@ trait Perimeter for Shape {
 
 -- Generic function with where clause
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
@@ -123,16 +123,16 @@ fn main() {
   shapes
     |> list.each { s ->
       println("  {describe(s)}")
-      println("    Area:      {fmt(s.area())}")
-      println("    Perimeter: {fmt(s.perimeter())}")
+      println("    Area:      {fmt(Area.area(s))}")
+      println("    Perimeter: {fmt(Perimeter.perimeter(s))}")
     }
   -- Sort shapes by area
   println("")
   println("-- Sorted by Area (ascending) --")
-  let sorted = shapes |> list.sort_by { s -> s.area() }
-  sorted |> list.each { s -> println("  {describe(s)} -> area = {fmt(s.area())}") }
+  let sorted = shapes |> list.sort_by { s -> Area.area(s) }
+  sorted |> list.each { s -> println("  {describe(s)} -> area = {fmt(Area.area(s))}") }
   -- Total area
-  let total_area = shapes |> list.map { s -> s.area() } |> list.fold(0.0) { acc, a -> acc + a }
+  let total_area = shapes |> list.map { s -> Area.area(s) } |> list.fold(0.0) { acc, a -> acc + a }
   println("")
   println("Total area: {fmt(total_area)}")
   -- Colors and styled shapes
diff --git a/examples/traits.silt b/examples/traits.silt
index e407961ea..21c785ec8 100644
--- a/examples/traits.silt
+++ b/examples/traits.silt
@@ -24,7 +24,7 @@ fn area(shape) {
 fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
-  shapes |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  shapes |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes |> list.map { s -> area(s) } |> list.fold(0.0) { acc, a -> acc + a }
   println("\nTotal area: {total}")
   let big = shapes |> list.filter { s -> area(s) > 10.0 }
diff --git a/fuzz/corpus/fuzz_compiler/http_client.silt b/fuzz/corpus/fuzz_compiler/http_client.silt
index 5ebaa97db..12a3ca26f 100644
--- a/fuzz/corpus/fuzz_compiler/http_client.silt
+++ b/fuzz/corpus/fuzz_compiler/http_client.silt
@@ -20,16 +20,16 @@ fn fetch_repos(user) {
   -- its caller.
   let resp = match http.get("https://api.github.com/users/{user}/repos") {
     Ok(r) -> r
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   -- The body is the bytes that arrived; JSON is text.
   let text = match bytes.to_string(resp.body) {
     Ok(text) -> text
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   match json.parse_list(text, Repo) {
     Ok(repos) -> Ok(repos)
-    Err(e) -> Err(e.message())
+    Err(e) -> Err(Error.message(e))
   }
 }
 
diff --git a/fuzz/corpus/fuzz_compiler/http_server.silt b/fuzz/corpus/fuzz_compiler/http_server.silt
index cff3c0e01..e9c253201 100644
--- a/fuzz/corpus/fuzz_compiler/http_server.silt
+++ b/fuzz/corpus/fuzz_compiler/http_server.silt
@@ -47,9 +47,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> json_response(201, todo)
-          Err(e) -> json_response(400, #{ "error": e.message() })
+          Err(e) -> json_response(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> json_response(400, #{ "error": e.message() })
+        Err(e) -> json_response(400, #{ "error": Error.message(e) })
       }
       (http.GET, ["todos", id_str]) -> match int.parse(id_str) {
         Ok(id) -> json_response(200, Todo { id: id, title: "Todo {id}", done: false })
diff --git a/fuzz/corpus/fuzz_compiler/json_time.silt b/fuzz/corpus/fuzz_compiler/json_time.silt
index 86ccc60c4..5c599757c 100644
--- a/fuzz/corpus/fuzz_compiler/json_time.silt
+++ b/fuzz/corpus/fuzz_compiler/json_time.silt
@@ -22,7 +22,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -32,13 +32,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -50,7 +50,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -66,6 +66,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/fuzz/corpus/fuzz_compiler/json_transform.silt b/fuzz/corpus/fuzz_compiler/json_transform.silt
index 6d2a267a8..084edb735 100644
--- a/fuzz/corpus/fuzz_compiler/json_transform.silt
+++ b/fuzz/corpus/fuzz_compiler/json_transform.silt
@@ -75,7 +75,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/fuzz/corpus/fuzz_compiler/kvstore.silt b/fuzz/corpus/fuzz_compiler/kvstore.silt
index e74c39ea1..fd922cc1b 100644
--- a/fuzz/corpus/fuzz_compiler/kvstore.silt
+++ b/fuzz/corpus/fuzz_compiler/kvstore.silt
@@ -84,7 +84,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -92,7 +92,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -103,7 +103,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/fuzz/corpus/fuzz_compiler/link_checker.silt b/fuzz/corpus/fuzz_compiler/link_checker.silt
index 72f749e45..6ab487d7f 100644
--- a/fuzz/corpus/fuzz_compiler/link_checker.silt
+++ b/fuzz/corpus/fuzz_compiler/link_checker.silt
@@ -23,7 +23,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/fuzz/corpus/fuzz_compiler/pipeline.silt b/fuzz/corpus/fuzz_compiler/pipeline.silt
index dda665606..bba06791e 100644
--- a/fuzz/corpus/fuzz_compiler/pipeline.silt
+++ b/fuzz/corpus/fuzz_compiler/pipeline.silt
@@ -159,7 +159,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_compiler/state_machine.silt b/fuzz/corpus/fuzz_compiler/state_machine.silt
index 198fb9c76..385083bc0 100644
--- a/fuzz/corpus/fuzz_compiler/state_machine.silt
+++ b/fuzz/corpus/fuzz_compiler/state_machine.silt
@@ -51,7 +51,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -59,7 +59,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -155,7 +155,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -191,7 +191,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/fuzz/corpus/fuzz_compiler/time_demo.silt b/fuzz/corpus/fuzz_compiler/time_demo.silt
index 0efdf76db..ea780972b 100644
--- a/fuzz/corpus/fuzz_compiler/time_demo.silt
+++ b/fuzz/corpus/fuzz_compiler/time_demo.silt
@@ -6,31 +6,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -42,11 +42,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -57,17 +57,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -79,14 +79,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -122,11 +122,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -138,11 +138,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/fuzz/corpus/fuzz_compiler/todo.silt b/fuzz/corpus/fuzz_compiler/todo.silt
index 6b7d05a98..be223ca9c 100644
--- a/fuzz/corpus/fuzz_compiler/todo.silt
+++ b/fuzz/corpus/fuzz_compiler/todo.silt
@@ -61,7 +61,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -78,13 +78,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/fuzz/corpus/fuzz_compiler/trait_zoo.silt b/fuzz/corpus/fuzz_compiler/trait_zoo.silt
index d861f0659..9181b9b2f 100644
--- a/fuzz/corpus/fuzz_compiler/trait_zoo.silt
+++ b/fuzz/corpus/fuzz_compiler/trait_zoo.silt
@@ -52,7 +52,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -97,7 +97,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/fuzz/corpus/fuzz_compiler/traits.silt b/fuzz/corpus/fuzz_compiler/traits.silt
index 794b0103a..0eaae4cc1 100644
--- a/fuzz/corpus/fuzz_compiler/traits.silt
+++ b/fuzz/corpus/fuzz_compiler/traits.silt
@@ -25,7 +25,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/fuzz/corpus/fuzz_formatter/birthdays.silt b/fuzz/corpus/fuzz_formatter/birthdays.silt
index 5cd804dd7..9431866f5 100644
--- a/fuzz/corpus/fuzz_formatter/birthdays.silt
+++ b/fuzz/corpus/fuzz_formatter/birthdays.silt
@@ -47,7 +47,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/fuzz/corpus/fuzz_formatter/concurrent_processor.silt b/fuzz/corpus/fuzz_formatter/concurrent_processor.silt
index a4442b900..f6b05a6f3 100644
--- a/fuzz/corpus/fuzz_formatter/concurrent_processor.silt
+++ b/fuzz/corpus/fuzz_formatter/concurrent_processor.silt
@@ -101,7 +101,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/fuzz/corpus/fuzz_formatter/config_parser.silt b/fuzz/corpus/fuzz_formatter/config_parser.silt
index c235a060c..ead4d6960 100644
--- a/fuzz/corpus/fuzz_formatter/config_parser.silt
+++ b/fuzz/corpus/fuzz_formatter/config_parser.silt
@@ -143,7 +143,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/fuzz/corpus/fuzz_formatter/csv_analyzer.silt b/fuzz/corpus/fuzz_formatter/csv_analyzer.silt
index 6d2ab00d3..4bdfc6328 100644
--- a/fuzz/corpus/fuzz_formatter/csv_analyzer.silt
+++ b/fuzz/corpus/fuzz_formatter/csv_analyzer.silt
@@ -112,7 +112,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_formatter/diff_tool.silt b/fuzz/corpus/fuzz_formatter/diff_tool.silt
index 7ec90d4b8..a4716b29c 100644
--- a/fuzz/corpus/fuzz_formatter/diff_tool.silt
+++ b/fuzz/corpus/fuzz_formatter/diff_tool.silt
@@ -111,11 +111,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/fuzz/corpus/fuzz_formatter/expr_eval.silt b/fuzz/corpus/fuzz_formatter/expr_eval.silt
index 906d51cea..f1907aaae 100644
--- a/fuzz/corpus/fuzz_formatter/expr_eval.silt
+++ b/fuzz/corpus/fuzz_formatter/expr_eval.silt
@@ -20,9 +20,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -205,16 +205,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -225,10 +225,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -239,7 +239,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -247,7 +247,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -255,7 +255,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/fuzz/corpus/fuzz_formatter/http_client.silt b/fuzz/corpus/fuzz_formatter/http_client.silt
index 5ebaa97db..12a3ca26f 100644
--- a/fuzz/corpus/fuzz_formatter/http_client.silt
+++ b/fuzz/corpus/fuzz_formatter/http_client.silt
@@ -20,16 +20,16 @@ fn fetch_repos(user) {
   -- its caller.
   let resp = match http.get("https://api.github.com/users/{user}/repos") {
     Ok(r) -> r
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   -- The body is the bytes that arrived; JSON is text.
   let text = match bytes.to_string(resp.body) {
     Ok(text) -> text
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   match json.parse_list(text, Repo) {
     Ok(repos) -> Ok(repos)
-    Err(e) -> Err(e.message())
+    Err(e) -> Err(Error.message(e))
   }
 }
 
diff --git a/fuzz/corpus/fuzz_formatter/http_server.silt b/fuzz/corpus/fuzz_formatter/http_server.silt
index cff3c0e01..e9c253201 100644
--- a/fuzz/corpus/fuzz_formatter/http_server.silt
+++ b/fuzz/corpus/fuzz_formatter/http_server.silt
@@ -47,9 +47,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> json_response(201, todo)
-          Err(e) -> json_response(400, #{ "error": e.message() })
+          Err(e) -> json_response(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> json_response(400, #{ "error": e.message() })
+        Err(e) -> json_response(400, #{ "error": Error.message(e) })
       }
       (http.GET, ["todos", id_str]) -> match int.parse(id_str) {
         Ok(id) -> json_response(200, Todo { id: id, title: "Todo {id}", done: false })
diff --git a/fuzz/corpus/fuzz_formatter/json_time.silt b/fuzz/corpus/fuzz_formatter/json_time.silt
index 86ccc60c4..5c599757c 100644
--- a/fuzz/corpus/fuzz_formatter/json_time.silt
+++ b/fuzz/corpus/fuzz_formatter/json_time.silt
@@ -22,7 +22,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -32,13 +32,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -50,7 +50,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -66,6 +66,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/fuzz/corpus/fuzz_formatter/json_transform.silt b/fuzz/corpus/fuzz_formatter/json_transform.silt
index 6d2a267a8..084edb735 100644
--- a/fuzz/corpus/fuzz_formatter/json_transform.silt
+++ b/fuzz/corpus/fuzz_formatter/json_transform.silt
@@ -75,7 +75,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/fuzz/corpus/fuzz_formatter/kvstore.silt b/fuzz/corpus/fuzz_formatter/kvstore.silt
index e74c39ea1..fd922cc1b 100644
--- a/fuzz/corpus/fuzz_formatter/kvstore.silt
+++ b/fuzz/corpus/fuzz_formatter/kvstore.silt
@@ -84,7 +84,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -92,7 +92,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -103,7 +103,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/fuzz/corpus/fuzz_formatter/link_checker.silt b/fuzz/corpus/fuzz_formatter/link_checker.silt
index 72f749e45..6ab487d7f 100644
--- a/fuzz/corpus/fuzz_formatter/link_checker.silt
+++ b/fuzz/corpus/fuzz_formatter/link_checker.silt
@@ -23,7 +23,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/fuzz/corpus/fuzz_formatter/pipeline.silt b/fuzz/corpus/fuzz_formatter/pipeline.silt
index dda665606..bba06791e 100644
--- a/fuzz/corpus/fuzz_formatter/pipeline.silt
+++ b/fuzz/corpus/fuzz_formatter/pipeline.silt
@@ -159,7 +159,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_formatter/state_machine.silt b/fuzz/corpus/fuzz_formatter/state_machine.silt
index 198fb9c76..385083bc0 100644
--- a/fuzz/corpus/fuzz_formatter/state_machine.silt
+++ b/fuzz/corpus/fuzz_formatter/state_machine.silt
@@ -51,7 +51,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -59,7 +59,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -155,7 +155,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -191,7 +191,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/fuzz/corpus/fuzz_formatter/time_demo.silt b/fuzz/corpus/fuzz_formatter/time_demo.silt
index 0efdf76db..ea780972b 100644
--- a/fuzz/corpus/fuzz_formatter/time_demo.silt
+++ b/fuzz/corpus/fuzz_formatter/time_demo.silt
@@ -6,31 +6,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -42,11 +42,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -57,17 +57,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -79,14 +79,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -122,11 +122,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -138,11 +138,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/fuzz/corpus/fuzz_formatter/todo.silt b/fuzz/corpus/fuzz_formatter/todo.silt
index 6b7d05a98..be223ca9c 100644
--- a/fuzz/corpus/fuzz_formatter/todo.silt
+++ b/fuzz/corpus/fuzz_formatter/todo.silt
@@ -61,7 +61,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -78,13 +78,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/fuzz/corpus/fuzz_formatter/trait_zoo.silt b/fuzz/corpus/fuzz_formatter/trait_zoo.silt
index d861f0659..9181b9b2f 100644
--- a/fuzz/corpus/fuzz_formatter/trait_zoo.silt
+++ b/fuzz/corpus/fuzz_formatter/trait_zoo.silt
@@ -52,7 +52,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -97,7 +97,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/fuzz/corpus/fuzz_formatter/traits.silt b/fuzz/corpus/fuzz_formatter/traits.silt
index 794b0103a..0eaae4cc1 100644
--- a/fuzz/corpus/fuzz_formatter/traits.silt
+++ b/fuzz/corpus/fuzz_formatter/traits.silt
@@ -25,7 +25,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/fuzz/corpus/fuzz_lexer/birthdays.silt b/fuzz/corpus/fuzz_lexer/birthdays.silt
index 5cd804dd7..9431866f5 100644
--- a/fuzz/corpus/fuzz_lexer/birthdays.silt
+++ b/fuzz/corpus/fuzz_lexer/birthdays.silt
@@ -47,7 +47,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/fuzz/corpus/fuzz_lexer/concurrent_processor.silt b/fuzz/corpus/fuzz_lexer/concurrent_processor.silt
index a4442b900..f6b05a6f3 100644
--- a/fuzz/corpus/fuzz_lexer/concurrent_processor.silt
+++ b/fuzz/corpus/fuzz_lexer/concurrent_processor.silt
@@ -101,7 +101,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/fuzz/corpus/fuzz_lexer/config_parser.silt b/fuzz/corpus/fuzz_lexer/config_parser.silt
index c235a060c..ead4d6960 100644
--- a/fuzz/corpus/fuzz_lexer/config_parser.silt
+++ b/fuzz/corpus/fuzz_lexer/config_parser.silt
@@ -143,7 +143,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/fuzz/corpus/fuzz_lexer/csv_analyzer.silt b/fuzz/corpus/fuzz_lexer/csv_analyzer.silt
index 6d2ab00d3..4bdfc6328 100644
--- a/fuzz/corpus/fuzz_lexer/csv_analyzer.silt
+++ b/fuzz/corpus/fuzz_lexer/csv_analyzer.silt
@@ -112,7 +112,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_lexer/diff_tool.silt b/fuzz/corpus/fuzz_lexer/diff_tool.silt
index 7ec90d4b8..a4716b29c 100644
--- a/fuzz/corpus/fuzz_lexer/diff_tool.silt
+++ b/fuzz/corpus/fuzz_lexer/diff_tool.silt
@@ -111,11 +111,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/fuzz/corpus/fuzz_lexer/expr_eval.silt b/fuzz/corpus/fuzz_lexer/expr_eval.silt
index 906d51cea..f1907aaae 100644
--- a/fuzz/corpus/fuzz_lexer/expr_eval.silt
+++ b/fuzz/corpus/fuzz_lexer/expr_eval.silt
@@ -20,9 +20,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -205,16 +205,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -225,10 +225,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -239,7 +239,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -247,7 +247,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -255,7 +255,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/fuzz/corpus/fuzz_lexer/http_client.silt b/fuzz/corpus/fuzz_lexer/http_client.silt
index 5ebaa97db..12a3ca26f 100644
--- a/fuzz/corpus/fuzz_lexer/http_client.silt
+++ b/fuzz/corpus/fuzz_lexer/http_client.silt
@@ -20,16 +20,16 @@ fn fetch_repos(user) {
   -- its caller.
   let resp = match http.get("https://api.github.com/users/{user}/repos") {
     Ok(r) -> r
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   -- The body is the bytes that arrived; JSON is text.
   let text = match bytes.to_string(resp.body) {
     Ok(text) -> text
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   match json.parse_list(text, Repo) {
     Ok(repos) -> Ok(repos)
-    Err(e) -> Err(e.message())
+    Err(e) -> Err(Error.message(e))
   }
 }
 
diff --git a/fuzz/corpus/fuzz_lexer/http_server.silt b/fuzz/corpus/fuzz_lexer/http_server.silt
index cff3c0e01..e9c253201 100644
--- a/fuzz/corpus/fuzz_lexer/http_server.silt
+++ b/fuzz/corpus/fuzz_lexer/http_server.silt
@@ -47,9 +47,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> json_response(201, todo)
-          Err(e) -> json_response(400, #{ "error": e.message() })
+          Err(e) -> json_response(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> json_response(400, #{ "error": e.message() })
+        Err(e) -> json_response(400, #{ "error": Error.message(e) })
       }
       (http.GET, ["todos", id_str]) -> match int.parse(id_str) {
         Ok(id) -> json_response(200, Todo { id: id, title: "Todo {id}", done: false })
diff --git a/fuzz/corpus/fuzz_lexer/json_time.silt b/fuzz/corpus/fuzz_lexer/json_time.silt
index 86ccc60c4..5c599757c 100644
--- a/fuzz/corpus/fuzz_lexer/json_time.silt
+++ b/fuzz/corpus/fuzz_lexer/json_time.silt
@@ -22,7 +22,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -32,13 +32,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -50,7 +50,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -66,6 +66,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/fuzz/corpus/fuzz_lexer/json_transform.silt b/fuzz/corpus/fuzz_lexer/json_transform.silt
index 6d2a267a8..084edb735 100644
--- a/fuzz/corpus/fuzz_lexer/json_transform.silt
+++ b/fuzz/corpus/fuzz_lexer/json_transform.silt
@@ -75,7 +75,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/fuzz/corpus/fuzz_lexer/kvstore.silt b/fuzz/corpus/fuzz_lexer/kvstore.silt
index e74c39ea1..fd922cc1b 100644
--- a/fuzz/corpus/fuzz_lexer/kvstore.silt
+++ b/fuzz/corpus/fuzz_lexer/kvstore.silt
@@ -84,7 +84,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -92,7 +92,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -103,7 +103,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/fuzz/corpus/fuzz_lexer/link_checker.silt b/fuzz/corpus/fuzz_lexer/link_checker.silt
index 72f749e45..6ab487d7f 100644
--- a/fuzz/corpus/fuzz_lexer/link_checker.silt
+++ b/fuzz/corpus/fuzz_lexer/link_checker.silt
@@ -23,7 +23,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/fuzz/corpus/fuzz_lexer/pipeline.silt b/fuzz/corpus/fuzz_lexer/pipeline.silt
index dda665606..bba06791e 100644
--- a/fuzz/corpus/fuzz_lexer/pipeline.silt
+++ b/fuzz/corpus/fuzz_lexer/pipeline.silt
@@ -159,7 +159,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_lexer/state_machine.silt b/fuzz/corpus/fuzz_lexer/state_machine.silt
index 198fb9c76..385083bc0 100644
--- a/fuzz/corpus/fuzz_lexer/state_machine.silt
+++ b/fuzz/corpus/fuzz_lexer/state_machine.silt
@@ -51,7 +51,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -59,7 +59,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -155,7 +155,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -191,7 +191,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/fuzz/corpus/fuzz_lexer/time_demo.silt b/fuzz/corpus/fuzz_lexer/time_demo.silt
index 0efdf76db..ea780972b 100644
--- a/fuzz/corpus/fuzz_lexer/time_demo.silt
+++ b/fuzz/corpus/fuzz_lexer/time_demo.silt
@@ -6,31 +6,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -42,11 +42,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -57,17 +57,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -79,14 +79,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -122,11 +122,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -138,11 +138,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/fuzz/corpus/fuzz_lexer/todo.silt b/fuzz/corpus/fuzz_lexer/todo.silt
index 6b7d05a98..be223ca9c 100644
--- a/fuzz/corpus/fuzz_lexer/todo.silt
+++ b/fuzz/corpus/fuzz_lexer/todo.silt
@@ -61,7 +61,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -78,13 +78,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/fuzz/corpus/fuzz_lexer/trait_zoo.silt b/fuzz/corpus/fuzz_lexer/trait_zoo.silt
index d861f0659..9181b9b2f 100644
--- a/fuzz/corpus/fuzz_lexer/trait_zoo.silt
+++ b/fuzz/corpus/fuzz_lexer/trait_zoo.silt
@@ -52,7 +52,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -97,7 +97,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/fuzz/corpus/fuzz_lexer/traits.silt b/fuzz/corpus/fuzz_lexer/traits.silt
index 794b0103a..0eaae4cc1 100644
--- a/fuzz/corpus/fuzz_lexer/traits.silt
+++ b/fuzz/corpus/fuzz_lexer/traits.silt
@@ -25,7 +25,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/fuzz/corpus/fuzz_parser/birthdays.silt b/fuzz/corpus/fuzz_parser/birthdays.silt
index 5cd804dd7..9431866f5 100644
--- a/fuzz/corpus/fuzz_parser/birthdays.silt
+++ b/fuzz/corpus/fuzz_parser/birthdays.silt
@@ -47,7 +47,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/fuzz/corpus/fuzz_parser/concurrent_processor.silt b/fuzz/corpus/fuzz_parser/concurrent_processor.silt
index a4442b900..f6b05a6f3 100644
--- a/fuzz/corpus/fuzz_parser/concurrent_processor.silt
+++ b/fuzz/corpus/fuzz_parser/concurrent_processor.silt
@@ -101,7 +101,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/fuzz/corpus/fuzz_parser/config_parser.silt b/fuzz/corpus/fuzz_parser/config_parser.silt
index c235a060c..ead4d6960 100644
--- a/fuzz/corpus/fuzz_parser/config_parser.silt
+++ b/fuzz/corpus/fuzz_parser/config_parser.silt
@@ -143,7 +143,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/fuzz/corpus/fuzz_parser/csv_analyzer.silt b/fuzz/corpus/fuzz_parser/csv_analyzer.silt
index 6d2ab00d3..4bdfc6328 100644
--- a/fuzz/corpus/fuzz_parser/csv_analyzer.silt
+++ b/fuzz/corpus/fuzz_parser/csv_analyzer.silt
@@ -112,7 +112,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_parser/diff_tool.silt b/fuzz/corpus/fuzz_parser/diff_tool.silt
index 7ec90d4b8..a4716b29c 100644
--- a/fuzz/corpus/fuzz_parser/diff_tool.silt
+++ b/fuzz/corpus/fuzz_parser/diff_tool.silt
@@ -111,11 +111,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/fuzz/corpus/fuzz_parser/expr_eval.silt b/fuzz/corpus/fuzz_parser/expr_eval.silt
index 906d51cea..f1907aaae 100644
--- a/fuzz/corpus/fuzz_parser/expr_eval.silt
+++ b/fuzz/corpus/fuzz_parser/expr_eval.silt
@@ -20,9 +20,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -205,16 +205,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -225,10 +225,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -239,7 +239,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -247,7 +247,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -255,7 +255,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/fuzz/corpus/fuzz_parser/http_client.silt b/fuzz/corpus/fuzz_parser/http_client.silt
index 5ebaa97db..12a3ca26f 100644
--- a/fuzz/corpus/fuzz_parser/http_client.silt
+++ b/fuzz/corpus/fuzz_parser/http_client.silt
@@ -20,16 +20,16 @@ fn fetch_repos(user) {
   -- its caller.
   let resp = match http.get("https://api.github.com/users/{user}/repos") {
     Ok(r) -> r
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   -- The body is the bytes that arrived; JSON is text.
   let text = match bytes.to_string(resp.body) {
     Ok(text) -> text
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   match json.parse_list(text, Repo) {
     Ok(repos) -> Ok(repos)
-    Err(e) -> Err(e.message())
+    Err(e) -> Err(Error.message(e))
   }
 }
 
diff --git a/fuzz/corpus/fuzz_parser/http_server.silt b/fuzz/corpus/fuzz_parser/http_server.silt
index cff3c0e01..e9c253201 100644
--- a/fuzz/corpus/fuzz_parser/http_server.silt
+++ b/fuzz/corpus/fuzz_parser/http_server.silt
@@ -47,9 +47,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> json_response(201, todo)
-          Err(e) -> json_response(400, #{ "error": e.message() })
+          Err(e) -> json_response(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> json_response(400, #{ "error": e.message() })
+        Err(e) -> json_response(400, #{ "error": Error.message(e) })
       }
       (http.GET, ["todos", id_str]) -> match int.parse(id_str) {
         Ok(id) -> json_response(200, Todo { id: id, title: "Todo {id}", done: false })
diff --git a/fuzz/corpus/fuzz_parser/json_time.silt b/fuzz/corpus/fuzz_parser/json_time.silt
index 86ccc60c4..5c599757c 100644
--- a/fuzz/corpus/fuzz_parser/json_time.silt
+++ b/fuzz/corpus/fuzz_parser/json_time.silt
@@ -22,7 +22,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -32,13 +32,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -50,7 +50,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -66,6 +66,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/fuzz/corpus/fuzz_parser/json_transform.silt b/fuzz/corpus/fuzz_parser/json_transform.silt
index 6d2a267a8..084edb735 100644
--- a/fuzz/corpus/fuzz_parser/json_transform.silt
+++ b/fuzz/corpus/fuzz_parser/json_transform.silt
@@ -75,7 +75,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/fuzz/corpus/fuzz_parser/kvstore.silt b/fuzz/corpus/fuzz_parser/kvstore.silt
index e74c39ea1..fd922cc1b 100644
--- a/fuzz/corpus/fuzz_parser/kvstore.silt
+++ b/fuzz/corpus/fuzz_parser/kvstore.silt
@@ -84,7 +84,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -92,7 +92,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -103,7 +103,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/fuzz/corpus/fuzz_parser/link_checker.silt b/fuzz/corpus/fuzz_parser/link_checker.silt
index 72f749e45..6ab487d7f 100644
--- a/fuzz/corpus/fuzz_parser/link_checker.silt
+++ b/fuzz/corpus/fuzz_parser/link_checker.silt
@@ -23,7 +23,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/fuzz/corpus/fuzz_parser/pipeline.silt b/fuzz/corpus/fuzz_parser/pipeline.silt
index dda665606..bba06791e 100644
--- a/fuzz/corpus/fuzz_parser/pipeline.silt
+++ b/fuzz/corpus/fuzz_parser/pipeline.silt
@@ -159,7 +159,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_parser/state_machine.silt b/fuzz/corpus/fuzz_parser/state_machine.silt
index 198fb9c76..385083bc0 100644
--- a/fuzz/corpus/fuzz_parser/state_machine.silt
+++ b/fuzz/corpus/fuzz_parser/state_machine.silt
@@ -51,7 +51,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -59,7 +59,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -155,7 +155,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -191,7 +191,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/fuzz/corpus/fuzz_parser/time_demo.silt b/fuzz/corpus/fuzz_parser/time_demo.silt
index 0efdf76db..ea780972b 100644
--- a/fuzz/corpus/fuzz_parser/time_demo.silt
+++ b/fuzz/corpus/fuzz_parser/time_demo.silt
@@ -6,31 +6,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -42,11 +42,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -57,17 +57,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -79,14 +79,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -122,11 +122,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -138,11 +138,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/fuzz/corpus/fuzz_parser/todo.silt b/fuzz/corpus/fuzz_parser/todo.silt
index 6b7d05a98..be223ca9c 100644
--- a/fuzz/corpus/fuzz_parser/todo.silt
+++ b/fuzz/corpus/fuzz_parser/todo.silt
@@ -61,7 +61,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -78,13 +78,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/fuzz/corpus/fuzz_parser/trait_zoo.silt b/fuzz/corpus/fuzz_parser/trait_zoo.silt
index d861f0659..9181b9b2f 100644
--- a/fuzz/corpus/fuzz_parser/trait_zoo.silt
+++ b/fuzz/corpus/fuzz_parser/trait_zoo.silt
@@ -52,7 +52,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -97,7 +97,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/fuzz/corpus/fuzz_parser/traits.silt b/fuzz/corpus/fuzz_parser/traits.silt
index 794b0103a..0eaae4cc1 100644
--- a/fuzz/corpus/fuzz_parser/traits.silt
+++ b/fuzz/corpus/fuzz_parser/traits.silt
@@ -25,7 +25,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/fuzz/corpus/fuzz_roundtrip/birthdays.silt b/fuzz/corpus/fuzz_roundtrip/birthdays.silt
index 5cd804dd7..9431866f5 100644
--- a/fuzz/corpus/fuzz_roundtrip/birthdays.silt
+++ b/fuzz/corpus/fuzz_roundtrip/birthdays.silt
@@ -47,7 +47,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/fuzz/corpus/fuzz_roundtrip/concurrent_processor.silt b/fuzz/corpus/fuzz_roundtrip/concurrent_processor.silt
index a4442b900..f6b05a6f3 100644
--- a/fuzz/corpus/fuzz_roundtrip/concurrent_processor.silt
+++ b/fuzz/corpus/fuzz_roundtrip/concurrent_processor.silt
@@ -101,7 +101,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/fuzz/corpus/fuzz_roundtrip/config_parser.silt b/fuzz/corpus/fuzz_roundtrip/config_parser.silt
index c235a060c..ead4d6960 100644
--- a/fuzz/corpus/fuzz_roundtrip/config_parser.silt
+++ b/fuzz/corpus/fuzz_roundtrip/config_parser.silt
@@ -143,7 +143,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/fuzz/corpus/fuzz_roundtrip/csv_analyzer.silt b/fuzz/corpus/fuzz_roundtrip/csv_analyzer.silt
index 6d2ab00d3..4bdfc6328 100644
--- a/fuzz/corpus/fuzz_roundtrip/csv_analyzer.silt
+++ b/fuzz/corpus/fuzz_roundtrip/csv_analyzer.silt
@@ -112,7 +112,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_roundtrip/diff_tool.silt b/fuzz/corpus/fuzz_roundtrip/diff_tool.silt
index 7ec90d4b8..a4716b29c 100644
--- a/fuzz/corpus/fuzz_roundtrip/diff_tool.silt
+++ b/fuzz/corpus/fuzz_roundtrip/diff_tool.silt
@@ -111,11 +111,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/fuzz/corpus/fuzz_roundtrip/expr_eval.silt b/fuzz/corpus/fuzz_roundtrip/expr_eval.silt
index 906d51cea..f1907aaae 100644
--- a/fuzz/corpus/fuzz_roundtrip/expr_eval.silt
+++ b/fuzz/corpus/fuzz_roundtrip/expr_eval.silt
@@ -20,9 +20,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -205,16 +205,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -225,10 +225,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -239,7 +239,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -247,7 +247,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -255,7 +255,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/fuzz/corpus/fuzz_roundtrip/http_client.silt b/fuzz/corpus/fuzz_roundtrip/http_client.silt
index 5ebaa97db..12a3ca26f 100644
--- a/fuzz/corpus/fuzz_roundtrip/http_client.silt
+++ b/fuzz/corpus/fuzz_roundtrip/http_client.silt
@@ -20,16 +20,16 @@ fn fetch_repos(user) {
   -- its caller.
   let resp = match http.get("https://api.github.com/users/{user}/repos") {
     Ok(r) -> r
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   -- The body is the bytes that arrived; JSON is text.
   let text = match bytes.to_string(resp.body) {
     Ok(text) -> text
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   match json.parse_list(text, Repo) {
     Ok(repos) -> Ok(repos)
-    Err(e) -> Err(e.message())
+    Err(e) -> Err(Error.message(e))
   }
 }
 
diff --git a/fuzz/corpus/fuzz_roundtrip/http_server.silt b/fuzz/corpus/fuzz_roundtrip/http_server.silt
index cff3c0e01..e9c253201 100644
--- a/fuzz/corpus/fuzz_roundtrip/http_server.silt
+++ b/fuzz/corpus/fuzz_roundtrip/http_server.silt
@@ -47,9 +47,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> json_response(201, todo)
-          Err(e) -> json_response(400, #{ "error": e.message() })
+          Err(e) -> json_response(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> json_response(400, #{ "error": e.message() })
+        Err(e) -> json_response(400, #{ "error": Error.message(e) })
       }
       (http.GET, ["todos", id_str]) -> match int.parse(id_str) {
         Ok(id) -> json_response(200, Todo { id: id, title: "Todo {id}", done: false })
diff --git a/fuzz/corpus/fuzz_roundtrip/json_time.silt b/fuzz/corpus/fuzz_roundtrip/json_time.silt
index 86ccc60c4..5c599757c 100644
--- a/fuzz/corpus/fuzz_roundtrip/json_time.silt
+++ b/fuzz/corpus/fuzz_roundtrip/json_time.silt
@@ -22,7 +22,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -32,13 +32,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -50,7 +50,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -66,6 +66,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/fuzz/corpus/fuzz_roundtrip/json_transform.silt b/fuzz/corpus/fuzz_roundtrip/json_transform.silt
index 6d2a267a8..084edb735 100644
--- a/fuzz/corpus/fuzz_roundtrip/json_transform.silt
+++ b/fuzz/corpus/fuzz_roundtrip/json_transform.silt
@@ -75,7 +75,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/fuzz/corpus/fuzz_roundtrip/kvstore.silt b/fuzz/corpus/fuzz_roundtrip/kvstore.silt
index e74c39ea1..fd922cc1b 100644
--- a/fuzz/corpus/fuzz_roundtrip/kvstore.silt
+++ b/fuzz/corpus/fuzz_roundtrip/kvstore.silt
@@ -84,7 +84,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -92,7 +92,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -103,7 +103,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/fuzz/corpus/fuzz_roundtrip/link_checker.silt b/fuzz/corpus/fuzz_roundtrip/link_checker.silt
index 72f749e45..6ab487d7f 100644
--- a/fuzz/corpus/fuzz_roundtrip/link_checker.silt
+++ b/fuzz/corpus/fuzz_roundtrip/link_checker.silt
@@ -23,7 +23,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/fuzz/corpus/fuzz_roundtrip/pipeline.silt b/fuzz/corpus/fuzz_roundtrip/pipeline.silt
index dda665606..bba06791e 100644
--- a/fuzz/corpus/fuzz_roundtrip/pipeline.silt
+++ b/fuzz/corpus/fuzz_roundtrip/pipeline.silt
@@ -159,7 +159,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_roundtrip/state_machine.silt b/fuzz/corpus/fuzz_roundtrip/state_machine.silt
index 198fb9c76..385083bc0 100644
--- a/fuzz/corpus/fuzz_roundtrip/state_machine.silt
+++ b/fuzz/corpus/fuzz_roundtrip/state_machine.silt
@@ -51,7 +51,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -59,7 +59,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -155,7 +155,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -191,7 +191,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/fuzz/corpus/fuzz_roundtrip/time_demo.silt b/fuzz/corpus/fuzz_roundtrip/time_demo.silt
index 0efdf76db..ea780972b 100644
--- a/fuzz/corpus/fuzz_roundtrip/time_demo.silt
+++ b/fuzz/corpus/fuzz_roundtrip/time_demo.silt
@@ -6,31 +6,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -42,11 +42,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -57,17 +57,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -79,14 +79,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -122,11 +122,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -138,11 +138,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/fuzz/corpus/fuzz_roundtrip/todo.silt b/fuzz/corpus/fuzz_roundtrip/todo.silt
index 6b7d05a98..be223ca9c 100644
--- a/fuzz/corpus/fuzz_roundtrip/todo.silt
+++ b/fuzz/corpus/fuzz_roundtrip/todo.silt
@@ -61,7 +61,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -78,13 +78,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/fuzz/corpus/fuzz_roundtrip/trait_zoo.silt b/fuzz/corpus/fuzz_roundtrip/trait_zoo.silt
index d861f0659..9181b9b2f 100644
--- a/fuzz/corpus/fuzz_roundtrip/trait_zoo.silt
+++ b/fuzz/corpus/fuzz_roundtrip/trait_zoo.silt
@@ -52,7 +52,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -97,7 +97,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/fuzz/corpus/fuzz_roundtrip/traits.silt b/fuzz/corpus/fuzz_roundtrip/traits.silt
index 794b0103a..0eaae4cc1 100644
--- a/fuzz/corpus/fuzz_roundtrip/traits.silt
+++ b/fuzz/corpus/fuzz_roundtrip/traits.silt
@@ -25,7 +25,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/fuzz/corpus/fuzz_run/run_records_traits.silt b/fuzz/corpus/fuzz_run/run_records_traits.silt
index 58d24d9b9..04ca9cdd1 100644
--- a/fuzz/corpus/fuzz_run/run_records_traits.silt
+++ b/fuzz/corpus/fuzz_run/run_records_traits.silt
@@ -30,6 +30,6 @@ fn main() {
   println("{p} {q}")
   println([p, q])
   let shapes = [Circle(2), Rect(3, 4)]
-  println(list.map(shapes) { s -> s.area() })
+  println(list.map(shapes) { s -> Area.area(s) })
   q.x + q.y
 }
diff --git a/fuzz/corpus/fuzz_typechecker/birthdays.silt b/fuzz/corpus/fuzz_typechecker/birthdays.silt
index 5cd804dd7..9431866f5 100644
--- a/fuzz/corpus/fuzz_typechecker/birthdays.silt
+++ b/fuzz/corpus/fuzz_typechecker/birthdays.silt
@@ -47,7 +47,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/fuzz/corpus/fuzz_typechecker/concurrent_processor.silt b/fuzz/corpus/fuzz_typechecker/concurrent_processor.silt
index a4442b900..f6b05a6f3 100644
--- a/fuzz/corpus/fuzz_typechecker/concurrent_processor.silt
+++ b/fuzz/corpus/fuzz_typechecker/concurrent_processor.silt
@@ -101,7 +101,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/fuzz/corpus/fuzz_typechecker/config_parser.silt b/fuzz/corpus/fuzz_typechecker/config_parser.silt
index c235a060c..ead4d6960 100644
--- a/fuzz/corpus/fuzz_typechecker/config_parser.silt
+++ b/fuzz/corpus/fuzz_typechecker/config_parser.silt
@@ -143,7 +143,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/fuzz/corpus/fuzz_typechecker/csv_analyzer.silt b/fuzz/corpus/fuzz_typechecker/csv_analyzer.silt
index 6d2ab00d3..4bdfc6328 100644
--- a/fuzz/corpus/fuzz_typechecker/csv_analyzer.silt
+++ b/fuzz/corpus/fuzz_typechecker/csv_analyzer.silt
@@ -112,7 +112,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_typechecker/diff_tool.silt b/fuzz/corpus/fuzz_typechecker/diff_tool.silt
index 7ec90d4b8..a4716b29c 100644
--- a/fuzz/corpus/fuzz_typechecker/diff_tool.silt
+++ b/fuzz/corpus/fuzz_typechecker/diff_tool.silt
@@ -111,11 +111,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/fuzz/corpus/fuzz_typechecker/expr_eval.silt b/fuzz/corpus/fuzz_typechecker/expr_eval.silt
index 906d51cea..f1907aaae 100644
--- a/fuzz/corpus/fuzz_typechecker/expr_eval.silt
+++ b/fuzz/corpus/fuzz_typechecker/expr_eval.silt
@@ -20,9 +20,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -205,16 +205,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -225,10 +225,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -239,7 +239,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -247,7 +247,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -255,7 +255,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/fuzz/corpus/fuzz_typechecker/http_client.silt b/fuzz/corpus/fuzz_typechecker/http_client.silt
index 5ebaa97db..12a3ca26f 100644
--- a/fuzz/corpus/fuzz_typechecker/http_client.silt
+++ b/fuzz/corpus/fuzz_typechecker/http_client.silt
@@ -20,16 +20,16 @@ fn fetch_repos(user) {
   -- its caller.
   let resp = match http.get("https://api.github.com/users/{user}/repos") {
     Ok(r) -> r
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   -- The body is the bytes that arrived; JSON is text.
   let text = match bytes.to_string(resp.body) {
     Ok(text) -> text
-    Err(e) -> return Err(e.message())
+    Err(e) -> return Err(Error.message(e))
   }
   match json.parse_list(text, Repo) {
     Ok(repos) -> Ok(repos)
-    Err(e) -> Err(e.message())
+    Err(e) -> Err(Error.message(e))
   }
 }
 
diff --git a/fuzz/corpus/fuzz_typechecker/http_server.silt b/fuzz/corpus/fuzz_typechecker/http_server.silt
index cff3c0e01..e9c253201 100644
--- a/fuzz/corpus/fuzz_typechecker/http_server.silt
+++ b/fuzz/corpus/fuzz_typechecker/http_server.silt
@@ -47,9 +47,9 @@ fn main() {
       (http.POST, ["todos"]) -> match bytes.to_string(req.body) {
         Ok(text) -> match json.parse(text, Todo) {
           Ok(todo) -> json_response(201, todo)
-          Err(e) -> json_response(400, #{ "error": e.message() })
+          Err(e) -> json_response(400, #{ "error": Error.message(e) })
         }
-        Err(e) -> json_response(400, #{ "error": e.message() })
+        Err(e) -> json_response(400, #{ "error": Error.message(e) })
       }
       (http.GET, ["todos", id_str]) -> match int.parse(id_str) {
         Ok(id) -> json_response(200, Todo { id: id, title: "Todo {id}", done: false })
diff --git a/fuzz/corpus/fuzz_typechecker/json_time.silt b/fuzz/corpus/fuzz_typechecker/json_time.silt
index 86ccc60c4..5c599757c 100644
--- a/fuzz/corpus/fuzz_typechecker/json_time.silt
+++ b/fuzz/corpus/fuzz_typechecker/json_time.silt
@@ -22,7 +22,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -32,13 +32,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -50,7 +50,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -66,6 +66,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/fuzz/corpus/fuzz_typechecker/json_transform.silt b/fuzz/corpus/fuzz_typechecker/json_transform.silt
index 6d2a267a8..084edb735 100644
--- a/fuzz/corpus/fuzz_typechecker/json_transform.silt
+++ b/fuzz/corpus/fuzz_typechecker/json_transform.silt
@@ -75,7 +75,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/fuzz/corpus/fuzz_typechecker/kvstore.silt b/fuzz/corpus/fuzz_typechecker/kvstore.silt
index e74c39ea1..fd922cc1b 100644
--- a/fuzz/corpus/fuzz_typechecker/kvstore.silt
+++ b/fuzz/corpus/fuzz_typechecker/kvstore.silt
@@ -84,7 +84,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -92,7 +92,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -103,7 +103,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/fuzz/corpus/fuzz_typechecker/link_checker.silt b/fuzz/corpus/fuzz_typechecker/link_checker.silt
index 72f749e45..6ab487d7f 100644
--- a/fuzz/corpus/fuzz_typechecker/link_checker.silt
+++ b/fuzz/corpus/fuzz_typechecker/link_checker.silt
@@ -23,7 +23,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/fuzz/corpus/fuzz_typechecker/pipeline.silt b/fuzz/corpus/fuzz_typechecker/pipeline.silt
index dda665606..bba06791e 100644
--- a/fuzz/corpus/fuzz_typechecker/pipeline.silt
+++ b/fuzz/corpus/fuzz_typechecker/pipeline.silt
@@ -159,7 +159,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/fuzz/corpus/fuzz_typechecker/state_machine.silt b/fuzz/corpus/fuzz_typechecker/state_machine.silt
index 198fb9c76..385083bc0 100644
--- a/fuzz/corpus/fuzz_typechecker/state_machine.silt
+++ b/fuzz/corpus/fuzz_typechecker/state_machine.silt
@@ -51,7 +51,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -59,7 +59,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -155,7 +155,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -191,7 +191,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/fuzz/corpus/fuzz_typechecker/time_demo.silt b/fuzz/corpus/fuzz_typechecker/time_demo.silt
index 0efdf76db..ea780972b 100644
--- a/fuzz/corpus/fuzz_typechecker/time_demo.silt
+++ b/fuzz/corpus/fuzz_typechecker/time_demo.silt
@@ -6,31 +6,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -42,11 +42,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -57,17 +57,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -79,14 +79,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -122,11 +122,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -138,11 +138,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/fuzz/corpus/fuzz_typechecker/todo.silt b/fuzz/corpus/fuzz_typechecker/todo.silt
index 6b7d05a98..be223ca9c 100644
--- a/fuzz/corpus/fuzz_typechecker/todo.silt
+++ b/fuzz/corpus/fuzz_typechecker/todo.silt
@@ -61,7 +61,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -78,13 +78,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/fuzz/corpus/fuzz_typechecker/trait_zoo.silt b/fuzz/corpus/fuzz_typechecker/trait_zoo.silt
index d861f0659..9181b9b2f 100644
--- a/fuzz/corpus/fuzz_typechecker/trait_zoo.silt
+++ b/fuzz/corpus/fuzz_typechecker/trait_zoo.silt
@@ -52,7 +52,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -97,7 +97,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/fuzz/corpus/fuzz_typechecker/traits.silt b/fuzz/corpus/fuzz_typechecker/traits.silt
index 794b0103a..0eaae4cc1 100644
--- a/fuzz/corpus/fuzz_typechecker/traits.silt
+++ b/fuzz/corpus/fuzz_typechecker/traits.silt
@@ -25,7 +25,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/src/ast.rs b/src/ast.rs
index 54ed106b1..e7975f5f7 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -18,12 +18,16 @@ pub struct Expr {
     pub res: Option<Res>,
     /// What a field access on a value means, filled in by the
     /// typechecker when the types are final: the compiler emits what it
-    /// says. `None` elsewhere (and on `m.f`, `Type.method`, a variant:
-    /// those are names, and `res` says what they name).
+    /// says; on `Trait.method`, the method the call reaches. `None`
+    /// elsewhere (and on `m.f`, `Type.method`, a variant: those are
+    /// names, and `res` says what they name).
     pub sel: Option<Selection>,
 }
 
-/// What `recv.name`, on a value, means.
+/// What `recv.name` means: on a value, a field; `Tr.name`, a method
+/// called through its trait, for the type of its argument of type
+/// `Self` (the receiver); on a type held in a value (`a.empty()` for a
+/// `type a`), a method that makes a value of it.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Selection {
     /// The record's field `name`.
@@ -31,21 +35,21 @@ pub enum Selection {
     /// In a call, `recv.name(args)`: the function the record's field
     /// `name` holds, called with `args`.
     FieldCall,
-    /// In a call: the method `name` of the impl of the trait `tr` for
-    /// the type `ty`, the receiver's, called with the receiver and
-    /// `args`.
+    /// The method `name` of the impl of the trait `tr` for the type
+    /// `ty`, the receiver's.
     Impl {
         tr: crate::defs::TraitId,
         ty: crate::defs::TypeId,
     },
-    /// In a call: the method `name` of the builtin trait `tr`
-    /// (Display, Equal, Compare, Hash) for a receiver whose type has no
-    /// written impl of it: the type has the trait by its structure.
+    /// The method `name` of the builtin trait `tr` (Compare, Hash,
+    /// Error, json's) for a receiver whose type has no written impl of
+    /// it: the VM's own.
     Native { tr: crate::defs::TraitId },
-    /// In a call: the method `name` of the trait `tr`, for a receiver
-    /// whose type is known only where the code runs (a type variable
-    /// bounded by the trait; a type passed as a value).
-    Dynamic { tr: crate::defs::TraitId },
+    /// The method `name` of the trait `tr`, for a receiver whose type is
+    /// known only where the code runs (a type variable bounded by the
+    /// trait; a type passed as a value). The receiver is the argument
+    /// `at` of a call through the trait: its first of type `Self`.
+    Dynamic { tr: crate::defs::TraitId, at: u8 },
 }
 
 impl Expr {
diff --git a/src/builtins/data.rs b/src/builtins/data.rs
index 0e6412863..ad28cf66c 100644
--- a/src/builtins/data.rs
+++ b/src/builtins/data.rs
@@ -462,7 +462,7 @@ mod tests {
     /// a handle has none.
     #[test]
     fn a_builtin_type_has_json_encode_when_the_writer_has_a_json_form_for_it() {
-        let (impls, _) = crate::typechecker::__trait_init_fingerprint_check_program();
+        let impls = crate::typechecker::__trait_init_fingerprint_check_program();
         let encode: BTreeSet<&str> = impls
             .iter()
             .filter_map(|stamp| stamp.strip_prefix("Encode:"))
diff --git a/src/bytecode/ops.rs b/src/bytecode/ops.rs
index f552cd3b1..90aa8da32 100644
--- a/src/bytecode/ops.rs
+++ b/src/bytecode/ops.rs
@@ -1031,12 +1031,14 @@ ops! {
     /// impl of the trait `of` names (see
     /// [`Globals::call_method`](super::Globals::call_method)) for the
     /// receiver's type, else the builtin trait's native method; call it
-    /// with the top `argc` values, the receiver first.
-    CallMethod { method: Method, argc: U8("arguments of a method call, the receiver included"), of: Trait } => pops argc, pushes 1;
+    /// with the top `argc` values. The receiver is the argument `at` of
+    /// them (the first of type `Self`: the first, but for a method whose
+    /// `Self` parameter comes later).
+    CallMethod { method: Method, argc: U8("arguments of a method call, the receiver included"), of: Trait, at: U8("the argument a method call finds its method by") } => pops argc, pushes 1;
     /// `CallMethod` in tail position: a method that is a closure runs
     /// in the current frame. Followed by `Return`, which returns the
     /// result of any other.
-    TailCallMethod { method: Method, argc: U8("arguments of a method call, the receiver included"), of: Trait } => pops argc, pushes 1;
+    TailCallMethod { method: Method, argc: U8("arguments of a method call, the receiver included"), of: Trait, at: U8("the argument a method call finds its method by") } => pops argc, pushes 1;
 
     /// Move TOS down to the frame's slot `slot` and drop every value
     /// that was above that slot: pop TOS, cut the frame back to `slot`
diff --git a/src/bytecode/verify.rs b/src/bytecode/verify.rs
index 4fe146bd9..b5f2791b9 100644
--- a/src/bytecode/verify.rs
+++ b/src/bytecode/verify.rs
@@ -361,6 +361,13 @@ fn check(
         Instr::CallMethod { argc: 0, .. } | Instr::TailCallMethod { argc: 0, .. } => {
             return fail(format!("`{op}` has no receiver"));
         }
+        Instr::CallMethod { argc, at, .. } | Instr::TailCallMethod { argc, at, .. }
+            if at >= argc =>
+        {
+            return fail(format!(
+                "`{op}` finds its method by argument {at} of {argc}"
+            ));
+        }
         Instr::CallBuiltin { builtin: id, argc } => {
             // (The operand was checked above: it is a row.)
             if let Ok(row) = builtin(op, id) {
@@ -661,6 +668,7 @@ mod tests {
             1,
             lo,
             hi,
+            0,
             op(Op::Return),
         ];
         let function = Function::unverified(0, 0, code, vec![Value::String("foo".into())]);
@@ -692,7 +700,7 @@ mod tests {
     #[test]
     fn bad_13_method_call_without_a_receiver() {
         let [lo, hi] = 0u16.to_le_bytes();
-        let code = vec![op(Op::CallMethod), 0, 0, 0, lo, hi, op(Op::Return)];
+        let code = vec![op(Op::CallMethod), 0, 0, 0, lo, hi, 0, op(Op::Return)];
         assert_eq!(
             rejected(code, vec![Value::String("foo".into())]),
             "at offset 0: `CallMethod` has no receiver"
@@ -706,12 +714,29 @@ mod tests {
             5,
             lo,
             hi,
+            0,
             op(Op::Return),
         ];
         assert_eq!(
             rejected(code, vec![Value::String("foo".into())]),
             "at offset 1: `CallMethod` takes 5 values off a frame of 1"
         );
+        // And by an argument it is not given.
+        let code = vec![
+            op(Op::Unit),
+            op(Op::CallMethod),
+            0,
+            0,
+            1,
+            lo,
+            hi,
+            1,
+            op(Op::Return),
+        ];
+        assert_eq!(
+            rejected(code, vec![Value::String("foo".into())]),
+            "at offset 1: `CallMethod` finds its method by argument 1 of 1"
+        );
     }
 
     #[test]
diff --git a/src/compiler/mod.rs b/src/compiler/mod.rs
index e4b5203f6..aa11bfa05 100644
--- a/src/compiler/mod.rs
+++ b/src/compiler/mod.rs
@@ -141,14 +141,6 @@ struct Local {
 
 // ── Compiler errors ─────────────────────────────────────────────────
 
-/// Whether the method `method` of the trait `t`, one the VM has for
-/// every type, takes no value of the type: `decode` of `json.Decode`,
-/// called on a type (`T.decode(v)`) with the type's descriptor as the
-/// receiver.
-fn takes_no_self(t: crate::defs::TraitId, method: Symbol) -> bool {
-    crate::defs::builtin_trait_id("Decode") == Some(t) && resolve(method) == "decode"
-}
-
 /// A defect in silt: the program reached the compiler with an error the
 /// typechecker reports (a builtin module used without an import, a
 /// `loop(...)` outside a loop or with the wrong number of arguments). The
@@ -1334,46 +1326,79 @@ impl<'a> Compiler<'a> {
                 self.emit(Asm::Constant { k: idx }, span)?;
             }
 
-            // `Int.display`, `Pt.compare` as a value, a method the VM has
-            // natively for the type: the function `{ a -> a.display() }`
-            // (`{ a, b -> a.compare(b) }` for the two-argument methods).
-            // The program wrote no closure there: the function has the
-            // method's name, `Int.display`, as a written method has.
+            // `Tr.m` as a value: the method of the one impl the checker
+            // selected, or the function `{ a, b -> Tr.m(a, b) }`, which
+            // finds it where it runs. The program wrote no closure there:
+            // the function has the method's name, `Tr.m`.
+            ExprKind::FieldAccess(of, method, _) if self.res_trait(of.res).is_some() => {
+                let tr = self.res_trait(of.res).expect("a trait");
+                if let Some(crate::ast::Selection::Impl { tr, ty }) = expr.sel
+                    && let Some(slot) = self.globals.method(tr, ty, &resolve(*method))
+                {
+                    self.emit(Asm::GetGlobal { slot }, span)?;
+                } else {
+                    let arity = match &expr.ty {
+                        Some(Type::Fun(params, _)) => params.len(),
+                        _ => return Err(checker_missed(span, "a trait method of no type")),
+                    };
+                    let names: Vec<Symbol> =
+                        (0..arity).map(|k| intern(&format!("__arg{k}__"))).collect();
+                    let ident = |name: Symbol| Expr::new(ExprKind::Ident(name), span);
+                    let call = Expr::new(
+                        ExprKind::Call(
+                            Box::new(expr.clone()),
+                            names.iter().map(|n| ident(*n)).collect(),
+                        ),
+                        span,
+                    );
+                    let lambda = Expr::new(
+                        ExprKind::Lambda {
+                            params: names
+                                .iter()
+                                .map(|n| crate::ast::Param {
+                                    kind: crate::ast::ParamKind::Data,
+                                    pattern: crate::ast::Pattern::new(
+                                        crate::ast::PatternKind::Ident(*n),
+                                        span,
+                                    ),
+                                    ty: None,
+                                })
+                                .collect(),
+                            body: Box::new(call),
+                        },
+                        span,
+                    );
+                    let method_name = format!("{}.{method}", self.units.defs.get(tr.0).name);
+                    let around = self
+                        .contexts
+                        .last_mut()
+                        .map(|context| std::mem::replace(&mut context.closures, method_name));
+                    let compiled = self.compile_expr(&lambda);
+                    if let (Some(context), Some(around)) = (self.contexts.last_mut(), around) {
+                        context.closures = around;
+                    }
+                    compiled?;
+                }
+            }
+
+            // `T.decode` as a value, a method the VM has natively for the
+            // type: the function `{ v -> T.decode(v) }`. The program wrote
+            // no closure there: the function has the method's name,
+            // `T.decode`, as a written method has.
             ExprKind::FieldAccess(of, method, _)
-                if let Some(TypeMember::Native(tr)) = self.type_member(expr)? =>
+                if let Some(TypeMember::Native(_)) = self.type_member(expr)? =>
             {
                 let ty = match &of.kind {
                     ExprKind::Ident(ty) | ExprKind::FieldAccess(_, ty, _) => *ty,
                     _ => return Err(checker_missed(span, "a method of no named type")),
                 };
                 let method_name = format!("{ty}.{method}");
-                let names: &[&str] = match resolve(*method).as_str() {
-                    "compare" | "equal" => &["__self__", "__other__"],
-                    "decode" => &["__value__"],
-                    _ => &["__self__"],
-                };
+                let names: &[&str] = &["__value__"];
                 let ident = |name: &str| Expr::new(ExprKind::Ident(intern(name)), span);
-                let call = match takes_no_self(tr, *method) {
-                    // `T.decode` as a value: `{ v -> T.decode(v) }`.
-                    true => Expr::new(
-                        ExprKind::Call(Box::new(expr.clone()), vec![ident(names[0])]),
-                        span,
-                    ),
-                    false => {
-                        let mut access = Expr::new(
-                            ExprKind::FieldAccess(Box::new(ident(names[0])), *method, span),
-                            span,
-                        );
-                        access.sel = Some(crate::ast::Selection::Native { tr });
-                        Expr::new(
-                            ExprKind::Call(
-                                Box::new(access),
-                                names[1..].iter().map(|n| ident(n)).collect(),
-                            ),
-                            span,
-                        )
-                    }
-                };
+                let call = Expr::new(
+                    ExprKind::Call(Box::new(expr.clone()), vec![ident(names[0])]),
+                    span,
+                );
                 let lambda = Expr::new(
                     ExprKind::Lambda {
                         params: names
@@ -1929,9 +1954,11 @@ impl<'a> Compiler<'a> {
             self.emit(Asm::CallBuiltin { builtin, argc }, span)?;
         } else if let ExprKind::FieldAccess(receiver, method, _) = &callee.kind {
             let member = self.type_member(callee)?;
-            if let Some(TypeMember::Native(t)) = member
-                && takes_no_self(t, *method)
-            {
+            if self.res_trait(receiver.res).is_some() {
+                // `Tr.m(args)`: the method of the impl the checker
+                // selected for the type of the arguments.
+                self.compile_trait_call(callee, *method, args, span, tail)?;
+            } else if let Some(TypeMember::Native(t)) = member {
                 // `T.decode(v)`: the VM's method of the type, which takes
                 // no value of it; the type's descriptor chooses it.
                 let Some(descriptor) = self.type_value(receiver.res) else {
@@ -1940,19 +1967,7 @@ impl<'a> Compiler<'a> {
                 let idx = self.add_constant(descriptor, span)?;
                 self.emit(Asm::Constant { k: idx }, span)?;
                 self.compile_operands(args.iter().copied())?;
-                self.emit_call_method(*method, args.len() + 1, t, tail, span)?;
-            } else if let Some(TypeMember::Native(t)) = member {
-                // `Int.display(1)`, `Pt.compare(a, b)`: a method the VM
-                // has natively for the type, not a global; the first
-                // argument is the receiver.
-                if args.is_empty() {
-                    return Err(checker_missed(
-                        span,
-                        &format!("the call of '{method}' through its type with no receiver"),
-                    ));
-                }
-                self.compile_operands(args.iter().copied())?;
-                self.emit_call_method(*method, args.len(), t, tail, span)?;
+                self.emit_call_method(*method, args.len() + 1, t, 0, tail, span)?;
             } else if let Some(TypeMember::Slot(slot)) = member {
                 // `Pt.make(1)`, `m.Pt.make(1)`: a method reached
                 // through its type.
@@ -1967,7 +1982,8 @@ impl<'a> Compiler<'a> {
                 let argc = args.len();
                 self.emit_call(argc, tail, span)?;
             } else {
-                // Method call on a value: expr.method(args)
+                // A field's function, or a method on a type held in a
+                // value (`a.empty()` for a `type a`).
                 self.compile_method_call(callee, receiver, *method, args, span, tail)?;
             }
         } else {
@@ -1979,8 +1995,48 @@ impl<'a> Compiler<'a> {
         Ok(())
     }
 
-    /// Compile `receiver.method(args)`, a call on a value, as the
-    /// checker's `Selection` on `callee` says.
+    /// Compile `Tr.method(args)`, a call through a trait, as the
+    /// checker's `Selection` on `callee` says: the method of one impl,
+    /// a call of its global; else the method found where the code runs,
+    /// by the type of the first argument.
+    fn compile_trait_call(
+        &mut self,
+        callee: &Expr,
+        method: Symbol,
+        args: &[&Expr],
+        span: Span,
+        tail: bool,
+    ) -> Result<(), Diagnostic> {
+        use crate::ast::Selection;
+        match callee.sel {
+            Some(Selection::Impl { tr, ty })
+                if let Some(slot) = self.globals.method(tr, ty, &resolve(method)) =>
+            {
+                self.emit(Asm::GetGlobal { slot }, span)?;
+                self.compile_operands(args.iter().copied())?;
+                self.emit_call(args.len(), tail, span)
+            }
+            // Found where the code runs, by the type of the argument of
+            // type `Self` (a builtin trait's is the first).
+            Some(Selection::Dynamic { tr, at }) if usize::from(at) < args.len() => {
+                self.compile_operands(args.iter().copied())?;
+                self.emit_call_method(method, args.len(), tr, usize::from(at), tail, span)
+            }
+            Some(Selection::Impl { tr, .. } | Selection::Native { tr }) if !args.is_empty() => {
+                self.compile_operands(args.iter().copied())?;
+                self.emit_call_method(method, args.len(), tr, 0, tail, span)
+            }
+            _ => Err(checker_missed(
+                span,
+                &format!("the call of '{method}' through its trait with no selection"),
+            )),
+        }
+    }
+
+    /// Compile `receiver.method(args)` as the checker's `Selection` on
+    /// `callee` says: the function a field holds, or, on a type held in
+    /// a value (`a.empty()` for a `type a`), the method of the type's
+    /// impl, found where the code runs.
     fn compile_method_call(
         &mut self,
         callee: &Expr,
@@ -2000,27 +2056,18 @@ impl<'a> Compiler<'a> {
                 self.compile_operands(args.iter().copied())?;
                 self.emit_call(args.len(), tail, span)
             }
-            // One impl's method: a call of its global, like a function's.
-            Some(Selection::Impl { tr, ty })
-                if let Some(slot) = self.globals.method(tr, ty, &resolve(method)) =>
-            {
-                self.emit(Asm::GetGlobal { slot }, span)?;
-                self.compile_operands(with_receiver)?;
-                self.emit_call(args.len() + 1, tail, span)
-            }
-            // The method is found where the code runs, by the receiver's
-            // type. (An impl with no global is a builtin type's that the
-            // VM has natively.)
-            Some(
-                Selection::Impl { tr, .. } | Selection::Native { tr } | Selection::Dynamic { tr },
-            ) => {
+            // The method is found where the code runs, by the type the
+            // descriptor carries.
+            Some(Selection::Dynamic { tr, .. }) => {
                 self.compile_operands(with_receiver)?;
-                self.emit_call_method(method, args.len() + 1, tr, tail, span)
+                self.emit_call_method(method, args.len() + 1, tr, 0, tail, span)
+            }
+            Some(Selection::Impl { .. } | Selection::Native { .. } | Selection::Field) | None => {
+                Err(checker_missed(
+                    span,
+                    &format!("the call of '{method}' with no selection"),
+                ))
             }
-            Some(Selection::Field) | None => Err(checker_missed(
-                span,
-                &format!("the call of '{method}' with no selection"),
-            )),
         }
     }
 
@@ -2442,13 +2489,14 @@ impl<'a> Compiler<'a> {
     }
 
     /// Emit `CallMethod` of `method` of the trait `t` with `argc`
-    /// values (the receiver first) on the stack; in tail position
-    /// (`tail`), `TailCallMethod; Return`.
+    /// values on the stack, found by the type of the one at `at` (the
+    /// receiver); in tail position (`tail`), `TailCallMethod; Return`.
     fn emit_call_method(
         &mut self,
         method: Symbol,
         argc: usize,
         t: crate::defs::TraitId,
+        at: usize,
         tail: bool,
         span: Span,
     ) -> Result<(), Diagnostic> {
@@ -2466,10 +2514,26 @@ impl<'a> Compiler<'a> {
             limit_diagnostic(limit, span)
         })?;
         if tail {
-            self.emit(Asm::TailCallMethod { method, argc, of }, span)?;
+            self.emit(
+                Asm::TailCallMethod {
+                    method,
+                    argc,
+                    of,
+                    at,
+                },
+                span,
+            )?;
             self.emit(Asm::Return, span)
         } else {
-            self.emit(Asm::CallMethod { method, argc, of }, span)
+            self.emit(
+                Asm::CallMethod {
+                    method,
+                    argc,
+                    of,
+                    at,
+                },
+                span,
+            )
         }
     }
 
@@ -3722,14 +3786,15 @@ fn main() { list.length([1, 2, 3]) }
         let fns = compile(
             r#"
 type Foo { x: Int }
-trait Display for Foo {
-    fn display(self) -> String { "foo" }
+trait Show { fn show(self) -> String }
+trait Show for Foo {
+    fn show(self) -> String { "foo" }
 }
-fn shown(x: a) -> String where a: Display { x.display() }
+fn shown(x: a) -> String where a: Show { Show.show(x) }
 fn field(r: {f: Fn(Int) -> Int}) -> Int { r.f(1) }
 fn main() {
     let f = Foo { x: 1 }
-    f.display()
+    Show.show(f)
 }
 "#,
         );
diff --git a/src/diagnostic.rs b/src/diagnostic.rs
index b87a744d1..496f6f0bb 100644
--- a/src/diagnostic.rs
+++ b/src/diagnostic.rs
@@ -143,8 +143,8 @@ codes! {
     NoSuchField = "E0306", Type;
     MissingField = "E0307", Type;
     UnknownMethod = "E0308", Type;
-    /// A method called in a way it cannot be (a method without `self` on
-    /// a value).
+    /// A method called in a way it cannot be: through its trait, one
+    /// that takes no value of the type, or one of `Display` and `Equal`.
     InvalidMethodCall = "E0309", Type;
     /// A method several traits provide.
     AmbiguousMethod = "E0310", Type;
diff --git a/src/disassemble.rs b/src/disassemble.rs
index a979c95ec..e0c4083ad 100644
--- a/src/disassemble.rs
+++ b/src/disassemble.rs
@@ -170,13 +170,29 @@ fn disassemble_instruction(
         }
         // CallMethod: the id of the method's name, argc, and the name
         // with the trait whose method it calls (shown after the name
-        // when the call names one).
-        Instr::CallMethod { method, argc, of } | Instr::TailCallMethod { method, argc, of } => {
+        // when the call names one), and the argument it is found by
+        // where that is not the first.
+        Instr::CallMethod {
+            method,
+            argc,
+            of,
+            at,
+        }
+        | Instr::TailCallMethod {
+            method,
+            argc,
+            of,
+            at,
+        } => {
             let named = globals.method_name(method).unwrap_or("?");
             let line = format!("{offset:04}  {name:<20} {method:<5} {argc:<3} ; \"{named}\"");
-            match globals.trait_name(of) {
+            let line = match globals.trait_name(of) {
                 Some(t) => format!("{line} of {t}"),
                 None => line,
+            };
+            match at {
+                0 => line,
+                at => format!("{line}, by argument {at}"),
             }
         }
 
@@ -543,6 +559,7 @@ mod tests {
             method,
             argc: 1,
             of: 0,
+            at: 0,
         };
         emitter.emit(call, span()).unwrap();
         emitter.emit(Asm::Return, span()).unwrap();
@@ -553,7 +570,7 @@ mod tests {
             "{output}"
         );
         // The next instruction is decoded after the trait operand.
-        assert!(output.contains("0006  Return"), "{output}");
+        assert!(output.contains("0007  Return"), "{output}");
     }
 
     #[test]
diff --git a/src/lsp/ast_walk.rs b/src/lsp/ast_walk.rs
index 9f6871b25..86761e459 100644
--- a/src/lsp/ast_walk.rs
+++ b/src/lsp/ast_walk.rs
@@ -173,6 +173,45 @@ pub(super) fn find_field_access_at(program: &Program, cursor: usize) -> Option<(
     found
 }
 
+/// The method named through its trait whose name holds byte `cursor`
+/// (`size` in `Sized.size(b)`), as its trait and its name.
+pub(super) fn find_trait_method_at(
+    program: &Program,
+    cursor: usize,
+) -> Option<(crate::defs::TraitId, Symbol)> {
+    fn walk(expr: &Expr, cursor: usize, found: &mut Option<(crate::defs::TraitId, Symbol)>) {
+        if let ExprKind::FieldAccess(receiver, field, field_span) = &expr.kind
+            && (field_span.start as usize..=field_span.end as usize).contains(&cursor)
+            && receiver.ty.is_none()
+            && let Some(
+                Selection::Impl { tr, .. }
+                | Selection::Native { tr }
+                | Selection::Dynamic { tr, .. },
+            ) = expr.sel
+        {
+            *found = Some((tr, *field));
+        }
+        visit_expr_children(expr, |child| walk(child, cursor, found));
+    }
+    let mut found = None;
+    for decl in &program.decls {
+        match decl {
+            Decl::Fn(f) => walk(&f.body, cursor, &mut found),
+            Decl::Let { value, .. } => walk(value, cursor, &mut found),
+            Decl::TraitImpl(ti) => ti
+                .methods
+                .iter()
+                .for_each(|m| walk(&m.body, cursor, &mut found)),
+            Decl::Trait(t) => t
+                .methods
+                .iter()
+                .for_each(|m| walk(&m.body, cursor, &mut found)),
+            _ => {}
+        }
+    }
+    found
+}
+
 /// Find the identifier name at the cursor byte offset.
 ///
 /// Visits `ExprKind::Ident` use-sites AND binding sites:
diff --git a/src/lsp/completion.rs b/src/lsp/completion.rs
index afc2a8448..e3501f3e2 100644
--- a/src/lsp/completion.rs
+++ b/src/lsp/completion.rs
@@ -45,6 +45,11 @@ impl Server {
             if let Some(items) = self.module_member_completions(doc, &prefix, cursor) {
                 return Some(CompletionResponse::Array(items));
             }
+            // A trait's name before the dot: the methods called through
+            // it.
+            if let Some(items) = self.trait_method_completions(doc, &prefix, cursor) {
+                return Some(CompletionResponse::Array(items));
+            }
             // An enum's name before the dot: its variants.
             if let Some(items) = self.enum_variant_completions(doc, &prefix, cursor) {
                 return Some(CompletionResponse::Array(items));
@@ -217,17 +222,11 @@ impl Server {
         Some(CompletionResponse::Array(items))
     }
 
-    /// Produce completions after a `.` — either module functions, record
-    /// fields, or methods available on the receiver's inferred type.
-    ///
-    /// DX-G4: when the LSP can confidently infer the type of
-    /// the receiver expression (a let-bound local with an annotation, or
-    /// an identifier whose type was recovered from the typed AST), the
-    /// emitted method set is narrowed to only those methods registered
-    /// for that type's canonical head name. When the type cannot be
-    /// inferred we fall back to the union of all method names declared
-    /// in the program — preserving discoverability rather than silently
-    /// hiding completions.
+    /// Produce completions after a `.`: a builtin module's members, or
+    /// the fields of the receiver's type when the LSP can infer it (a
+    /// let-bound local, or an identifier whose type was recovered from
+    /// the typed AST). A dot after a value is a field: no trait's method
+    /// is offered there (they are offered after the trait's name).
     fn dot_completions(
         &self,
         checked: Option<&Checked>,
@@ -313,9 +312,8 @@ impl Server {
         };
         let program = &*checked.program;
 
-        // Resolve the receiver's inferred type once. Used both for the
-        // record-field path and the method-narrowing path below. Two
-        // narrow sources are tried:
+        // The receiver's inferred type, for its fields. Two sources are
+        // tried:
         //
         //   (a) a let-bound local in scope at the cursor whose type was
         //       recovered from the value expression (annotation included);
@@ -324,16 +322,9 @@ impl Server {
         //       variables.
         //
         // Anything else (complex expressions, generics with unresolved
-        // tyvars, non-identifier prefixes) leaves `receiver_ty = None`
-        // and the method path falls back to every method the module
-        // knows — "narrow when safe, never silently lose completions".
+        // tyvars, non-identifier prefixes) leaves `receiver_ty = None`:
+        // no fields are offered.
         let locals = locals_at_offset(program, cursor);
-        // A builtin module this build lacks (`postgres.` without the
-        // postgres feature): its import is the error, and it has nothing
-        // to offer; the methods of every type are not its members.
-        if module::missing_feature(prefix).is_some() && !locals.iter().any(|l| l.name == prefix) {
-            return items;
-        }
         let receiver_ty: Option<Type> = locals
             .iter()
             .rev()
@@ -342,7 +333,6 @@ impl Server {
             .or_else(|| find_ident_type_by_name(program, prefix));
 
         // 2. Record fields, if the receiver is a record-shaped type.
-        let mut emitted_field_labels: HashSet<String> = HashSet::new();
         if let Some(ref ty) = receiver_ty
             && let Some(fields) = record_fields_from_type(ty, &checked.record_fields)
         {
@@ -353,25 +343,7 @@ impl Server {
                     detail: Some(format!("{field_ty}")),
                     ..CompletionItem::default()
                 });
-                emitted_field_labels.insert(name.clone());
-            }
-        }
-
-        // 3. Method completions: the methods the checker knows for the
-        //    receiver type's canonical name, or every method it knows
-        //    when the type is unknown.
-        let methods = methods_for_receiver(&checked.methods, receiver_ty.as_ref());
-        for label in methods {
-            // Don't duplicate a name that already came through as a
-            // field — fields and methods occupy the same `name.` slot.
-            if emitted_field_labels.contains(&label) {
-                continue;
             }
-            items.push(CompletionItem {
-                label,
-                kind: Some(CompletionItemKind::METHOD),
-                ..CompletionItem::default()
-            });
         }
 
         items.sort_by(|a, b| a.label.cmp(&b.label));
@@ -379,6 +351,41 @@ impl Server {
         items
     }
 
+    /// The methods of the trait `prefix` names in the open document
+    /// `doc` that a call through it calls, each with its signature,
+    /// unless a local binding of that name shadows it.
+    fn trait_method_completions(
+        &self,
+        doc: &Document,
+        prefix: &str,
+        cursor: usize,
+    ) -> Option<Vec<CompletionItem>> {
+        if doc.program.as_ref().is_some_and(|program| {
+            locals_at_offset(program, cursor)
+                .iter()
+                .any(|local| local.name == prefix)
+        }) {
+            return None;
+        }
+        let id = self.trait_written(doc, prefix)?;
+        let mut items: Vec<CompletionItem> = (self.trait_call_methods(doc, id).into_iter())
+            .map(|m| CompletionItem {
+                label: resolve(m.name),
+                kind: Some(CompletionItemKind::METHOD),
+                detail: Some(m.label),
+                documentation: m.doc.map(|d| {
+                    Documentation::MarkupContent(MarkupContent {
+                        kind: MarkupKind::Markdown,
+                        value: d,
+                    })
+                }),
+                ..CompletionItem::default()
+            })
+            .collect();
+        items.sort_by(|a, b| a.label.cmp(&b.label));
+        Some(items)
+    }
+
     /// The variants of the enum `prefix` names in the open document `doc`
     /// (declared there or imported by name), unless a local binding of
     /// that name shadows it.
@@ -495,7 +502,6 @@ impl Server {
         let tables = self.checked_tables(doc)?;
         Some(Checked {
             program: checked.ast.clone(),
-            methods: tables.methods(&|module| imports(&checked.ast, module)),
             record_fields: tables.record_fields(),
         })
     }
@@ -538,8 +544,8 @@ impl Server {
     /// `parse_fn_decl`, which leaves a *recovery stub* for
     /// the enclosing function — an `FnDecl` with an empty body. Every
     /// prior `let` in that function disappears from the AST, which means
-    /// `locals_at_offset` returns nothing for the receiver `xs` and the
-    /// type-narrowing path can't pin down its type.
+    /// `locals_at_offset` returns nothing for the receiver `xs` and its
+    /// fields cannot be offered.
     ///
     /// The fix-up gives the project's session, for a moment, a copy of
     /// the text where the partial dot is followed by a placeholder
@@ -599,7 +605,6 @@ impl Server {
         let tables = project.session.tables();
         let checked = project.session.module_analysis(id).map(|checked| Checked {
             program: checked.ast.clone(),
-            methods: tables.methods(&|module| imports(&checked.ast, module)),
             record_fields: tables.record_fields(),
         });
         project.set_text(&path, &original);
@@ -638,39 +643,9 @@ fn member_item(view: &ModuleView, member: Symbol, kind: MemberKind) -> Completio
 /// it.
 struct Checked {
     program: Arc<Program>,
-    methods: Vec<(crate::types::TypeRef, Symbol)>,
     record_fields: RecordFields,
 }
 
-// ── Method enumeration for dot-completion ──────────────────────────
-
-/// Whether `program` imports the module `module`.
-fn imports(program: &Program, module: &str) -> bool {
-    program.decls.iter().any(|decl| {
-        matches!(decl, crate::ast::Decl::Import(target, _) if resolve(target.module()) == module)
-    })
-}
-
-/// The names of the methods a value of type `receiver_ty` has, from the
-/// checker's `methods` (the type impls key it by, method name): those of
-/// the type's head, or every method when the type is unknown.
-fn methods_for_receiver(
-    methods: &[(crate::types::TypeRef, Symbol)],
-    receiver_ty: Option<&Type>,
-) -> Vec<String> {
-    // Unresolved variables, anonymous records and bottom-typed
-    // expressions have no dispatch head: they do not narrow.
-    let head = receiver_ty.and_then(crate::types::canonical::head_of_canon);
-    let mut names: Vec<String> = methods
-        .iter()
-        .filter(|(ty, _)| head.is_none_or(|head| *ty == head))
-        .map(|(_, method)| resolve(*method))
-        .collect();
-    names.sort();
-    names.dedup();
-    names
-}
-
 // ── Dot-completion helpers ─────────────────────────────────────────
 
 /// Extract the identifier (or postfix-call / index-expression receiver)
@@ -834,65 +809,3 @@ fn extract_dot_prefix(source: &str, pos: &Position) -> Option<String> {
 // `KEYWORDS` is sourced from `crate::lexer::KEYWORDS` — the authoritative
 // list maintained alongside the lexer's keyword match arms. Re-introducing
 // a hand-rolled list here is guarded by `tests/meta/lexer_keyword_parity_tests.rs`.
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    /// The methods of a user impl and of the builtin derives, as the
-    /// session's analysis of `source` has them.
-    fn methods(source: &str) -> Vec<(crate::types::TypeRef, Symbol)> {
-        let (mut session, file) = crate::session::testing::session_with(&[("main.silt", source)]);
-        session.analyze(file);
-        session.tables().methods(&|_| true)
-    }
-
-    const IMPLS: &str = "trait UpperCaser { fn to_upper(self) -> String }\n\
-                         trait UpperCaser for String { fn to_upper(self) -> String { \"X\" } }\n\
-                         trait IntListHead { fn head_int(self) -> Int }\n\
-                         trait IntListHead for List(a) { fn head_int(self) -> Int { 0 } }\n\
-                         fn main() { 0 }\n";
-
-    /// A known receiver type narrows the methods to those of its
-    /// canonical name, the builtin derived ones included.
-    #[test]
-    fn methods_narrow_to_the_receiver_type() {
-        let methods = methods(IMPLS);
-        let list = methods_for_receiver(&methods, Some(&Type::List(Box::new(Type::Int))));
-        assert!(list.contains(&"head_int".to_string()), "{list:?}");
-        assert!(list.contains(&"display".to_string()), "{list:?}");
-        assert!(!list.contains(&"to_upper".to_string()), "{list:?}");
-        let string = methods_for_receiver(&methods, Some(&Type::String));
-        assert!(string.contains(&"to_upper".to_string()), "{string:?}");
-        assert!(!string.contains(&"head_int".to_string()), "{string:?}");
-    }
-
-    /// A method without `self` is called on the type: it is not offered
-    /// after a value, of its type or of an unknown one.
-    #[test]
-    fn a_method_without_self_is_not_offered_after_a_value() {
-        let methods = methods(
-            "trait Mk {\n  fn make(n: Int) -> Self\n  fn twice(self) -> Self\n}\n\
-             trait Mk for Int {\n  fn make(n: Int) -> Int { n }\n  \
-             fn twice(self) -> Int { self * 2 }\n}\nfn main() { 0 }\n",
-        );
-        for receiver in [Some(&Type::Int), None] {
-            let offered = methods_for_receiver(&methods, receiver);
-            assert!(offered.contains(&"twice".to_string()), "{offered:?}");
-            assert!(!offered.contains(&"make".to_string()), "{offered:?}");
-        }
-    }
-
-    /// An unknown receiver type offers every method the module knows.
-    #[test]
-    fn an_unknown_receiver_gets_every_method() {
-        let methods = methods(IMPLS);
-        let all = methods_for_receiver(&methods, None);
-        for name in [
-            "to_upper", "head_int", "display", "equal", "compare", "hash",
-        ] {
-            assert!(all.contains(&name.to_string()), "{name} missing: {all:?}");
-        }
-        assert_eq!(all, methods_for_receiver(&methods, Some(&Type::Var(0))));
-    }
-}
diff --git a/src/lsp/hover.rs b/src/lsp/hover.rs
index a844bf9b2..fa3c6e3c0 100644
--- a/src/lsp/hover.rs
+++ b/src/lsp/hover.rs
@@ -104,6 +104,19 @@ impl Server {
             return self.builtin_type_hover_text(doc, ty).map(markdown);
         }
 
+        // A method named through its trait (`size` in `Sized.size(b)`):
+        // the method as its trait declares it, and its doc comment.
+        if let Some((tr, method)) = super::ast_walk::find_trait_method_at(program, cursor)
+            && let Some(m) =
+                (self.trait_call_methods(doc, tr).into_iter()).find(|m| m.name == method)
+        {
+            let mut value = format!("```silt\n{}\n```", m.label);
+            if let Some(text) = m.doc.filter(|text| !text.is_empty()) {
+                value.push_str(&format!("\n\n---\n\n{text}"));
+            }
+            return Some(markdown(value));
+        }
+
         // A trait named (`Display` in `where a: Display`, in an impl's
         // header, in its own declaration): its signature and its doc.
         if let Some(tr) = self.trait_named_at(uri, cursor)
diff --git a/src/lsp/names.rs b/src/lsp/names.rs
index bf5a32f83..df255ea37 100644
--- a/src/lsp/names.rs
+++ b/src/lsp/names.rs
@@ -55,9 +55,10 @@ impl LocalName {
     }
 }
 
-/// A method name at a call or access on a value, `x.scale(2)`: no name
-/// of a definition (a method has none of its own), but the checker says
-/// which method it is.
+/// A method name at a call through its trait, `Sized.scale(x, 2)`, or
+/// on a type held in a value, `a.empty()`: no name of a definition (a
+/// method has none of its own), but the checker says which method it
+/// is.
 pub(super) struct MethodUse {
     pub(super) span: Span,
     pub(super) name: Symbol,
@@ -359,9 +360,9 @@ impl<'a> Names<'a> {
             ExprKind::FieldAccess(receiver, field, field_span) => {
                 // `m.f`, `m.Circle`, `Shape.Circle`: the member's own
                 // name, which the resolver resolved. (The span of a
-                // field access is its receiver's.) On a value the name
-                // is a field or a method: no name of a definition, and
-                // not of the trait the checker selected the method from.
+                // field access is its receiver's.) After a trait
+                // (`Sized.size`) the name is the method the checker
+                // selected; on a value it is a field.
                 let qualified = match receiver.res {
                     Some(Res::Module(_)) => true,
                     Some(Res::Def(id)) => self.table().get(id).is_type(),
diff --git a/src/lsp/semantic_tokens.rs b/src/lsp/semantic_tokens.rs
index 11143ee3d..472febaf4 100644
--- a/src/lsp/semantic_tokens.rs
+++ b/src/lsp/semantic_tokens.rs
@@ -294,6 +294,29 @@ fn emit_expr_tokens(
                 emit_expr_tokens(v, source, doc, server, out);
             }
         }
+        // A method named through its trait (`Greet.greet`): the trait
+        // an INTERFACE, the method a FUNCTION.
+        ExprKind::FieldAccess(receiver, field, field_span)
+            if receiver.ty.is_none()
+                && matches!(
+                    expr.sel,
+                    Some(
+                        crate::ast::Selection::Impl { .. }
+                            | crate::ast::Selection::Native { .. }
+                            | crate::ast::Selection::Dynamic { .. }
+                    )
+                ) =>
+        {
+            match &receiver.kind {
+                ExprKind::Ident(name) => {
+                    let start = receiver.span.start as usize;
+                    push_token_at_offset(source, start, &resolve(*name), TT_INTERFACE, out);
+                }
+                _ => emit_expr_tokens(receiver, source, doc, server, out),
+            }
+            let start = field_span.start as usize;
+            push_token_at_offset(source, start, &resolve(*field), TT_FUNCTION, out);
+        }
         ExprKind::Block(stmts) => {
             for stmt in stmts {
                 emit_stmt_tokens(stmt, source, doc, server, out);
diff --git a/src/lsp/signature_help.rs b/src/lsp/signature_help.rs
index 9817a2231..0624f4f11 100644
--- a/src/lsp/signature_help.rs
+++ b/src/lsp/signature_help.rs
@@ -39,6 +39,21 @@ impl Server {
         let before = tokens.partition_point(|tok| (tok.span.start as usize) < cursor);
         let (fn_name, active_param) = call_site(&tokens[..before])?;
 
+        // `Tr.m(`: the method of the trait, as the trait declares it.
+        if let Some((tr, method)) = fn_name.rsplit_once('.')
+            && let Some(id) = self.trait_written(doc, tr)
+        {
+            let m = (self.trait_call_methods(doc, id).into_iter())
+                .find(|m| resolve(m.name) == method)?;
+            let params_info = (m.params.iter())
+                .map(|range| ParameterInformation {
+                    label: ParameterLabel::LabelOffsets(*range),
+                    documentation: None,
+                })
+                .collect();
+            return Some(self.signature(m.label, params_info, m.doc, active_param));
+        }
+
         // Look up in definitions first, then builtins.
         let fn_sym = intern(&fn_name);
         // A member of an imported module: `m.f(`, or `f(` with `f` from
@@ -74,6 +89,19 @@ impl Server {
                 (label, params_info, doc_text)
             };
 
+        Some(self.signature(label, params_info, doc_text, active_param))
+    }
+
+    /// The help of a call of the signature `label`, whose parameters are
+    /// `params_info`, documented by `doc_text`, at its parameter
+    /// `active_param`.
+    fn signature(
+        &self,
+        label: String,
+        params_info: Vec<ParameterInformation>,
+        doc_text: Option<String>,
+        active_param: u32,
+    ) -> SignatureHelp {
         // A client that does not read label offsets gets each
         // parameter as its text, a substring of the label.
         let params_info = if self.label_offsets {
@@ -100,7 +128,7 @@ impl Server {
             })
         });
 
-        Some(SignatureHelp {
+        SignatureHelp {
             signatures: vec![SignatureInformation {
                 label,
                 documentation,
@@ -109,7 +137,7 @@ impl Server {
             }],
             active_signature: Some(0),
             active_parameter: Some(active_param),
-        })
+        }
     }
 }
 
@@ -223,12 +251,17 @@ fn call_site(tokens: &[Tok]) -> Option<(String, u32)> {
             .is_some_and(|tok| tok.kind == Token::Dot)
     };
     let name = name_at(paren.checked_sub(1))?;
-    // `m.f(`: a member of a module. A longer path (`a.b.f(`) is a method
-    // or a field of a value, which has no signature here.
+    // `m.f(`: a member of a module, or `Tr.f(`, a method through its
+    // trait; `m.Tr.f(`, through a trait of a module. A longer path is a
+    // field of a value, which has no signature here.
     if is_dot(paren.checked_sub(2)) {
         let module = name_at(paren.checked_sub(3))?;
         if is_dot(paren.checked_sub(4)) {
-            return None;
+            let outer = name_at(paren.checked_sub(5))?;
+            if is_dot(paren.checked_sub(6)) {
+                return None;
+            }
+            return Some((format!("{outer}.{module}.{name}"), *commas));
         }
         return Some((format!("{module}.{name}"), *commas));
     }
diff --git a/src/lsp/trait_hover.rs b/src/lsp/trait_hover.rs
index ba24eeb3c..efaa667ac 100644
--- a/src/lsp/trait_hover.rs
+++ b/src/lsp/trait_hover.rs
@@ -22,27 +22,20 @@ impl Server {
         let session = &self.projects.get(&module.project)?.session;
         let def = session.defs().get(id.0);
         let (signature, doc_text) = if def.module.is_builtin() || !def.span.is_in_source() {
-            let (name, module) = crate::defs::builtin_trait_of_id(id.0)?;
-            match module {
+            let (decl, q) = self.trait_decl(doc, id)?;
+            match q {
                 // A trait of the prelude: the checker's declaration.
-                None => {
-                    let decl = crate::typechecker::builtin_trait_decls()
-                        .into_iter()
-                        .find(|t| resolve(t.name) == name)?;
-                    (signature(&decl, None), decl.doc.clone())
-                }
+                None => (signature(&decl, None), decl.doc.clone()),
                 // A builtin module's (`json.Encode`): the declaration of
                 // the registry, and its section of the module's page.
                 // It is written as a program names it: the trait and the
                 // module's types with the module (`json.Value`).
-                Some(module) => {
-                    let registry = crate::builtins::registry::registry();
-                    let of = registry.modules.iter().find(|m| m.name == module)?;
-                    let program = crate::builtins::registry::parse(of.traits);
-                    let decl = declared(&program.decls, |t| resolve(t.name) == name)?;
-                    let section = self.builtin_docs.get(&format!("{module}.{name}"));
+                Some(q) => {
+                    let section = self
+                        .builtin_docs
+                        .get(&format!("{}.{}", q.module, decl.name));
                     (
-                        written(decl, Some(&Qualify::of(of))),
+                        written(&decl, Some(&q)),
                         section.map(|s| below_signature(s)),
                     )
                 }
@@ -62,6 +55,151 @@ impl Server {
     }
 }
 
+impl Server {
+    /// The declaration of the trait `id` in the session of the open
+    /// document `doc`, with how a builtin module's names are written
+    /// (`None` for a trait of a file or of the prelude).
+    fn trait_decl(&self, doc: &Document, id: TraitId) -> Option<(TraitDecl, Option<Qualify>)> {
+        let module = doc.module.as_ref()?;
+        let session = &self.projects.get(&module.project)?.session;
+        let def = session.defs().get(id.0);
+        if !def.module.is_builtin() && def.span.is_in_source() {
+            let analysis = session.module_analysis(def.module)?;
+            let decl = declared(&analysis.ast.decls, |t| t.name_span == def.span)?;
+            return Some((decl.clone(), None));
+        }
+        let (name, module) = crate::defs::builtin_trait_of_id(id.0)?;
+        match module {
+            None => crate::typechecker::builtin_trait_decls()
+                .into_iter()
+                .find(|t| resolve(t.name) == name)
+                .map(|decl| (decl, None)),
+            Some(module) => {
+                let registry = crate::builtins::registry::registry();
+                let of = registry.modules.iter().find(|m| m.name == module)?;
+                let program = crate::builtins::registry::parse(of.traits);
+                let decl = declared(&program.decls, |t| resolve(t.name) == name)?;
+                Some((decl.clone(), Some(Qualify::of(of))))
+            }
+        }
+    }
+
+    /// The trait `prefix` names in the open document `doc` (`Greet`, a
+    /// trait of the prelude, `m.Greet` through an imported module), as
+    /// the module's analysis binds it.
+    pub(super) fn trait_written(&self, doc: &Document, prefix: &str) -> Option<TraitId> {
+        use crate::typechecker::names::Binding;
+        let scope = &self.checked_module(doc)?.scope;
+        let module = doc.module.as_ref()?;
+        let session = &self.projects.get(&module.project)?.session;
+        let (_, builtin) = crate::typechecker::names::builtins();
+        let binding = match prefix.split_once('.') {
+            None => {
+                let name = crate::intern::intern(prefix);
+                (scope.values.get(&name))
+                    .or_else(|| scope.types.get(&name))
+                    .or_else(|| builtin.prelude.values.get(&name))
+                    .or_else(|| builtin.prelude.types.get(&name))
+            }
+            Some((m, t)) => {
+                let Some(Binding::Module(id)) = scope.values.get(&crate::intern::intern(m)) else {
+                    return None;
+                };
+                let exports = match id.is_builtin() {
+                    true => builtin.modules.get(id),
+                    false => session.module_analysis(*id).map(|a| &a.scope.exports),
+                }?;
+                let name = crate::intern::intern(t);
+                exports
+                    .values
+                    .get(&name)
+                    .or_else(|| exports.types.get(&name))
+            }
+        };
+        let Some(Binding::Def(id)) = binding else {
+            return None;
+        };
+        match session.defs().get(*id).kind {
+            crate::defs::DefKind::Trait(t) => Some(t),
+            _ => None,
+        }
+    }
+
+    /// The methods of the trait `id` a program calls through it
+    /// (`Greet.greet(x)`): those that take a value of the type, but
+    /// `Display`'s and `Equal`'s, each with its signature.
+    pub(super) fn trait_call_methods(&self, doc: &Document, id: TraitId) -> Vec<TraitMethod> {
+        let Some((decl, q)) = self.trait_decl(doc, id) else {
+            return Vec::new();
+        };
+        let uncalled = crate::defs::builtin_trait_of_id(id.0)
+            .is_some_and(|(name, _)| matches!(name, "Display" | "Equal"));
+        decl.methods
+            .iter()
+            .filter(|f| !uncalled && takes_self(f))
+            .map(|f| trait_method(q.as_ref(), f))
+            .collect()
+    }
+}
+
+/// A method of a trait as a call through the trait shows it.
+pub(super) struct TraitMethod {
+    pub(super) name: crate::intern::Symbol,
+    /// `fn greet(self) -> String`.
+    pub(super) label: String,
+    /// Where each parameter is in `label`.
+    pub(super) params: Vec<[u32; 2]>,
+    pub(super) doc: Option<String>,
+}
+
+/// Whether the method `f` takes a value of the trait's type: a
+/// parameter `self`, or one of type `Self`.
+fn takes_self(f: &FnDecl) -> bool {
+    f.params.iter().any(|p| {
+        matches!(&p.pattern.kind, PatternKind::Ident(name) if resolve(*name) == "self")
+            || matches!(
+                &p.ty,
+                Some(TypeExpr {
+                    kind: TypeExprKind::SelfType,
+                    ..
+                })
+            )
+    })
+}
+
+/// The method `f` as `method` writes it, with where each parameter is.
+fn trait_method(q: Option<&Qualify>, f: &FnDecl) -> TraitMethod {
+    let mut label = format!("fn {}(", f.name);
+    let mut params = Vec::new();
+    for (k, p) in f.params.iter().enumerate() {
+        if k > 0 {
+            label.push_str(", ");
+        }
+        let name = match &p.pattern.kind {
+            PatternKind::Ident(name) => resolve(*name),
+            _ => "_".to_string(),
+        };
+        let text = match &p.ty {
+            Some(ty) => format!("{name}: {}", type_expr(q, ty)),
+            None => name,
+        };
+        let start = label.len() as u32;
+        label.push_str(&text);
+        params.push([start, label.len() as u32]);
+    }
+    label.push(')');
+    if let Some(ret) = &f.return_type {
+        label.push_str(&format!(" -> {}", type_expr(q, ret)));
+    }
+    label.push_str(&where_clauses(q, &f.where_clauses));
+    TraitMethod {
+        name: f.name,
+        label,
+        params,
+        doc: f.doc.clone(),
+    }
+}
+
 impl Server {
     /// What hover shows for silt's own type `id`: its declaration as the
     /// registry has it (a builtin module's written as a program names
diff --git a/src/lsp/workspace.rs b/src/lsp/workspace.rs
index 8b1de0e11..257ad7dac 100644
--- a/src/lsp/workspace.rs
+++ b/src/lsp/workspace.rs
@@ -462,7 +462,7 @@ impl Server {
         let method = names.methods.iter().find(|m| holds(m.span, cursor))?;
         let (tr, ty) = match method.selection {
             Selection::Impl { tr, ty } => (tr, Some(ty)),
-            Selection::Native { tr } | Selection::Dynamic { tr } => (tr, None),
+            Selection::Native { tr } | Selection::Dynamic { tr, .. } => (tr, None),
             Selection::Field | Selection::FieldCall => return None,
         };
         let named = |methods: &[FnDecl]| {
diff --git a/src/repl.rs b/src/repl.rs
index 998af7a47..4508e760c 100644
--- a/src/repl.rs
+++ b/src/repl.rs
@@ -727,7 +727,7 @@ mod tests {
             );
         }
         // The session is what it was.
-        assert_eq!(value(&mut repl, "U(1).m()"), "a");
+        assert_eq!(value(&mut repl, "A.m(U(1))"), "a");
         assert_eq!(value(&mut repl, "f(U(2))"), "U(2)");
     }
 
diff --git a/src/session/mod.rs b/src/session/mod.rs
index 0a3692657..b9e857347 100644
--- a/src/session/mod.rs
+++ b/src/session/mod.rs
@@ -625,44 +625,15 @@ impl Session {
         for d in &ordering.cycles {
             push(d, &mut out);
         }
-        // An unknown method that a trait of a module not imported has:
-        // the help that names the module, now that all are checked.
-        let helped = |id: ModuleId, d: &Diagnostic| {
-            let mut d = d.clone();
-            if !self.cells.info.contains_key(&id) {
-                // (Only an error that says a type has no such method:
-                // another error may stand at the same place.)
-                let about_a_method = matches!(
-                    d.code,
-                    Code::UnknownMethod | Code::UnknownField | Code::UnresolvedName
-                );
-                if about_a_method && d.is_error() {
-                    let reach = self.graph.reach(id);
-                    let imports_back = |owner| self.graph.reach(owner).contains(&id);
-                    for (span, help) in typechecker::out_of_reach_helps(
-                        &self.tables,
-                        &self.defs,
-                        id,
-                        &reach,
-                        imports_back,
-                    ) {
-                        if span == d.span && !d.help.contains(&help) {
-                            d.help.push(help);
-                        }
-                    }
-                }
-            }
-            d
-        };
         if let Some(analysis) = self.analyses.get(&entry) {
             for d in &analysis.diagnostics {
-                push(&helped(entry, d), &mut out);
+                push(d, &mut out);
             }
         }
         for &id in ordering.modules.iter().filter(|&&id| id != entry) {
             if let Some(analysis) = self.analyses.get(&id) {
                 for d in analysis.diagnostics.iter().filter(|d| d.is_error()) {
-                    push(&helped(id, d), &mut out);
+                    push(d, &mut out);
                 }
             }
         }
diff --git a/src/typechecker/builtin_env.rs b/src/typechecker/builtin_env.rs
index a8436b2af..06552230d 100644
--- a/src/typechecker/builtin_env.rs
+++ b/src/typechecker/builtin_env.rs
@@ -342,7 +342,6 @@ fn enter_registry(checker: &mut TypeChecker, env: &mut TypeEnv) {
                         method_type: Type::Fun(vec![self_ty.clone()], Box::new(Type::String)),
                         structural: false,
                         trait_name: Some(key),
-                        receiver: true,
                         preds: Vec::new(),
                     },
                 );
@@ -412,38 +411,25 @@ fn argument_checks(row: &crate::builtins::registry::Row, ty: &Type) -> Vec<Pred>
 /// registrations of the builtin init, for the policy locks
 /// in `tests/cli/trait_init_parity_tests.rs`.
 ///
-/// Returns `(trait_impls, method_keys)` where:
-/// - `trait_impls` is the set of `"Trait:Type"` pairs registered in
-///   `trait_impl_set`.
-/// - `method_keys` is the set of `"Type.method"` pairs the builtins
-///   have (`Tables::methods`).
+/// Returns the set of `"Trait:Type"` pairs registered in
+/// `trait_impl_set`.
 ///
 /// Stringifies the `Symbol` keys so test code doesn't need access to
 /// the crate-private `Symbol`/`intern` types.
 #[doc(hidden)]
-pub fn __trait_init_fingerprint_check_program() -> (
-    std::collections::BTreeSet<String>,
-    std::collections::BTreeSet<String>,
-) {
+pub fn __trait_init_fingerprint_check_program() -> std::collections::BTreeSet<String> {
     use std::collections::BTreeSet;
     let mut checker = TypeChecker::new();
     let mut env = TypeEnv::new();
     register_prelude(&mut checker, &mut env);
     enter_registry(&mut checker, &mut env);
     register_builtin_trait_impls(&mut checker);
-    let trait_impls: BTreeSet<String> = checker
+    checker
         .tables
         .trait_impl_set
         .iter()
         .map(|(tr, ty)| format!("{}:{}", resolve(tr.name), resolve(ty.name)))
-        .collect();
-    let method_keys: BTreeSet<String> = checker
-        .tables
-        .methods(&|_| true)
-        .iter()
-        .map(|(ty, m)| format!("{}.{}", resolve(ty.name), resolve(*m)))
-        .collect();
-    (trait_impls, method_keys)
+        .collect::<BTreeSet<String>>()
 }
 
 /// Test-only introspection for the built-in trait declarations
diff --git a/src/typechecker/builtin_traits.rs b/src/typechecker/builtin_traits.rs
index 622c1e417..ede8540e8 100644
--- a/src/typechecker/builtin_traits.rs
+++ b/src/typechecker/builtin_traits.rs
@@ -111,8 +111,8 @@ pub fn builtin_trait_decls() -> Vec<TraitDecl> {
             is_pub: true,
             span: dummy_span,
             doc: Some(
-                "How a value is shown: `println`, `print`, interpolation, `.display()`\n\
-                 and `string.from` show it so. A type has it by its structure, or by an\n\
+                "How a value is shown: `println`, `print`, interpolation and\n\
+                 `string.from` show it so. A type has it by its structure, or by an\n\
                  impl written in the module that declares the type."
                     .to_string(),
             ),
@@ -213,7 +213,7 @@ pub fn builtin_trait_decls() -> Vec<TraitDecl> {
                     .to_string(),
             ),
         },
-        // trait Error: Display { fn message(self) -> String { self.display() } }
+        // trait Error: Display { fn message(self) -> String { "{self}" } }
         TraitDecl {
             name: intern("Error"),
             name_span: dummy_span,
diff --git a/src/typechecker/declare_traits.rs b/src/typechecker/declare_traits.rs
index 4fb16f0ee..e8f065bda 100644
--- a/src/typechecker/declare_traits.rs
+++ b/src/typechecker/declare_traits.rs
@@ -175,7 +175,6 @@ impl TypeChecker {
                             method_type: substitute_vars(method_ty, &mapping),
                             structural: false,
                             trait_name: Some(*trait_name),
-                            receiver: trait_info.receivers.contains(method_name),
                             preds,
                         },
                     );
@@ -657,13 +656,13 @@ impl TypeChecker {
     /// another module. Why, for the impl of trait `T` for type `Y`,
     /// written in module `I` (`T`'s or `Y`'s):
     ///
-    /// - A call that names the impl where it is written (`y.m()` with
-    ///   `y: Y`, `Y.m`), in a module `X`: `X` has `T` and `Y` in its
+    /// - A call that names the impl where it is written (`T.m(y)` with
+    ///   `y: Y`), in a module `X`: `X` has `T` and `Y` in its
     ///   types. A type comes into a module's types only through what
     ///   the module imports, and a method of `T` is selected only where
     ///   `T`'s module is imported, directly or through imports
     ///   (`method_entry`). So `X` imports `I`, or is `I`.
-    /// - A call decided where the code runs (`x.m()` with `x: a where
+    /// - A call decided where the code runs (`T.m(x)` with `x: a where
     ///   a: T`, a default method, the formatter for `Display`), in a
     ///   module that need not import `Y`'s module. If `I` is `T`'s
     ///   module, the calling code names `T`, so its module imports `I`,
@@ -1808,7 +1807,6 @@ impl TypeChecker {
                     method_type: fn_type,
                     structural: false,
                     trait_name: Some(trait_key),
-                    receiver: declared_receiver.unwrap_or_else(|| writes_self(method)),
                     preds: (method_constraints.iter().cloned())
                         .chain(self.given_to(&method_rigid, trait_key, target_type, method.name))
                         .collect(),
@@ -1897,7 +1895,6 @@ impl TypeChecker {
                         method_type: substitute_vars(ty, &mapping),
                         structural: false,
                         trait_name: Some(trait_key),
-                        receiver: info.receivers.contains(name),
                         preds: method_constraints,
                     },
                 );
diff --git a/src/typechecker/inference.rs b/src/typechecker/inference.rs
index da3642729..6ee83b8fb 100644
--- a/src/typechecker/inference.rs
+++ b/src/typechecker/inference.rs
@@ -49,11 +49,18 @@ enum CallForm {
 
 /// The call to write for a method without `self` where only a type
 /// variable is at hand: on a `type` parameter of that variable.
-pub(super) fn on_type_parameter(var: Symbol, method: Symbol, method_ty: &Type) -> String {
-    format!(
-        "{}, where `{var}` is a `type {var}` parameter",
-        on_type_call(&resolve(var), method, method_ty)
-    )
+/// How a program does what the method `method` of the builtin trait
+/// `tr` would, where that method is not called (`display`, `equal`):
+/// the help of an error at a call of it. `None` for any other method.
+pub(super) fn uncallable_builtin(tr: TraitKey, method: Symbol, x: &str) -> Option<String> {
+    let builtin = crate::defs::builtin_trait_id(&resolve(tr.name)) == Some(tr.id);
+    match (builtin, resolve(tr.name).as_str(), resolve(method).as_str()) {
+        (true, "Display", "display") => Some(format!(
+            "show a value with interpolation, `\"{{{x}}}\"`, or with `string.from({x})`"
+        )),
+        (true, "Equal", "equal") => Some(format!("compare with `==`: `{x} == y`")),
+        _ => None,
+    }
 }
 
 /// The call of the method `method`, of the type `method_ty`, on the type
@@ -156,37 +163,7 @@ pub(super) fn format_record_field_suggestion(
     (base, help)
 }
 
-/// The "unknown method '<field>' on <Type>" message, with a "did you
-/// mean `<cand>`?" help when one of `methods`, the names of the type's
-/// methods, is close to `field` (`suggest::suggest_similar`).
-pub(super) fn format_unknown_method_message(
-    field: Symbol,
-    display_type_name: &str,
-    methods: &[Symbol],
-) -> (String, Option<String>) {
-    let field_str = resolve(field);
-    let base = format!("unknown method '{field_str}' on {display_type_name}");
-    let candidates: Vec<String> = methods.iter().map(|m| resolve(*m).to_string()).collect();
-    let help = suggest_similar(&field_str, candidates.iter())
-        .map(|hint| format!("did you mean `{hint}`?"));
-    (base, help)
-}
-
 impl TypeChecker {
-    /// The "unknown method" message for `field` of the type `ty`, with
-    /// a method of a similar name as its help. That it was reported is
-    /// kept (`note_unknown_method`).
-    fn unknown_method_message(
-        &mut self,
-        field: Symbol,
-        display: &str,
-        ty: TypeRef,
-        span: Span,
-    ) -> (String, Option<String>) {
-        self.note_unknown_method(span, ty, field);
-        format_unknown_method_message(field, display, &self.method_names(ty))
-    }
-
     /// Put `var: trait_name` (at the trait arguments `args`) in scope,
     /// and with it each supertrait, at the arguments the trait's
     /// declaration gives it: `where a: Ordered` with
@@ -239,50 +216,29 @@ impl TypeChecker {
         &mut self,
         recv: &Type,
         method: Symbol,
-        on_type: bool,
         span: Span,
     ) -> Option<Type> {
-        let (tr, others, result) = match resolve(method).as_str() {
-            // (Called through the type only: it takes no `self`.)
-            "decode" if !on_type => return None,
-            "compare" => ("Compare", 1, Some(Type::Int)),
-            "equal" => ("Equal", 1, Some(Type::Bool)),
-            "hash" => ("Hash", 0, Some(Type::Int)),
-            "display" => ("Display", 0, Some(Type::String)),
-            "encode" => (
-                "Encode",
-                0,
-                Some(Type::Generic(TypeRef::builtin("Value"), vec![])),
-            ),
-            "decode" => ("Decode", 0, None),
-            _ => return None,
-        };
-        let tr = TraitKey::builtin(tr);
+        // (The structural methods that take a value of the type are
+        // called through their traits; through the type, `decode`.)
+        if resolve(method) != "decode" {
+            return None;
+        }
+        let tr = TraitKey::builtin("Decode");
         let head = self.type_name_for_impl(&self.apply(recv))?;
         // (A trait of a builtin module, where the module checked does
-        // not import it, gives no method: `.encode()` needs `import
+        // not import it, gives no method: `T.decode` needs `import
         // json`.)
         if !self.by_structure(tr, head) || self.unreached(tr).is_some() {
             return None;
         }
-        let ty = match result {
-            Some(result) => {
-                let mut params = vec![recv.clone()];
-                params.extend(std::iter::repeat_n(recv.clone(), others));
-                Type::Fun(params, Box::new(result))
-            }
-            None => {
-                let info = self.tables.traits.get(&tr)?;
-                let (_, declared) = info.methods.iter().find(|(name, _)| *name == method)?;
-                let mapping = HashMap::from([(info.self_var, recv.clone())]);
-                substitute_vars(declared, &mapping)
-            }
+        let ty = {
+            let info = self.tables.traits.get(&tr)?;
+            let (_, declared) = info.methods.iter().find(|(name, _)| *name == method)?;
+            let mapping = HashMap::from([(info.self_var, recv.clone())]);
+            substitute_vars(declared, &mapping)
         };
         // (A refusal of `T.decode` names it so.)
-        let callee = match tr.is_builtin("Decode") {
-            true => intern(&format!("{head}.{method}")),
-            false => method,
-        };
+        let callee = intern(&format!("{head}.{method}"));
         self.want(
             Pred::Trait {
                 tr,
@@ -296,7 +252,6 @@ impl TypeChecker {
                 op: None,
             },
         );
-        self.last_field_access_was_method = true;
         self.method_trait = Some(tr);
         Some(ty)
     }
@@ -602,236 +557,17 @@ impl TypeChecker {
         (owner != self.module).then_some(module)
     }
 
-    /// The private trait of another module that alone provides `method`:
-    /// every impl that has a method of that name is of such a trait, and
-    /// no trait this module may name declares it.
-    fn only_private_provider(&self, method: Symbol) -> Option<TraitKey> {
-        // (A structural trait's method is every type's.)
-        let name = resolve(method);
-        if STRUCTURAL_METHODS.iter().any(|(_, m)| *m == name) {
-            return None;
-        }
-        let mut providers = self
-            .tables
-            .impl_methods
-            .keys()
-            .filter(|(_, m, _)| *m == method)
-            .map(|(_, _, tr)| *tr);
-        let first = providers.next()?;
-        if self.private_owner(first).is_none() || providers.any(|t| self.private_owner(t).is_none())
-        {
-            return None;
-        }
-        let visible_declares = self.tables.traits.iter().any(|(key, info)| {
-            self.private_owner(*key).is_none() && info.methods.iter().any(|(n, _)| *n == method)
-        });
-        (!visible_declares).then_some(first)
-    }
-
-    /// The method `field` of a value whose type is the annotation
-    /// variable `r`, with the trait that declares it; `None` when there
-    /// is none, which is reported. An annotation variable has the
-    /// methods of its bounds, and nothing else: no field, no method of a
-    /// trait the declaration does not promise. This is the one answer,
-    /// whether the receiver was known where the call is written or
-    /// became known later.
-    pub(super) fn bound_method(
-        &mut self,
-        r: RigidId,
-        field: Symbol,
-        span: Span,
-    ) -> Option<(TraitKey, Type)> {
-        let matches = self.bound_methods(r, field);
-        let matches = self.on_a_value(matches, |(t, _)| *t, field);
-        if matches.len() > 1 {
-            let traits: Vec<TraitKey> = matches.iter().map(|(t, _)| *t).collect();
-            self.ambiguous_bound_method(
-                field,
-                &format!("a value of type `{}`", r.name),
-                r,
-                &traits,
-                span,
-            );
-            return None;
-        }
-        if let Some((trait_name, scheme)) = matches.first() {
-            let receiver = self
-                .tables
-                .traits
-                .get(trait_name)
-                .is_none_or(|info| info.receivers.contains(&field));
-            let method_ty = self.instantiate_method(scheme, field, span);
-            let on_type = on_type_parameter(r.name, field, &method_ty);
-            return match self.takes_no_self(receiver, field, &on_type, span) {
-                true => None,
-                false => Some((*trait_name, method_ty)),
-            };
-        }
-        // One of its bounds names an unknown trait (reported): the
-        // method may be that trait's.
-        if self.unknown_bounds.contains(&r.var) {
-            return None;
-        }
-        let mut bounds: Vec<TraitKey> = self
-            .bounds
-            .get(&r.var)
-            .map(|bounds| bounds.iter().map(|(t, _)| *t).collect())
-            .unwrap_or_default();
-        distinct(&mut bounds);
-        if bounds.is_empty() {
-            self.errors.push(
-                Diagnostic::error(
-                    Code::UnknownMethod,
-                    span,
-                    format!(
-                        "no field or method '{field}' on a value of type `{}`: \
-                         the type variable has no trait bound",
-                        r.name
-                    ),
-                )
-                .with_help(format!(
-                    "a value of type `{0}` has only the methods its bounds \
-                     promise: add `where {0}: SomeTrait`",
-                    r.name
-                )),
-            );
-        } else {
-            let bounds = bounds
-                .iter()
-                .map(|s| format!("{s}"))
-                .collect::<Vec<_>>()
-                .join(" + ");
-            self.error(
-                Code::UnknownMethod,
-                format!("no method '{field}' found in trait constraints ({bounds})"),
-                span,
-            );
-        }
-        None
-    }
-
-    /// `value.method` where the method has no `self` (`receiver`, the
-    /// fact its trait declares: `TraitInfo::receivers`): reported, with
-    /// `on_type` as the call to write instead (`` `Int.empty()` ``). A
-    /// method without `self` is called on a type, never on a value: none
-    /// of its parameters is for the receiver.
-    pub(super) fn takes_no_self(
-        &mut self,
-        receiver: bool,
-        method_name: Symbol,
-        on_type: &str,
-        span: Span,
-    ) -> bool {
-        let no_self = !receiver;
-        if no_self {
-            self.error(
-                Code::InvalidMethodCall,
-                format!(
-                    "method `{method_name}` takes no `self` — \
-                     call it on the type instead: {on_type}"
-                ),
-                span,
-            );
-        }
-        no_self
-    }
-
-    /// The type of `receiver.method` for the impl method `entry`: the
-    /// method's scheme instantiated (`instantiate`), with the receiver
-    /// unified with its `self` parameter, so that what the impl's header
-    /// and the method ask of the receiver's parts is checked against the
-    /// receiver's type; on a part still unknown it waits like any
-    /// predicate owed.
-    pub(super) fn dispatch_method_entry(
-        &mut self,
-        entry: &MethodEntry,
-        method_name: Symbol,
-        receiver_ty: &Type,
-        span: Span,
-    ) -> Type {
-        self.last_field_access_was_method = true;
-        let head = self.type_name_for_impl(&self.apply(receiver_ty));
-        // A method of a trait another module declares without `pub` can
-        // be called only in that module.
-        if let Some(trait_name) = entry.trait_name
-            && self.private_owner(trait_name).is_some()
-        {
-            self.private_method(trait_name, method_name, span);
-            return Type::Error;
-        }
-        if let Some(head) = head
-            && self.ambiguous_method_call(head, method_name, false, span)
-        {
-            return Type::Error;
-        }
-        // A method of a structural trait: the type has it when it has
-        // the trait by its structure, which the call owes. The entry
-        // only says that the name is the trait's.
-        if entry.structural
-            && let Some(method_ty) = self.structural_method(receiver_ty, method_name, false, span)
-        {
-            return method_ty;
-        }
-        self.method_trait = self.entry_trait(entry, method_name);
-        // What the impl and the method ask of the receiver's parts and
-        // of the method's own type variables is owed, and checked once
-        // the receiver is unified with the method's `self` below.
-        let owed_before = self.wanted.len();
-        let scheme = self.method_scheme(entry);
-        let instantiated_ty = self.instantiate_method(&scheme, method_name, span);
-        // A method without `self` has no place for the receiver.
-        let on = self
-            .type_name_for_impl(&self.apply(receiver_ty))
-            .map_or_else(|| "SomeType".to_string(), |ty| ty.to_string());
-        let on_type = on_type_call(&on, method_name, &instantiated_ty);
-        if self.takes_no_self(entry.receiver, method_name, &on_type, span) {
-            return Type::Error;
-        }
-        // Unify the receiver with the method's self param so concrete
-        // receiver element types flow into the impl's tyvars before the
-        // constraint check below.
-        if let Type::Fun(params, _) = &instantiated_ty
-            && let Some(self_param) = params.first()
-        {
-            self.unify(receiver_ty, self_param, span);
-        }
-        // A method of a structural trait (`.compare()`, `.equal()`,
-        // `.hash()`, a derived `.display()`) is the receiver's when its
-        // parts have the trait too.
-        if let Some(tr) = self.entry_trait(entry, method_name)
-            && let Some(head) = head
-            && crate::defs::builtin_trait_id(&resolve(tr.name)) == Some(tr.id)
-            && self.by_structure(tr, head)
-        {
-            self.want(
-                Pred::Trait {
-                    tr,
-                    args: Vec::new(),
-                    subject: receiver_ty.clone(),
-                    asker: None,
-                },
-                Origin {
-                    span,
-                    callee: Some(method_name),
-                    op: None,
-                },
-            );
-        }
-        self.solve_wanted(owed_before);
-        self.apply(&instantiated_ty)
-    }
-
-    /// Resolve a method on a type descriptor (`TypeOf(inner)`). The
-    /// descriptor is a type carrier — lookup uses `inner`'s effective type
-    /// name (for concrete inners) or the active trait constraints (for a
-    /// type variable inner). Returns the method's function type with all
-    /// `Self` references substituted to `inner`.
+    /// Resolve a method that makes a value on a type descriptor
+    /// (`TypeOf(inner)`, `a.empty()`). The descriptor is a type carrier —
+    /// lookup uses `inner`'s effective type name (for concrete inners) or
+    /// the active trait constraints (for a type variable inner). Returns
+    /// the method's function type with all `Self` references substituted
+    /// to `inner`; a method that takes a value of the type is reported
+    /// (it is called through its trait).
     ///
-    /// Unlike value-receiver dispatch, the descriptor does NOT occupy an
-    /// argument slot of the method. Callers signal this by leaving
-    /// `last_field_access_was_method = false` after this returns, so the
-    /// downstream Call arm unifies args with params[0..] rather than
-    /// params[1..].
+    /// The descriptor occupies no parameter of the method:
+    /// `receiver_taken` stays false, so the call unifies its arguments
+    /// with all of the method's parameters.
     pub(super) fn resolve_type_descriptor_method(
         &mut self,
         inner: &Type,
@@ -902,6 +638,10 @@ impl TypeChecker {
                     );
                     return None;
                 }
+                if self.self_param(matches[0].0, field).is_some() {
+                    self.through_its_trait(&inner.to_string(), matches[0].0, field, span);
+                    return Some(Type::Error);
+                }
                 self.method_trait = Some(matches[0].0);
                 let instantiated = self.instantiate_method(&matches[0].1, field, span);
                 Some(self.apply(&instantiated))
@@ -911,14 +651,21 @@ impl TypeChecker {
                 // the effective type name (same path as
                 // `type_name_for_impl`).
                 let name = self.type_name_for_impl(&inner)?;
-                let entry = self.method_entry(name, field, true)?;
+                let entry = self.method_entry(name, field)?;
+                if let Some(tr) = self.entry_trait(&entry, field)
+                    && self.self_param(tr, field).is_some()
+                {
+                    let shown = self.show_type(&inner);
+                    self.through_its_trait(&shown, tr, field, span);
+                    return Some(Type::Error);
+                }
                 if let Some(trait_name) = entry.trait_name
                     && self.private_owner(trait_name).is_some()
                 {
                     self.private_method(trait_name, field, span);
                     return Some(Type::Error);
                 }
-                if self.ambiguous_method_call(name, field, true, span) {
+                if self.ambiguous_method_call(name, field, span) {
                     return Some(Type::Error);
                 }
                 if self.of_every_shape(name, &entry, field, span) {
@@ -935,11 +682,317 @@ impl TypeChecker {
         }
     }
 
-    /// `T.method` where the method is one of a builtin structural trait
-    /// that the type `ty`, of the instance `inner`, has by its structure
-    /// (`Int.display`, `P.compare`): the method `structural_method`
-    /// gives a value of `inner`. Written through the type, every
-    /// parameter is an argument of the call, the receiver too.
+    /// The trait an expression names (`Greet`, `m.Greet`, `Compare`), as
+    /// the resolver resolved it; `None` for anything else.
+    pub(super) fn trait_named(&self, expr: &Expr) -> Option<TraitKey> {
+        if !matches!(expr.kind, ExprKind::Ident(_) | ExprKind::FieldAccess(..)) {
+            return None;
+        }
+        match expr.res {
+            Some(crate::defs::Res::Def(id)) => self.trait_key(id),
+            _ => None,
+        }
+    }
+
+    /// The type of `Tr.field`, a method of the trait `tr` called through
+    /// it: the method's type with a type of its own for `Self`, whose
+    /// impl the call reaches (the type of the arguments it is given).
+    /// The use owes `Self: Tr`, the method's own bounds, and what the
+    /// method of that impl asks (`Pred::Via`), as a call on a value of
+    /// that type would. A method that takes no value of type `Self`
+    /// cannot say which impl it is of: it is called on a type.
+    fn trait_method(
+        &mut self,
+        tr: TraitKey,
+        field: Symbol,
+        receiver: Option<(Type, Span)>,
+        span: Span,
+    ) -> Type {
+        let Some(info) = self.tables.traits.get(&tr).cloned() else {
+            return Type::Error;
+        };
+        let Some((_, method_ty)) = info.methods.iter().find(|(n, _)| *n == field) else {
+            let message = format!("trait '{}' has no method '{field}'", self.show_trait(tr));
+            let names: Vec<String> = info.methods.iter().map(|(n, _)| resolve(*n)).collect();
+            let help = super::suggest::suggest_similar(&resolve(field), &names)
+                .map(|name| format!("did you mean '{name}'?"));
+            self.error_help(Code::UnknownMethod, (message, help), span);
+            return Type::Error;
+        };
+        if let Some(how) = uncallable_builtin(tr, field, "x") {
+            self.error_help(
+                Code::InvalidMethodCall,
+                (
+                    format!("trait '{}' has no callable methods", self.show_trait(tr)),
+                    Some(how),
+                ),
+                span,
+            );
+            return Type::Error;
+        }
+        if self.private_owner(tr).is_some() {
+            self.private_method(tr, field, span);
+            return Type::Error;
+        }
+        let takes_self = matches!(method_ty, Type::Fun(params, _)
+            if params.iter().any(|p| matches!(p, Type::Var(v) if *v == info.self_var)));
+        if !takes_self {
+            self.errors.push(
+                Diagnostic::error(
+                    Code::InvalidMethodCall,
+                    span,
+                    format!(
+                        "method '{field}' of trait '{}' takes no value of the type, so it is \
+                         called on a type",
+                        self.show_trait(tr)
+                    ),
+                )
+                .with_help(format!(
+                    "call it on a type, {}, or on a `type a` parameter, {}",
+                    on_type_call("T", field, method_ty),
+                    on_type_call("a", field, method_ty)
+                )),
+            );
+            return Type::Error;
+        }
+        // Called with its first argument a value of a type that has an
+        // impl written: the method of that impl, as a function of the
+        // impl's module calls it, owing what the impl's header and the
+        // method's body ask (`dispatch_method_entry`).
+        if let Some((recv, _)) = &receiver {
+            let recv = self.apply(recv);
+            let entry = match crate::types::canonical::canonicalize(&self.tables.resolver, &recv) {
+                Type::Var(_) | Type::Rigid(_) | Type::Error | Type::Never => None,
+                canon => (self.type_name_for_impl(&canon))
+                    .and_then(|head| self.tables.impl_methods.get(head, field, tr))
+                    .filter(|entry| !entry.structural)
+                    .cloned(),
+            };
+            if let Some(entry) = entry {
+                self.method_trait = Some(tr);
+                self.trait_call_self.insert(span, recv.clone());
+                self.receiver_taken = true;
+                let owed_before = self.wanted.len();
+                let scheme = self.method_scheme(&entry);
+                let ty = self.instantiate_method(&scheme, field, span);
+                if let Type::Fun(params, _) = &ty
+                    && let Some(first) = params.first()
+                {
+                    self.unify(&recv, first, span);
+                }
+                self.solve_wanted(owed_before);
+                return self.apply(&ty);
+            }
+        }
+        let self_ty = self.fresh_var();
+        let mut mapping: HashMap<TyVar, Type> = HashMap::new();
+        mapping.insert(info.self_var, self_ty.clone());
+        let params: Vec<Type> = info
+            .param_var_ids
+            .iter()
+            .map(|v| {
+                let fresh = self.fresh_var();
+                mapping.insert(*v, fresh.clone());
+                fresh
+            })
+            .collect();
+        let ty = substitute_vars(method_ty, &mapping);
+        let preds: Vec<Pred> = info
+            .method_bounds
+            .get(&field)
+            .into_iter()
+            .flatten()
+            .map(|pred| pred.substitute(&mapping))
+            .chain([Pred::Via {
+                tr,
+                method: field,
+                receiver: self_ty.clone(),
+                method_ty: ty.clone(),
+                passer: None,
+                at: None,
+            }])
+            .collect();
+        let own: Vec<TyVar> = free_vars_in(method_ty)
+            .into_iter()
+            .filter(|v| !mapping.contains_key(v))
+            .collect();
+        let scheme = Scheme {
+            vars: own,
+            preds,
+            ty,
+        };
+        if let Some((recv, _)) = &receiver {
+            self.unify(recv, &self_ty, span);
+        }
+        self.want(
+            Pred::Trait {
+                tr,
+                args: params,
+                subject: self_ty.clone(),
+                asker: None,
+            },
+            Origin {
+                span: receiver.as_ref().map_or(span, |(_, at)| *at),
+                callee: Some(field),
+                op: None,
+            },
+        );
+        self.method_trait = Some(tr);
+        self.trait_call_self.insert(span, self_ty);
+        self.receiver_taken = receiver.is_some();
+        let method_ty = self.instantiate_method(&scheme, field, span);
+        self.apply(&method_ty)
+    }
+
+    /// Report `recv.field` where a value of the type `ty` has no field
+    /// `field` (`fields`: the fields it has): when a trait in sight has a
+    /// method of that name, or a builtin module of the type a function,
+    /// the help says how to call it; else a field of a similar name.
+    pub(super) fn no_field(
+        &mut self,
+        ty: &Type,
+        field: Symbol,
+        recv: Option<&Expr>,
+        fields: &[(Symbol, Type)],
+        span: Span,
+    ) {
+        let shown = self.show_type(ty);
+        let base = format!("type '{shown}' has no field '{field}'");
+        let placeholder = match ty {
+            Type::List(_) => "xs",
+            _ => "x",
+        };
+        let written = match recv.map(|recv| &recv.kind) {
+            Some(ExprKind::Ident(name)) => resolve(*name),
+            _ => placeholder.to_string(),
+        };
+        let help = match self.method_help(ty, field, &written) {
+            Some(help) => Some(help),
+            None => format_record_field_suggestion(base.clone(), field, fields).1,
+        };
+        self.error_help(Code::UnknownField, (base, help), span);
+    }
+
+    /// How to call the method or function `field` that a dot after a
+    /// value of the type `ty`, written `written`, names, if a trait in
+    /// sight or a builtin module of the type has one of that name: the
+    /// help of `no_field`.
+    pub(super) fn method_help(&self, ty: &Type, field: Symbol, written: &str) -> Option<String> {
+        let mut traits: Vec<TraitKey> = (self.tables.traits.iter())
+            .filter(|(_, info)| info.methods.iter().any(|(n, _)| *n == field))
+            .map(|(t, _)| *t)
+            .filter(|t| self.sees_trait(*t) && self.private_owner(*t).is_none())
+            .collect();
+        traits.sort_by_key(|t| self.show_trait(*t));
+        if let Some(tr) = traits.first().copied() {
+            if let Some(how) = uncallable_builtin(tr, field, written) {
+                return Some(how);
+            }
+            let shown = self.show_trait(tr);
+            let params = self.method_arity(tr, field);
+            return Some(match self.self_param(tr, field) {
+                Some(_) => {
+                    let rest = if params > 1 { ", .." } else { "" };
+                    format!(
+                        "`{field}` is a method of trait `{shown}`: call it as \
+                         `{shown}.{field}({written}{rest})`"
+                    )
+                }
+                None => {
+                    // (A type variable is called on as the `type a`
+                    // parameter that would name it.)
+                    let (on, parameter) = match ty {
+                        Type::Rigid(r) => (
+                            r.name.to_string(),
+                            format!(", where `{0}` is a `type {0}` parameter", r.name),
+                        ),
+                        _ => (
+                            self.type_name_for_impl(ty)
+                                .map_or_else(|| "T".to_string(), |t| t.name.to_string()),
+                            String::new(),
+                        ),
+                    };
+                    let args = if params > 0 { ".." } else { "" };
+                    format!(
+                        "`{field}` is a method of trait `{shown}` that makes a value: call it \
+                         on the type, `{on}.{field}({args})`{parameter}"
+                    )
+                }
+            });
+        }
+        let module = match ty {
+            Type::List(_) => "list",
+            Type::String => "string",
+            Type::Map(..) => "map",
+            Type::Set(_) => "set",
+            Type::Int => "int",
+            Type::Float => "float",
+            Type::Channel(_) => "channel",
+            Type::Generic(name, _) if name.is_builtin("Option") => "option",
+            Type::Generic(name, _) if name.is_builtin("Result") => "result",
+            Type::Generic(name, _) if name.is_builtin("Bytes") => "bytes",
+            _ => return None,
+        };
+        crate::builtins::registry::registry()
+            .row(module, &resolve(field))
+            .filter(|row| row.enabled)
+            .map(|_| {
+                format!(
+                    "`{field}` is a function of module `{module}`: call it as \
+                     `{module}.{field}({written})`"
+                )
+            })
+    }
+
+    /// Report `T.field`, through the type `on`, of the method `field` of
+    /// the trait `tr`, which takes a value of the type: it is called
+    /// through its trait.
+    fn through_its_trait(&mut self, on: &str, tr: TraitKey, field: Symbol, span: Span) {
+        let shown = self.show_trait(tr);
+        let more = self.self_param(tr, field).is_some() && self.method_arity(tr, field) > 1;
+        let rest = if more { ", .." } else { "" };
+        let help = match uncallable_builtin(tr, field, "x") {
+            Some(how) => how,
+            None => format!(
+                "`{field}` is a method of trait `{shown}`: call it as `{shown}.{field}(x{rest})`"
+            ),
+        };
+        self.error_help(
+            Code::UnknownMethod,
+            (format!("type '{on}' has no method '{field}'"), Some(help)),
+            span,
+        );
+    }
+
+    /// The number of parameters of the method `field` of the trait `tr`.
+    fn method_arity(&self, tr: TraitKey, field: Symbol) -> usize {
+        (self.tables.traits.get(&tr))
+            .and_then(|info| info.methods.iter().find(|(n, _)| *n == field))
+            .and_then(|(_, ty)| match ty {
+                Type::Fun(params, _) => Some(params.len()),
+                _ => None,
+            })
+            .unwrap_or(0)
+    }
+
+    /// The index of the first parameter of type `Self` of the method
+    /// `field` of the trait `tr`: the argument a call through the trait
+    /// picks the impl by. `None` when the method has none, or the trait
+    /// no such method.
+    pub(super) fn self_param(&self, tr: TraitKey, field: Symbol) -> Option<usize> {
+        let info = self.tables.traits.get(&tr)?;
+        let (_, ty) = info.methods.iter().find(|(n, _)| *n == field)?;
+        match ty {
+            Type::Fun(params, _) => params
+                .iter()
+                .position(|p| matches!(p, Type::Var(v) if *v == info.self_var)),
+            _ => None,
+        }
+    }
+
+    /// `T.decode` where the type `ty`, of the instance `inner`, has
+    /// `json.Decode` by its structure: the method `structural_method`
+    /// gives `inner`.
     fn structural_type_method(
         &mut self,
         ty: TypeRef,
@@ -947,8 +1000,7 @@ impl TypeChecker {
         field: Symbol,
         span: Span,
     ) -> Type {
-        let method = self.structural_method(inner, field, true, span);
-        self.last_field_access_was_method = false;
+        let method = self.structural_method(inner, field, span);
         match method {
             Some(method) => self.apply(&method),
             // The type has the method by its structure, so the
@@ -1037,9 +1089,6 @@ impl TypeChecker {
             format!("type '{shown}' has no method '{field}'"),
         );
         let qualified = intern(&format!("{module}.{field}"));
-        if let Some(ty) = ty {
-            self.note_unknown_method(span, ty, field);
-        }
         if crate::module::is_builtin_module(&module) && builtin_env_has(qualified) {
             d = d.with_help(format!(
                 "did you mean `{module}.{field}`, a function of module `{module}`?"
@@ -1597,7 +1646,7 @@ impl TypeChecker {
         // Reset the method-dispatch flag so a stale value from an
         // earlier field access does not leak into this call, and read it
         // before the arguments are checked (they may overwrite it).
-        self.last_field_access_was_method = false;
+        self.receiver_taken = false;
         self.named_use = Self::callee_label(callee).map(|label| Origin {
             span,
             callee: Some(label),
@@ -1605,13 +1654,29 @@ impl TypeChecker {
         });
         self.callee_position = true;
         self.unknown_receiver = None;
+        // `Tr.m(x, ..)`: the argument of type `Self` is checked with the
+        // callee, as a receiver: the impl is the one for its type.
+        let through_trait = match &callee.kind {
+            ExprKind::FieldAccess(obj, field, _) if !args.is_empty() => self
+                .trait_named(obj)
+                .is_some_and(|tr| self.self_param(tr, *field) == Some(0)),
+            _ => false,
+        };
+        if through_trait {
+            let receiver = args.remove(0);
+            self.callee_position = false;
+            let recv_ty = self.infer_expr(receiver, env);
+            self.callee_position = true;
+            self.trait_receiver = Some((recv_ty, receiver.span));
+        }
         let callee_ty = self.infer_expr(callee, env);
+        self.trait_receiver = None;
         self.callee_position = false;
         self.named_use = None;
         let callee_ty = self.apply(&callee_ty);
-        let is_method_call = self.last_field_access_was_method;
-        self.last_field_access_was_method = false;
-        // `x.m(args)` where the type of `x` is unknown: the call waits
+        let receiver_taken_by_callee = self.receiver_taken;
+        self.receiver_taken = false;
+        // `x.f(args)` where the type of `x` is unknown: the call waits
         // for it.
         if let Some((recv, name)) = self.unknown_receiver.take() {
             let args: Vec<Type> = args.iter_mut().map(|a| self.infer_expr(a, env)).collect();
@@ -1637,10 +1702,13 @@ impl TypeChecker {
                 // A method call supplies `self` implicitly
                 // (`dispatch_method_entry` has unified it with the
                 // receiver), so the arguments line up with `params[1..]`.
-                let implicit_self = usize::from(is_method_call);
+                let implicit_self = usize::from(receiver_taken_by_callee);
                 // (A method has its `self`: `takes_no_self` refused the
                 // access otherwise.)
-                let written_params = params.len().saturating_sub(implicit_self);
+                let written_params = match through_trait {
+                    true => params.len(),
+                    false => params.len().saturating_sub(implicit_self),
+                };
                 // What the callee's use owes for a type variable of a
                 // parameter is owed for that argument: a bound that
                 // fails is reported at it.
@@ -1773,7 +1841,7 @@ impl TypeChecker {
                             CallForm::BarePipe => span,
                         };
                         // A parameter the callee calls as a statement.
-                        let statement = match is_method_call {
+                        let statement = match receiver_taken_by_callee {
                             true => None,
                             false => self.statement_unit(callee, i),
                         };
@@ -1815,18 +1883,32 @@ impl TypeChecker {
                         CallForm::Call => {
                             // A method's receiver is not one of the
                             // arguments the call writes.
-                            let what = match (&callee.kind, callee_name) {
-                                (ExprKind::FieldAccess(_, method, _), _) if is_method_call => {
-                                    format!("method `{method}`")
+                            // (A call through a trait writes its
+                            // receiver: it counts.)
+                            let (what, written, got) = match (&callee.kind, callee_name) {
+                                (ExprKind::FieldAccess(obj, method, _), _) if through_trait => {
+                                    let shown = match self.trait_named(obj) {
+                                        Some(tr) => format!("`{}.{method}`", self.show_trait(tr)),
+                                        None => format!("method `{method}`"),
+                                    };
+                                    (shown, written_params, args.len() + 1)
                                 }
-                                (_, Some(name)) => format!("`{name}`"),
-                                _ => "function".to_string(),
+                                (ExprKind::FieldAccess(obj, method, _), _)
+                                    if let Some(tr) = self.trait_named(obj) =>
+                                {
+                                    let shown = format!("`{}.{method}`", self.show_trait(tr));
+                                    (shown, written_params, args.len())
+                                }
+                                (_, Some(name)) => {
+                                    (format!("`{name}`"), written_params, args.len())
+                                }
+                                _ => ("function".to_string(), written_params, args.len()),
                             };
                             let message = format!(
                                 "{what} expects {} {}, got {}",
-                                written_params,
-                                plural(written_params, "argument", "arguments"),
-                                args.len()
+                                written,
+                                plural(written, "argument", "arguments"),
+                                got
                             );
                             (message, None)
                         }
@@ -1933,31 +2015,7 @@ impl TypeChecker {
         {
             expr.res = None;
         }
-        let called = self.callee_position;
         let ty = self.infer_expr_kind(expr, env);
-        // A method is called, not taken: `x.m` that is not a callee is a
-        // field.
-        let ty = if self.last_field_access_was_method && !called {
-            self.last_field_access_was_method = false;
-            self.method_trait = None;
-            let ExprKind::FieldAccess(_, method, _) = &expr.kind else {
-                unreachable!()
-            };
-            self.errors.push(
-                Diagnostic::error(
-                    Code::InvalidMethodCall,
-                    expr.span,
-                    format!("method '{method}' is not a value: a method is called"),
-                )
-                .with_help(format!(
-                    "call it, `x.{method}(..)`, or pass a closure that does, `{{ x -> x.{method}(..) }}`"
-                )),
-            );
-            expr.ty = Some(Type::Error);
-            Type::Error
-        } else {
-            ty
-        };
         if let Some(t) = self.method_trait.take() {
             expr.res = Some(crate::defs::Res::Def(t.id.0));
         }
@@ -2212,7 +2270,7 @@ impl TypeChecker {
             }
 
             ExprKind::FieldAccess(obj, field, _) => {
-                self.last_field_access_was_method = false;
+                self.receiver_taken = false;
                 let field = *field;
                 // What the resolver said the access names: nothing (it
                 // reported why, or the module failed to load), a variant
@@ -2272,8 +2330,16 @@ impl TypeChecker {
                     expr.ty = Some(ty.clone());
                     return ty;
                 }
-                // `Type.method`: a method of a type, called through it
-                // (`Shape.describe`, `m.Shape.describe`, `Int.display`).
+                // `Trait.method`: a method of a trait, called through it
+                // (`Greet.greet(x)`, `m.Greet.greet`, `Compare.compare`).
+                if let Some(tr) = self.trait_named(obj) {
+                    let receiver = self.trait_receiver.take();
+                    let ty = self.trait_method(tr, field, receiver, span);
+                    expr.ty = Some(ty.clone());
+                    return ty;
+                }
+                // `Type.method`: a method that makes a value, called
+                // through its type (`Int.empty`, `m.Shape.default`).
                 let type_ref = match (&obj.kind, obj.res) {
                     (ExprKind::Ident(name), None) => self.named_type(None, *name),
                     (ExprKind::Ident(_) | ExprKind::FieldAccess(..), res) => self.res_type(res),
@@ -2281,7 +2347,7 @@ impl TypeChecker {
                 };
                 if let Some(ty) = type_ref {
                     let key = (canonical_head(&self.tables.resolver, ty), field);
-                    if let Some(entry) = self.method_entry(key.0, key.1, true) {
+                    if let Some(entry) = self.method_entry(key.0, key.1) {
                         if let Some(trait_name) = entry.trait_name
                             && self.private_owner(trait_name).is_some()
                         {
@@ -2289,7 +2355,21 @@ impl TypeChecker {
                             expr.ty = Some(Type::Error);
                             return Type::Error;
                         }
-                        if self.ambiguous_method_call(key.0, field, true, span) {
+                        // A method that takes a value of the type is
+                        // called through its trait.
+                        if let Some(tr) = self.entry_trait(&entry, field)
+                            && self.self_param(tr, field).is_some()
+                        {
+                            // (The help names a trait whose method is
+                            // called: a program's before `Display`.)
+                            let tr = (self.method_providers(key.0, field).into_iter())
+                                .find(|t| uncallable_builtin(*t, field, "x").is_none())
+                                .unwrap_or(tr);
+                            self.through_its_trait(&resolve(ty.name), tr, field, span);
+                            expr.ty = Some(Type::Error);
+                            return Type::Error;
+                        }
+                        if self.ambiguous_method_call(key.0, field, span) {
                             expr.ty = Some(Type::Error);
                             return Type::Error;
                         }
@@ -2342,30 +2422,26 @@ impl TypeChecker {
 
                 // Could be record.field — infer the object type
                 let obj_ty = self.infer_expr(obj, env);
-                self.last_field_access_was_method = false;
+                self.receiver_taken = false;
                 let obj_ty = self.apply(&obj_ty);
                 // Canonicalise before dispatch so a receiver whose type
                 // is written through an alias lands in the arm of the
                 // type it stands for.
                 let obj_ty = crate::types::canonical::canonicalize(&self.tables.resolver, &obj_ty);
 
-                // Field / method access
+                // A dot after a value is a field: a record's (its type's
+                // or an anonymous one's), or, on a value whose type is
+                // still unknown, the field of a record that has one.
                 //
                 // `TypeOf(inner)` values (descriptors produced by `type a`
-                // parameters or bare type names like `Int`) dispatch to
-                // trait methods on `inner`'s type. The descriptor is a
-                // type carrier, not a value argument — the downstream
-                // Call arm therefore sees `is_method_call = false`, so
-                // arg unification runs with no offset and the fn body's
-                // parameter slots line up one-for-one with the user's
-                // explicit arguments.
+                // parameters or bare type names like `Int`) call the
+                // methods of `inner` that make a value of it.
                 if let Type::Generic(gname, gargs) = &obj_ty
                     && gname.is_builtin(crate::defs::TYPE_OF)
                     && gargs.len() == 1
                 {
                     let resolved = self.resolve_type_descriptor_method(&gargs[0], field, span);
                     if let Some(ty) = resolved {
-                        self.last_field_access_was_method = false;
                         expr.ty = Some(ty.clone());
                         return ty;
                     }
@@ -2397,25 +2473,10 @@ impl TypeChecker {
                             };
                             self.unify(&obj_ty, &extended, span);
                             result_ty
-                        } else if let Some(method_ty) =
-                            self.structural_method(&obj_ty, field, false, span)
-                        {
-                            // A method every value has that its parts
-                            // allow (`{a: 1}.display()`), as on a tuple.
-                            expr.ty = Some(method_ty.clone());
-                            return method_ty;
                         } else {
-                            // ERR-GAP (round 81 F2): mirror the sibling
-                            // Record / Generic field-access sites and
-                            // append a did-you-mean hint.
                             let candidates: Vec<(Symbol, Type)> =
                                 fields.iter().map(|(k, v)| (*k, v.clone())).collect();
-                            let base = format!("anon record has no field '{field}'");
-                            self.error_help(
-                                Code::NoSuchField,
-                                format_record_field_suggestion(base, field, &candidates),
-                                span,
-                            );
+                            self.no_field(&obj_ty, field, Some(obj), &candidates, span);
                             Type::Error
                         }
                     }
@@ -2458,177 +2519,38 @@ impl TypeChecker {
                             expr.ty = Some(resolved.clone());
                             return resolved;
                         }
-                        // Check method table (trait methods)
-                        if let Some(entry) = self.method_entry(*type_name, field, false) {
-                            let instantiated =
-                                self.dispatch_method_entry(&entry, field, &obj_ty, span);
-                            let resolved = self.apply(&instantiated);
-                            expr.ty = Some(resolved.clone());
-                            return resolved;
-                        }
-                        // Legacy fallback: check TypeEnv for "TypeName.method"
-                        let key = intern(&format!("{type_name}.{field}"));
-                        if let Some(scheme) = env.lookup(key) {
-                            let scheme = scheme.clone();
-                            let result = self.instantiate(&scheme);
-                            let resolved = self.apply(&result);
-                            expr.ty = Some(resolved.clone());
-                            return resolved;
-                        }
-                        // A method of a structural trait the type has
-                        // no entry for (`Some(1).compare(Some(2))`).
-                        if let Some(method_ty) = self.structural_method(&obj_ty, field, false, span)
-                        {
-                            expr.ty = Some(method_ty.clone());
-                            return method_ty;
-                        }
-                        // GAP (round 35 F7): thread did-you-mean suggestion
-                        // through the Generic/named-record field-access
-                        // path so `u.nam` on `type User { name, age }`
-                        // prints `did you mean 'name'?`.
-                        self.note_unknown_method(span, *type_name, field);
-                        let shown = self.show_type(&Type::Generic(*type_name, vec![]));
-                        let base = format!("unknown field or method '{field}' on type {shown}");
-                        let msg = if let Some(rec_info) = self.tables.records.get(type_name) {
-                            format_record_field_suggestion(base, field, &rec_info.fields)
-                        } else {
-                            (base, None)
-                        };
-                        self.error_help(Code::UnknownField, msg, span);
-                        Type::Error
-                    }
-                    // Primitive types — check method table for trait methods.
-                    // Channel and Fn have no structural traits to
-                    // speak of, but user-defined trait impls register entries
-                    // under the canonical names "Channel" / "Fn" via
-                    // `type_name_for_impl` (see `src/typechecker/mod.rs:2081`,
-                    // `src/typechecker/mod.rs:2092`), so dispatch must route those
-                    // receivers through the same `method_table` lookup. The
-                    // `"Fn"` key matches `canonical_name(Type::Fun)`,
-                    // `head_of_canon`, and `dispatch_type_for_value`
-                    // — round 71 follow-up unified all four sites on `"Fn"`.
-                    Type::Int
-                    | Type::Float
-                    | Type::Bool
-                    | Type::String
-                    | Type::Unit
-                    | Type::Channel(_)
-                    | Type::Fun(_, _) => {
-                        // `Unit` is the key of `()` (it matches
-                        // canonical_name(Type::Unit) and
-                        // dispatch_type_for_value(Value::Unit)), `Fn` of a
-                        // function.
-                        let type_name = head_of(&obj_ty).expect("a primitive head has a type");
-                        if let Some(entry) = self.method_entry(type_name, field, false) {
-                            let instantiated =
-                                self.dispatch_method_entry(&entry, field, &obj_ty, span);
-                            let resolved = self.apply(&instantiated);
-                            expr.ty = Some(resolved.clone());
-                            return resolved;
-                        }
-                        // GAP (round 23 #3): append "did you mean ...?"
-                        // when a near edit-distance method is registered
-                        // on this type. Keep the existing "on type <Name>"
-                        // header so prior-lock tests that match only the
-                        // header prefix still pass; the hint is appended
-                        // on its own `help:` line.
-                        // A method of an impl the resolver rejected: reported there.
-                        if self.unresolved_impl_methods.contains(&field) {
-                            return Type::Error;
-                        }
-                        let display = format!("type {type_name}");
-                        let message = self.unknown_method_message(field, &display, type_name, span);
-                        self.error_help(Code::UnknownMethod, message, span);
+                        let fields = (self.tables.records.get(type_name))
+                            .map(|rec| rec.fields.clone())
+                            .unwrap_or_default();
+                        self.no_field(&obj_ty, field, Some(obj), &fields, span);
                         Type::Error
                     }
-                    // Collection types.
-                    //
-                    // Round 77 BLOAT D3: the four container arms (List,
-                    // Tuple, Map, Set) are line-for-line identical
-                    // except for the literal type-name string. They
-                    // collapse onto a single arm that asks
-                    // `type_name_for_impl` for the canonical name.
-                    // Adding a fifth container head only requires
-                    // extending the match pattern below — not cloning
-                    // a fourth body. The unknown-method error wording
-                    // matches the pre-fix form (`unknown method 'X' on
-                    // List` — without the `type` prefix used by the
-                    // primitive arm above), preserving observable
-                    // behavior across all four heads.
-                    t @ (Type::List(_) | Type::Tuple(_) | Type::Map(_, _) | Type::Set(_)) => {
-                        let type_name = self
-                            .type_name_for_impl(t)
-                            .expect("container head has canonical name");
-                        if let Some(entry) = self.method_entry(type_name, field, false) {
-                            let instantiated =
-                                self.dispatch_method_entry(&entry, field, &obj_ty, span);
-                            let resolved = self.apply(&instantiated);
-                            expr.ty = Some(resolved.clone());
-                            return resolved;
-                        }
-                        // GAP (round 92): `t.0` parses as a FieldAccess
-                        // with an all-numeric "method" name (the parser
-                        // keeps a dedicated tuple-index arm), but tuple
-                        // indexing is intentionally unsupported (round 69
-                        // decision — docs-only). The generic "unknown
-                        // method '0' on Tuple" wording misled users into
-                        // thinking they typo'd a method name. Emit a
-                        // targeted diagnostic pointing at destructuring
-                        // instead. Numeric "methods" can only arise from
-                        // tuple-index syntax, so this never shadows a real
-                        // method lookup.
-                        if matches!(t, Type::Tuple(_)) {
-                            let field_str = resolve(field);
-                            if !field_str.is_empty()
-                                && field_str.bytes().all(|b| b.is_ascii_digit())
-                            {
-                                self.error(
-                                    Code::UnsupportedOperation,
-                                    format!(
-                                        "tuple indexing ('t.{field_str}') is not supported; \
-                                         destructure instead: 'let (a, b) = t'"
-                                    ),
-                                    span,
-                                );
-                                return Type::Error;
-                            }
-                        }
-                        // A method of an impl the resolver rejected: reported there.
-                        if self.unresolved_impl_methods.contains(&field) {
-                            return Type::Error;
-                        }
-                        let display = resolve(type_name.name).to_string();
-                        let message = self.unknown_method_message(field, &display, type_name, span);
-                        self.error_help(Code::UnknownMethod, message, span);
+                    // GAP (round 92): `t.0` parses as a FieldAccess with an
+                    // all-numeric field name, but tuple indexing is
+                    // intentionally unsupported (round 69 decision): the
+                    // targeted diagnostic points at destructuring instead.
+                    Type::Tuple(_)
+                        if !resolve(field).is_empty()
+                            && resolve(field).bytes().all(|b| b.is_ascii_digit()) =>
+                    {
+                        self.error(
+                            Code::UnsupportedOperation,
+                            format!(
+                                "tuple indexing ('t.{field}') is not supported; \
+                                 destructure instead: 'let (a, b) = t'"
+                            ),
+                            span,
+                        );
                         Type::Error
                     }
-                    Type::Rigid(r) => match self.bound_method(*r, field, span) {
-                        Some((trait_name, method_ty)) => {
-                            self.last_field_access_was_method = true;
-                            self.method_trait = Some(trait_name);
-                            let resolved = self.apply(&method_ty);
-                            expr.ty = Some(resolved.clone());
-                            return resolved;
-                        }
-                        None => Type::Error,
-                    },
                     Type::Var(_) => {
-                        // A method only another module's private trait
-                        // provides cannot be called here, whatever the
-                        // receiver turns out to be.
-                        if called && let Some(trait_name) = self.only_private_provider(field) {
-                            self.private_method(trait_name, field, span);
-                            expr.ty = Some(Type::Error);
-                            return Type::Error;
-                        }
                         if called {
-                            // `x.m(..)`: what it calls is decided with
+                            // `x.f(..)`: what it calls is decided with
                             // the type of `x` (`check_call`).
                             self.unknown_receiver = Some((obj_ty.clone(), field));
                             self.fresh_var()
                         } else {
-                            // `x.f`: a record with the field `f`,
-                            // whatever methods traits declare.
+                            // `x.f`: a record with the field `f`.
                             let result_ty = self.fresh_var();
                             let row_ty = Type::AnonRecord {
                                 fields: std::collections::BTreeMap::from([(
@@ -2641,19 +2563,13 @@ impl TypeChecker {
                             result_ty
                         }
                     }
-                    Type::Error => {
+                    Type::Error | Type::Never => {
                         // Prior error — propagate to prevent cascading false positives
                         Type::Error
                     }
+                    // Any other type has no fields.
                     _ => {
-                        self.error(
-                            Code::UnknownField,
-                            format!(
-                                "unknown field or method '{field}' on type {}",
-                                self.show_type(&obj_ty)
-                            ),
-                            span,
-                        );
+                        self.no_field(&obj_ty, field, Some(obj), &[], span);
                         Type::Error
                     }
                 }
diff --git a/src/typechecker/inference/tests.rs b/src/typechecker/inference/tests.rs
index 512df65db..46dd79c93 100644
--- a/src/typechecker/inference/tests.rs
+++ b/src/typechecker/inference/tests.rs
@@ -319,11 +319,14 @@ fn test_trait_constraint_method_resolved() {
     // A constrained type variable should allow calling trait methods
     assert_no_errors(
         r#"
-trait Display for a {
-  fn display(self) -> String { "?" }
+trait Shown {
+  fn shown(self) -> String
 }
-fn show(x: a) -> String where a: Display {
-  x.display()
+trait Shown for Int {
+  fn shown(self) -> String { "?" }
+}
+fn show(x: a) -> String where a: Shown {
+  Shown.shown(x)
 }
 fn main() { show(42) }
         "#,
@@ -332,18 +335,15 @@ fn main() { show(42) }
 
 #[test]
 fn test_trait_constraint_unknown_method_errors() {
-    // A constrained type variable should NOT allow calling methods not in the trait
+    // A value of a constrained type variable has no fields
     assert_has_error(
         r#"
-trait Display for a {
-  fn display(self) -> String { "?" }
-}
 fn show(x: a) -> String where a: Display {
   x.nonexistent()
 }
 fn main() { show(42) }
         "#,
-        "no method 'nonexistent' found in trait constraints",
+        "type 'a' has no field 'nonexistent'",
     );
 }
 
diff --git a/src/typechecker/init_order.rs b/src/typechecker/init_order.rs
index ccf16f8a1..dad4b982b 100644
--- a/src/typechecker/init_order.rs
+++ b/src/typechecker/init_order.rs
@@ -48,8 +48,8 @@
 //!
 //! 4. A `Display` impl the formatter calls. Showing a value
 //!    (interpolation, a builtin whose signature asks `Display` of its
-//!    argument, called or handed on as a value, and `.display()` on a
-//!    type with no impl of its own) calls the written `Display` impl of
+//!    argument, called or handed on as a value) calls the written
+//!    `Display` impl of
 //!    every part of the value that has one. The parts a value of a type
 //!    can have are the type's: its arguments, and, for a record or an
 //!    enum of the module, the types of its fields, and theirs. Showing
@@ -118,7 +118,7 @@ struct Node<'a> {
 const OUTSIDE: usize = 0;
 
 /// Whether a value of the type `ty` is made of builtin types only, all
-/// known: a builtin trait's method on it (`[1, 2].display()`) calls no
+/// known: a builtin trait's method on it (`Hash.hash([1, 2])`) calls no
 /// code a program writes.
 fn builtin_through(checker: &TypeChecker, ty: &Type) -> bool {
     let all = |parts: &[Type]| parts.iter().all(|t| builtin_through(checker, t));
@@ -608,11 +608,17 @@ impl TypeChecker {
                     kind: ExprKind::FieldAccess(recv, method, _),
                     sel,
                     res,
+                    span,
                     ..
                 }) = mention.expr
                 else {
                     return;
                 };
+                // The type the method is of: the receiver's, or, called
+                // through the trait (`Hash.hash(x)`), the type its
+                // argument of type `Self` has.
+                let recv_ty: Option<Type> = (recv.ty.clone())
+                    .or_else(|| self.trait_call_self.get(span).map(|t| self.apply(t)));
                 // The method of the impl of `tr` for `ty`: the impl's
                 // own, the trait's default, or code outside the module
                 // (but a builtin trait's method on a value, of the type
@@ -632,27 +638,26 @@ impl TypeChecker {
                     }
                 };
                 match sel {
-                    Some(Selection::Impl { tr, ty }) => one_impl(*tr, *ty, recv.ty.as_ref()),
+                    Some(Selection::Impl { tr, ty }) => one_impl(*tr, *ty, recv_ty.as_ref()),
                     // A receiver decided where the code runs: every
                     // impl of the method in the module, the trait's
                     // default, and, for a trait of another module or a
                     // builtin one, impls and defaults outside it.
-                    // (`display` of such a receiver shows it, `encode`
-                    // writes it, `decode` of a type decodes into it.)
-                    Some(Selection::Dynamic { tr })
-                        if [display, encode, decode]
+                    // (`encode` of such a receiver writes it, `decode` of
+                    // a type decodes into it.)
+                    Some(Selection::Dynamic { tr, .. })
+                        if [encode, decode]
                             .iter()
                             .any(|t| t.id == *tr && *method == method_of(*t))
-                            && recv.ty.is_some() =>
+                            && recv_ty.is_some() =>
                     {
-                        if let Some(ty) = &recv.ty
-                            && let Some(tr) =
-                                [display, encode, decode].into_iter().find(|t| t.id == *tr)
+                        if let Some(ty) = &recv_ty
+                            && let Some(tr) = [encode, decode].into_iter().find(|t| t.id == *tr)
                         {
                             show(tr, ty);
                         }
                     }
-                    Some(Selection::Dynamic { tr }) => {
+                    Some(Selection::Dynamic { tr, .. }) => {
                         for &target in of_trait.get(&(*tr, *method)).into_iter().flatten() {
                             add(target);
                         }
@@ -660,20 +665,19 @@ impl TypeChecker {
                             add(OUTSIDE);
                         }
                     }
-                    // The VM's own method of a builtin trait: `display`
-                    // shows the receiver, `encode` writes it, `decode` of
-                    // a type decodes into it; the others call no code a
-                    // program writes.
+                    // The VM's own method of a builtin trait: `encode`
+                    // writes the receiver, `decode` of a type decodes into
+                    // it; the others call no code a program writes.
                     Some(Selection::Native { tr }) => {
-                        if let Some(ty) = &recv.ty
-                            && let Some(tr) =
-                                [display, encode, decode].into_iter().find(|t| t.id == *tr)
+                        if let Some(ty) = &recv_ty
+                            && let Some(tr) = [encode, decode].into_iter().find(|t| t.id == *tr)
                         {
                             show(tr, ty);
                         }
                     }
                     Some(Selection::Field | Selection::FieldCall) => {}
-                    // `Type.method`: that impl's method.
+                    // `Type.method`, a method that makes a value: that
+                    // impl's method.
                     None => {
                         if recv.ty.is_none()
                             && let Some(crate::defs::Res::Def(id)) = res
@@ -686,7 +690,7 @@ impl TypeChecker {
                             match ty {
                                 Some(ty) => {
                                     let ty = canonical_head(&self.tables.resolver, ty);
-                                    // (`Int.display`: a type without
+                                    // (`Int.empty`: a type without
                                     // parameters is all of the value's.)
                                     let whole = Type::Generic(ty, Vec::new());
                                     let of = matches!(
diff --git a/src/typechecker/mod.rs b/src/typechecker/mod.rs
index 9aa4d28b2..1970d3d79 100644
--- a/src/typechecker/mod.rs
+++ b/src/typechecker/mod.rs
@@ -187,7 +187,8 @@ pub struct TypeChecker {
     /// to a builtin, which a use of it then names in a note.
     pub(super) passing_on: Option<Symbol>,
     /// Whether the expression checked next is the callee of a call:
-    /// `x.m` there is a method call, anywhere else a field.
+    /// `x.f` there is a call of the function a field holds, which waits
+    /// for the type of `x` (`unknown_receiver`).
     pub(super) callee_position: bool,
     /// The receiver and the name of the callee just checked, when it is
     /// `x.m` and the type of `x` is unknown: `check_call` lets the call
@@ -282,21 +283,23 @@ pub struct TypeChecker {
     /// its body sees it, by the impl's type, the method and the trait,
     /// until the body is checked.
     pub(super) impl_sigs: HashMap<(TypeRef, Symbol, TraitKey), FnSig>,
-    /// Set by the FieldAccess arm of infer_expr: `true` when the last
-    /// FieldAccess resolved via method dispatch (trait method table),
-    /// `false` when it resolved via record-field or module-qualified
-    /// lookup.  Read by the Call arm immediately after inferring the
-    /// callee to decide arity semantics (method call adds implicit self;
-    /// field/module calls do not).
-    pub(super) last_field_access_was_method: bool,
+    /// Set by the inference of a call through a trait (`Greet.greet(x)`)
+    /// whose argument of type `Self` was checked with the callee
+    /// (`trait_receiver`): read by `check_call` right after the callee,
+    /// the call's other arguments line up with the method's parameters
+    /// after that one.
+    pub(super) receiver_taken: bool,
     /// The trait whose method the field access being inferred calls,
     /// which `infer_expr` records on the access (`Expr::res`): the
     /// compiler keys the call by it.
     pub(super) method_trait: Option<TraitKey>,
-    /// The traits of the method calls resolved in the deferred pass, by
-    /// the span of the access; `resolve_all_types` records each on its
-    /// access.
-    pub(super) deferred_method_traits: HashMap<Span, TraitKey>,
+    /// The type each call through a trait (`Greet.greet(x)`) gives the
+    /// trait's `Self`, by the span of the access: the impl the call
+    /// reaches is the one for that type (`resolve_all_types`).
+    pub(super) trait_call_self: HashMap<Span, Type>,
+    /// The argument of type `Self` of the call through a trait whose
+    /// callee is being inferred, with its place (`check_call`).
+    pub(super) trait_receiver: Option<(Type, Span)>,
     /// The traits the module names by its imports (`import m.{ T }`),
     /// and the modules it imports: their traits it sees too.
     pub(super) seen_traits: std::collections::HashSet<crate::defs::DefId>,
@@ -436,9 +439,10 @@ impl TypeChecker {
             let_order: Vec::new(),
             let_rings: Vec::new(),
             impl_sigs: HashMap::new(),
-            last_field_access_was_method: false,
+            receiver_taken: false,
             method_trait: None,
-            deferred_method_traits: HashMap::new(),
+            trait_call_self: HashMap::new(),
+            trait_receiver: None,
             seen_traits: std::collections::HashSet::new(),
             seen_modules: std::collections::HashSet::new(),
             builtin_imports: std::collections::HashSet::new(),
@@ -1453,64 +1457,6 @@ pub struct ModuleCheck {
     pub let_order: Vec<Span>,
 }
 
-/// For the module `module`, checked, with every other module of its
-/// program: at each place it reported that a type has no method of
-/// some name, the help that names a trait with such a method for the
-/// type whose module `module` does not reach (`reach`: the modules it
-/// imports, and theirs, and so on). It is made from the whole program's
-/// impls, so it does not depend on the order the modules were checked
-/// in. A module that itself imports `module` (`imports_back`) cannot be
-/// imported by it: the help then says where the trait would have to be.
-pub fn out_of_reach_helps(
-    tables: &Tables,
-    defs: &crate::defs::DefTable,
-    module: crate::session::ModuleId,
-    reach: &std::collections::HashSet<crate::session::ModuleId>,
-    imports_back: impl Fn(crate::session::ModuleId) -> bool,
-) -> Vec<(Span, String)> {
-    let mut helps = Vec::new();
-    for (span, ty, method) in tables.unknown_methods.get(&module).into_iter().flatten() {
-        let mut found: Vec<(String, String, bool)> = tables
-            .impl_methods
-            .providers(*ty, *method)
-            .iter()
-            .filter_map(|t| {
-                let owner = defs.get(t.id.0).module;
-                let private = tables
-                    .traits
-                    .get(t)
-                    .is_some_and(|info| info.private_to.is_some());
-                if owner == module || owner.is_builtin() || reach.contains(&owner) || private {
-                    return None;
-                }
-                let name = tables.module_names.get(&owner)?;
-                Some((resolve(t.name), resolve(*name), imports_back(owner)))
-            })
-            .collect();
-        // (A module that can be imported first.)
-        found.sort_by(|a, b| (a.2, &a.0, &a.1).cmp(&(b.2, &b.0, &b.1)));
-        match found.first() {
-            Some((tr, owner, false)) => helps.push((
-                *span,
-                format!(
-                    "trait '{tr}' of module '{owner}' has a method '{method}' for this type; \
-                     import '{owner}' to call it"
-                ),
-            )),
-            Some((tr, owner, true)) => helps.push((
-                *span,
-                format!(
-                    "trait '{tr}' of module '{owner}' has a method '{method}' for this type, \
-                     but '{owner}' imports this module and cannot be imported by it; the \
-                     trait would have to be declared in a module this one can import"
-                ),
-            )),
-            None => {}
-        }
-    }
-    helps
-}
-
 /// The context a module is checked in, from the session.
 pub struct ModuleContext<'a> {
     /// The module checked.
diff --git a/src/typechecker/names.rs b/src/typechecker/names.rs
index e0caf16d2..0939f8b37 100644
--- a/src/typechecker/names.rs
+++ b/src/typechecker/names.rs
@@ -345,6 +345,19 @@ pub fn resolve_module(
             scope.types.entry(*name).or_insert(Binding::Poisoned);
         }
     }
+    // The trait of an impl that names no trait is reported at the impl;
+    // a call through the trait is not reported again.
+    for decl in &program.decls {
+        if let Decl::TraitImpl(ti) = decl
+            && ti.trait_module.is_none()
+            && !scope.values.contains_key(&ti.trait_name)
+            && !scope.types.contains_key(&ti.trait_name)
+            && !builtins.prelude.values.contains_key(&ti.trait_name)
+            && !builtins.prelude.types.contains_key(&ti.trait_name)
+        {
+            scope.values.insert(ti.trait_name, Binding::Poisoned);
+        }
+    }
     let mut resolver = Resolver {
         defs,
         kind,
diff --git a/src/typechecker/resolve.rs b/src/typechecker/resolve.rs
index bf29c7bee..d2a9500d6 100644
--- a/src/typechecker/resolve.rs
+++ b/src/typechecker/resolve.rs
@@ -530,12 +530,6 @@ impl TypeChecker {
             if let Some(ty) = &expr.ty {
                 expr.ty = Some(self.apply(ty));
             }
-            // A method call resolved in the deferred pass: its trait.
-            if matches!(expr.kind, ExprKind::FieldAccess(..))
-                && let Some(t) = self.deferred_method_traits.get(&expr.span)
-            {
-                expr.res = Some(crate::defs::Res::Def(t.id.0));
-            }
             self.select(expr);
         });
     }
@@ -558,8 +552,20 @@ impl TypeChecker {
                     right.sel = Some(Selection::FieldCall);
                 }
             }
-            ExprKind::FieldAccess(recv, _, _) => {
+            ExprKind::FieldAccess(recv, field, _) => {
                 let called = expr.sel.take().is_some();
+                // `Tr.m`: the method of the impl for the type the call
+                // gives `Self`.
+                if let Some(self_ty) = self.trait_call_self.get(&expr.span)
+                    && let Some(crate::defs::Res::Def(id)) = expr.res
+                    && let Some(tr) = self.trait_key(id)
+                {
+                    // (The receiver is the argument of type `Self`.)
+                    let at = self.self_param(tr, *field).unwrap_or(0);
+                    let at = u8::try_from(at).unwrap_or(u8::MAX);
+                    expr.sel = Some(self.method_selection(tr, self_ty, at));
+                    return;
+                }
                 // A receiver the checker gave no type is a name: a
                 // module, a type (`m.f`, `Shape.Circle`, `Pt.make`).
                 let Some(recv_ty) = &recv.ty else {
@@ -570,7 +576,7 @@ impl TypeChecker {
                     _ => None,
                 };
                 expr.sel = Some(match tr {
-                    Some(tr) => self.method_selection(tr, recv_ty),
+                    Some(tr) => self.method_selection(tr, recv_ty, 0),
                     None if called => Selection::FieldCall,
                     None => Selection::Field,
                 });
@@ -580,17 +586,17 @@ impl TypeChecker {
     }
 
     /// What a call of a method of the trait `tr` on a receiver of the
-    /// type `recv` runs.
-    fn method_selection(&self, tr: TraitKey, recv: &Type) -> crate::ast::Selection {
+    /// type `recv`, the argument `at` of the call, runs.
+    fn method_selection(&self, tr: TraitKey, recv: &Type, at: u8) -> crate::ast::Selection {
         use crate::ast::Selection;
         let recv = crate::types::canonical::canonicalize(&self.tables.resolver, &self.apply(recv));
         match &recv {
             Type::Var(_) | Type::Rigid(_) | Type::Error | Type::Never => {
-                Selection::Dynamic { tr: tr.id }
+                Selection::Dynamic { tr: tr.id, at }
             }
             // A type passed as a value: the method of the type it is.
             Type::Generic(name, _) if name.is_builtin(crate::defs::TYPE_OF) => {
-                Selection::Dynamic { tr: tr.id }
+                Selection::Dynamic { tr: tr.id, at }
             }
             // A trait the type has by its structure (the sealed three,
             // `Display` with no written impl) is the VM's own method;
diff --git a/src/typechecker/scheme.rs b/src/typechecker/scheme.rs
index e85afa470..7eb29a919 100644
--- a/src/typechecker/scheme.rs
+++ b/src/typechecker/scheme.rs
@@ -65,7 +65,7 @@ impl TypeChecker {
         // trait.)
         self.decide_tries();
         self.default_rebuilds();
-        self.default_selects(true);
+        self.default_selects();
         for i in self.closed_mark..self.wanted.len() {
             if self.wanted[i].solved {
                 continue;
diff --git a/src/typechecker/size_locks.rs b/src/typechecker/size_locks.rs
index ce80976b7..208910686 100644
--- a/src/typechecker/size_locks.rs
+++ b/src/typechecker/size_locks.rs
@@ -35,8 +35,8 @@ fn record_info_size_locked() {
 fn trait_info_size_locked() {
     // Stage 5 shrank its spans from 24 to 12 bytes; stage 6 added `self_var`,
     // `var_names` and `method_bounds`, which a default body and an impl
-    // are checked with, and `receivers`, which says where `x.m(..)` may
-    // call a method. `builtin_needs` and `via_needs`: what the default
+    // are checked with, and `receivers`, which says where an impl's
+    // method writes `self`. `builtin_needs` and `via_needs`: what the default
     // bodies ask of their annotation variables for the builtins and the
     // trait methods they give them to.
     assert_eq!(
diff --git a/src/typechecker/solve.rs b/src/typechecker/solve.rs
index 5b5988978..135142459 100644
--- a/src/typechecker/solve.rs
+++ b/src/typechecker/solve.rs
@@ -25,9 +25,9 @@ pub(crate) enum Goal {
     /// A predicate a use owes.
     Pred(Pred),
     /// `recv.name(args)`, with the result `result`, where the receiver's
-    /// type was unknown at the call: which method or function-typed
-    /// field it calls is decided when the receiver's type is (`select`),
-    /// and when the definition is generalised if it still is not.
+    /// type was unknown at the call: the function-typed field it calls
+    /// is checked when the receiver's type is known (`select_call`), and
+    /// when the definition is generalised if it still is not.
     Select {
         recv: Type,
         name: Symbol,
@@ -377,59 +377,8 @@ impl TypeChecker {
         }
     }
 
-    /// A method call whose receiver was a type variable when it was
-    /// inferred and is the type `type_name` now: `true` when the type has
-    /// the method. The call's trait is recorded by its span
-    /// (`deferred_method_traits`), which `resolve_all_types` writes on
-    /// the access; a call that sees the method in two traits is
-    /// ambiguous, as anywhere.
-    pub(super) fn deferred_method_call(
-        &mut self,
-        type_name: TypeRef,
-        field: Symbol,
-        obj_ty: &Type,
-        result_ty: &Type,
-        span: Span,
-    ) -> bool {
-        let Some(entry) = self.method_entry(type_name, field, false) else {
-            return false;
-        };
-        let instantiated = self.dispatch_method_entry(&entry, field, obj_ty, span);
-        if let Some(t) = self.method_trait.take() {
-            self.deferred_method_traits.insert(span, t);
-        }
-        let method_ty = self.apply(&instantiated);
-        self.unify_deferred_method(result_ty, &method_ty, span);
-        true
-    }
-
-    /// Unify the type a method call on an unknown receiver was given
-    /// (`result_ty`) with the method it turned out to call.
-    ///
-    /// Method types include `self` as the first param. When the call
-    /// site originally saw this field access as an unknown Var, it
-    /// unified the var with a function type built from the *explicit*
-    /// args only (no receiver). Strip `self` when adapting.
-    pub(super) fn unify_deferred_method(&mut self, result_ty: &Type, method_ty: &Type, span: Span) {
-        let result_resolved = self.apply(result_ty);
-        match (&result_resolved, method_ty) {
-            (Type::Fun(call_params, call_ret), Type::Fun(method_params, method_ret))
-                if method_params.len() == call_params.len() + 1 =>
-            {
-                for (cp, mp) in call_params.iter().zip(method_params.iter().skip(1)) {
-                    self.unify(cp, mp, span);
-                }
-                self.unify(call_ret, method_ret, span);
-            }
-            _ => {
-                self.unify(result_ty, method_ty, span);
-            }
-        }
-    }
-
     /// Decide what `recv.field(args)` calls, now that the receiver's type
-    /// is known: a method of the type (its impls, or the bounds of an
-    /// annotation variable), or the function a field of the record holds.
+    /// is known: the function a field of the record holds.
     fn select_call(
         &mut self,
         recv: &Type,
@@ -438,21 +387,12 @@ impl TypeChecker {
         result: Type,
         span: Span,
     ) {
-        let obj_ty = recv.clone();
         let result_ty = Type::Fun(args, Box::new(result));
         let resolved =
             crate::types::canonical::canonicalize(&self.tables.resolver, &self.apply(recv));
         match &resolved {
             Type::Error | Type::Never => {}
             Type::Var(_) => unreachable!("a selection waits while its receiver is unknown"),
-            // The receiver became an annotation variable: it has the
-            // methods of its bounds, and nothing else.
-            Type::Rigid(r) => {
-                if let Some((trait_name, method_ty)) = self.bound_method(*r, field, span) {
-                    self.deferred_method_traits.insert(span, trait_name);
-                    self.unify_deferred_method(&result_ty, &method_ty, span);
-                }
-            }
             Type::AnonRecord { fields: af, tail } => {
                 if let Some(field_ty) = af.get(&field) {
                     let ft = field_ty.clone();
@@ -464,17 +404,9 @@ impl TypeChecker {
                     };
                     self.unify(&resolved, &extended, span);
                 } else {
-                    // ERR-GAP (round 81 F2): match the sibling Record /
-                    // Generic deferred sites and append a did-you-mean
-                    // hint when a near-edit-distance field exists.
                     let candidates: Vec<(Symbol, Type)> =
                         af.iter().map(|(k, v)| (*k, v.clone())).collect();
-                    let base = format!("anon record has no field '{field}'");
-                    self.error_help(
-                        Code::NoSuchField,
-                        format_record_field_suggestion(base, field, &candidates),
-                        span,
-                    );
+                    self.no_field(&resolved, field, None, &candidates, span);
                 }
             }
             Type::Generic(type_name, type_args) => {
@@ -513,47 +445,13 @@ impl TypeChecker {
                     self.unify(&result_ty, &field_ty, span);
                     return;
                 }
-                // Also check the method table for trait methods.
-                if self.deferred_method_call(type_name, field, &obj_ty, &result_ty, span) {
-                    return;
-                }
-                // A method of a structural trait the type has no entry
-                // for.
-                if let Some(method_ty) = self.structural_method(&obj_ty, field, false, span) {
-                    self.last_field_access_was_method = false;
-                    if let Some(t) = self.method_trait.take() {
-                        self.deferred_method_traits.insert(span, t);
-                    }
-                    self.unify_deferred_method(&result_ty, &method_ty, span);
-                    return;
-                }
-                // GAP (round 35 F7): thread did-you-mean suggestion
-                // through the Generic/named-record deferred path.
-                let shown = self.show_type(&Type::Generic(type_name, vec![]));
-                let base = format!("unknown field or method '{field}' on type {shown}");
-                let msg = if let Some(rec_info) = self.tables.records.get(&type_name) {
-                    format_record_field_suggestion(base, field, &rec_info.fields)
-                } else {
-                    (base, None)
-                };
-                self.error_help(Code::UnknownField, msg, span);
-            }
-            // A builtin type (`Int`, `List`, ...): its trait methods.
-            _ => {
-                if let Some(type_name) = self.type_name_for_impl(&resolved)
-                    && self.deferred_method_call(type_name, field, &obj_ty, &result_ty, span)
-                {
-                    return;
-                }
-                self.error(
-                    Code::UnknownField,
-                    format!(
-                        "unknown field or method '{field}' on type {}",
-                        self.show_type(&resolved)
-                    ),
-                    span,
-                );
+                let fields = (self.tables.records.get(&type_name))
+                    .map(|rec| rec.fields.clone())
+                    .unwrap_or_default();
+                self.no_field(&resolved, field, None, &fields, span);
             }
+            // Any other type has no fields.
+            _ => self.no_field(&resolved, field, None, &[], span),
         }
     }
 
@@ -1161,14 +1059,10 @@ impl TypeChecker {
         self.close_level();
     }
 
-    /// Decide each call `x.m(args)` of the scope just left whose
-    /// receiver is still unknown and is the scope's to generalise. When
-    /// exactly one trait the module sees declares a method `m`, the call
-    /// is that method's and `x` is bounded by the trait
-    /// (`fn g(x) { x.greet() }` is `a -> String where a: Greet`). When
-    /// none does, `x` is a record with a function in its field `m`. When
-    /// several do, the receiver needs an annotation.
-    pub(super) fn default_selects(&mut self, wait_if_several: bool) {
+    /// Decide each call `x.f(args)` of the scope just left whose
+    /// receiver is still unknown and is the scope's to generalise: `x` is
+    /// a record with a function in its field `m`.
+    pub(super) fn default_selects(&mut self) {
         let mine: Vec<usize> = (self.closed_mark..self.wanted.len())
             .filter(|&i| {
                 !self.wanted[i].solved
@@ -1193,9 +1087,7 @@ impl TypeChecker {
                 continue;
             };
             // (An earlier one of these may have decided this receiver.)
-            if matches!(self.apply(&recv), Type::Var(_))
-                && !(wait_if_several && self.traits_declaring(name).len() > 1)
-            {
+            if matches!(self.apply(&recv), Type::Var(_)) {
                 self.wanted[i].solved = true;
                 let call_ty = Type::Fun(args, Box::new(result));
                 self.default_select(&recv, name, call_ty, origin.span);
@@ -1205,127 +1097,14 @@ impl TypeChecker {
         self.close_level();
     }
 
-    /// The traits in sight that declare a method `name` a call on a
-    /// value may mean (`on_a_value`), in the order of their names.
-    fn traits_declaring(&self, name: Symbol) -> Vec<TraitKey> {
-        let mut traits: Vec<TraitKey> = self
-            .tables
-            .traits
-            .iter()
-            .filter(|(_, info)| info.methods.iter().any(|(n, _)| *n == name))
-            .map(|(t, _)| *t)
-            .filter(|t| self.sees_trait(*t))
-            .collect();
-        traits.sort_by_key(|t| self.show_trait(*t));
-        self.on_a_value(traits, |t| *t, name)
-    }
-
-    /// Of `candidates` (each of the trait `trait_of` says) for a call of
-    /// `method` on a value, those the call may mean: a method without
-    /// `self` is never one, of any trait. Where none takes `self`, the
-    /// first alone, which the call reports as taking none.
-    pub(super) fn on_a_value<C>(
-        &self,
-        mut candidates: Vec<C>,
-        trait_of: impl Fn(&C) -> TraitKey,
-        method: Symbol,
-    ) -> Vec<C> {
-        let takes_self = |c: &C| {
-            (self.tables.traits.get(&trait_of(c)))
-                .is_none_or(|info| info.receivers.contains(&method))
-        };
-        match candidates.iter().any(takes_self) {
-            true => candidates.retain(takes_self),
-            false => candidates.truncate(1),
-        }
-        candidates
-    }
-
+    /// `x.name(..)` whose receiver nothing decided: `x` is a record with
+    /// a function of the call's type in its field `name`.
     fn default_select(&mut self, recv: &Type, name: Symbol, call_ty: Type, span: Span) {
-        let traits = self.traits_declaring(name);
-        match traits.as_slice() {
-            [] => {
-                let row = Type::AnonRecord {
-                    fields: std::collections::BTreeMap::from([(name, call_ty)]),
-                    tail: RowTail::Var(self.fresh_tyvar_id()),
-                };
-                self.unify(recv, &row, span);
-            }
-            [tr] => {
-                let info = self.tables.traits[tr].clone();
-                let (_, method_ty) = info
-                    .methods
-                    .iter()
-                    .find(|(n, _)| *n == name)
-                    .expect("the trait declares the method");
-                // A method without `self` is not what a value's `.{name}`
-                // calls, and says nothing of the receiver.
-                let receiver = info.receivers.contains(&name);
-                let on_type = on_type_call("SomeType", name, method_ty);
-                if self.takes_no_self(receiver, name, &on_type, span) {
-                    return;
-                }
-                // The trait's parameters are what the receiver's impl
-                // will say; the method's own variables are new.
-                let mut mapping: HashMap<TyVar, Type> = HashMap::new();
-                mapping.insert(info.self_var, recv.clone());
-                let params: Vec<Type> = info
-                    .param_var_ids
-                    .iter()
-                    .map(|v| {
-                        let fresh = self.fresh_var();
-                        mapping.insert(*v, fresh.clone());
-                        fresh
-                    })
-                    .collect();
-                let ty = substitute_vars(method_ty, &mapping);
-                // (And what the method of the receiver's impl asks.)
-                let preds: Vec<Pred> = info
-                    .method_bounds
-                    .get(&name)
-                    .into_iter()
-                    .flatten()
-                    .map(|pred| pred.substitute(&mapping))
-                    .chain([Pred::Via {
-                        tr: *tr,
-                        method: name,
-                        receiver: recv.clone(),
-                        method_ty: ty.clone(),
-                        passer: None,
-                        at: None,
-                    }])
-                    .collect();
-                let own: Vec<TyVar> = free_vars_in(method_ty)
-                    .into_iter()
-                    .filter(|v| !mapping.contains_key(v))
-                    .collect();
-                let scheme = Scheme {
-                    vars: own,
-                    preds,
-                    ty,
-                };
-                let origin = Origin {
-                    span,
-                    callee: Some(name),
-                    op: None,
-                };
-                self.want(
-                    Pred::Trait {
-                        tr: *tr,
-                        args: params,
-                        subject: recv.clone(),
-                        asker: None,
-                    },
-                    origin,
-                );
-                let method_ty = self.instantiate_method(&scheme, name, span);
-                self.deferred_method_traits.insert(span, *tr);
-                self.unify_deferred_method(&call_ty, &method_ty, span);
-            }
-            several => {
-                self.ambiguous_method(name, "a value whose type is not known", several, span);
-            }
-        }
+        let row = Type::AnonRecord {
+            fields: std::collections::BTreeMap::from([(name, call_ty)]),
+            tail: RowTail::Var(self.fresh_tyvar_id()),
+        };
+        self.unify(recv, &row, span);
     }
 
     /// Report that `method`, called on `on` (`type 'Int'`, `a value
@@ -2466,40 +2245,35 @@ impl TypeChecker {
         self.builtin_imports.contains(&module) || self.seen_traits.contains(&t.id.0)
     }
 
-    /// The traits that give the type `ty` a method `method`, in the
-    /// order of their names: those of the session's impls, and the
-    /// structural trait whose method it is when no impl of that trait
-    /// is written for the type, for a call through the type (`on_type`,
-    /// `T.method(..)`) or on a value (`on_a_value`).
-    fn method_providers(&self, ty: TypeRef, method: Symbol, on_type: bool) -> Vec<TraitKey> {
+    /// The traits that give the type `ty` a method `method` for a call
+    /// through the type (`T.method(..)`), in the order of their names:
+    /// those of the session's impls, and the structural trait whose
+    /// method it is when no impl of that trait is written for the type.
+    pub(super) fn method_providers(&self, ty: TypeRef, method: Symbol) -> Vec<TraitKey> {
         let mut traits = self.tables.impl_methods.providers(ty, method).to_vec();
-        if let Some(tr) = self.structural_provider(ty, method, on_type)
+        if let Some(tr) = self.structural_provider(ty, method)
             && !traits.contains(&tr)
         {
             traits.push(tr);
         }
         traits.sort_by_key(|t| self.show_trait(*t));
-        match on_type {
-            true => traits,
-            false => self.on_a_value(traits, |t| *t, method),
-        }
+        // Through the type, a method that makes a value: one that takes
+        // a value of the type is called through its trait, so it is no
+        // candidate where another trait gives the type a method of the
+        // name that makes one.
+        if traits.iter().any(|t| self.self_param(*t, method).is_none()) {
+            traits.retain(|t| self.self_param(*t, method).is_none());
+        }
+        traits
     }
 
     /// The structural trait whose method `method` the type `ty` has by
     /// its structure: one of their names, of a type that has the name
     /// (`Tables::has_structural_name`) and no written impl of the trait.
-    /// A structural method that takes no `self` (`decode`) is no method
-    /// of a call on a value (not `on_type`): such a call means another
-    /// trait's method of the name, if one has it.
-    fn structural_provider(&self, ty: TypeRef, method: Symbol, on_type: bool) -> Option<TraitKey> {
+    fn structural_provider(&self, ty: TypeRef, method: Symbol) -> Option<TraitKey> {
         let name = resolve(method);
         let (tr_name, _) = STRUCTURAL_METHODS.iter().find(|(_, m)| *m == name)?;
         let tr = TraitKey::builtin(tr_name);
-        let takes_self =
-            (self.tables.traits.get(&tr)).is_none_or(|info| info.receivers.contains(&method));
-        if !on_type && !takes_self {
-            return None;
-        }
         (self.tables.has_structural_name(tr, ty)
             && self.by_structure(tr, ty)
             && self.unreached(tr).is_none())
@@ -2536,13 +2310,8 @@ impl TypeChecker {
     /// reach by its imports it has not. It is decided from the impls'
     /// rows each time. (For a call that is ambiguous the first
     /// candidate's: `ambiguous_method_call` reports it.)
-    pub(super) fn method_entry(
-        &self,
-        ty: TypeRef,
-        method: Symbol,
-        on_type: bool,
-    ) -> Option<MethodEntry> {
-        let providers = self.method_providers(ty, method, on_type);
+    pub(super) fn method_entry(&self, ty: TypeRef, method: Symbol) -> Option<MethodEntry> {
+        let providers = self.method_providers(ty, method);
         let tr = match self.meant_provider(&providers) {
             Ok(tr) => tr?,
             Err(candidates) => candidates[0],
@@ -2558,59 +2327,20 @@ impl TypeChecker {
                 method_type: Type::Error,
                 structural: true,
                 trait_name: None,
-                receiver: true,
                 preds: Vec::new(),
             }),
         }
     }
 
-    /// Whether a value of the type `ty` has a method `method`, whatever
-    /// the module checked may call.
-    pub(super) fn has_method(&self, ty: TypeRef, method: Symbol) -> bool {
-        !self.method_providers(ty, method, false).is_empty()
-    }
-
-    /// The names of the methods of the type `ty`.
-    pub(super) fn method_names(&self, ty: TypeRef) -> Vec<Symbol> {
-        let mut names: Vec<Symbol> = self
-            .tables
-            .impl_methods
-            .keys()
-            .filter(|(of, _, _)| *of == ty)
-            .map(|(_, method, _)| *method)
-            .collect();
-        for (_, method) in STRUCTURAL_METHODS {
-            let method = intern(method);
-            if self.structural_provider(ty, method, false).is_some() {
-                names.push(method);
-            }
-        }
-        names.sort();
-        names.dedup();
-        names
-    }
-
-    /// Keep that the type `ty` was reported at `span` to have no method
-    /// `method`: a trait of a module that is not imported may have one,
-    /// which is known once the whole program is checked.
-    pub(super) fn note_unknown_method(&mut self, span: Span, ty: TypeRef, method: Symbol) {
-        self.tables
-            .unknown_methods
-            .entry(self.module)
-            .or_default()
-            .push((span, ty, method));
-    }
-
     /// Whether a call of `method` of `ty` is ambiguous here; if so, it is
     /// reported at `span`.
     pub(super) fn ambiguous_method_call(
         &mut self,
         ty: TypeRef,
         method: Symbol,
-        on_type: bool,
         span: Span,
     ) -> bool {
-        let providers = self.method_providers(ty, method, on_type);
+        let providers = self.method_providers(ty, method);
         let Err(traits) = self.meant_provider(&providers) else {
             return false;
         };
@@ -2618,16 +2348,13 @@ impl TypeChecker {
         self.ambiguous_method(method, &on, &traits, span);
         // Called through the type (`T.decode(v)`), there is no receiver
         // to annotate: a function bounded by the trait says which (a
-        // program's trait where one is among them, `Pretty` over `Display`).
-        if on_type {
-            let named = (traits.iter())
-                .find(|t| crate::defs::builtin_trait_of_id(t.id.0).is_none())
-                .or(traits.first())
-                .map(|t| self.show_trait(*t))
-                .unwrap_or_default();
-            let Some(last) = self.errors.last_mut() else {
-                return true;
-            };
+        // program's trait where one is among them).
+        let named = (traits.iter())
+            .find(|t| crate::defs::builtin_trait_of_id(t.id.0).is_none())
+            .or(traits.first())
+            .map(|t| self.show_trait(*t))
+            .unwrap_or_default();
+        if let Some(last) = self.errors.last_mut() {
             last.help = vec![format!(
                 "say which is meant: call it through a function bounded by the trait you mean, \
                  `where a: {named}`"
diff --git a/src/typechecker/tables.rs b/src/typechecker/tables.rs
index 1ec8ced1d..5b10b1cbb 100644
--- a/src/typechecker/tables.rs
+++ b/src/typechecker/tables.rs
@@ -47,8 +47,8 @@ pub(super) struct TraitInfo {
     /// Implementing this trait on a type requires every supertrait to also
     /// be implemented for the same type (validated in
     /// `validate_trait_impls`). `expand_with_supertraits` walks this list
-    /// transitively to enable supertrait method calls inside `where`
-    /// clauses.
+    /// transitively, so a `where` bound gives its supertraits' bounds
+    /// too.
     pub(super) supertraits: Vec<TraitKey>,
     /// Parallel to `supertraits`: the TypeExpr args supplied to each
     /// supertrait reference. For `trait Sub(a): Super(a)` the entry for
@@ -62,9 +62,8 @@ pub(super) struct TraitInfo {
     /// type for `Self` and its trait arguments for the parameters.
     pub(super) methods: Vec<(Symbol, Type)>,
     /// The methods that take a receiver: those whose first parameter is
-    /// written `self`. This is the one fact of whether `x.m(..)` may
-    /// call a method; a method without `self` is called on a type
-    /// (`Int.make(1)`), whatever its parameters are.
+    /// written `self`. An impl writes `self` where its trait does, and
+    /// only there.
     pub(super) receivers: std::collections::HashSet<Symbol>,
     /// The bounds each method's own `where` clauses put on its type
     /// variables, with the bound's trait arguments. They are part of the
@@ -128,9 +127,6 @@ pub(crate) struct MethodEntry {
     /// The trait whose impl provides the method. `None` for a
     /// structural trait's method (`structural`), which is no impl's.
     pub(super) trait_name: Option<TraitKey>,
-    /// Whether the method takes a receiver, as its trait declares it
-    /// (`TraitInfo::receivers`).
-    pub(super) receiver: bool,
     /// What every use of the method owes, on the variables of
     /// `method_type`: the `where` clauses of the impl's header
     /// (`trait Greet for Box(a) where a: Greet`) and the bounds the
@@ -280,7 +276,7 @@ pub(super) type ImplMethodKey = (TypeRef, Symbol, TraitKey);
 /// The methods of the session's impls: one row for each method of each
 /// impl, by its type, its name and its trait, entered by the module that
 /// writes the impl. The impls of two traits that each have a method `m`
-/// for one type are two rows; what `x.m()` means in a module is decided
+/// for one type are two rows; what `T.m(..)` means in a module is decided
 /// from the rows each time (`TypeChecker::method_entry`), never written
 /// back. `providers` is an index of the rows, kept with them.
 #[derive(Clone, Default)]
@@ -357,12 +353,6 @@ pub struct Tables {
     pub(super) traits: Table<HashMap<TraitKey, TraitInfo>, TraitKey>,
     /// The methods of every impl, by type, name and trait.
     pub(super) impl_methods: ImplMethods,
-    /// Where each module reported that a type has no method of some
-    /// name: the place, the type, the name. Once every module of a
-    /// program is checked, a trait out of the module's reach that has
-    /// such a method is named there ([`out_of_reach_helps`]).
-    pub(super) unknown_methods:
-        HashMap<crate::session::ModuleId, Vec<(crate::source::Span, TypeRef, Symbol)>>,
     /// Tracks which (trait_name, type) pairs have been implemented.
     pub(super) trait_impl_set:
         Table<std::collections::HashSet<(TraitKey, TypeRef)>, (TraitKey, TypeRef)>,
@@ -541,54 +531,6 @@ impl Tables {
         }
     }
 
-    /// Every method a value has, as (the type impls key the value's type
-    /// by, the method's name): those of the impls that take `self`, and those of the
-    /// structural traits (of a builtin type, the traits it is stamped
-    /// with; of a type a program declares, all their names). A
-    /// structural trait of a builtin module (`json.Encode`) gives its
-    /// method only where `imports` says the module is imported.
-    pub fn methods(&self, imports: &dyn Fn(&str) -> bool) -> Vec<(TypeRef, Symbol)> {
-        // (A method without `self` is called on the type, not on a
-        // value.)
-        let mut methods: std::collections::HashSet<(TypeRef, Symbol)> = self
-            .impl_methods
-            .rows
-            .iter()
-            .filter(|(_, entry)| entry.receiver)
-            .map(|((ty, method, _), _)| (*ty, *method))
-            .collect();
-        let declared = self
-            .records
-            .keys()
-            .chain(self.enums.keys())
-            .filter(|ty| builtin_type_name(**ty).is_none());
-        for (name, method) in STRUCTURAL_METHODS {
-            let tr = TraitKey::builtin(name);
-            if let Some((_, Some(module))) = crate::defs::builtin_trait_of_id(tr.id.0)
-                && !imports(module)
-            {
-                continue;
-            }
-            let method = intern(method);
-            // (`decode` is called on the type.)
-            if self
-                .traits
-                .get(&tr)
-                .is_some_and(|info| !info.receivers.contains(&method))
-            {
-                continue;
-            }
-            methods.extend(
-                self.trait_impl_set
-                    .iter()
-                    .filter(|(t, _)| *t == tr)
-                    .map(|(_, ty)| (*ty, method)),
-            );
-            methods.extend(declared.clone().map(|ty| (*ty, method)));
-        }
-        methods.into_iter().collect()
-    }
-
     /// Whether a value of the type `ty` has the method of the structural
     /// trait `tr` as a name: a builtin type when it is stamped with the
     /// trait, a type a program declares always (whether it has the
@@ -630,7 +572,6 @@ impl Tables {
         ));
         rows.extend(keys("scheme", self.schemes.keys()));
         rows.extend(keys("statement-units", self.statement_units.keys()));
-        rows.extend(keys("unknown-methods", self.unknown_methods.keys()));
         rows.extend(keys("waiting", self.waiting.keys()));
         rows.extend(keys("rows-of", self.rows.keys()));
         rows.extend(keys(
@@ -690,7 +631,6 @@ impl Tables {
     /// it was a REPL cell that is dropped.
     pub fn forget(&mut self, module: crate::session::ModuleId) {
         self.waiting.remove(&module);
-        self.unknown_methods.remove(&module);
         let Some(rows) = self.rows.remove(&module) else {
             return;
         };
diff --git a/src/typechecker/tests.rs b/src/typechecker/tests.rs
index fc5bf9dc3..073e36f53 100644
--- a/src/typechecker/tests.rs
+++ b/src/typechecker/tests.rs
@@ -543,7 +543,7 @@ trait Display for Shape {
 
 fn main() {
   let s = Circle(5.0)
-  s.display()
+  "{s}"
 }
         "#,
     );
@@ -1663,7 +1663,7 @@ fn main() {
   p.z
 }
             "#,
-        "unknown field or method 'z' on type Point",
+        "type 'Point' has no field 'z'",
     );
 }
 
diff --git a/src/typechecker/unify.rs b/src/typechecker/unify.rs
index eec38890b..d2d29a57f 100644
--- a/src/typechecker/unify.rs
+++ b/src/typechecker/unify.rs
@@ -174,7 +174,7 @@ impl TypeChecker {
         self.close_level();
         self.decide_tries();
         self.default_rebuilds();
-        self.default_selects(false);
+        self.default_selects();
     }
 
     /// Make variables as the scope `exit_level` just left did, until
@@ -637,22 +637,22 @@ impl TypeChecker {
             let shown = self.written_type(*name);
             let mut fault = Fault::new(
                 Code::NoSuchField,
-                format!(
-                    "record {shown} has no field{} {}",
-                    if missing.len() == 1 { "" } else { "s" },
-                    missing
-                        .iter()
-                        .map(|f| format!("'{f}'"))
-                        .collect::<Vec<_>>()
-                        .join(", ")
-                ),
+                match missing.as_slice() {
+                    [field] => format!("type '{shown}' has no field '{field}'"),
+                    _ => format!(
+                        "record {shown} has no fields {}",
+                        missing
+                            .iter()
+                            .map(|f| format!("'{f}'"))
+                            .collect::<Vec<_>>()
+                            .join(", ")
+                    ),
+                },
             );
-            // A method of the record is not a field of it: what reads
-            // a record's fields calls a field.
-            if let Some(method) = missing.iter().find(|f| self.has_method(*name, intern(f))) {
-                fault.help = Some(format!(
-                    "'{method}' is a method of `{shown}`, and what is asked for here is a record with a field '{method}': a value whose fields are read is a record, and `x.{method}(..)` on it calls a field; annotate it, `p: {shown}`"
-                ));
+            // A method of a trait is not a field: it is called through
+            // its trait.
+            if let [field] = missing.as_slice() {
+                fault.help = self.method_help(nominal, intern(field), "x");
             }
             out.push(fault);
             return;
@@ -1021,6 +1021,38 @@ impl TypeChecker {
                 }
             }
 
+            // ── Open row × a type with no fields ─────────────────────
+            // What a dot after a value of unknown type asked for (`x.f`,
+            // `x.f(..)`): the value's type has no field.
+            (
+                Type::AnonRecord {
+                    fields,
+                    tail: RowTail::Var(_),
+                },
+                other,
+            )
+            | (
+                other,
+                Type::AnonRecord {
+                    fields,
+                    tail: RowTail::Var(_),
+                },
+            ) if !matches!(
+                other,
+                Type::AnonRecord { .. } | Type::Var(_) | Type::Error | Type::Never
+            ) && !matches!(other, Type::Generic(name, _) if self.tables.records.contains_key(name))
+                && !fields.is_empty() =>
+            {
+                let field = *fields.keys().next().expect("a field");
+                let shown = self.show_type(other);
+                let mut fault = Fault::new(
+                    Code::UnknownField,
+                    format!("type '{shown}' has no field '{field}'"),
+                );
+                fault.help = self.method_help(other, field, "x");
+                out.push(fault);
+            }
+
             (Type::Generic(n1, a1), Type::Generic(n2, a2)) => {
                 if n1 != n2 {
                     // Round 80 BROKEN B1+B2: this arm formatted the bare
diff --git a/src/value/fmt.rs b/src/value/fmt.rs
index b2eea3ab6..e5a454dac 100644
--- a/src/value/fmt.rs
+++ b/src/value/fmt.rs
@@ -312,7 +312,7 @@ fn begin<'a>(
         }
         Value::Variant(variant) => {
             // A builtin error is shown as its message, the text its
-            // `message()` gives: one text for both.
+            // `Error.message` gives: one text for both.
             if shown && let Some(message) = crate::builtins::error_text(variant) {
                 return f.write_str(&message).map(|()| None);
             }
diff --git a/src/vm/dispatch.rs b/src/vm/dispatch.rs
index 48d61ae5b..ecb7154f9 100644
--- a/src/vm/dispatch.rs
+++ b/src/vm/dispatch.rs
@@ -104,8 +104,10 @@ pub(super) fn resume_native(
 impl Vm {
     // ── Built-in trait methods on primitive types ──────────────────
 
-    /// Handle built-in trait methods like .display(), .equal(), .compare()
-    /// on primitive types. Returns Some(result) if handled, None otherwise.
+    /// The methods of the structural traits a program calls,
+    /// `Compare.compare` and `Hash.hash`, for a value whose type has the
+    /// trait by its structure. Returns Some(result) if handled, None
+    /// otherwise.
     pub(super) fn dispatch_trait_method(
         &self,
         receiver: &Value,
@@ -113,72 +115,6 @@ impl Vm {
         extra_args: &[Value],
     ) -> Option<Result<Value, VmError>> {
         match method {
-            "display" => {
-                if !extra_args.is_empty() {
-                    return Some(Err(VmError::new("display() takes no arguments".into())));
-                }
-                // Runtime Display gate — the .display() twin of the
-                // round-95 `Op::DisplayValue` gate (src/vm/run.rs
-                // ~:1457). For a *concrete* receiver the typechecker
-                // already rejects `.display()` on no-Display types
-                // ("unknown method 'display' on type Fn"), but silt
-                // enforces inferred trait bounds at the EXECUTION site
-                // for polymorphic code, so a Var-typed receiver reaches
-                // this arm ungated. Pre-fix, `fn show(x: a) -> String
-                // { x.display() }` over a lambda / channel / task handle
-                // silently rendered `<fn:..>` / `<channel:0>` /
-                // `<handle:0>` — while the equivalent interpolation
-                // `"{x}"` errored at runtime and the sibling `.equal()` /
-                // `.compare()` arms below carry their own runtime gates.
-                // Reject the same set here, sourced from the single
-                // oracle `Vm::value_implements_display` so the two
-                // execution-site gates cannot drift. Records, variants
-                // (incl. stdlib error enums) and every printable
-                // built-in pass the oracle and fall through unchanged.
-                if !Self::value_implements_display(receiver) {
-                    // Same canonical-name reporting as Op::DisplayValue:
-                    // function-shaped values collapse to "Fn" via
-                    // `dispatch_type_name`; the descriptor values
-                    // (whose canonical name is the *carried* type name)
-                    // fall back to their kind so the diagnostic names
-                    // the descriptor kind, not the reflected type.
-                    let name = match receiver {
-                        Value::TypeDescriptor(_) | Value::PrimitiveDescriptor(_) => {
-                            receiver.kind().to_string()
-                        }
-                        _ => crate::types::canonical::dispatch_type_name(receiver),
-                    };
-                    return Some(Err(VmError::new(format!(
-                        "type '{name}' does not implement Display"
-                    ))));
-                }
-                if let Err(too_long) = receiver.writable() {
-                    return Some(Err(too_long.into()));
-                }
-                Some(Ok(Value::String(self.display_value(receiver).into())))
-            }
-            "equal" => {
-                if extra_args.len() != 1 {
-                    return Some(Err(VmError::new("equal() takes 1 argument".into())));
-                }
-                // Execution-site backstop mirroring the `Op::Eq` gate
-                // (`equality_operand_violation`, src/vm/run.rs): an
-                // operand that is, or transitively contains, a
-                // function-shaped leaf has no Equal impl. A polymorphic
-                // wrapper (`fn eq(a: x, b: x) -> Bool { a.equal(b) }`)
-                // can launder such values past the typechecker's
-                // concrete-operand gate, and `PartialEq for Value` would
-                // silently answer by function and captures.
-                if receiver.contains_fn() || extra_args[0].contains_fn() {
-                    return Some(Err(VmError::new(
-                        "type 'Fn' does not implement Equal".into(),
-                    )));
-                }
-                // `Equal` is structural: `PartialEq for Value`
-                // (src/value/key.rs) is its one implementation, for `==`
-                // and for `.equal()`.
-                Some(Ok(Value::Bool(*receiver == extra_args[0])))
-            }
             "compare" => {
                 if extra_args.len() != 1 {
                     return Some(Err(VmError::new("compare() takes 1 argument".into())));
@@ -190,7 +126,7 @@ impl Vm {
                 // arm can defer to `Value::cmp`, which orders closures of
                 // two functions by the functions' addresses — an
                 // ASLR-nondeterministic result for a
-                // polymorphic `fn cmp(a: x, b: x) -> Int { a.compare(b) }`
+                // polymorphic `fn cmp(a: x, b: x) -> Int { Compare.compare(a, b) }`
                 // laundering a container of functions past the typechecker.
                 if receiver.contains_fn() || other.contains_fn() {
                     return Some(Err(VmError::new(
@@ -209,7 +145,7 @@ impl Vm {
                     // `Compare` is structural: `Ord for Value`
                     // (src/value/key.rs) orders records by their
                     // declared fields and variants by declaration, for
-                    // `<` and for `.compare()`.
+                    // `<` and for `Compare.compare`.
                     (Value::Variant(..), Value::Variant(..))
                     | (Value::Record(..), Value::Record(..)) => receiver.cmp(other),
                     //
@@ -242,10 +178,10 @@ impl Vm {
                 if !extra_args.is_empty() {
                     return Some(Err(VmError::new("hash() takes no arguments".into())));
                 }
-                // Execution-site backstop mirroring the `"equal"` /
-                // `"compare"` arms above: a receiver that is, or
-                // transitively contains, a function-shaped leaf has no
-                // Hash (the checker rejects `[{ y -> y }].hash()`; a
+                // Execution-site backstop mirroring the `"compare"` arm
+                // above: a receiver that is, or transitively contains, a
+                // function-shaped leaf has no Hash (the checker rejects
+                // `Hash.hash([{ y -> y }])`; a
                 // function has none of the structural traits). The
                 // std `Hash` impl on `Value` hashes every closure as a
                 // constant discriminant tag ("not meaningfully
diff --git a/src/vm/mod.rs b/src/vm/mod.rs
index 00e2993ad..baca9e659 100644
--- a/src/vm/mod.rs
+++ b/src/vm/mod.rs
@@ -814,9 +814,7 @@ impl Vm {
 
     /// Whether a runtime value's type has a Display impl — the single
     /// runtime-side oracle for the string-interpolation Display gate
-    /// (`Op::DisplayValue`, src/vm/run.rs) and the polymorphic
-    /// `.display()` method gate (`dispatch_trait_method`'s "display"
-    /// arm, src/vm/dispatch.rs).
+    /// (`Op::DisplayValue`, src/vm/run.rs).
     ///
     /// This mirrors the typechecker's compile-time gate: the typechecker
     /// reduces a *concrete* operand to its canonical name
diff --git a/src/vm/run.rs b/src/vm/run.rs
index 876bdfeaa..670483519 100644
--- a/src/vm/run.rs
+++ b/src/vm/run.rs
@@ -1218,13 +1218,23 @@ impl Vm {
                         ok!(self.show(&msg, |_, text| Err(VmError::new(format!("panic: {text}")))));
                     go_on!(ok!(self.enter_step(step)));
                 }
-                Instr::CallMethod { method, argc, of } => {
+                Instr::CallMethod {
+                    method,
+                    argc,
+                    of,
+                    at,
+                } => {
                     save!();
-                    go_on!(ok!(self.call_method(method, argc, of, false)));
+                    go_on!(ok!(self.call_method(method, argc, of, at, false)));
                 }
-                Instr::TailCallMethod { method, argc, of } => {
+                Instr::TailCallMethod {
+                    method,
+                    argc,
+                    of,
+                    at,
+                } => {
                     save!();
-                    go_on!(ok!(self.call_method(method, argc, of, true)));
+                    go_on!(ok!(self.call_method(method, argc, of, at, true)));
                 }
                 Instr::Slide { slot } => {
                     // Keep the top value and cut the frame back to
@@ -1571,12 +1581,14 @@ impl Vm {
         method: u16,
         argc: usize,
         trait_index: u16,
+        at: usize,
         tail: bool,
     ) -> Result<DispatchResult, VmError> {
         let receiver_slot = self.stack.len() - argc;
         // (The receiver is looked at where it is: a method of an impl
-        // is found by its type alone.)
-        let receiver = &self.stack[receiver_slot];
+        // is found by its type alone. It is the argument `at`, the
+        // first of the method's of type `Self`.)
+        let receiver = &self.stack[receiver_slot + at];
         let receiver_type = crate::types::canonical::dispatch_type_for_value(receiver);
         // Descriptor-as-receiver (e.g. `Int.default()`,
         // `body.decode(Todo)` where the descriptor is piped in) is
@@ -1660,16 +1672,7 @@ impl Vm {
             return self.enter_step(step);
         }
         // No impl has the method for the receiver's type: what the
-        // call does then goes by the method's name. Called through a
-        // type (`a.display(x)` for a `type a`, `t.compare(x, y)` for a
-        // type held in `t`), the descriptor only chose the type: the
-        // value the method is of is the first argument.
-        let argc = if descriptor_receiver && argc > 1 {
-            self.stack.remove(receiver_slot);
-            argc - 1
-        } else {
-            argc
-        };
+        // call does then goes by the method's name.
         let receiver = self.stack[receiver_slot].clone();
         let slots = self.view.entry.clone();
         // (The compiler checks each function against the globals of
@@ -1686,16 +1689,6 @@ impl Vm {
                 "the call of method '{method_name}' names a trait the program does not have"
             )));
         }
-        // `display` of a value whose parts a written impl may show.
-        if method_name == "display"
-            && argc == 1
-            && slots.any_shown()
-            && Self::value_implements_display(&receiver)
-        {
-            self.stack.truncate(receiver_slot);
-            let step = self.shown(&receiver)?;
-            return self.enter_step(step);
-        }
         // `encode` of a value whose type has no written `json.Encode`
         // impl: its structural form, with the impls of its parts.
         if method_name == "encode"
diff --git a/src/vm/show.rs b/src/vm/show.rs
index d3dcf4caa..2200f8ab7 100644
--- a/src/vm/show.rs
+++ b/src/vm/show.rs
@@ -1,5 +1,5 @@
-//! Showing a value: `println`, `print`, interpolation, `.display()`,
-//! `string.from`, a panic's message.
+//! Showing a value: `println`, `print`, interpolation, `string.from`, a
+//! panic's message.
 //!
 //! A value is shown by the VM's formatter (`Value`'s `Display`), but a
 //! record or variant of a type the program wrote a `Display` impl for is
diff --git a/src/vm/tests.rs b/src/vm/tests.rs
index a9585f094..1650a05cb 100644
--- a/src/vm/tests.rs
+++ b/src/vm/tests.rs
@@ -2315,7 +2315,7 @@ fn test_custom_display_trait() {
             }
             fn main() {
                 let s = Circle(5.0)
-                s.display()
+                "{s}"
             }
         "#,
     );
@@ -3403,13 +3403,13 @@ trait Step for C {
   fn go(self, k: Int) -> Int {
     match k {
       0 -> 1 / k
-      _ -> self.go(k - 1)
+      _ -> Step.go(self, k - 1)
     }
   }
 }
 fn main() {
   let c = C { n: 1 }
-  println(c.go(5))
+  println(Step.go(c, 5))
 }
 ";
         assert_eq!(
@@ -4406,6 +4406,7 @@ mod type_confusion {
                     method: 0,
                     argc: 1,
                     of: 0,
+                    at: 0,
                 },
                 span(),
             )
@@ -6148,10 +6149,20 @@ mod methods_in_place {
     }
 
     fn call(argc: u8, tail: bool) -> Asm<'static> {
-        let (method, argc, of) = (0, usize::from(argc), 0);
+        let (method, argc, of, at) = (0, usize::from(argc), 0, 0);
         match tail {
-            true => Asm::TailCallMethod { method, argc, of },
-            false => Asm::CallMethod { method, argc, of },
+            true => Asm::TailCallMethod {
+                method,
+                argc,
+                of,
+                at,
+            },
+            false => Asm::CallMethod {
+                method,
+                argc,
+                of,
+                at,
+            },
         }
     }
 
diff --git a/tests/cli/stage7_io_timeout_tests.rs b/tests/cli/stage7_io_timeout_tests.rs
index 1091f0196..93db08160 100644
--- a/tests/cli/stage7_io_timeout_tests.rs
+++ b/tests/cli/stage7_io_timeout_tests.rs
@@ -63,7 +63,7 @@ fn main() {
     match tcp.accept(listener) {
       Err(tcp.Timeout) -> println("timed out")
       Ok(_) -> println("a connection")
-      Err(e) -> println("another error: {e.message()}")
+      Err(e) -> println("another error: {Error.message(e)}")
     }
   }
 }
@@ -125,7 +125,7 @@ fn main() {
   }
   match tcp.read(peer, 10) {
     Ok(got) -> println("the peer read {bytes.length(got)} bytes: the end")
-    Err(e) -> println("the peer: {e.message()}")
+    Err(e) -> println("the peer: {Error.message(e)}")
   }
 }
 "#;
@@ -157,7 +157,7 @@ fn main() {
   match stream.write_to_tcp(chunks, client) {
     Err(tcp.Timeout) -> println("the write timed out")
     Ok(_) -> println("all was written")
-    Err(e) -> println("the write: {e.message()}")
+    Err(e) -> println("the write: {Error.message(e)}")
   }
 }
 "#;
diff --git a/tests/cli/trait_init_parity_tests.rs b/tests/cli/trait_init_parity_tests.rs
index 1ac1a10c6..e297b35d3 100644
--- a/tests/cli/trait_init_parity_tests.rs
+++ b/tests/cli/trait_init_parity_tests.rs
@@ -13,7 +13,7 @@ fn trait_impls_cover_every_builtin_trait_name() {
     // on at least one primitive. If a future edit removes all auto-derived
     // registrations for a trait, this catches it before downstream
     // diagnostics get mysterious.
-    let (impls, _) = __trait_init_fingerprint_check_program();
+    let impls = __trait_init_fingerprint_check_program();
     for trait_name in ["Equal", "Compare", "Hash", "Display"] {
         let has_some = impls
             .iter()
@@ -30,7 +30,7 @@ fn primitives_get_all_four_traits() {
     // Lock the derive policy: every primitive should have all four
     // built-in traits registered. If policy shifts, this test makes
     // the change visible.
-    let (impls, _) = __trait_init_fingerprint_check_program();
+    let impls = __trait_init_fingerprint_check_program();
     // Round 75 TYPE-3 flipped the Unit canonical direction from
     // `Unit → ()` to `() → Unit`, aligning with the VM dispatch
     // oracle. The trait_impl_set keys now use "Unit" not "()".
@@ -54,7 +54,7 @@ fn non_ordering_container_types_lack_compare() {
     // Map and Set have no order. Option and Result have no `compare`
     // method entry (they are ordered by their structure, like any enum).
     // A tuple is ordered part by part and has Compare.
-    let (impls, _) = __trait_init_fingerprint_check_program();
+    let impls = __trait_init_fingerprint_check_program();
     assert!(impls.contains("Compare:Tuple"));
     for type_name in ["Map", "Set", "Option", "Result"] {
         let key = format!("Compare:{type_name}");
diff --git a/tests/concurrency/io_timeout_watchdog_tests.rs b/tests/concurrency/io_timeout_watchdog_tests.rs
index e0e9975c3..2f4923f27 100644
--- a/tests/concurrency/io_timeout_watchdog_tests.rs
+++ b/tests/concurrency/io_timeout_watchdog_tests.rs
@@ -124,7 +124,7 @@ fn main() {
   let handle = task.spawn({ ->
     match io.read_line() {
       Ok(_) -> "unexpected_ok"
-      Err(e) -> e.message()
+      Err(e) -> Error.message(e)
     }
   })
   println(task.join(handle))
@@ -220,12 +220,12 @@ fn main() {{
         match tcp.read(s, 1024) {{
           Ok(_) -> "unexpected-ok"
           Err(tcp.Timeout) -> "tcp-timeout"
-          Err(other) -> "other:{{other.message()}}"
+          Err(other) -> "other:{{Error.message(other)}}"
         }}
       }})
       println(task.join(outcome))
     }}
-    Err(e) -> println("connect-err:{{e.message()}}")
+    Err(e) -> println("connect-err:{{Error.message(e)}}")
   }}
 }}
 "#
diff --git a/tests/concurrency/repl_tasks_see_later_entries_tests.rs b/tests/concurrency/repl_tasks_see_later_entries_tests.rs
index cf3ec46f0..ed9383125 100644
--- a/tests/concurrency/repl_tasks_see_later_entries_tests.rs
+++ b/tests/concurrency/repl_tasks_see_later_entries_tests.rs
@@ -210,7 +210,7 @@ fn a_task_calls_a_method_of_an_impl_of_a_later_entry() {
     assert_tasks_see(
         "trait N { fn n(self) -> String }",
         "trait N for Int { fn n(self) -> String { \"int\" } }",
-        "5.n()",
+        "N.n(5)",
         "int",
     );
 }
@@ -222,7 +222,7 @@ fn a_task_calls_a_method_of_an_impl_of_a_later_entry() {
 #[test]
 fn a_task_finds_an_impl_of_a_later_entry_through_an_earlier_generic_function() {
     assert_tasks_see(
-        "trait N { fn n(self) -> String }\nfn call(v: a) -> String where a: N { v.n() }",
+        "trait N { fn n(self) -> String }\nfn call(v: a) -> String where a: N { N.n(v) }",
         "type Q { q: Int }\n\
          trait N for Int { fn n(self) -> String { \"int\" } }\n\
          trait N for Q { fn n(self) -> String { \"q{self.q}\" } }",
@@ -232,12 +232,12 @@ fn a_task_finds_an_impl_of_a_later_entry_through_an_earlier_generic_function() {
 }
 
 /// A `Display` impl of a later entry is used wherever the value is
-/// shown: in an interpolation and by `.display()`, inside a list. It
+/// shown: in an interpolation and by `string.from`, inside a list. It
 /// was not used, and nothing said so: `[Q {q: 2}]|[Q {q: 2}]`.
 #[test]
 fn a_task_shows_a_value_with_the_display_impl_of_a_later_entry() {
     assert_tasks_see(
-        "fn sh(v: a) -> String where a: Display { \"{v}|{v.display()}\" }",
+        "import string\nfn sh(v: a) -> String where a: Display { \"{v}|{string.from(v)}\" }",
         "type Q { q: Int }\ntrait Display for Q { fn display(self) -> String { \"Q!\" } }",
         "sh([Q { q: 2 }])",
         "[Q!]|[Q!]",
@@ -279,7 +279,7 @@ fn a_task_calls_a_method_of_a_trait_of_a_later_entry() {
     assert_tasks_see(
         "",
         "trait M { fn m(self) -> String }\ntrait M for Int { fn m(self) -> String { \"m{self}\" } }",
-        "{\n  let call = { y -> y.m() }\n  call(7)\n}",
+        "{\n  let call = { y -> M.m(y) }\n  call(7)\n}",
         "m7",
     );
 }
@@ -307,7 +307,7 @@ fn a_task_decodes_into_record_types_of_a_later_entry() {
 fn the_function_of_a_deadline_sees_later_entries_in_a_task_of_an_earlier_one() {
     assert_tasks_see(
         "import time\ntrait N { fn n(self) -> String }\n\
-         fn call(v: a) -> String where a: N { v.n() }",
+         fn call(v: a) -> String where a: N { N.n(v) }",
         "fn later() -> String { \"fn\" }\n\
          trait N for Int { fn n(self) -> String { \"int\" } }\n\
          type Q { q: Int }\n\
@@ -341,7 +341,7 @@ fn burn(n) {{
   }}
 }}
 trait N {{ fn n(self) -> String }}
-fn call(v: a) -> String where a: N {{ v.n() }}
+fn call(v: a) -> String where a: N {{ N.n(v) }}
 fn work(left) {{
   match left {{
     0 -> ()
@@ -546,11 +546,11 @@ fn work(left) {
   }
 }
 let worker = task.spawn { -> work(2) }
-channel.send(jobs, { -> 5.n() })
+channel.send(jobs, { -> N.n(5) })
 channel.receive(outs)
 trait N for Int { fn n(self) -> String { \"second\" } }
-5.n()
-channel.send(jobs, { -> 5.n() })
+N.n(5)
+channel.send(jobs, { -> N.n(5) })
 channel.receive(outs)
 task.join(worker)
 ",
@@ -755,7 +755,7 @@ fn a_session_sets_no_slot_twice() {
     for entry in [
         "import task\nimport channel\nimport io",
         "let jobs = channel.new(8)\nlet outs = channel.new(8)",
-        "trait N { fn n(self) -> String }\nfn call(v: a) -> String where a: N { v.n() }",
+        "trait N { fn n(self) -> String }\nfn call(v: a) -> String where a: N { N.n(v) }",
         "fn work() {\n  match channel.receive(jobs) {\n    Some(job) -> {\n      \
          channel.send(outs, job())\n      work()\n    }\n    None -> ()\n  }\n}",
         "let worker = task.spawn { -> work() }",
@@ -767,21 +767,21 @@ fn a_session_sets_no_slot_twice() {
     assert_eq!(
         run("let stamp = \"one\"\n\
              trait N for Int { fn n(self) -> String { \"first {stamp}\" } }\n\
-             let sent = channel.send(jobs, { -> \"{stamp} {5.n()} {call(5)}\" })\n\
+             let sent = channel.send(jobs, { -> \"{stamp} {N.n(5)} {call(5)}\" })\n\
              let got = channel.receive(outs)\n\
              let boom = 1 / 0"),
         failed("division by zero")
     );
     // The impl is gone with the entry, for the session and for the task.
-    assert!(run("5.n()").is_err());
+    assert!(run("N.n(5)").is_err());
     // It is written again, and differently.
     assert_eq!(
         run("trait N for Int { fn n(self) -> String { \"second\" } }"),
         ok("()")
     );
-    assert_eq!(run("\"{5.n()} {call(5)}\""), ok("second second"));
+    assert_eq!(run("\"{N.n(5)} {call(5)}\""), ok("second second"));
     assert_eq!(
-        run("channel.send(jobs, { -> \"{5.n()} {call(5)}\" })"),
+        run("channel.send(jobs, { -> \"{N.n(5)} {call(5)}\" })"),
         ok("()")
     );
     assert_eq!(run("channel.receive(outs)"), ok("Some(second second)"));
@@ -799,7 +799,7 @@ fn a_session_sets_no_slot_twice() {
     assert_eq!(run("channel.receive(outs)"), ok("Some(two tag-two)"));
     for entry in [
         "let stamp = \"again\"",
-        "fn call(v: a) -> String where a: N { \"again {v.n()}\" }",
+        "fn call(v: a) -> String where a: N { \"again {N.n(v)}\" }",
         "type Q { q: Int }",
         "trait N for Q { fn n(self) -> String { \"q\" } }",
         "type Q { r: Int }",
diff --git a/tests/database/a_channel_is_notified_under_the_name_it_was_listened_on.silt b/tests/database/a_channel_is_notified_under_the_name_it_was_listened_on.silt
index 6b37454ea..959d32c38 100644
--- a/tests/database/a_channel_is_notified_under_the_name_it_was_listened_on.silt
+++ b/tests/database/a_channel_is_notified_under_the_name_it_was_listened_on.silt
@@ -31,14 +31,14 @@ fn round_trip(db: postgres.PgPool, name: String) {
           match got {
             Ok(Some(n)) -> println("{name}: got {n.payload} on {n.channel}")
             Ok(None) -> println("{name}: the listener ended")
-            Err(e) -> println("{name}: nothing came ({e.message()})")
+            Err(e) -> println("{name}: nothing came ({Error.message(e)})")
           }
         }
-        Err(e) -> println("notify {name}: {e.message()}")
+        Err(e) -> println("notify {name}: {Error.message(e)}")
       }
       channel.close(ch)
     }
-    Err(e) -> println("listen {name}: {e.message()}")
+    Err(e) -> println("listen {name}: {Error.message(e)}")
   }
 }
 
@@ -49,11 +49,11 @@ fn refused(db: postgres.PgPool, name: String) {
       println("listen took it")
       channel.close(ch)
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match postgres.notify(db, name, "x") {
     Ok(_) -> println("notify took it")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
@@ -76,6 +76,6 @@ fn main() {
       }
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_connect_nobody_waits_for_leaves_no_session.silt b/tests/database/a_connect_nobody_waits_for_leaves_no_session.silt
index 33202883a..45c7f428f 100644
--- a/tests/database/a_connect_nobody_waits_for_leaves_no_session.silt
+++ b/tests/database/a_connect_nobody_waits_for_leaves_no_session.silt
@@ -34,7 +34,7 @@ fn sessions(db: postgres.PgPool) -> String {
   let sql = "SELECT count(*)::int AS n FROM pg_stat_activity WHERE application_name = 'silt_given_up_connect'"
   match postgres.query(db, sql, (), json.Value) {
     Ok(rows) -> "{rows}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
@@ -47,7 +47,7 @@ fn main() {
         match got {
           -- In time: the program closes the pool itself.
           Ok(Ok(other)) -> postgres.close(other)
-          Ok(Err(e)) -> println("connect: {e.message()}")
+          Ok(Err(e)) -> println("connect: {Error.message(e)}")
           Err(_) -> ()
         }
       }
@@ -57,6 +57,6 @@ fn main() {
       println("after: {sessions(db)}")
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_connection_the_server_ended_is_not_taken.silt b/tests/database/a_connection_the_server_ended_is_not_taken.silt
index 7f35e667c..cedb1588f 100644
--- a/tests/database/a_connection_the_server_ended_is_not_taken.silt
+++ b/tests/database/a_connection_the_server_ended_is_not_taken.silt
@@ -50,7 +50,7 @@ fn round(db: postgres.PgPool, observer: postgres.PgPool) -> Result(String, postg
   match postgres.query(db, "SELECT pg_backend_pid()::int8 AS pid", (), Pid) {
     Ok([row]) when row.pid != pid -> Ok("a new connection")
     Ok(_) -> Ok("the same connection")
-    Err(e) -> Ok("the statement failed: {e.message()}")
+    Err(e) -> Ok("the statement failed: {Error.message(e)}")
   }
 }
 
@@ -60,7 +60,7 @@ fn main() {
       let answers = 1..20 |> list.map { _ ->
         match round(db, observer) {
           Ok(answer) -> answer
-          Err(e) -> "the round failed: {e.message()}"
+          Err(e) -> "the round failed: {Error.message(e)}"
         }
       }
       let other = answers |> list.filter { a -> a != "a new connection" }
diff --git a/tests/database/a_cursor_ends_at_a_batch_that_fails.silt b/tests/database/a_cursor_ends_at_a_batch_that_fails.silt
index 4645d1439..eacf2d686 100644
--- a/tests/database/a_cursor_ends_at_a_batch_that_fails.silt
+++ b/tests/database/a_cursor_ends_at_a_batch_that_fails.silt
@@ -32,6 +32,6 @@ fn main() {
       println("transact: {done}")
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_field_is_decoded_by_its_json_decode_impl.silt b/tests/database/a_field_is_decoded_by_its_json_decode_impl.silt
index 6b1c8b69f..4e0e4c156 100644
--- a/tests/database/a_field_is_decoded_by_its_json_decode_impl.silt
+++ b/tests/database/a_field_is_decoded_by_its_json_decode_impl.silt
@@ -73,7 +73,7 @@ FROM generate_series(1, 2) g
     Ok(db) -> {
       match postgres.query(db, sql, (), Row) {
         Ok(rows) -> list.each(rows) { r -> println(r) }
-        Err(e) -> println("query: {e.message()}")
+        Err(e) -> println("query: {Error.message(e)}")
       }
       let read = postgres.transact(db) { tx ->
         let c = postgres.cursor(tx, sql, (), 1, Row)?
@@ -85,10 +85,10 @@ FROM generate_series(1, 2) g
       println("a cursor: {read}")
       match postgres.stream(db, sql, (), Row) {
         Ok(rows) -> channel.each(rows) { r -> println("a stream: {r}") }
-        Err(e) -> println("a stream: {e.message()}")
+        Err(e) -> println("a stream: {Error.message(e)}")
       }
       postgres.close(db)
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/a_listen_nobody_waits_for_gives_its_connection_back.silt b/tests/database/a_listen_nobody_waits_for_gives_its_connection_back.silt
index 7b3770a21..170123c0a 100644
--- a/tests/database/a_listen_nobody_waits_for_gives_its_connection_back.silt
+++ b/tests/database/a_listen_nobody_waits_for_gives_its_connection_back.silt
@@ -29,16 +29,16 @@ fn main() {
         match got {
           -- In time: the program closes its listener itself.
           Ok(Ok(ch)) -> channel.close(ch)
-          Ok(Err(e)) -> println("listen: {e.message()}")
+          Ok(Err(e)) -> println("listen: {Error.message(e)}")
           Err(_) -> ()
         }
       }
       match postgres.query(db, "SELECT 1 AS n", (), json.Value) {
         Ok(rows) -> println("the pool serves: {list.length(rows)} row")
-        Err(e) -> println("query: {e.message()}")
+        Err(e) -> println("query: {Error.message(e)}")
       }
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_parameter_is_written_as_its_json_encode_impl_says.silt b/tests/database/a_parameter_is_written_as_its_json_encode_impl_says.silt
index 697693598..7be22c129 100644
--- a/tests/database/a_parameter_is_written_as_its_json_encode_impl_says.silt
+++ b/tests/database/a_parameter_is_written_as_its_json_encode_impl_says.silt
@@ -40,7 +40,7 @@ fn main() {
       println(postgres.execute(db, "SELECT $1::jsonb", (m,)))
       match postgres.stream(db, "SELECT $1::jsonb::text AS v", ((m, "a"),), Out) {
         Ok(rows) -> println("a stream: {channel.receive(rows)}")
-        Err(e) -> println("a stream: {e.message()}")
+        Err(e) -> println("a stream: {Error.message(e)}")
       }
       let read = postgres.transact(db) { tx ->
         let c = postgres.cursor(tx, "SELECT $1::jsonb::text AS v", (#{"price": m},), 2, Out)?
@@ -50,6 +50,6 @@ fn main() {
       }
       println("a cursor: {read}")
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/a_parameter_that_cannot_be_sent.silt b/tests/database/a_parameter_that_cannot_be_sent.silt
index 9a067e85c..f5981190f 100644
--- a/tests/database/a_parameter_that_cannot_be_sent.silt
+++ b/tests/database/a_parameter_that_cannot_be_sent.silt
@@ -25,24 +25,24 @@ fn main() {
     Ok(db) -> {
       match postgres.query(db, "SELECT cardinality($1::bytea[])::text AS v", ([pic, pic],), Out) {
         Ok(rows) -> println("into a bytea[]: {rows}")
-        Err(e) -> println("into a bytea[]: {e.message()}")
+        Err(e) -> println("into a bytea[]: {Error.message(e)}")
       }
       match postgres.stream(db, "SELECT $1::jsonb::text AS v", ([pic],), Out) {
         Ok(rows) -> {
           match channel.receive(rows) {
             Some(Ok(row)) -> println("a stream into jsonb: {row}")
             Some(Err(postgres.Other(why))) -> println("a stream into jsonb: Other({why})")
-            Some(Err(e)) -> println("a stream into jsonb: {e.message()}")
+            Some(Err(e)) -> println("a stream into jsonb: {Error.message(e)}")
             None -> println("a stream into jsonb: closed")
           }
           println("then: {channel.receive(rows)}")
         }
-        Err(e) -> println("a stream into jsonb: {e.message()}")
+        Err(e) -> println("a stream into jsonb: {Error.message(e)}")
       }
       println("a query into jsonb:")
       let _ = postgres.query(db, "SELECT $1::jsonb::text AS v", ([pic],), Out)
       println("not reached")
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_pool_opens_connections_when_it_needs_them.silt b/tests/database/a_pool_opens_connections_when_it_needs_them.silt
index a9d1cc7c7..d81ca32a7 100644
--- a/tests/database/a_pool_opens_connections_when_it_needs_them.silt
+++ b/tests/database/a_pool_opens_connections_when_it_needs_them.silt
@@ -32,7 +32,7 @@ fn sessions(db: postgres.PgPool) -> String {
   match postgres.query(db, sql, (), N) {
     Ok([row]) -> "{row.n}"
     Ok(rows) -> "{rows}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
@@ -50,12 +50,12 @@ fn main() {
       sleepers |> list.each { t ->
         match task.join(t) {
           Ok(_) -> ()
-          Err(e) -> println("a statement at once: {e.message()}")
+          Err(e) -> println("a statement at once: {Error.message(e)}")
         }
       }
       println("after two statements at once: {sessions(db)}")
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_pool_statement_without_its_connection_is_not_sent.silt b/tests/database/a_pool_statement_without_its_connection_is_not_sent.silt
index 6a38e23b9..2e026c711 100644
--- a/tests/database/a_pool_statement_without_its_connection_is_not_sent.silt
+++ b/tests/database/a_pool_statement_without_its_connection_is_not_sent.silt
@@ -29,7 +29,7 @@ fn main() {
         println(
           match late {
             Ok(_) -> "the insert came back"
-            Err(e) -> "task.deadline: {e.message()}"
+            Err(e) -> "task.deadline: {Error.message(e)}"
           },
         )
         Ok(())
@@ -37,16 +37,16 @@ fn main() {
       println(
         match done {
           Ok(_) -> "main's transaction: Ok"
-          Err(e) -> "main's transaction: {e.message()}"
+          Err(e) -> "main's transaction: {Error.message(e)}"
         },
       )
       time.sleep(time.ms(300))
       match postgres.query(pool, "SELECT count(*)::int AS n FROM silt_late_statement", (), json.Value) {
         Ok(rows) -> println("rows: {rows}")
-        Err(e) -> println("count: {e.message()}")
+        Err(e) -> println("count: {Error.message(e)}")
       }
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_record_in_a_field_decodes_an_enum_by_json_s_rules.silt b/tests/database/a_record_in_a_field_decodes_an_enum_by_json_s_rules.silt
index 46b9275f4..d39e4ed45 100644
--- a/tests/database/a_record_in_a_field_decodes_an_enum_by_json_s_rules.silt
+++ b/tests/database/a_record_in_a_field_decodes_an_enum_by_json_s_rules.silt
@@ -28,7 +28,7 @@ fn url() -> String {
 fn show(r: Result(List(a), postgres.PostgresError)) where a: Display {
   match r {
     Ok(rows) -> println(rows)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
@@ -43,6 +43,6 @@ fn main() {
       show(postgres.query(db, "SELECT json_build_object('state', $1::jsonb) AS inner", (Paused(4),), Wrapped))
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_row_type_with_an_impl_is_decoded_by_it.silt b/tests/database/a_row_type_with_an_impl_is_decoded_by_it.silt
index 5f346be8b..66bdee05d 100644
--- a/tests/database/a_row_type_with_an_impl_is_decoded_by_it.silt
+++ b/tests/database/a_row_type_with_an_impl_is_decoded_by_it.silt
@@ -54,11 +54,11 @@ fn main() {
       println(postgres.query(db, "SELECT g AS n FROM generate_series(1, 2) g", (), Size))
       match postgres.query(db, "SELECT 'x' AS n", (), Size) {
         Ok(rows) -> println(rows)
-        Err(e) -> println("Err: {e.message()}")
+        Err(e) -> println("Err: {Error.message(e)}")
       }
       match postgres.query(db, "SELECT 1 AS m", (), Size) {
         Ok(rows) -> println(rows)
-        Err(e) -> println("Err: {e.message()}")
+        Err(e) -> println("Err: {Error.message(e)}")
       }
       let read = postgres.transact(db) { tx ->
         let c = postgres.cursor(tx, "SELECT g AS n FROM generate_series(1, 3) g", (), 2, Size)?
@@ -69,6 +69,6 @@ fn main() {
       println("a cursor: {read}")
       postgres.close(db)
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/a_statement_behind_its_own_unread_stream_fails.silt b/tests/database/a_statement_behind_its_own_unread_stream_fails.silt
index 796b74553..d2b5507f5 100644
--- a/tests/database/a_statement_behind_its_own_unread_stream_fails.silt
+++ b/tests/database/a_statement_behind_its_own_unread_stream_fails.silt
@@ -27,11 +27,11 @@ fn main() {
         match postgres.query(tx, "SELECT 1::int8 AS n", (), N) {
           Ok(found) -> println("the statement ran: {found}")
           Err(postgres.Other(text)) -> println("the statement: Other({text})")
-          Err(e) -> println("the statement: {e.message()}")
+          Err(e) -> println("the statement: {Error.message(e)}")
         }
         match postgres.execute(tx, "SELECT 1", ()) {
           Ok(n) -> println("execute ran: {n}")
-          Err(e) -> println("execute: {e.message()}")
+          Err(e) -> println("execute: {Error.message(e)}")
         }
         channel.close(rows)
         postgres.query(tx, "SELECT 2::int8 AS n", (), N)
@@ -39,6 +39,6 @@ fn main() {
       println("transact: {done}")
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_statement_behind_its_own_unread_stream_of_impls_fails.silt b/tests/database/a_statement_behind_its_own_unread_stream_of_impls_fails.silt
index 9b2968a2f..9f4cf6f5b 100644
--- a/tests/database/a_statement_behind_its_own_unread_stream_of_impls_fails.silt
+++ b/tests/database/a_statement_behind_its_own_unread_stream_of_impls_fails.silt
@@ -44,11 +44,11 @@ fn main() {
         match postgres.query(tx, "SELECT 1::int8 AS n", (), N) {
           Ok(found) -> println("the statement ran: {found}")
           Err(postgres.Other(text)) -> println("the statement: Other({text})")
-          Err(e) -> println("the statement: {e.message()}")
+          Err(e) -> println("the statement: {Error.message(e)}")
         }
         match postgres.execute(tx, "SELECT 1", ()) {
           Ok(n) -> println("execute ran: {n}")
-          Err(e) -> println("execute: {e.message()}")
+          Err(e) -> println("execute: {Error.message(e)}")
         }
         channel.close(rows)
         postgres.query(tx, "SELECT 2::int8 AS n", (), N)
@@ -56,6 +56,6 @@ fn main() {
       println("transact: {done}")
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_statement_right_after_the_server_ends_its_sessions_runs.silt b/tests/database/a_statement_right_after_the_server_ends_its_sessions_runs.silt
index 613307f8a..5367702b7 100644
--- a/tests/database/a_statement_right_after_the_server_ends_its_sessions_runs.silt
+++ b/tests/database/a_statement_right_after_the_server_ends_its_sessions_runs.silt
@@ -62,7 +62,7 @@ fn rounds(db: postgres.PgPool, observer: postgres.PgPool, then: Fn() -> ()) -> L
       then()
       match postgres.query(db, "SELECT 1::int8 AS n", (), N) {
         Ok(_) -> "ok"
-        Err(e) -> e.message()
+        Err(e) -> Error.message(e)
       }
     }
     |> list.filter { answer -> answer != "ok" }
diff --git a/tests/database/a_statement_that_never_got_the_connection_gives_up.silt b/tests/database/a_statement_that_never_got_the_connection_gives_up.silt
index 3d8fa55cc..674b694ac 100644
--- a/tests/database/a_statement_that_never_got_the_connection_gives_up.silt
+++ b/tests/database/a_statement_that_never_got_the_connection_gives_up.silt
@@ -31,17 +31,17 @@ fn main() {
         let late = task.deadline(time.ms(200)) { -> postgres.query(tx, "SELECT 1::int8 AS n", (), N) }
         match late {
           Ok(answer) -> println("the waiting statement answered: {answer}")
-          Err(e) -> println("the waiting statement: {e.message()}")
+          Err(e) -> println("the waiting statement: {Error.message(e)}")
         }
         match task.join(sleeper) {
           Ok(_) -> println("the running statement: Ok")
-          Err(e) -> println("the running statement: {e.message()}")
+          Err(e) -> println("the running statement: {Error.message(e)}")
         }
         postgres.query(tx, "SELECT 2::int8 AS n", (), N)
       }
       println("transact: {done}")
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/a_stream_ends_at_an_impls_error.silt b/tests/database/a_stream_ends_at_an_impls_error.silt
index 4a2a7d214..a876fba83 100644
--- a/tests/database/a_stream_ends_at_an_impls_error.silt
+++ b/tests/database/a_stream_ends_at_an_impls_error.silt
@@ -52,12 +52,12 @@ fn main() {
       println("an Err:")
       match postgres.stream(db, string.replace(sql, ":k", "7"), (), R) {
         Ok(rows) -> drain(rows)
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       println("a failure:")
       match postgres.stream(db, string.replace(sql, ":k", "0"), (), R) {
         Ok(rows) -> drain(rows)
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       println("closed:")
       match postgres.stream(db, "SELECT g AS n, to_jsonb(g::text) AS code FROM generate_series(1, 100000) g", (), R) {
@@ -66,10 +66,10 @@ fn main() {
           channel.close(rows)
           println("  closed")
         }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       postgres.close(db)
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/a_stream_whose_impl_waits_forever_is_a_deadlock.silt b/tests/database/a_stream_whose_impl_waits_forever_is_a_deadlock.silt
index 6b08c70d1..23b71e248 100644
--- a/tests/database/a_stream_whose_impl_waits_forever_is_a_deadlock.silt
+++ b/tests/database/a_stream_whose_impl_waits_forever_is_a_deadlock.silt
@@ -36,9 +36,9 @@ fn main() {
     Ok(db) -> {
       match postgres.stream(db, "SELECT to_jsonb(g) AS stuck FROM generate_series(1, 3) g", (), S) {
         Ok(rows) -> println("first: {channel.receive(rows)}")
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/a_stream_with_impls_ends_with_its_reader.silt b/tests/database/a_stream_with_impls_ends_with_its_reader.silt
index 63b6d2976..fa69e6666 100644
--- a/tests/database/a_stream_with_impls_ends_with_its_reader.silt
+++ b/tests/database/a_stream_with_impls_ends_with_its_reader.silt
@@ -37,7 +37,7 @@ fn url() -> String {
 fn first(rows: Channel(Result(R, postgres.PostgresError))) -> String {
   match channel.receive(rows) {
     Some(Ok(row)) -> "the first row: {row}"
-    Some(Err(e)) -> e.message()
+    Some(Err(e)) -> Error.message(e)
     None -> "no row"
   }
 }
@@ -55,16 +55,16 @@ fn main() {
             let _ = channel.receive(never)
             "the function ended"
           }
-          Err(e) -> e.message()
+          Err(e) -> Error.message(e)
         }
       }
       match late {
         Ok(said) -> println(said)
-        Err(e) -> println("task.deadline: {e.message()}")
+        Err(e) -> println("task.deadline: {Error.message(e)}")
       }
       match postgres.query(pool, "SELECT 1 AS n, to_jsonb('1'::text) AS code", (), R) {
         Ok(rows) -> println("the next statement: {rows}")
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       let got: Channel(String) = channel.new(1)
       let reader = task.spawn { ->
@@ -75,7 +75,7 @@ fn main() {
             let _ = channel.receive(never)
             ()
           }
-          Err(e) -> channel.send(got, e.message())
+          Err(e) -> channel.send(got, Error.message(e))
         }
       }
       match channel.receive(got) {
@@ -85,6 +85,6 @@ fn main() {
       task.cancel(reader)
       println("the reader is cancelled, main returns")
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/a_stream_with_impls_keeps_its_rows_errors_and_end.silt b/tests/database/a_stream_with_impls_keeps_its_rows_errors_and_end.silt
index e3f603026..5924ca504 100644
--- a/tests/database/a_stream_with_impls_keeps_its_rows_errors_and_end.silt
+++ b/tests/database/a_stream_with_impls_keeps_its_rows_errors_and_end.silt
@@ -75,7 +75,7 @@ fn drain(rows: Channel(Result(R, postgres.PostgresError))) {
         true -> loop(n + 1)
         false -> (n, "row {n + 1} is out of order: {row}")
       }
-      Some(Err(e)) -> (n, "Err({e.message()})")
+      Some(Err(e)) -> (n, "Err({Error.message(e)})")
       None -> (n, "(end)")
     }
   }
@@ -93,7 +93,7 @@ fn stream(db: postgres.PgPool, n: String, code: String) {
   let sql = string.replace(string.replace(sql, ":n", n), ":code", code)
   match postgres.stream(db, sql, (), R) {
     Ok(rows) -> drain(rows)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
@@ -123,17 +123,17 @@ fn main() {
           channel.close(rows)
           println("  {n} rows, closed")
         }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       match postgres.query(db, "SELECT 1 AS n, to_jsonb('1'::text) AS code", (), R) {
         Ok(rows) -> println("  the next statement: {rows}")
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       println("in a transaction:")
       let done = postgres.transact(db) { tx ->
         match postgres.stream(tx, "SELECT g AS n, CASE WHEN g % 3 = 0 THEN NULL ELSE to_jsonb(g::text) END AS code FROM generate_series(1, 2000) g", (), R) {
           Ok(rows) -> drain(rows)
-          Err(e) -> println(e.message())
+          Err(e) -> println(Error.message(e))
         }
         Ok(())
       }
@@ -145,7 +145,7 @@ fn main() {
             match channel.receive(rows) {
               Some(Ok(row)) -> loop(n + 1, sum + row.slow.n)
               Some(Err(e)) -> {
-                println(e.message())
+                println(Error.message(e))
                 (n, sum)
               }
               None -> (n, sum)
@@ -153,10 +153,10 @@ fn main() {
           }
           println("  {n} rows, their sum {sum}")
         }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       postgres.close(db)
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/a_stream_with_impls_sends_each_row_when_it_is_finished.silt b/tests/database/a_stream_with_impls_sends_each_row_when_it_is_finished.silt
index 23091cf11..bc3b257a2 100644
--- a/tests/database/a_stream_with_impls_sends_each_row_when_it_is_finished.silt
+++ b/tests/database/a_stream_with_impls_sends_each_row_when_it_is_finished.silt
@@ -120,7 +120,7 @@ fn main() {
           println("  {first}")
           channel.close(rows)
         }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       println("an impl that waits for the reader:")
       match postgres.stream(db, "SELECT to_jsonb(g) AS step FROM generate_series(1, 5) g", (), T) {
@@ -131,11 +131,11 @@ fn main() {
                 println("  read {r.step.n}")
                 let _ = io.write_file(marker(r.step.n), "")
               }
-              Err(e) -> println("  Err {e.message()}")
+              Err(e) -> println("  Err {Error.message(e)}")
             }
           }
         }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       loop n = 1 {
         match n <= 5 {
@@ -153,7 +153,7 @@ fn main() {
           println("  {first}")
           channel.close(rows)
         }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       println("  the next statement: {postgres.query(db, "SELECT 1 AS n", (), One)}")
       println("an impl that calls env.set:")
@@ -163,7 +163,7 @@ fn main() {
             match channel.receive(rows) {
               Some(Ok(_)) -> loop(n + 1)
               Some(Err(e)) -> {
-                println("  Err {e.message()}")
+                println("  Err {Error.message(e)}")
                 n
               }
               None -> n
@@ -171,11 +171,11 @@ fn main() {
           }
           println("  {n} rows")
         }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       println("  F8P_SEEN: {env.get("F8P_SEEN")}")
       postgres.close(db)
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/aborted_transaction_is_not_committed.silt b/tests/database/aborted_transaction_is_not_committed.silt
index 46dbaa7e3..ea515f00e 100644
--- a/tests/database/aborted_transaction_is_not_committed.silt
+++ b/tests/database/aborted_transaction_is_not_committed.silt
@@ -23,14 +23,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -39,7 +39,7 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
 fn said(answer: Result(a, postgres.PostgresError)) -> String {
   match answer {
     Ok(_) -> "Ok"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
@@ -71,6 +71,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_aborted", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/an_impl_error_in_a_field_is_the_columns_type_mismatch.silt b/tests/database/an_impl_error_in_a_field_is_the_columns_type_mismatch.silt
index a737e5ce9..19f078f38 100644
--- a/tests/database/an_impl_error_in_a_field_is_the_columns_type_mismatch.silt
+++ b/tests/database/an_impl_error_in_a_field_is_the_columns_type_mismatch.silt
@@ -38,7 +38,7 @@ fn url() -> String {
 fn show(r: Result(a, postgres.PostgresError)) -> String where a: Display {
   match r {
     Ok(v) -> "Ok({v})"
-    Err(e) -> "Err({e.message()})"
+    Err(e) -> "Err({Error.message(e)})"
   }
 }
 
@@ -65,6 +65,6 @@ fn main() {
       println("transact: {read}")
       postgres.close(db)
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/bytes_as_a_field_or_in_a_list_is_read.silt b/tests/database/bytes_as_a_field_or_in_a_list_is_read.silt
index 4faf3cbdc..9017326d7 100644
--- a/tests/database/bytes_as_a_field_or_in_a_list_is_read.silt
+++ b/tests/database/bytes_as_a_field_or_in_a_list_is_read.silt
@@ -20,7 +20,7 @@ fn rows(db: postgres.PgPool, sql: String, type a) -> Result(List(a), postgres.Po
 fn show(r: Result(List(a), postgres.PostgresError)) {
   match r {
     Ok(rows) -> println("{list.length(rows)} rows")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
@@ -30,6 +30,6 @@ fn main() {
       show(rows(db, "SELECT '\\x00ff'::bytea AS b, ARRAY['\\x01'::bytea] AS bs", Plain))
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/callback_deadline_aborts_its_transaction.silt b/tests/database/callback_deadline_aborts_its_transaction.silt
index 7bd29c042..fe90385a6 100644
--- a/tests/database/callback_deadline_aborts_its_transaction.silt
+++ b/tests/database/callback_deadline_aborts_its_transaction.silt
@@ -32,14 +32,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -48,7 +48,7 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
 fn said(answer: Result(a, postgres.PostgresError)) -> String {
   match answer {
     Ok(_) -> "Ok"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
@@ -79,7 +79,7 @@ fn main() {
           println(
             match late {
               Ok(answer) -> "the statement: {said(answer)}"
-              Err(e) -> "task.deadline: {e.message()}"
+              Err(e) -> "task.deadline: {Error.message(e)}"
             },
           )
           println("the next statement: {said(postgres.execute(tx, "SELECT 1", ()))}")
@@ -116,6 +116,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_callback_deadline", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/cancel_of_a_statement_in_a_transaction.silt b/tests/database/cancel_of_a_statement_in_a_transaction.silt
index a981785e7..8988cbace 100644
--- a/tests/database/cancel_of_a_statement_in_a_transaction.silt
+++ b/tests/database/cancel_of_a_statement_in_a_transaction.silt
@@ -31,14 +31,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -86,7 +86,7 @@ fn main() {
           }
           match ended {
             Ok(said) -> println("the task went on with {said}")
-            Err(e) -> println("the task went on with {e.message()}")
+            Err(e) -> println("the task went on with {Error.message(e)}")
           }
         }
         println("statements that wait for it in the server: {until(pool, waiting(), 1)}")
@@ -102,6 +102,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_cancel_tx", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/cancel_of_a_statement_in_flight.silt b/tests/database/cancel_of_a_statement_in_flight.silt
index 12f5cbc4e..24d3a197e 100644
--- a/tests/database/cancel_of_a_statement_in_flight.silt
+++ b/tests/database/cancel_of_a_statement_in_flight.silt
@@ -32,14 +32,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -93,6 +93,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_cancel", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/cancel_request_reaches_no_other_statement.silt b/tests/database/cancel_request_reaches_no_other_statement.silt
index 5c6bf8884..de62b6244 100644
--- a/tests/database/cancel_request_reaches_no_other_statement.silt
+++ b/tests/database/cancel_request_reaches_no_other_statement.silt
@@ -49,6 +49,6 @@ fn main() {
       println("rounds in which main's statement failed: {failed}")
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/cancelled_task_starts_no_statement.silt b/tests/database/cancelled_task_starts_no_statement.silt
index 3d2746b46..f10f883b3 100644
--- a/tests/database/cancelled_task_starts_no_statement.silt
+++ b/tests/database/cancelled_task_starts_no_statement.silt
@@ -36,14 +36,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -77,7 +77,7 @@ fn main() {
           json.Value,
         ) {
           Ok(rows) -> channel.send(streams, rows)
-          Err(e) -> println("postgres.stream: {e.message()}")
+          Err(e) -> println("postgres.stream: {Error.message(e)}")
         }
         let _ = postgres.execute(
           pool,
@@ -108,6 +108,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_cancelled", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/channel_each_raises_the_failure_of_a_streams_impl.silt b/tests/database/channel_each_raises_the_failure_of_a_streams_impl.silt
index 2747f7f43..a74e8c591 100644
--- a/tests/database/channel_each_raises_the_failure_of_a_streams_impl.silt
+++ b/tests/database/channel_each_raises_the_failure_of_a_streams_impl.silt
@@ -33,10 +33,10 @@ fn main() {
       let sql = "SELECT to_jsonb(3 - g) AS code FROM generate_series(1, 4) g"
       match postgres.stream(db, sql, (), R) {
         Ok(rows) -> channel.each(rows) { row -> println(row) }
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
       println("not reached")
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/database/connect_errors.silt b/tests/database/connect_errors.silt
index f161a3b74..7bed2d5ba 100644
--- a/tests/database/connect_errors.silt
+++ b/tests/database/connect_errors.silt
@@ -36,7 +36,7 @@ fn said(answer: Result(postgres.PgPool, postgres.PostgresError), told: Bool) ->
         _ -> "another error"
       }
       match told {
-        true -> "{variant}: {e.message()}"
+        true -> "{variant}: {Error.message(e)}"
         false -> variant
       }
     }
diff --git a/tests/database/connect_to_a_server_that_never_answers.silt b/tests/database/connect_to_a_server_that_never_answers.silt
index 13b93673c..93d636653 100644
--- a/tests/database/connect_to_a_server_that_never_answers.silt
+++ b/tests/database/connect_to_a_server_that_never_answers.silt
@@ -20,7 +20,7 @@ fn until_closed(conn: tcp.TcpStream) -> String {
         0 -> "the client closed the connection"
         _ -> loop()
       }
-      Err(e) -> "the read failed: {e.message()}"
+      Err(e) -> "the read failed: {Error.message(e)}"
     }
   }
 }
@@ -38,7 +38,7 @@ fn main() {
       println("connect: connected")
     }
     Err(postgres.Timeout) -> println("connect: Timeout")
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
   when let Ok(conn) = task.join(server) else {
     panic("cannot accept")
diff --git a/tests/database/dates_go_back_as_they_were_read.silt b/tests/database/dates_go_back_as_they_were_read.silt
index 5a9790f35..27c197d57 100644
--- a/tests/database/dates_go_back_as_they_were_read.silt
+++ b/tests/database/dates_go_back_as_they_were_read.silt
@@ -89,6 +89,6 @@ fn main() {
       println("done: {done}")
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/deadline_over_a_statement_in_a_transaction.silt b/tests/database/deadline_over_a_statement_in_a_transaction.silt
index 10355837b..c0f7a8fc8 100644
--- a/tests/database/deadline_over_a_statement_in_a_transaction.silt
+++ b/tests/database/deadline_over_a_statement_in_a_transaction.silt
@@ -33,14 +33,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -90,8 +90,8 @@ fn main() {
           }
           match late {
             Ok(Ok(said)) -> "the function ended with {said}"
-            Ok(Err(e)) -> "the function ended with {e.message()}"
-            Err(e) -> "task.deadline: {e.message()}"
+            Ok(Err(e)) -> "the function ended with {Error.message(e)}"
+            Err(e) -> "task.deadline: {Error.message(e)}"
           }
         }
         println("statements that wait for it in the server: {until(pool, waiting(), 1)}")
@@ -106,6 +106,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_deadline_tx", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/deadline_over_a_statement_in_flight.silt b/tests/database/deadline_over_a_statement_in_flight.silt
index be666dc3b..a181c476e 100644
--- a/tests/database/deadline_over_a_statement_in_flight.silt
+++ b/tests/database/deadline_over_a_statement_in_flight.silt
@@ -30,14 +30,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -76,13 +76,13 @@ fn main() {
             (),
           ) {
             Ok(_) -> "the statement's answer"
-            Err(e) -> e.message()
+            Err(e) -> Error.message(e)
           }
         }
         println(
           match late {
             Ok(said) -> "the function ended with {said}"
-            Err(e) -> "task.deadline: {e.message()}"
+            Err(e) -> "task.deadline: {Error.message(e)}"
           },
         )
         println("statements that wait for the lock in the server: {until(pool, waiting(), 1)}")
@@ -97,6 +97,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_deadline", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/deadline_while_waiting_for_a_connection.silt b/tests/database/deadline_while_waiting_for_a_connection.silt
index cd4c15356..a42a151b8 100644
--- a/tests/database/deadline_while_waiting_for_a_connection.silt
+++ b/tests/database/deadline_while_waiting_for_a_connection.silt
@@ -31,8 +31,8 @@ fn main() {
         println(
           match late {
             Ok(Ok(said)) -> "the function ended with {said}"
-            Ok(Err(e)) -> "the function ended with {e.message()}"
-            Err(e) -> "task.deadline: {e.message()}"
+            Ok(Err(e)) -> "the function ended with {Error.message(e)}"
+            Err(e) -> "task.deadline: {Error.message(e)}"
           },
         )
         postgres.query(tx, "SELECT 1", (), json.Value)
@@ -40,11 +40,11 @@ fn main() {
       println(
         match done {
           Ok(_) -> "main's transaction: Ok"
-          Err(e) -> "main's transaction: {e.message()}"
+          Err(e) -> "main's transaction: {Error.message(e)}"
         },
       )
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/errors_of_statements.silt b/tests/database/errors_of_statements.silt
index 0efd779bb..2fd1c9649 100644
--- a/tests/database/errors_of_statements.silt
+++ b/tests/database/errors_of_statements.silt
@@ -25,14 +25,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -41,7 +41,7 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
 fn said(answer: Result(a, postgres.PostgresError)) -> String {
   match answer {
     Ok(_) -> "Ok"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
@@ -114,6 +114,6 @@ fn main() {
       postgres.close(pool)
       show("a closed pool", postgres.query(pool, "SELECT 1", (), json.Value))
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/execute_counts_and_returning.silt b/tests/database/execute_counts_and_returning.silt
index 7e4afe1fd..6d5b5b536 100644
--- a/tests/database/execute_counts_and_returning.silt
+++ b/tests/database/execute_counts_and_returning.silt
@@ -52,10 +52,10 @@ fn main() {
     Ok(db) -> {
       match counts(db) {
         Ok(left) -> println("left: {left}")
-        Err(e) -> println("failed: {e.message()}")
+        Err(e) -> println("failed: {Error.message(e)}")
       }
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/io_timeout_leaves_a_commit_alone.silt b/tests/database/io_timeout_leaves_a_commit_alone.silt
index 311d7660d..756ba6c45 100644
--- a/tests/database/io_timeout_leaves_a_commit_alone.silt
+++ b/tests/database/io_timeout_leaves_a_commit_alone.silt
@@ -24,14 +24,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -40,7 +40,7 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
 fn said(answer: Result(a, postgres.PostgresError)) -> String {
   match answer {
     Ok(_) -> "Ok"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
@@ -69,6 +69,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP FUNCTION silt_database_io_timeout_slow()", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/parameters_of_every_type.silt b/tests/database/parameters_of_every_type.silt
index 461213a0f..eea2abdbe 100644
--- a/tests/database/parameters_of_every_type.silt
+++ b/tests/database/parameters_of_every_type.silt
@@ -31,7 +31,7 @@ fn url() -> String {
 fn show(db: postgres.PgPool, what: String, sql: String, ps: p) {
   match postgres.query(db, sql, ps, Out) {
     Ok(rows) -> println("{what}: {rows}")
-    Err(e) -> println("{what}: {e.message()}")
+    Err(e) -> println("{what}: {Error.message(e)}")
   }
 }
 
@@ -70,10 +70,10 @@ fn main() {
       show(db, "none", "SELECT 'no parameters' AS v", ())
       match postgres.query(db, "SELECT id FROM generate_series(1, 9) AS id WHERE id = ANY($1)", ([2, 5],), Ids) {
         Ok(rows) -> println("= ANY($1): {rows}")
-        Err(e) -> println("= ANY($1): {e.message()}")
+        Err(e) -> println("= ANY($1): {Error.message(e)}")
       }
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/rows_of_every_decoded_type.silt b/tests/database/rows_of_every_decoded_type.silt
index 4d60d268f..e5c09f379 100644
--- a/tests/database/rows_of_every_decoded_type.silt
+++ b/tests/database/rows_of_every_decoded_type.silt
@@ -92,10 +92,10 @@ fn main() {
     Ok(db) -> {
       match row(db) {
         Ok(_) -> ()
-        Err(e) -> println("failed: {e.message()}")
+        Err(e) -> println("failed: {Error.message(e)}")
       }
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/rows_that_do_not_fit.silt b/tests/database/rows_that_do_not_fit.silt
index 6b22c7d81..f6f9bd1a8 100644
--- a/tests/database/rows_that_do_not_fit.silt
+++ b/tests/database/rows_that_do_not_fit.silt
@@ -61,7 +61,7 @@ fn said(e: postgres.PostgresError) -> String {
     postgres.Other(text) -> "Other({text})"
     _ -> "another error"
   }
-  "{variant}\n  {e.message()}"
+  "{variant}\n  {Error.message(e)}"
 }
 
 fn show(what: String, answer: Result(List(a), postgres.PostgresError)) where a: Display {
@@ -111,6 +111,6 @@ fn main() {
       let _ = postgres.execute(db, "DROP TABLE pg2_fit", ())
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/select_one.silt b/tests/database/select_one.silt
index df8e0216d..07557b99f 100644
--- a/tests/database/select_one.silt
+++ b/tests/database/select_one.silt
@@ -17,10 +17,10 @@ fn main() {
     Ok(pool) -> {
       match postgres.query(pool, "SELECT 1 AS one", (), One) {
         Ok(rows) -> println(rows)
-        Err(e) -> println("query: {e.message()}")
+        Err(e) -> println("query: {Error.message(e)}")
       }
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/stream_and_cursor_of_a_record_type.silt b/tests/database/stream_and_cursor_of_a_record_type.silt
index 633e4602f..71b74cd7f 100644
--- a/tests/database/stream_and_cursor_of_a_record_type.silt
+++ b/tests/database/stream_and_cursor_of_a_record_type.silt
@@ -29,13 +29,13 @@ fn drain(db: postgres.PgPool, sql: String) {
           loop()
         }
         Some(Err(e)) -> {
-          println("  Err: {e.message()}")
+          println("  Err: {Error.message(e)}")
           loop()
         }
         None -> println("  closed")
       }
     }
-    Err(e) -> println("  stream: {e.message()}")
+    Err(e) -> println("  stream: {Error.message(e)}")
   }
 }
 
@@ -71,10 +71,10 @@ fn main() {
       }
       match refused {
         Ok(rows) -> println("a cursor that does not fit: {rows}")
-        Err(e) -> println("a cursor that does not fit: {e.message()}")
+        Err(e) -> println("a cursor that does not fit: {Error.message(e)}")
       }
       postgres.close(db)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/stream_closed_by_its_receiver.silt b/tests/database/stream_closed_by_its_receiver.silt
index c7ab5c9cc..2c267eff8 100644
--- a/tests/database/stream_closed_by_its_receiver.silt
+++ b/tests/database/stream_closed_by_its_receiver.silt
@@ -35,14 +35,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -84,7 +84,7 @@ fn main() {
                 let pad = string.length(row.pad)
                 "the first row: mark {row.silt_database_stream_closed_mark}, a pad of {pad}"
               }
-              Some(Err(e)) -> e.message()
+              Some(Err(e)) -> Error.message(e)
               _ -> "no row"
             },
           )
@@ -95,14 +95,14 @@ fn main() {
           println("closed by the receiver")
           println("sessions that run it after the close: {until(watch, running(), 0)}")
         }
-        Err(e) -> println("postgres.stream: {e.message()}")
+        Err(e) -> println("postgres.stream: {Error.message(e)}")
       }
       let after = count(pool, "SELECT 1")
       println("the pool answers after it: {after} row")
       postgres.close(pool)
       postgres.close(watch)
     }
-    (Err(e), _) -> println("connect: {e.message()}")
-    (_, Err(e)) -> println("connect: {e.message()}")
+    (Err(e), _) -> println("connect: {Error.message(e)}")
+    (_, Err(e)) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/stream_left_unread.silt b/tests/database/stream_left_unread.silt
index 5e7c3fb59..69386792a 100644
--- a/tests/database/stream_left_unread.silt
+++ b/tests/database/stream_left_unread.silt
@@ -26,14 +26,14 @@ fn main() {
         println(
           match channel.receive(rows) {
             Some(Ok(row)) -> "the first row is {row}"
-            Some(Err(e)) -> e.message()
+            Some(Err(e)) -> Error.message(e)
             _ -> "no row"
           },
         )
         println("main returns, the stream unread")
       }
-      Err(e) -> println("postgres.stream: {e.message()}")
+      Err(e) -> println("postgres.stream: {Error.message(e)}")
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/stream_left_unread_in_a_transaction.silt b/tests/database/stream_left_unread_in_a_transaction.silt
index 574bdc246..7bd166fdc 100644
--- a/tests/database/stream_left_unread_in_a_transaction.silt
+++ b/tests/database/stream_left_unread_in_a_transaction.silt
@@ -25,14 +25,14 @@ fn count(pool: postgres.PgPool, sql: String) -> Int {
       match channel.receive(rows) {
         Some(Ok(_)) -> loop(n + 1)
         Some(Err(e)) -> {
-          println("count: {e.message()}")
+          println("count: {Error.message(e)}")
           -1
         }
         _ -> n
       }
     }
     Err(e) -> {
-      println("count: {e.message()}")
+      println("count: {Error.message(e)}")
       -1
     }
   }
@@ -54,7 +54,7 @@ fn main() {
             println(
               match channel.receive(rows) {
                 Some(Ok(_)) -> "the stream gave a row"
-                Some(Err(e)) -> e.message()
+                Some(Err(e)) -> Error.message(e)
                 _ -> "no row"
               },
             )
@@ -69,6 +69,6 @@ fn main() {
       let _ = postgres.execute(pool, "DROP TABLE silt_database_stream_in_tx", ())
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/stream_of_a_cancelled_reader.silt b/tests/database/stream_of_a_cancelled_reader.silt
index 4b51f2b80..b48b149c2 100644
--- a/tests/database/stream_of_a_cancelled_reader.silt
+++ b/tests/database/stream_of_a_cancelled_reader.silt
@@ -27,7 +27,7 @@ fn main() {
           Ok(rows) -> {
             let first = match channel.receive(rows) {
               Some(Ok(_)) -> "the reader has a row"
-              Some(Err(e)) -> e.message()
+              Some(Err(e)) -> Error.message(e)
               _ -> "no row"
             }
             channel.send(got, first)
@@ -36,7 +36,7 @@ fn main() {
             let _ = channel.receive(got)
             ()
           }
-          Err(e) -> channel.send(got, "postgres.stream: {e.message()}")
+          Err(e) -> channel.send(got, "postgres.stream: {Error.message(e)}")
         }
       }
       match channel.receive(got) {
@@ -46,6 +46,6 @@ fn main() {
       task.cancel(reader)
       println("the reader is cancelled, main returns")
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/database/transaction_used_after_its_end.silt b/tests/database/transaction_used_after_its_end.silt
index 976126f6d..7c3b1f906 100644
--- a/tests/database/transaction_used_after_its_end.silt
+++ b/tests/database/transaction_used_after_its_end.silt
@@ -20,7 +20,7 @@ fn said(answer: Result(a, postgres.PostgresError)) -> String {
   match answer {
     Ok(_) -> "Ok"
     Err(postgres.Closed) -> "Closed"
-    Err(e) -> "another error: {e.message()}"
+    Err(e) -> "another error: {Error.message(e)}"
   }
 }
 
@@ -56,6 +56,6 @@ fn main() {
       }
       postgres.close(pool)
     }
-    Err(e) -> println("connect: {e.message()}")
+    Err(e) -> println("connect: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/cli/disasm/disasm_rendering__a_method_found_by_a_later_argument.silt b/tests/golden/cli/disasm/disasm_rendering__a_method_found_by_a_later_argument.silt
new file mode 100644
index 000000000..501702d5a
--- /dev/null
+++ b/tests/golden/cli/disasm/disasm_rendering__a_method_found_by_a_later_argument.silt
@@ -0,0 +1,22 @@
+-- cmd: disasm
+-- A call through a trait whose argument of type Self is not the first,
+-- on a bounded type variable: `CallMethod` finds the method by that
+-- argument, which the disassembly names.
+-- stdout-contains: TailCallMethod       0     2   ; "scale" of Scale, by argument 1
+trait Scale {
+  fn scale(by: Int, x: Self) -> Self
+}
+
+trait Scale for Int {
+  fn scale(by: Int, x: Self) -> Self {
+    by * x
+  }
+}
+
+fn twice(x: a) -> a where a: Scale {
+  Scale.scale(2, x)
+}
+
+fn main() {
+  println(twice(5))
+}
diff --git a/tests/golden/cli/disasm/disasm_rendering__record_update_method_builtin_variant.silt b/tests/golden/cli/disasm/disasm_rendering__record_update_method_builtin_variant.silt
index e0cda824f..d68e0de09 100644
--- a/tests/golden/cli/disasm/disasm_rendering__record_update_method_builtin_variant.silt
+++ b/tests/golden/cli/disasm/disasm_rendering__record_update_method_builtin_variant.silt
@@ -1,12 +1,11 @@
 -- cmd: disasm
--- The operand rendering of the opcodes main compiles to. `q.display()`
--- on a record with no Display impl of its own is the VM's own method
--- of the trait (CallMethod).
+-- The operand rendering of the opcodes main compiles to. `Hash.hash(q)`
+-- on a record is the VM's own method of the trait (CallMethod).
 -- (Variant construction compiles to the constructor as a constant + Call.)
 -- stdout-contains: == main (arity=0, upvalues=0) ==
 -- stdout-contains: RecordUpdate         1
 -- stdout-contains: |  field 3     ; "x"
--- stdout-contains: CallMethod           0     1   ; "display" of Display
+-- stdout-contains: CallMethod           0     1   ; "hash" of Hash
 -- stdout-contains: CallBuiltin          1     ; string.length
 -- stdout-contains: Constant             8     ; <constructor:Circle>
 import string
@@ -21,7 +20,7 @@ type Shape {
 fn main() {
   let p = Point { x: 1, y: 2 }
   let q = p.{ x: 5 }
-  println(q.display())
+  println(Hash.hash(q))
   println(string.length("abc"))
   let s = Circle(3)
   println(s)
diff --git a/tests/golden/cli/disasm/disasm_slots__globals_named_by_definition/main.silt b/tests/golden/cli/disasm/disasm_slots__globals_named_by_definition/main.silt
index cd88bb7ae..4d67fb837 100644
--- a/tests/golden/cli/disasm/disasm_slots__globals_named_by_definition/main.silt
+++ b/tests/golden/cli/disasm/disasm_slots__globals_named_by_definition/main.silt
@@ -8,10 +8,11 @@
 -- stdout-contains: ; util.secret
 -- stdout-contains: ; Pt.display
 import util
+import string
 type Pt { x: Int }
 trait Display for Pt { fn display(self) -> String { "pt" } }
 let limit = 3
 fn main() {
   println(util.helper(limit))
-  println(Pt { x: 1 }.display())
+  println(string.from(Pt { x: 1 }))
 }
diff --git a/tests/golden/cli/doors/stage5_doors__trait_item_import_runs/main.silt b/tests/golden/cli/doors/stage5_doors__trait_item_import_runs/main.silt
index bbbb90fec..2d3d03aba 100644
--- a/tests/golden/cli/doors/stage5_doors__trait_item_import_runs/main.silt
+++ b/tests/golden/cli/doors/stage5_doors__trait_item_import_runs/main.silt
@@ -9,6 +9,6 @@ fn first(p: Pair(Int)) -> Int {
 }
 
 fn main() {
-  println(5.describe())
+  println(Describe.describe(5))
   println(first((1, 2)))
 }
diff --git a/tests/golden/cli/repl/repl__a_failed_entry__display_impl_with_a_wrong_body.silt b/tests/golden/cli/repl/repl__a_failed_entry__display_impl_with_a_wrong_body.silt
index fa8c89e6c..4642c0873 100644
--- a/tests/golden/cli/repl/repl__a_failed_entry__display_impl_with_a_wrong_body.silt
+++ b/tests/golden/cli/repl/repl__a_failed_entry__display_impl_with_a_wrong_body.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
 -- stderr-contains: type mismatch: expected String, got Int
--- stdin: type U { U(Int) }\n"{U(1)}"\ntrait Display for U { fn display(self) -> String { 3 } }\n"{U(1)}"\nU(2)\n[U(3)]\nU(4).display()\nprintln(U(5))\nfn show(x: a) -> String where a: Display { "{x}" }\nshow(U(6))\nU(7) == U(7)\n:quit\n
+-- stdin: type U { U(Int) }\n"{U(1)}"\ntrait Display for U { fn display(self) -> String { 3 } }\n"{U(1)}"\nU(2)\n[U(3)]\n"{U(4)}"\nprintln(U(5))\nfn show(x: a) -> String where a: Display { "{x}" }\nshow(U(6))\nU(7) == U(7)\n:quit\n
 -- An entry that writes a Display impl and fails leaves the session as it
 -- was: the type is shown, printed and bounded by its structure as before.
diff --git a/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.silt b/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.silt
index e744263f5..d6767880d 100644
--- a/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.silt
+++ b/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.silt
@@ -1,7 +1,6 @@
 -- cmd: repl
 -- stderr-contains: type mismatch: expected Int, got String
--- stderr-contains: ambiguous method 'm' on type 'U': provided by traits
--- stdin: type U { U(Int) }\ntrait A { fn m(self) -> String }\ntrait A for U { fn m(self) -> String { "a" } }\nU(1).m()\ntrait B { fn m(self) -> Int }\nU(1).m()\ntrait B for U { fn m(self) -> Int { "bad" } }\nU(1).m()\nfn go(x: U) -> String { x.m() }\ngo(U(2))\ntrait B for U { fn m(self) -> Int { 7 } }\nU(1).m()\n:quit\n
+-- stdin: type U { U(Int) }\ntrait A { fn m(self) -> String }\ntrait A for U { fn m(self) -> String { "a" } }\nA.m(U(1))\ntrait B { fn m(self) -> Int }\nA.m(U(1))\ntrait B for U { fn m(self) -> Int { "bad" } }\nA.m(U(1))\nfn go(x: U) -> String { A.m(x) }\ngo(U(2))\ntrait B for U { fn m(self) -> Int { 7 } }\nA.m(U(1))\nB.m(U(1))\n:quit\n
 -- Two traits with a method `m`: the failed impl of the second leaves the
 -- first one's `m` (it was lost: the row of the method table was written
--- over). With both impls the call is ambiguous.
+-- over). With both impls each call names its trait.
diff --git a/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.stdout b/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.stdout
index 726c5d362..551f27b94 100644
--- a/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.stdout
+++ b/tests/golden/cli/repl/repl__a_failed_entry__second_trait_with_a_method_of_the_same_name.stdout
@@ -3,3 +3,5 @@ a
 a
 a
 a
+a
+7
diff --git a/tests/golden/cli/repl/repl__a_failed_entry__user_trait_with_structural_method_names.silt b/tests/golden/cli/repl/repl__a_failed_entry__user_trait_with_structural_method_names.silt
index 136c5581f..78b6fef71 100644
--- a/tests/golden/cli/repl/repl__a_failed_entry__user_trait_with_structural_method_names.silt
+++ b/tests/golden/cli/repl/repl__a_failed_entry__user_trait_with_structural_method_names.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
 -- stderr-contains: type mismatch: expected Int, got String
--- stdin: type U { U(Int) }\ntrait Mine { fn equal(self, o: Self) -> Int\n  fn hash(self) -> String\n  fn display(self) -> Int }\nU(1).equal(U(1))\ntrait Mine for U { fn equal(self, o: Self) -> Int { "bad" }\n  fn hash(self) -> String { "h" }\n  fn display(self) -> Int { 1 } }\nU(1).equal(U(1))\nU(1) == U(1)\n#{ U(1): 1 }\n"{U(1)}"\nU(1).display()\nfn need_e(x: a) -> Int where a: Equal { 1 }\nneed_e(U(1))\n:quit\n
+-- stdin: type U { U(Int) }\ntrait Mine { fn equal(self, o: Self) -> Int\n  fn hash(self) -> String\n  fn display(self) -> Int }\nU(1) == U(1)\ntrait Mine for U { fn equal(self, o: Self) -> Int { "bad" }\n  fn hash(self) -> String { "h" }\n  fn display(self) -> Int { 1 } }\nU(1) == U(1)\nU(1) == U(1)\n#{ U(1): 1 }\n"{U(1)}"\n"{U(1)}"\nfn need_e(x: a) -> Int where a: Equal { 1 }\nneed_e(U(1))\n:quit\n
 -- A trait of the session with methods named `equal`, `hash` and `display`:
 -- its failed impl changes nothing of what those names mean for the type.
diff --git a/tests/golden/cli/repl/repl__a_trait_method_on_a_type_variable_is_checked_at_a_later_entry.silt b/tests/golden/cli/repl/repl__a_trait_method_on_a_type_variable_is_checked_at_a_later_entry.silt
index 6b2b71355..b5d2bbab0 100644
--- a/tests/golden/cli/repl/repl__a_trait_method_on_a_type_variable_is_checked_at_a_later_entry.silt
+++ b/tests/golden/cli/repl/repl__a_trait_method_on_a_type_variable_is_checked_at_a_later_entry.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: import json\ntype Src { s: String }\ntrait Loader { fn load(self, type a) -> Result(a, json.JsonError) where a: json.Decode }\ntrait Loader for Src { fn load(self, type a) -> Result(a, json.JsonError) { json.parse(self.s, a) } }\nfn go(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode { l.load(b) }\ntype Blob { b: Bytes }\ntype Fine { n: Int }\ngo(Src { s: "\{\"n\": 1}" }, Fine)\ngo(Src { s: "\{}" }, Blob)\n:quit\n
+-- stdin: import json\ntype Src { s: String }\ntrait Loader { fn load(self, type a) -> Result(a, json.JsonError) where a: json.Decode }\ntrait Loader for Src { fn load(self, type a) -> Result(a, json.JsonError) { json.parse(self.s, a) } }\nfn go(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode { Loader.load(l, b) }\ntype Blob { b: Bytes }\ntype Fine { n: Int }\ngo(Src { s: "\{\"n\": 1}" }, Fine)\ngo(Src { s: "\{}" }, Blob)\n:quit\n
 -- A trait, its impl and a generic function that calls its method on a
 -- bounded parameter, each in an entry of its own: a later entry that
 -- calls the function is checked with the type it gives.
diff --git a/tests/golden/cli/repl/repl__an_impl_for_a_type_of_an_earlier_entry.silt b/tests/golden/cli/repl/repl__an_impl_for_a_type_of_an_earlier_entry.silt
index b0dd0cdd6..dfe40b51d 100644
--- a/tests/golden/cli/repl/repl__an_impl_for_a_type_of_an_earlier_entry.silt
+++ b/tests/golden/cli/repl/repl__an_impl_for_a_type_of_an_earlier_entry.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: type P { n: Int }\nlet p = P { n: 1 }\np\ntrait Display for P { fn display(self) -> String { "#{self.n}" } }\np\n[p, P { n: 2 }]\ntrait Sz { fn sz(self) -> Int }\ntrait Sz for P { fn sz(self) -> Int { self.n } }\np.sz()\n:quit\n
+-- stdin: type P { n: Int }\nlet p = P { n: 1 }\np\ntrait Display for P { fn display(self) -> String { "#{self.n}" } }\np\n[p, P { n: 2 }]\ntrait Sz { fn sz(self) -> Int }\ntrait Sz for P { fn sz(self) -> Int { self.n } }\nSz.sz(p)\n:quit\n
 -- The entries of one session count as one module for where an impl is
 -- written: a type of one entry gets its `Display` impl, and an impl of
 -- a trait of another entry, in a later one. A value made before the
diff --git a/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_but_referred_to.silt b/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_but_referred_to.silt
index 927e7ced4..9d00195ec 100644
--- a/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_but_referred_to.silt
+++ b/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_but_referred_to.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: trait Greet { fn greet(self) -> String }\ntrait Greet for Int { fn greet(self) -> String { "int" } }\nfn hello(x: a) -> String where a: Greet { x.greet() }\nimport channel\nlet ch = channel.new(4)\nfn f() {\n  match channel.try_receive(ch) {\n    channel.Message(m) -> println(hello(m))\n    _ -> println("none")\n  }\n}\nfn g() { f() }\nfn f() { println("new f") }\nchannel.send(ch, "s")\ng()\n:quit\n
+-- stdin: trait Greet { fn greet(self) -> String }\ntrait Greet for Int { fn greet(self) -> String { "int" } }\nfn hello(x: a) -> String where a: Greet { Greet.greet(x) }\nimport channel\nlet ch = channel.new(4)\nfn f() {\n  match channel.try_receive(ch) {\n    channel.Message(m) -> println(hello(m))\n    _ -> println("none")\n  }\n}\nfn g() { f() }\nfn f() { println("new f") }\nchannel.send(ch, "s")\ng()\n:quit\n
 -- stderr-contains: error[type]: this input gives a value a type an earlier input does not allow: type 'String' does not implement trait 'Greet'
 -- stderr-contains: --> <repl:9>:1:1
 -- A cell is bound to what its names meant when it was entered: `g`
diff --git a/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_function.silt b/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_function.silt
index 081bc2c52..c82ee6568 100644
--- a/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_function.silt
+++ b/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__redefined_function.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: trait Greet { fn greet(self) -> String }\ntrait Greet for Int { fn greet(self) -> String { "int" } }\nfn hello(x: a) -> String where a: Greet { x.greet() }\nimport channel\nlet ch = channel.new(4)\nfn f() {\n  match channel.try_receive(ch) {\n    channel.Message(m) -> println(hello(m))\n    _ -> println("none")\n  }\n}\nfn f() { println("new f") }\nchannel.send(ch, "s")\nf()\n:quit\n
+-- stdin: trait Greet { fn greet(self) -> String }\ntrait Greet for Int { fn greet(self) -> String { "int" } }\nfn hello(x: a) -> String where a: Greet { Greet.greet(x) }\nimport channel\nlet ch = channel.new(4)\nfn f() {\n  match channel.try_receive(ch) {\n    channel.Message(m) -> println(hello(m))\n    _ -> println("none")\n  }\n}\nfn f() { println("new f") }\nchannel.send(ch, "s")\nf()\n:quit\n
 -- stderr-not-contains: error
 -- A check that waits in a function's body goes with the function: once
 -- `f` is defined again and nothing refers to the old one, the channel
diff --git a/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__where_bound.silt b/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__where_bound.silt
index 894797206..a6d1b1c6b 100644
--- a/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__where_bound.silt
+++ b/tests/golden/cli/repl/repl__check_waits_for_a_later_cell__where_bound.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: trait Greet { fn greet(self) -> String }\ntrait Greet for Int { fn greet(self) -> String { "int" } }\nfn hello(x: a) -> String where a: Greet { x.greet() }\nimport channel\nlet ch = channel.new(4)\nfn f() {\n  match channel.receive(ch) {\n    Some(m) -> println(hello(m))\n    None -> ()\n  }\n}\nchannel.send(ch, "s")\nchannel.send(ch, 3)\nf()\n:quit\n
+-- stdin: trait Greet { fn greet(self) -> String }\ntrait Greet for Int { fn greet(self) -> String { "int" } }\nfn hello(x: a) -> String where a: Greet { Greet.greet(x) }\nimport channel\nlet ch = channel.new(4)\nfn f() {\n  match channel.receive(ch) {\n    Some(m) -> println(hello(m))\n    None -> ()\n  }\n}\nchannel.send(ch, "s")\nchannel.send(ch, 3)\nf()\n:quit\n
 -- stderr-contains: error[type]: this input gives a value a type an earlier input does not allow: type 'String' does not implement trait 'Greet'
 -- stderr-contains: --> <repl:7>:1:1
 -- stderr-contains: ::: <repl:6>:3:30
diff --git a/tests/golden/cli/repl/repl__default_method_of_a_trait_of_an_earlier_entry.silt b/tests/golden/cli/repl/repl__default_method_of_a_trait_of_an_earlier_entry.silt
index d64f7da31..000135f22 100644
--- a/tests/golden/cli/repl/repl__default_method_of_a_trait_of_an_earlier_entry.silt
+++ b/tests/golden/cli/repl/repl__default_method_of_a_trait_of_an_earlier_entry.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: type P { n: Int }\ntrait Sz { fn sz(self) -> Int  fn dbl(self) -> Int { self.sz() * 2 } }\ntrait Sz for Int { fn sz(self) -> Int { self } }\n4.dbl()\nfn dy(x: a) -> Int where a: Sz { x.dbl() }\ndy(4)\nlet k = 5\ntrait Sz for P { fn sz(self) -> Int { self.n + k } }\nP { n: 1 }.sz()\nP { n: 1 }.dbl()\ndy(P { n: 2 })\nP.sz(P { n: 9 })\nP.dbl(P { n: 9 })\nimport list\nlist.map([P { n: 1 }], P.dbl)\n:quit\n
+-- stdin: type P { n: Int }\ntrait Sz { fn sz(self) -> Int  fn dbl(self) -> Int { Sz.sz(self) * 2 } }\ntrait Sz for Int { fn sz(self) -> Int { self } }\nSz.dbl(4)\nfn dy(x: a) -> Int where a: Sz { Sz.dbl(x) }\ndy(4)\nlet k = 5\ntrait Sz for P { fn sz(self) -> Int { self.n + k } }\nSz.sz(P { n: 1 })\nSz.dbl(P { n: 1 })\ndy(P { n: 2 })\nSz.sz(P { n: 9 })\nSz.dbl(P { n: 9 })\nimport list\nlist.map([P { n: 1 }], Sz.dbl)\n:quit\n
 -- A default method is the trait's one function, for every impl that
 -- leaves it out, whichever entry declared the trait: an impl written
 -- in a later entry (`trait Sz for P`), and one of the same entry as the
diff --git a/tests/golden/cli/repl/repl__field_method__impl_in_a_later_entry.silt b/tests/golden/cli/repl/repl__field_method__impl_in_a_later_entry.silt
index 7720cbc86..2d4b5b2f7 100644
--- a/tests/golden/cli/repl/repl__field_method__impl_in_a_later_entry.silt
+++ b/tests/golden/cli/repl/repl__field_method__impl_in_a_later_entry.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: type H { run: Int, n: Int }\ntrait Run { fn run(self) -> Int }\ntrait Run for H { fn run(self) -> Int { 7 } }\nlet h = H { run: 1, n: 2 }\nh.run\nfn bounded(r: a) -> Int where a: Run { r.run() }\nbounded(h)\ntrait Run for Int { fn run(self) -> Int { self } }\nbounded(3)\n:quit\n
+-- stdin: type H { run: Int, n: Int }\ntrait Run { fn run(self) -> Int }\ntrait Run for H { fn run(self) -> Int { 7 } }\nlet h = H { run: 1, n: 2 }\nh.run\nfn bounded(r: a) -> Int where a: Run { Run.run(r) }\nbounded(h)\ntrait Run for Int { fn run(self) -> Int { self } }\nbounded(3)\n:quit\n
 -- An entry that adds an impl whose method is named like a field of a
 -- record of an earlier entry is the error, and adds nothing: the
 -- session goes on without the impl (`bounded(h)` has no `Run` for `H`).
diff --git a/tests/golden/cli/repl/repl__field_method__redeclared_type_is_a_new_type.silt b/tests/golden/cli/repl/repl__field_method__redeclared_type_is_a_new_type.silt
index 195c7f574..306fd5a5c 100644
--- a/tests/golden/cli/repl/repl__field_method__redeclared_type_is_a_new_type.silt
+++ b/tests/golden/cli/repl/repl__field_method__redeclared_type_is_a_new_type.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: type H { n: Int }\ntrait Run { fn run(self) -> Int }\ntrait Run for H { fn run(self) -> Int { 7 } }\nlet old = H { n: 2 }\ntype H { run: Int, n: Int }\nlet new = H { run: 1, n: 2 }\nold.run()\nnew.run\nfn bounded(r: a) -> Int where a: Run { r.run() }\nbounded(old)\nbounded(new)\ntrait Run for H { fn run(self) -> Int { 8 } }\n:quit\n
+-- stdin: type H { n: Int }\ntrait Run { fn run(self) -> Int }\ntrait Run for H { fn run(self) -> Int { 7 } }\nlet old = H { n: 2 }\ntype H { run: Int, n: Int }\nlet new = H { run: 1, n: 2 }\nRun.run(old)\nnew.run\nfn bounded(r: a) -> Int where a: Run { Run.run(r) }\nbounded(old)\nbounded(new)\ntrait Run for H { fn run(self) -> Int { 8 } }\n:quit\n
 -- A type declared again is a new type with no impls (stage 5 decision
 -- D4): declaring `H` again with a field `run` is no clash with the impl
 -- of `Run` for the old `H`, which the old values keep. The new `H` has
diff --git a/tests/golden/cli/repl/repl__json_encode_s_method_needs_import_json.silt b/tests/golden/cli/repl/repl__json_encode_s_method_needs_import_json.silt
index e76a56f7f..e6d0ebbec 100644
--- a/tests/golden/cli/repl/repl__json_encode_s_method_needs_import_json.silt
+++ b/tests/golden/cli/repl/repl__json_encode_s_method_needs_import_json.silt
@@ -1,7 +1,6 @@
 -- cmd: repl
--- stderr-contains: unknown field or method 'encode' on type P
--- stderr-contains: unknown method 'encode' on type Int
+-- stderr-contains: module 'json' is not imported
 -- stdout-contains: Object(#{"x": Int(1)})
--- stdin: type P { x: Int }\nP { x: 1 }.encode()\n1.encode()\nimport json\nP { x: 1 }.encode()\n:quit\n
--- In the REPL too, `encode` is a value's method once an entry imports
+-- stdin: type P { x: Int }\njson.Encode.encode(P { x: 1 })\nimport json\njson.Encode.encode(P { x: 1 })\n:quit\n
+-- In the REPL too, `json.Encode.encode` is called once an entry imports
 -- json, and not before.
diff --git a/tests/golden/cli/repl/repl__redefined_type_keeps_its_impls.silt b/tests/golden/cli/repl/repl__redefined_type_keeps_its_impls.silt
index 49fb608b4..5e8eaebbd 100644
--- a/tests/golden/cli/repl/repl__redefined_type_keeps_its_impls.silt
+++ b/tests/golden/cli/repl/repl__redefined_type_keeps_its_impls.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: type P { x: Int }\ntrait Display for P { fn display(self) -> String { "old P" } }\nlet a = P { x: 1 }\ntype P { x: Int }\ntrait Display for P { fn display(self) -> String { "new P" } }\nlet b = P { x: 2 }\na.display()\nb.display()\n:quit\n
+-- stdin: type P { x: Int }\ntrait Display for P { fn display(self) -> String { "old P" } }\nlet a = P { x: 1 }\ntype P { x: Int }\ntrait Display for P { fn display(self) -> String { "new P" } }\nlet b = P { x: 2 }\n"{a}"\n"{b}"\n:quit\n
 -- Redefinition is early-bound (stage 5 decision D4): a type declared
 -- again is a new type with impls of its own, so a value of the old type
 -- keeps the old type's Display impl.
diff --git a/tests/golden/cli/repl/repl__trait_impl_replaces_the_derived_one.silt b/tests/golden/cli/repl/repl__trait_impl_replaces_the_derived_one.silt
index ed7b61ce1..9ddfa019b 100644
--- a/tests/golden/cli/repl/repl__trait_impl_replaces_the_derived_one.silt
+++ b/tests/golden/cli/repl/repl__trait_impl_replaces_the_derived_one.silt
@@ -1,5 +1,5 @@
 -- cmd: repl
--- stdin: type Box { v: Int }\ntrait Display for Box { fn display(self) -> String { "Box({self.v})" } }\n1 + 1\nlet b = Box { v: 3 }\nb.display()\n"{b.display()} {b == Box { v: 3 }}"\ntrait Display for Box { fn display(self) -> String { "again" } }\nb.display()\nfn show(x: Box) -> String { x.display() }\nshow(Box { v: 4 })\n:quit\n
+-- stdin: type Box { v: Int }\ntrait Display for Box { fn display(self) -> String { "Box({self.v})" } }\n1 + 1\nlet b = Box { v: 3 }\n"{b}"\n"{b} {b == Box { v: 3 }}"\ntrait Display for Box { fn display(self) -> String { "again" } }\n"{b}"\nfn show(x: Box) -> String { "{x}" }\nshow(Box { v: 4 })\n:quit\n
 -- stderr-contains: error[type]: duplicate implementation of trait 'Display' for type 'Box'
 -- stderr-contains:  --> <repl:7>:1:1
 -- A written `Display` impl for a type of an earlier input replaces the
diff --git a/tests/golden/concurrency/deadline/task_deadline__a_read_in_flight_is_shut_down.silt b/tests/golden/concurrency/deadline/task_deadline__a_read_in_flight_is_shut_down.silt
index 4bc32e3f0..a4960a9ec 100644
--- a/tests/golden/concurrency/deadline/task_deadline__a_read_in_flight_is_shut_down.silt
+++ b/tests/golden/concurrency/deadline/task_deadline__a_read_in_flight_is_shut_down.silt
@@ -25,6 +25,6 @@ fn main() {
   match tcp.read(conn, 16) {
     Err(tcp.Closed) -> println("then the connection is closed")
     Ok(read) -> println("then still open (read {bytes.length(read)})")
-    Err(e) -> println("then {e.message()}")
+    Err(e) -> println("then {Error.message(e)}")
   }
 }
diff --git a/tests/golden/concurrency/deadline/task_deadline__ends_a_pending_accept.silt b/tests/golden/concurrency/deadline/task_deadline__ends_a_pending_accept.silt
index dac349413..0bf205305 100644
--- a/tests/golden/concurrency/deadline/task_deadline__ends_a_pending_accept.silt
+++ b/tests/golden/concurrency/deadline/task_deadline__ends_a_pending_accept.silt
@@ -14,8 +14,8 @@ fn main() {
   match task.deadline(time.ms(50), { -> tcp.accept(listener) }) {
     Err(task.Timeout) -> println("the deadline passed")
     Ok(Ok(_)) -> println("accepted a connection")
-    Ok(Err(e)) -> println("tcp: {e.message()}")
-    Err(e) -> println(e.message())
+    Ok(Err(e)) -> println("tcp: {Error.message(e)}")
+    Err(e) -> println(Error.message(e))
   }
   -- The listener is as it was: a connection is accepted.
   when let Ok(_) = tcp.connect("127.0.0.1:{tcp.local_port(listener)}") else { panic("cannot connect") }
diff --git a/tests/golden/concurrency/deadline/task_deadline__gives_ok_of_what_the_function_returns.silt b/tests/golden/concurrency/deadline/task_deadline__gives_ok_of_what_the_function_returns.silt
index 78161af26..46618b7bb 100644
--- a/tests/golden/concurrency/deadline/task_deadline__gives_ok_of_what_the_function_returns.silt
+++ b/tests/golden/concurrency/deadline/task_deadline__gives_ok_of_what_the_function_returns.silt
@@ -17,6 +17,6 @@ fn main() {
   match run(time.seconds(60), { -> [1, 2, 3] }) {
     Ok(xs) -> println(xs)
     Err(task.Timeout) -> println("timed out")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/concurrency/io/conventions__a_handler_answers_a_malformed_query_itself.silt b/tests/golden/concurrency/io/conventions__a_handler_answers_a_malformed_query_itself.silt
index 67530a49e..8c178c1e9 100644
--- a/tests/golden/concurrency/io/conventions__a_handler_answers_a_malformed_query_itself.silt
+++ b/tests/golden/concurrency/io/conventions__a_handler_answers_a_malformed_query_itself.silt
@@ -33,7 +33,7 @@ fn main() {
   list.each(["/?name=a%20b", "/?name=%ZZ", "/?name=%FF", "/?other=1", "/?name=c"]) { path ->
     match http.get("{base}{path}") {
       Ok(r) -> println("{r.status} {text(r.body)}")
-      Err(e) -> println("error: {e.message()}")
+      Err(e) -> println("error: {Error.message(e)}")
     }
   }
   task.cancel(server)
diff --git a/tests/golden/concurrency/io/conventions__a_request_s_header_names_are_lower_case_and_its_body_is_bytes.silt b/tests/golden/concurrency/io/conventions__a_request_s_header_names_are_lower_case_and_its_body_is_bytes.silt
index dfe416527..7f78564e2 100644
--- a/tests/golden/concurrency/io/conventions__a_request_s_header_names_are_lower_case_and_its_body_is_bytes.silt
+++ b/tests/golden/concurrency/io/conventions__a_request_s_header_names_are_lower_case_and_its_body_is_bytes.silt
@@ -62,7 +62,7 @@ fn main() {
   println(ask(port, bytes.from_list([0, 255, 254, 104]) |> result.unwrap_or(bytes.empty())))
   match http.get("http://127.0.0.1:{port}/") {
     Ok(r) -> println("{map.get(r.headers, "x-answered-by")} {map.contains(r.headers, "X-Answered-By")}")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   task.cancel(server)
 }
diff --git a/tests/golden/concurrency/io/http_bodies__a_body_is_text_only_where_the_program_says_so.silt b/tests/golden/concurrency/io/http_bodies__a_body_is_text_only_where_the_program_says_so.silt
index c0fdc2858..5561d02bf 100644
--- a/tests/golden/concurrency/io/http_bodies__a_body_is_text_only_where_the_program_says_so.silt
+++ b/tests/golden/concurrency/io/http_bodies__a_body_is_text_only_where_the_program_says_so.silt
@@ -44,7 +44,7 @@ fn main() {
     println("{what}")
     match http.request(http.POST, url, body, #{}) {
       Ok(resp) -> println("  the client:  {bytes.to_hex(resp.body)} {as_text(resp.body)}")
-      Err(e) -> println("  the client: {e.message()}")
+      Err(e) -> println("  the client: {Error.message(e)}")
     }
   }
   task.cancel(server)
diff --git a/tests/golden/concurrency/io/http_bodies__a_body_over_the_limit_is_an_error_not_a_cut_body.silt b/tests/golden/concurrency/io/http_bodies__a_body_over_the_limit_is_an_error_not_a_cut_body.silt
index ffa1fc94c..ce91955a4 100644
--- a/tests/golden/concurrency/io/http_bodies__a_body_over_the_limit_is_an_error_not_a_cut_body.silt
+++ b/tests/golden/concurrency/io/http_bodies__a_body_over_the_limit_is_an_error_not_a_cut_body.silt
@@ -72,7 +72,7 @@ fn show(what: String, got: Result(http.Response, http.HttpError)) {
       println("{what}: Ok, {length} bytes, the last is {bytes.get(resp.body, length - 1)}")
     }
     Err(http.InvalidResponse(why)) -> println("{what}: Err(InvalidResponse(\"{why}\"))")
-    Err(e) -> println("{what}: another error: {e.message()}")
+    Err(e) -> println("{what}: another error: {Error.message(e)}")
   }
 }
 
diff --git a/tests/golden/concurrency/io/http_bodies__a_chunked_body_arrives_whole.silt b/tests/golden/concurrency/io/http_bodies__a_chunked_body_arrives_whole.silt
index 18bbb1ac3..1d059b2d0 100644
--- a/tests/golden/concurrency/io/http_bodies__a_chunked_body_arrives_whole.silt
+++ b/tests/golden/concurrency/io/http_bodies__a_chunked_body_arrives_whole.silt
@@ -118,6 +118,6 @@ fn main() {
   task.join(writer)
   match got {
     Ok(resp) -> show("  http.get gets", resp.body)
-    Err(e) -> println("  http.get: {e.message()}")
+    Err(e) -> println("  http.get: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/concurrency/io/http_bodies__a_handler_s_answer_has_the_content_type_it_sets_and_no_other.silt b/tests/golden/concurrency/io/http_bodies__a_handler_s_answer_has_the_content_type_it_sets_and_no_other.silt
index d80243e00..007ad7f7e 100644
--- a/tests/golden/concurrency/io/http_bodies__a_handler_s_answer_has_the_content_type_it_sets_and_no_other.silt
+++ b/tests/golden/concurrency/io/http_bodies__a_handler_s_answer_has_the_content_type_it_sets_and_no_other.silt
@@ -38,7 +38,7 @@ fn main() {
   ["/text", "/set", "/empty", "/bytes"] |> list.each { path ->
     match http.get("http://127.0.0.1:{port}{path}") {
       Ok(resp) -> println("{path}: {bytes.to_hex(resp.body)}, content-type {map.get(resp.headers, "content-type")}")
-      Err(e) -> println("{path}: {e.message()}")
+      Err(e) -> println("{path}: {Error.message(e)}")
     }
   }
 
diff --git a/tests/golden/concurrency/io/http_bodies__a_head_request_gets_the_length_and_no_body.silt b/tests/golden/concurrency/io/http_bodies__a_head_request_gets_the_length_and_no_body.silt
index abc0d6084..6eae62a79 100644
--- a/tests/golden/concurrency/io/http_bodies__a_head_request_gets_the_length_and_no_body.silt
+++ b/tests/golden/concurrency/io/http_bodies__a_head_request_gets_the_length_and_no_body.silt
@@ -84,7 +84,7 @@ fn main() {
   println("http.request")
   match http.request(http.HEAD, "http://127.0.0.1:{port}/", bytes.empty(), #{}) {
     Ok(resp) -> println("  gets {resp.status}, content-length {map.get(resp.headers, "content-length")}, {bytes.length(resp.body)} bytes")
-    Err(e) -> println("  {e.message()}")
+    Err(e) -> println("  {Error.message(e)}")
   }
 
   println("a client written by hand")
diff --git a/tests/golden/concurrency/io/http_bodies__an_answer_without_a_body_that_says_packed_is_empty.silt b/tests/golden/concurrency/io/http_bodies__an_answer_without_a_body_that_says_packed_is_empty.silt
index 36d331edd..b6eb326ae 100644
--- a/tests/golden/concurrency/io/http_bodies__an_answer_without_a_body_that_says_packed_is_empty.silt
+++ b/tests/golden/concurrency/io/http_bodies__an_answer_without_a_body_that_says_packed_is_empty.silt
@@ -35,7 +35,7 @@ fn main() {
         let named = ["content-encoding", "content-length", "etag"] |> list.filter { name -> map.contains(resp.headers, name) }
         println("{method} {path}: {resp.status}, {bytes.length(resp.body)} bytes, of the three headers: {named}")
       }
-      Err(e) -> println("{method} {path}: Err {e.message()}")
+      Err(e) -> println("{method} {path}: Err {Error.message(e)}")
     }
   }
   task.cancel(server)
diff --git a/tests/golden/concurrency/io/http_bodies__an_empty_body_is_empty_at_the_four_places.silt b/tests/golden/concurrency/io/http_bodies__an_empty_body_is_empty_at_the_four_places.silt
index 8ebe021df..045e7c819 100644
--- a/tests/golden/concurrency/io/http_bodies__an_empty_body_is_empty_at_the_four_places.silt
+++ b/tests/golden/concurrency/io/http_bodies__an_empty_body_is_empty_at_the_four_places.silt
@@ -79,7 +79,7 @@ fn main() {
   let server = task.spawn { -> http.serve(listener, answer) }
   match http.request(http.POST, "http://127.0.0.1:{port}/", bytes.empty(), #{}) {
     Ok(resp) -> println("  http.request gets: {resp.status}, {bytes.length(resp.body)} bytes, equal to bytes.empty(): {resp.body == bytes.empty()}")
-    Err(e) -> println("  http.request: {e.message()}")
+    Err(e) -> println("  http.request: {Error.message(e)}")
   }
 
   println("a client written by hand to http.serve")
@@ -105,6 +105,6 @@ fn main() {
   println("  the request on the wire: {length_line(sent)}, {bytes.length(body_of(sent) |> option.unwrap_or(bytes.empty()))} bytes after the head")
   match got {
     Ok(resp) -> println("  http.request gets: {resp.status}, {bytes.length(resp.body)} bytes, equal to bytes.empty(): {resp.body == bytes.empty()}")
-    Err(e) -> println("  http.request: {e.message()}")
+    Err(e) -> println("  http.request: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/concurrency/io/http_bodies__every_byte_value_arrives_at_the_four_places.silt b/tests/golden/concurrency/io/http_bodies__every_byte_value_arrives_at_the_four_places.silt
index 880bc617e..7a5936f4c 100644
--- a/tests/golden/concurrency/io/http_bodies__every_byte_value_arrives_at_the_four_places.silt
+++ b/tests/golden/concurrency/io/http_bodies__every_byte_value_arrives_at_the_four_places.silt
@@ -83,7 +83,7 @@ fn main() {
   let server = task.spawn { -> http.serve(listener, answer) }
   match http.request(http.POST, "http://127.0.0.1:{port}/", upwards(), #{}) {
     Ok(resp) -> show("  http.request gets", resp.body)
-    Err(e) -> println("  http.request: {e.message()}")
+    Err(e) -> println("  http.request: {Error.message(e)}")
   }
 
   -- The client says that it closes, so the answer ends where the
@@ -110,6 +110,6 @@ fn main() {
   show("  the request on the wire", task.join(reader))
   match got {
     Ok(resp) -> show("  http.request gets", resp.body)
-    Err(e) -> println("  http.request: {e.message()}")
+    Err(e) -> println("  http.request: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/concurrency/io/http_client__a_request_says_silt_and_its_version_unless_the_program_says_otherwise.silt b/tests/golden/concurrency/io/http_client__a_request_says_silt_and_its_version_unless_the_program_says_otherwise.silt
index 3a011994d..215bc27b1 100644
--- a/tests/golden/concurrency/io/http_client__a_request_says_silt_and_its_version_unless_the_program_says_otherwise.silt
+++ b/tests/golden/concurrency/io/http_client__a_request_says_silt_and_its_version_unless_the_program_says_otherwise.silt
@@ -39,7 +39,7 @@ fn shown(got: Result(http.Response, http.HttpError)) -> String {
         _ -> agent
       }
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/concurrency/io/io_op__a_given_up_tls_connect_frees_its_thread.silt b/tests/golden/concurrency/io/io_op__a_given_up_tls_connect_frees_its_thread.silt
index 31666b7d6..53ea92941 100644
--- a/tests/golden/concurrency/io/io_op__a_given_up_tls_connect_frees_its_thread.silt
+++ b/tests/golden/concurrency/io/io_op__a_given_up_tls_connect_frees_its_thread.silt
@@ -26,6 +26,6 @@ fn main() {
   give_up(tcp.local_port(listener), 70)
   match io.read_file("io_op__a_given_up_tls_connect_frees_its_thread.silt") {
     Ok(text) -> println("read the file: {string.length(text) > 0}")
-    Err(e) -> println("read_file: {e.message()}")
+    Err(e) -> println("read_file: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_its_test_test.silt b/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_its_test_test.silt
index cd3bdaacc..8d9480f81 100644
--- a/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_its_test_test.silt
+++ b/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_its_test_test.silt
@@ -15,7 +15,7 @@ import test
 fn get(url) {
   match http.get(url) {
     Ok(r) -> r.status
-    Err(e) -> panic(e.message())
+    Err(e) -> panic(Error.message(e))
   }
 }
 
diff --git a/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_the_program.silt b/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_the_program.silt
index 54dd78ad7..d21783b01 100644
--- a/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_the_program.silt
+++ b/tests/golden/concurrency/io/stage7_c5__a_cancelled_server_does_not_keep_the_program.silt
@@ -13,7 +13,7 @@ import tcp
 fn get(url) {
   match http.get(url) {
     Ok(r) -> "status {r.status}"
-    Err(e) -> "error {e.message()}"
+    Err(e) -> "error {Error.message(e)}"
   }
 }
 
diff --git a/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_again_at_once.silt b/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_again_at_once.silt
index 7e50bec40..48709188a 100644
--- a/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_again_at_once.silt
+++ b/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_again_at_once.silt
@@ -27,7 +27,7 @@ fn main() {
     }
     let answer = match http.get(url) {
       Ok(r) -> text(r.body)
-      Err(e) -> e.message()
+      Err(e) -> Error.message(e)
     }
     task.cancel(server)
     match answer == "round {round}" {
diff --git a/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_by_one_server.silt b/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_by_one_server.silt
index d98c704ea..f4866f848 100644
--- a/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_by_one_server.silt
+++ b/tests/golden/concurrency/io/stage7_c6__a_listener_is_served_by_one_server.silt
@@ -24,7 +24,7 @@ fn main() {
   -- The server serves when it has answered.
   match http.get("http://127.0.0.1:{tcp.local_port(listener)}/") {
     Ok(r) -> println("{r.status} {text(r.body)}")
-    Err(e) -> println("error: {e.message()}")
+    Err(e) -> println("error: {Error.message(e)}")
   }
   http.serve(listener) { _req -> http.Response { status: 200, body: bytes.from_string("second"), headers: #{} } }
 }
diff --git a/tests/golden/concurrency/io/stage7_c6__a_served_listener_is_its_servers_alone.silt b/tests/golden/concurrency/io/stage7_c6__a_served_listener_is_its_servers_alone.silt
index bec05770f..3b77398b7 100644
--- a/tests/golden/concurrency/io/stage7_c6__a_served_listener_is_its_servers_alone.silt
+++ b/tests/golden/concurrency/io/stage7_c6__a_served_listener_is_its_servers_alone.silt
@@ -20,7 +20,7 @@ fn text(body: Bytes) -> String {
 fn get(url) {
   match http.get(url) {
     Ok(r) -> "{r.status} {text(r.body)}"
-    Err(e) -> "error: {e.message()}"
+    Err(e) -> "error: {Error.message(e)}"
   }
 }
 
@@ -36,7 +36,7 @@ fn main() {
   let refused = 1..100 |> list.map { _ ->
     match tcp.accept(listener) {
       Ok(_) -> "a connection"
-      Err(e) -> e.message()
+      Err(e) -> Error.message(e)
     }
   }
   println(refused |> list.unique)
@@ -52,9 +52,9 @@ fn main() {
   match tcp.accept(listener) {
     Ok(conn) -> match tcp.read_exact(conn, 5) {
       Ok(hello) -> println("accepted a client that sent {bytes.length(hello)} bytes")
-      Err(e) -> println("accepted a connection that says nothing: {e.message()}")
+      Err(e) -> println("accepted a connection that says nothing: {Error.message(e)}")
     }
-    Err(e) -> println("accept: {e.message()}")
+    Err(e) -> println("accept: {Error.message(e)}")
   }
   let _ = task.join(client)
 
diff --git a/tests/golden/concurrency/io/stage7_c6__a_server_takes_the_listener_from_an_accept_that_waits.silt b/tests/golden/concurrency/io/stage7_c6__a_server_takes_the_listener_from_an_accept_that_waits.silt
index bf747bb92..7e749f7f3 100644
--- a/tests/golden/concurrency/io/stage7_c6__a_server_takes_the_listener_from_an_accept_that_waits.silt
+++ b/tests/golden/concurrency/io/stage7_c6__a_server_takes_the_listener_from_an_accept_that_waits.silt
@@ -20,7 +20,7 @@ fn main() {
   let waiting = task.spawn { ->
     match tcp.accept(listener) {
       Ok(_) -> "a connection"
-      Err(e) -> e.message()
+      Err(e) -> Error.message(e)
     }
   }
   let server = task.spawn { ->
@@ -31,7 +31,7 @@ fn main() {
   println("the accept: {task.join(waiting)}")
   match http.get("http://127.0.0.1:{tcp.local_port(listener)}/") {
     Ok(r) -> println("the client: {r.status} {text(r.body)}")
-    Err(e) -> println("the client: {e.message()}")
+    Err(e) -> println("the client: {Error.message(e)}")
   }
   task.cancel(server)
 }
diff --git a/tests/golden/concurrency/io/stage7_c6__an_accept_after_a_server_gets_a_client.silt b/tests/golden/concurrency/io/stage7_c6__an_accept_after_a_server_gets_a_client.silt
index 0cac169d3..48c255a87 100644
--- a/tests/golden/concurrency/io/stage7_c6__an_accept_after_a_server_gets_a_client.silt
+++ b/tests/golden/concurrency/io/stage7_c6__an_accept_after_a_server_gets_a_client.silt
@@ -35,9 +35,9 @@ fn main() {
           tcp.close(conn)
           "a client"
         }
-        Err(e) -> "a connection that says nothing: {e.message()}"
+        Err(e) -> "a connection that says nothing: {Error.message(e)}"
       }
-      Err(e) -> "no connection: {e.message()}"
+      Err(e) -> "no connection: {Error.message(e)}"
     }
     let _ = task.join(client)
     match got {
diff --git a/tests/golden/concurrency/io/stage7_c6__long_polls_all_enter_their_handlers.silt b/tests/golden/concurrency/io/stage7_c6__long_polls_all_enter_their_handlers.silt
index e08f6a7af..28656dad7 100644
--- a/tests/golden/concurrency/io/stage7_c6__long_polls_all_enter_their_handlers.silt
+++ b/tests/golden/concurrency/io/stage7_c6__long_polls_all_enter_their_handlers.silt
@@ -35,7 +35,7 @@ fn main() {
     task.spawn { ->
       match http.get("http://127.0.0.1:{port}/wait") {
         Ok(r) -> "{r.status} {text(r.body)}"
-        Err(e) -> "error: {e.message()}"
+        Err(e) -> "error: {Error.message(e)}"
       }
     }
   }
diff --git a/tests/golden/concurrency/io/stage7_c6__requests_in_flight_are_answered_503_when_their_server_ends.silt b/tests/golden/concurrency/io/stage7_c6__requests_in_flight_are_answered_503_when_their_server_ends.silt
index d8d634643..c331b3c6b 100644
--- a/tests/golden/concurrency/io/stage7_c6__requests_in_flight_are_answered_503_when_their_server_ends.silt
+++ b/tests/golden/concurrency/io/stage7_c6__requests_in_flight_are_answered_503_when_their_server_ends.silt
@@ -38,7 +38,7 @@ fn main() {
   let get = { path ->
     match http.get("http://127.0.0.1:{port}{path}") {
       Ok(r) -> "{r.status} {text(r.body)}"
-      Err(e) -> "error: {e.message()}"
+      Err(e) -> "error: {Error.message(e)}"
     }
   }
   let clients = 1..5 |> list.map { _ -> task.spawn { -> get("/wait") } }
diff --git a/tests/golden/concurrency/stack/stage7_v2__method_recursion_50000_deep_in_a_task.silt b/tests/golden/concurrency/stack/stage7_v2__method_recursion_50000_deep_in_a_task.silt
index 7bedbe62b..1300c13ac 100644
--- a/tests/golden/concurrency/stack/stage7_v2__method_recursion_50000_deep_in_a_task.silt
+++ b/tests/golden/concurrency/stack/stage7_v2__method_recursion_50000_deep_in_a_task.silt
@@ -10,13 +10,13 @@ trait Countdown for Int {
   fn down(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).down()
+      _ -> 1 + Countdown.down(self - 1)
     }
   }
 }
 
 fn main() {
-  let h = task.spawn({ -> 50000.down() })
+  let h = task.spawn({ -> Countdown.down(50000) })
   println(task.join(h))
-  println(50000.down())
+  println(Countdown.down(50000))
 }
diff --git a/tests/golden/frontend/deep/round92_deep_expr__enum_variant_lex_compare.silt b/tests/golden/frontend/deep/round92_deep_expr__enum_variant_lex_compare.silt
index 6b763ad14..9c7c01926 100644
--- a/tests/golden/frontend/deep/round92_deep_expr__enum_variant_lex_compare.silt
+++ b/tests/golden/frontend/deep/round92_deep_expr__enum_variant_lex_compare.silt
@@ -1,6 +1,6 @@
 type T { V(Int, Int, Int) }
-fn cmp_gen(x: t, y: t) -> Int where t: Compare { x.compare(y) }
-fn eq_gen(x: t, y: t) -> Bool where t: Equal { x.equal(y) }
+fn cmp_gen(x: t, y: t) -> Int where t: Compare { Compare.compare(x, y) }
+fn eq_gen(x: t, y: t) -> Bool where t: Equal { x == y }
 fn main() {
   println(cmp_gen(V(1, 9, 9), V(2, 0, 0)))
   println(cmp_gen(V(1, 2, 9), V(1, 3, 0)))
diff --git a/tests/golden/frontend/deep/round92_deep_expr__record_compare_first_differing_field_wins.silt b/tests/golden/frontend/deep/round92_deep_expr__record_compare_first_differing_field_wins.silt
index 74193a255..44b8e2fbe 100644
--- a/tests/golden/frontend/deep/round92_deep_expr__record_compare_first_differing_field_wins.silt
+++ b/tests/golden/frontend/deep/round92_deep_expr__record_compare_first_differing_field_wins.silt
@@ -1,5 +1,5 @@
 type P { a: Int, b: Int, c: Int }
-fn cmp_gen(x: t, y: t) -> Int where t: Compare { x.compare(y) }
+fn cmp_gen(x: t, y: t) -> Int where t: Compare { Compare.compare(x, y) }
 fn main() {
   -- a decides (later fields disagree loudly)
   println(cmp_gen(P { a: 1, b: 9, c: 9 }, P { a: 2, b: 0, c: 0 }))
diff --git a/tests/golden/frontend/deep/round92_deep_expr__wide_record_derives_semantics.silt b/tests/golden/frontend/deep/round92_deep_expr__wide_record_derives_semantics.silt
index 3bbf09abb..f71f65576 100644
--- a/tests/golden/frontend/deep/round92_deep_expr__wide_record_derives_semantics.silt
+++ b/tests/golden/frontend/deep/round92_deep_expr__wide_record_derives_semantics.silt
@@ -82,9 +82,9 @@ type W {
   f78: Int,
   f79: Int
 }
-fn cmp_gen(x: t, y: t) -> Int where t: Compare { x.compare(y) }
-fn eq_gen(x: t, y: t) -> Bool where t: Equal { x.equal(y) }
-fn show(x: t) -> String where t: Display { x.display() }
+fn cmp_gen(x: t, y: t) -> Int where t: Compare { Compare.compare(x, y) }
+fn eq_gen(x: t, y: t) -> Bool where t: Equal { x == y }
+fn show(x: t) -> String where t: Display { "{x}" }
 fn main() {
   let lo = W { f0: 0, f1: 1, f2: 2, f3: 3, f4: 4, f5: 5, f6: 6, f7: 7, f8: 8, f9: 9, f10: 10, f11: 11, f12: 12, f13: 13, f14: 14, f15: 15, f16: 16, f17: 17, f18: 18, f19: 19, f20: 20, f21: 21, f22: 22, f23: 23, f24: 24, f25: 25, f26: 26, f27: 27, f28: 28, f29: 29, f30: 30, f31: 31, f32: 32, f33: 33, f34: 34, f35: 35, f36: 36, f37: 37, f38: 38, f39: 39, f40: 40, f41: 41, f42: 42, f43: 43, f44: 44, f45: 45, f46: 46, f47: 47, f48: 48, f49: 49, f50: 50, f51: 51, f52: 52, f53: 53, f54: 54, f55: 55, f56: 56, f57: 57, f58: 58, f59: 59, f60: 60, f61: 61, f62: 62, f63: 63, f64: 64, f65: 65, f66: 66, f67: 67, f68: 68, f69: 69, f70: 70, f71: 71, f72: 72, f73: 73, f74: 74, f75: 75, f76: 76, f77: 77, f78: 78, f79: 1000 }
   let hi = W { f0: 0, f1: 1, f2: 2, f3: 3, f4: 4, f5: 5, f6: 6, f7: 7, f8: 8, f9: 9, f10: 10, f11: 11, f12: 12, f13: 13, f14: 14, f15: 15, f16: 16, f17: 17, f18: 18, f19: 19, f20: 20, f21: 21, f22: 22, f23: 23, f24: 24, f25: 25, f26: 26, f27: 27, f28: 28, f29: 29, f30: 30, f31: 31, f32: 32, f33: 33, f34: 34, f35: 35, f36: 36, f37: 37, f38: 38, f39: 39, f40: 40, f41: 41, f42: 42, f43: 43, f44: 44, f45: 45, f46: 46, f47: 47, f48: 48, f49: 49, f50: 50, f51: 51, f52: 52, f53: 53, f54: 54, f55: 55, f56: 56, f57: 57, f58: 58, f59: 59, f60: 60, f61: 61, f62: 62, f63: 63, f64: 64, f65: 65, f66: 66, f67: 67, f68: 68, f69: 69, f70: 70, f71: 71, f72: 72, f73: 73, f74: 74, f75: 75, f76: 76, f77: 77, f78: 78, f79: 2000 }
diff --git a/tests/golden/frontend/deep/round92_deep_expr__wide_record_display_nests_interpolation.silt b/tests/golden/frontend/deep/round92_deep_expr__wide_record_display_nests_interpolation.silt
index 0ef86fab5..96cf7d97f 100644
--- a/tests/golden/frontend/deep/round92_deep_expr__wide_record_display_nests_interpolation.silt
+++ b/tests/golden/frontend/deep/round92_deep_expr__wide_record_display_nests_interpolation.silt
@@ -136,5 +136,5 @@ type W {
 
 fn main() {
   let w = W { f0: 0, f1: 1, f2: 2, f3: 3, f4: 4, f5: 5, f6: 6, f7: 7, f8: 8, f9: 9, f10: 10, f11: 11, f12: 12, f13: 13, f14: 14, f15: 15, f16: 16, f17: 17, f18: 18, f19: 19, f20: 20, f21: 21, f22: 22, f23: 23, f24: 24, f25: 25, f26: 26, f27: 27, f28: 28, f29: 29, f30: 30, f31: 31, f32: 32, f33: 33, f34: 34, f35: 35, f36: 36, f37: 37, f38: 38, f39: 39, f40: 40, f41: 41, f42: 42, f43: 43, f44: 44, f45: 45, f46: 46, f47: 47, f48: 48, f49: 49, f50: 50, f51: 51, f52: 52, f53: 53, f54: 54, f55: 55, f56: 56, f57: 57, f58: 58, f59: 59, f60: 60, f61: 61, f62: 62, f63: 63, f64: 64, f65: 65, f66: 66, f67: 67, f68: 68, f69: 69, f70: 70, f71: 71, f72: 72, f73: 73, f74: 74, f75: 75, f76: 76, f77: 77, f78: 78, f79: 79, f80: 80, f81: 81, f82: 82, f83: 83, f84: 84, f85: 85, f86: 86, f87: 87, f88: 88, f89: 89, f90: 90, f91: 91, f92: 92, f93: 93, f94: 94, f95: 95, f96: 96, f97: 97, f98: 98, f99: 99, f100: 100, f101: 101, f102: 102, f103: 103, f104: 104, f105: 105, f106: 106, f107: 107, f108: 108, f109: 109, f110: 110, f111: 111, f112: 112, f113: 113, f114: 114, f115: 115, f116: 116, f117: 117, f118: 118, f119: 119, f120: 120, f121: 121, f122: 122, f123: 123, f124: 124, f125: 125, f126: 126, f127: 127, f128: 128, f129: 129 }
-  println(w.display())
+  println("{w}")
 }
diff --git a/tests/golden/frontend/fmt/printer__comments_after_open_brace.formatted b/tests/golden/frontend/fmt/printer__comments_after_open_brace.formatted
index 53a595f58..e0821d4c2 100644
--- a/tests/golden/frontend/fmt/printer__comments_after_open_brace.formatted
+++ b/tests/golden/frontend/fmt/printer__comments_after_open_brace.formatted
@@ -41,7 +41,7 @@ fn main() { -- entry point
     x * 2
   }
   println( -- everything
-    "{p.name()} {xs} {ys}",
+    "{Named.name(p)} {xs} {ys}",
   )
   let empty = [ -- nothing in it
   ]
diff --git a/tests/golden/frontend/fmt/printer__comments_after_open_brace.silt b/tests/golden/frontend/fmt/printer__comments_after_open_brace.silt
index 852b8c8b2..532f551dd 100644
--- a/tests/golden/frontend/fmt/printer__comments_after_open_brace.silt
+++ b/tests/golden/frontend/fmt/printer__comments_after_open_brace.silt
@@ -37,7 +37,7 @@ fn main() { -- entry point
     x * 2
   }
   println( -- everything
-    "{p.name()} {xs} {ys}")
+    "{Named.name(p)} {xs} {ys}")
   let empty = [ -- nothing in it
   ]
   let block = { -- a block
diff --git a/tests/golden/frontend/fmt/printer__smallest_int.formatted b/tests/golden/frontend/fmt/printer__smallest_int.formatted
index 55138d797..1c7290585 100644
--- a/tests/golden/frontend/fmt/printer__smallest_int.formatted
+++ b/tests/golden/frontend/fmt/printer__smallest_int.formatted
@@ -17,10 +17,10 @@ fn main() {
   let b = -(-9223372036854775808)
   let c = -(-(-9223372036854775808))
   let d = -(-0x8000000000000000)
-  let e = -9223372036854775808.sh()
-  let f = -9223372036854775808.sh()
+  let e = Sh.sh(-9223372036854775808)
+  let f = Sh.sh(-9223372036854775808)
   let g = -9223372036854775808 + 1
-  let h = 1.sh()
+  let h = Sh.sh(1)
   let i = 1.e5
   println("{a} {b} {c} {d} {e} {f} {g} {h} {i}")
 }
diff --git a/tests/golden/frontend/fmt/printer__smallest_int.silt b/tests/golden/frontend/fmt/printer__smallest_int.silt
index 42021547c..32b10bf66 100644
--- a/tests/golden/frontend/fmt/printer__smallest_int.silt
+++ b/tests/golden/frontend/fmt/printer__smallest_int.silt
@@ -15,10 +15,10 @@ fn main() {
   let b = - -9223372036854775808
   let c = -(-(- 9223372036854775808))
   let d = -(-0x8000000000000000)
-  let e = (-9223372036854775808).sh()
-  let f = -9223372036854775808.sh()
+  let e = Sh.sh(-9223372036854775808)
+  let f = Sh.sh(-9223372036854775808)
   let g = (- 9223372036854775808) + 1
-  let h = (1).sh()
+  let h = Sh.sh(1)
   let i = (1).e5
   println("{a} {b} {c} {d} {e} {f} {g} {h} {i}")
 }
diff --git a/tests/golden/frontend/recovery/one_error__a_stray_character_in_a_trait.silt b/tests/golden/frontend/recovery/one_error__a_stray_character_in_a_trait.silt
index 228ea3c9f..68ad77ea5 100644
--- a/tests/golden/frontend/recovery/one_error__a_stray_character_in_a_trait.silt
+++ b/tests/golden/frontend/recovery/one_error__a_stray_character_in_a_trait.silt
@@ -11,5 +11,5 @@ trait T for Int {
 }
 
 fn main() {
-  println("{1.m()} {2.m()}")
+  println("{T.m(1)} {T.m(2)}")
 }
diff --git a/tests/golden/frontend/recovery/one_error__a_stray_character_in_an_impl_method.silt b/tests/golden/frontend/recovery/one_error__a_stray_character_in_an_impl_method.silt
index afc56cde3..465baba88 100644
--- a/tests/golden/frontend/recovery/one_error__a_stray_character_in_an_impl_method.silt
+++ b/tests/golden/frontend/recovery/one_error__a_stray_character_in_an_impl_method.silt
@@ -11,5 +11,5 @@ trait T for Int {
 }
 
 fn main() {
-  println("{1.m()} {2.m()}")
+  println("{T.m(1)} {T.m(2)}")
 }
diff --git a/tests/golden/frontend/recovery/one_error__a_trait_that_does_not_parse_is_declared.silt b/tests/golden/frontend/recovery/one_error__a_trait_that_does_not_parse_is_declared.silt
index 8d9a37ea8..adc4dd3b9 100644
--- a/tests/golden/frontend/recovery/one_error__a_trait_that_does_not_parse_is_declared.silt
+++ b/tests/golden/frontend/recovery/one_error__a_trait_that_does_not_parse_is_declared.silt
@@ -11,5 +11,5 @@ trait T for Int {
 }
 
 fn main() {
-  println("{1.m()}")
+  println("{T.m(1)}")
 }
diff --git a/tests/golden/heavy/compute/stage6_perf__method_calls.silt b/tests/golden/heavy/compute/stage6_perf__method_calls.silt
index d5278edb8..6557da2d8 100644
--- a/tests/golden/heavy/compute/stage6_perf__method_calls.silt
+++ b/tests/golden/heavy/compute/stage6_perf__method_calls.silt
@@ -15,7 +15,7 @@ type Acc {
 trait Shape {
   fn area(self) -> Int
   fn double_area(self) -> Int {
-    self.area() * 2
+    Shape.area(self) * 2
   }
 }
 
@@ -38,14 +38,14 @@ trait Step for Vec2 {
 fn walk(v: Vec2, n: Int, acc: Int) -> Int {
   match n {
     0 -> acc
-    _ -> walk(v.add(Vec2 { x: 1, y: 0 }), n - 1, acc + v.area() % 7)
+    _ -> walk(Step.add(v, Vec2 { x: 1, y: 0 }), n - 1, acc + Shape.area(v) % 7)
   }
 }
 
 fn generic(s: a, n: Int, acc: Int) -> Int where a: Shape {
   match n {
     0 -> acc
-    _ -> generic(s, n - 1, acc + s.double_area() % 5)
+    _ -> generic(s, n - 1, acc + Shape.double_area(s) % 5)
   }
 }
 
diff --git a/tests/golden/heavy/compute/stage6_perf__showing_values.silt b/tests/golden/heavy/compute/stage6_perf__showing_values.silt
index 6d591377a..dcd69f748 100644
--- a/tests/golden/heavy/compute/stage6_perf__showing_values.silt
+++ b/tests/golden/heavy/compute/stage6_perf__showing_values.silt
@@ -37,7 +37,7 @@ fn run(n: Int, acc: Int) -> Int {
       let s = scene(n)
       let a = "{s}"
       let b = string.from((n, Some(s.shapes), #{ "k": [n, n] }))
-      let c = s.shapes.display()
+      let c = "{s.shapes}"
       let d = "{n} {s.name} {Point { x: n, y: n }} {[1, 2, 3]} {Some(n)}"
       run(n - 1, acc + string.length(a) + string.length(b) + string.length(c) + string.length(d))
     }
diff --git a/tests/golden/heavy/compute/stage7_perf__expr_tree.silt b/tests/golden/heavy/compute/stage7_perf__expr_tree.silt
index 79f872fe2..ce3f14196 100644
--- a/tests/golden/heavy/compute/stage7_perf__expr_tree.silt
+++ b/tests/golden/heavy/compute/stage7_perf__expr_tree.silt
@@ -27,9 +27,9 @@ trait Size for Expr {
     match self {
       Num(_) -> 1
       Var(_) -> 1
-      Add(l, r) -> 1 + l.size() + r.size()
-      Mul(l, r) -> 1 + l.size() + r.size()
-      Neg(e) -> 1 + e.size()
+      Add(l, r) -> 1 + Size.size(l) + Size.size(r)
+      Mul(l, r) -> 1 + Size.size(l) + Size.size(r)
+      Neg(e) -> 1 + Size.size(e)
     }
   }
 }
@@ -84,7 +84,7 @@ fn build(depth, seed) {
 fn main() {
   let tree = build(16, 1)
   let small = simplify(tree)
-  println("{tree.size()} {small.size()}")
+  println("{Size.size(tree)} {Size.size(small)}")
   let total = loop i = 0, acc = 0 {
     match i >= 60 {
       true -> acc
diff --git a/tests/golden/heavy/json/enum_decode__a_type_with_no_decoder_is_refused_whatever_the_document_holds.silt b/tests/golden/heavy/json/enum_decode__a_type_with_no_decoder_is_refused_whatever_the_document_holds.silt
index d87935332..7725f6cf5 100644
--- a/tests/golden/heavy/json/enum_decode__a_type_with_no_decoder_is_refused_whatever_the_document_holds.silt
+++ b/tests/golden/heavy/json/enum_decode__a_type_with_no_decoder_is_refused_whatever_the_document_holds.silt
@@ -34,7 +34,7 @@ fn from_toml(text: String, type a) -> Result(a, toml.TomlError) {
 fn show(r: Result(a, e)) where e: Error {
   match r {
     Ok(_) -> println("ok")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
diff --git a/tests/golden/heavy/json/integration_json_parse_list_invalid_field_error.silt b/tests/golden/heavy/json/integration_json_parse_list_invalid_field_error.silt
index 6b1ac83d4..835729de2 100644
--- a/tests/golden/heavy/json/integration_json_parse_list_invalid_field_error.silt
+++ b/tests/golden/heavy/json/integration_json_parse_list_invalid_field_error.silt
@@ -5,7 +5,7 @@ fn program() {
   match json.parse_list("[\{\"name\": \"Alice\", \"salary\": \"not_a_number\"\}]", Employee) {
     Ok(_) -> "unexpected"
     Err(json.TypeMismatch(expected, actual)) -> "{expected}/{actual}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/heavy/json/integration_json_parse_list_not_array_error.silt b/tests/golden/heavy/json/integration_json_parse_list_not_array_error.silt
index eaf1bf911..d83101866 100644
--- a/tests/golden/heavy/json/integration_json_parse_list_not_array_error.silt
+++ b/tests/golden/heavy/json/integration_json_parse_list_not_array_error.silt
@@ -5,7 +5,7 @@ fn program() {
   match json.parse_list("\{\"name\": \"Alice\"\}", Employee) {
     Ok(_) -> "unexpected"
     Err(json.TypeMismatch(expected, actual)) -> "{expected}/{actual}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/heavy/json/integration_json_parse_map_non_object_input.silt b/tests/golden/heavy/json/integration_json_parse_map_non_object_input.silt
index ad1a9d44c..85398d449 100644
--- a/tests/golden/heavy/json/integration_json_parse_map_non_object_input.silt
+++ b/tests/golden/heavy/json/integration_json_parse_map_non_object_input.silt
@@ -4,7 +4,7 @@ fn program() {
   match json.parse_map("[1, 2, 3]", String) {
     Ok(_) -> "unexpected"
     Err(json.TypeMismatch(expected, actual)) -> "{expected}/{actual}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/heavy/json/integration_json_parse_map_value_type_mismatch.silt b/tests/golden/heavy/json/integration_json_parse_map_value_type_mismatch.silt
index fe063397a..5a93609f9 100644
--- a/tests/golden/heavy/json/integration_json_parse_map_value_type_mismatch.silt
+++ b/tests/golden/heavy/json/integration_json_parse_map_value_type_mismatch.silt
@@ -4,7 +4,7 @@ fn program() {
   match json.parse_map("\{\"a\": \"hello\", \"b\": \"world\"\}", Int) {
     Ok(_) -> "unexpected"
     Err(json.TypeMismatch(expected, actual)) -> "{expected}/{actual}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/heavy/json/integration_json_parse_missing_field_error.silt b/tests/golden/heavy/json/integration_json_parse_missing_field_error.silt
index 9dde5e887..a14862e04 100644
--- a/tests/golden/heavy/json/integration_json_parse_missing_field_error.silt
+++ b/tests/golden/heavy/json/integration_json_parse_missing_field_error.silt
@@ -8,7 +8,7 @@ fn program() {
   match json.parse("\{\"name\": \"Alice\"\}", User) {
     Ok(_) -> "unexpected"
     Err(json.MissingField(f)) -> f
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/heavy/json/integration_json_parse_not_object_error.silt b/tests/golden/heavy/json/integration_json_parse_not_object_error.silt
index 96ed87ab5..f6c633a1f 100644
--- a/tests/golden/heavy/json/integration_json_parse_not_object_error.silt
+++ b/tests/golden/heavy/json/integration_json_parse_not_object_error.silt
@@ -5,7 +5,7 @@ fn program() {
   match json.parse("[1,2,3]", User) {
     Ok(_) -> "unexpected"
     Err(json.TypeMismatch(expected, actual)) -> "{expected}/{actual}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/heavy/json/integration_json_parse_wrong_type_error.silt b/tests/golden/heavy/json/integration_json_parse_wrong_type_error.silt
index 02701c60e..dacefa302 100644
--- a/tests/golden/heavy/json/integration_json_parse_wrong_type_error.silt
+++ b/tests/golden/heavy/json/integration_json_parse_wrong_type_error.silt
@@ -5,7 +5,7 @@ fn program() {
   match json.parse("\{\"name\": 42, \"age\": 30\}", User) {
     Ok(_) -> "unexpected"
     Err(json.TypeMismatch(expected, actual)) -> "{expected}/{actual}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/heavy/json/json_value__any_document_reads_into_it.silt b/tests/golden/heavy/json/json_value__any_document_reads_into_it.silt
index c5afe9d18..370aa1008 100644
--- a/tests/golden/heavy/json/json_value__any_document_reads_into_it.silt
+++ b/tests/golden/heavy/json/json_value__any_document_reads_into_it.silt
@@ -9,7 +9,7 @@ fn main() {
       println(v)
       println(json.stringify(v))
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   println(json.parse("""{"k": 1, "k": 2}""", json.Value))
   println(json.parse("7", json.Value))
diff --git a/tests/golden/heavy/json/time_text__a_year_past_9999_round_trips.silt b/tests/golden/heavy/json/time_text__a_year_past_9999_round_trips.silt
index 6265676e1..24b2d7379 100644
--- a/tests/golden/heavy/json/time_text__a_year_past_9999_round_trips.silt
+++ b/tests/golden/heavy/json/time_text__a_year_past_9999_round_trips.silt
@@ -27,7 +27,7 @@ fn main() {
       print(text)
       println(toml.parse(text, Moment) == Ok(m))
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   println(json.parse("""{"d": "12026-02-30", "dt": "12026-02-28T12:00:00"}""", Moment))
   println(json.parse("""{"d": "2026-02-28", "dt": "12026-02-28T12:00:00+01:00"}""", Moment))
diff --git a/tests/golden/heavy/json/time_text__dates_and_times_round_trip_through_toml.silt b/tests/golden/heavy/json/time_text__dates_and_times_round_trip_through_toml.silt
index 8c024d684..220ece440 100644
--- a/tests/golden/heavy/json/time_text__dates_and_times_round_trip_through_toml.silt
+++ b/tests/golden/heavy/json/time_text__dates_and_times_round_trip_through_toml.silt
@@ -35,7 +35,7 @@ fn main() {
       println(text)
       println(toml.parse(text, Moment) == Ok(m))
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match toml.stringify(f) {
     Ok(text) -> {
@@ -43,7 +43,7 @@ fn main() {
       println(toml.parse(text, Moment))
       println(toml.parse(text, Moment) == Ok(f))
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 
   let n = Nested {
@@ -59,7 +59,7 @@ fn main() {
       println(text)
       println(toml.parse(text, Nested) == Ok(n))
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 
   let past = Day { d: time.Date { year: -1, month: 1, day: 1 } }
@@ -68,6 +68,6 @@ fn main() {
       print(text)
       println(toml.parse(text, Day) == Ok(past))
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/heavy/lists/integration_builtin_display_list.silt b/tests/golden/heavy/lists/integration_builtin_display_list.silt
index c30659866..e8046cc75 100644
--- a/tests/golden/heavy/lists/integration_builtin_display_list.silt
+++ b/tests/golden/heavy/lists/integration_builtin_display_list.silt
@@ -1,5 +1,5 @@
 import io
-fn program() { [1, 2, 3].display() }
+fn program() { "{[1, 2, 3]}" }
 
 fn main() {
   println(io.inspect(program()))
diff --git a/tests/golden/heavy/numbers/integration_where_clause_multi_trait_bounds_mixed.silt b/tests/golden/heavy/numbers/integration_where_clause_multi_trait_bounds_mixed.silt
index 690fee798..f24e062ed 100644
--- a/tests/golden/heavy/numbers/integration_where_clause_multi_trait_bounds_mixed.silt
+++ b/tests/golden/heavy/numbers/integration_where_clause_multi_trait_bounds_mixed.silt
@@ -13,7 +13,7 @@ trait Display for Color {
 fn show_and_compare(a: t, b: u) where t: Equal + Compare, u: Display {
   let eq = a == a
   let lt = a < a
-  b.display()
+  "{b}"
 }
 
 fn program() {
diff --git a/tests/golden/heavy/strings/integration_builtin_display_string.silt b/tests/golden/heavy/strings/integration_builtin_display_string.silt
index ecdcfda63..ad05a111c 100644
--- a/tests/golden/heavy/strings/integration_builtin_display_string.silt
+++ b/tests/golden/heavy/strings/integration_builtin_display_string.silt
@@ -1,5 +1,6 @@
 import io
-fn program() { "hello".display() }
+import string
+fn program() { string.from("hello") }
 
 fn main() {
   println(io.inspect(program()))
diff --git a/tests/golden/heavy/traits/integration_builtin_compare_int.silt b/tests/golden/heavy/traits/integration_builtin_compare_int.silt
index 2ec8504f1..b4b042e3a 100644
--- a/tests/golden/heavy/traits/integration_builtin_compare_int.silt
+++ b/tests/golden/heavy/traits/integration_builtin_compare_int.silt
@@ -1,5 +1,5 @@
 import io
-fn program() { 3.compare(5) }
+fn program() { Compare.compare(3, 5) }
 
 fn main() {
   println(io.inspect(program()))
diff --git a/tests/golden/heavy/traits/integration_builtin_display_bool.silt b/tests/golden/heavy/traits/integration_builtin_display_bool.silt
index 917ec4ade..c00cf5200 100644
--- a/tests/golden/heavy/traits/integration_builtin_display_bool.silt
+++ b/tests/golden/heavy/traits/integration_builtin_display_bool.silt
@@ -1,5 +1,5 @@
 import io
-fn program() { true.display() }
+fn program() { "{true}" }
 
 fn main() {
   println(io.inspect(program()))
diff --git a/tests/golden/heavy/traits/integration_builtin_display_int.silt b/tests/golden/heavy/traits/integration_builtin_display_int.silt
index dc2288ed1..75f6efbb6 100644
--- a/tests/golden/heavy/traits/integration_builtin_display_int.silt
+++ b/tests/golden/heavy/traits/integration_builtin_display_int.silt
@@ -1,5 +1,5 @@
 import io
-fn program() { 42.display() }
+fn program() { "{42}" }
 
 fn main() {
   println(io.inspect(program()))
diff --git a/tests/golden/heavy/traits/integration_builtin_equal_int.silt b/tests/golden/heavy/traits/integration_builtin_equal_int.silt
index e14dae51b..f46a7862f 100644
--- a/tests/golden/heavy/traits/integration_builtin_equal_int.silt
+++ b/tests/golden/heavy/traits/integration_builtin_equal_int.silt
@@ -1,5 +1,5 @@
 import io
-fn program() { 42.equal(42) }
+fn program() { 42 == 42 }
 
 fn main() {
   println(io.inspect(program()))
diff --git a/tests/golden/heavy/traits/integration_enum_and_trait.silt b/tests/golden/heavy/traits/integration_enum_and_trait.silt
index 2bf06628d..0da2850eb 100644
--- a/tests/golden/heavy/traits/integration_enum_and_trait.silt
+++ b/tests/golden/heavy/traits/integration_enum_and_trait.silt
@@ -24,6 +24,6 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
 
   shapes
-  |> list.map { s -> (s.display(), area(s)) }
+  |> list.map { s -> ("{s}", area(s)) }
   |> list.each { pair -> println("{pair}") }
 }
diff --git a/tests/golden/heavy/traits/integration_self_type_in_trait.silt b/tests/golden/heavy/traits/integration_self_type_in_trait.silt
index 9573185d7..6d404e4f3 100644
--- a/tests/golden/heavy/traits/integration_self_type_in_trait.silt
+++ b/tests/golden/heavy/traits/integration_self_type_in_trait.silt
@@ -12,7 +12,7 @@ trait Monoid for Int {
 
 fn program() {
   let x = Int.empty()
-  let y = Int.combine(3, 4)
+  let y = Monoid.combine(3, 4)
   x + y
 }
 
diff --git a/tests/golden/heavy/traits/integration_where_clause_with_display.silt b/tests/golden/heavy/traits/integration_where_clause_with_display.silt
index 75a2aa1cd..f70d87101 100644
--- a/tests/golden/heavy/traits/integration_where_clause_with_display.silt
+++ b/tests/golden/heavy/traits/integration_where_clause_with_display.silt
@@ -11,7 +11,7 @@ trait Display for Shape {
 }
 
 fn show(x: a) where a: Display {
-  x.display()
+  "{x}"
 }
 
 fn program() {
diff --git a/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__bytes_to_hex_lowercase.silt b/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__bytes_to_hex_lowercase.silt
index 221bbece0..825a40b14 100644
--- a/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__bytes_to_hex_lowercase.silt
+++ b/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__bytes_to_hex_lowercase.silt
@@ -2,6 +2,6 @@ import bytes
 fn main() {
   match bytes.from_hex("deadbeefABCDEF") {
     Ok(b) -> println(bytes.to_hex(b))
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__lowercase_table.silt b/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__lowercase_table.silt
index 65187ec37..8801ba3dc 100644
--- a/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__lowercase_table.silt
+++ b/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__lowercase_table.silt
@@ -5,7 +5,7 @@ fn main() {
   list.each(digits) { d ->
     match bytes.from_hex("0{d}") {
       Ok(b) -> println(bytes.to_hex(b))
-      Err(e) -> println(e.message())
+      Err(e) -> println(Error.message(e))
     }
   }
 }
diff --git a/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__uppercase_table.silt b/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__uppercase_table.silt
index c9c827abc..b8a0827db 100644
--- a/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__uppercase_table.silt
+++ b/tests/golden/lang/builtins/builtin_nibble_to_hex_helper__uppercase_table.silt
@@ -7,9 +7,9 @@ fn main() {
     match bytes.from_hex("0{d}") {
       Ok(b) -> match bytes.to_string(b) {
         Ok(s) -> println(encoding.form_encode([("k", s)]))
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
       }
-      Err(e) -> println(e.message())
+      Err(e) -> println(Error.message(e))
     }
   }
 }
diff --git a/tests/golden/lang/callables/fn_params__destructuring_patterns.silt b/tests/golden/lang/callables/fn_params__destructuring_patterns.silt
index b59aaa5ac..1ee0329d6 100644
--- a/tests/golden/lang/callables/fn_params__destructuring_patterns.silt
+++ b/tests/golden/lang/callables/fn_params__destructuring_patterns.silt
@@ -30,5 +30,5 @@ fn main() {
   println(g(P { x: 1, y: 2 }))
   println(h((5, 6)))
   println(k(Wrap(4), P { x: 1, y: 0 }))
-  println(P { x: 1, y: 2 }.sum((10, 20)))
+  println(Sum.sum(P { x: 1, y: 2 }, (10, 20)))
 }
diff --git a/tests/golden/lang/callables/pipe__into_a_method_call.silt b/tests/golden/lang/callables/pipe__into_a_method_call.silt
index 15662d283..eee737ff6 100644
--- a/tests/golden/lang/callables/pipe__into_a_method_call.silt
+++ b/tests/golden/lang/callables/pipe__into_a_method_call.silt
@@ -8,9 +8,9 @@ trait Adder for Int { fn add(self, x: Int) -> Int { self + x } }
 type Opt { Wrap(Int) }
 fn main() {
   let a = Acc { base: 100 }
-  println(5 |> a.add())
-  println(5 |> a.add)
-  println(5 |> 3.add())
+  println(Adder.add(a, 5))
+  println(Adder.add(a, 5))
+  println(Adder.add(3, 5))
   println(5 |> Wrap)
   println(5 |> Wrap())
   println([1, 2] |> list.map({ x -> x + 1 }))
diff --git a/tests/golden/lang/collections/range_is_a_list.silt b/tests/golden/lang/collections/range_is_a_list.silt
index acd67f3c1..85b51e97e 100644
--- a/tests/golden/lang/collections/range_is_a_list.silt
+++ b/tests/golden/lang/collections/range_is_a_list.silt
@@ -27,7 +27,7 @@ fn main() {
   println("")
   println("{1..3} and {(1..3, 5..4)}")
   println(string.from(1..3))
-  println((1..3).display())
+  println("{1..3}")
   println(io.inspect(1..3))
   println(io.inspect(Span { name: "s", over: 1..3 }))
   println(Span { name: "s", over: 2..2 })
@@ -66,9 +66,9 @@ fn main() {
   println(1..3 < [1, 2, 4])
   println([1, 2] < 1..3)
   println(2..3 > [1, 9, 9])
-  println((1..3).hash() == [1, 2, 3].hash())
-  println(list.tail(0..3).hash() == [1, 2, 3].hash())
-  println((1..3).hash() == [1, 2, 4].hash())
+  println(Hash.hash(1..3) == Hash.hash([1, 2, 3]))
+  println(Hash.hash(list.tail(0..3)) == Hash.hash([1, 2, 3]))
+  println(Hash.hash(1..3) == Hash.hash([1, 2, 4]))
   println(set.length(#[1..3, [1, 2, 3], list.tail(0..3)]))
   println(map.get(#{[1, 2, 3]: "found"}, 1..3))
   println(list.sort([2..3, [1, 5], 1..4, []]))
diff --git a/tests/golden/lang/collections/range_of_many_holds_no_element.silt b/tests/golden/lang/collections/range_of_many_holds_no_element.silt
index c8a316ae8..7191c98eb 100644
--- a/tests/golden/lang/collections/range_of_many_holds_no_element.silt
+++ b/tests/golden/lang/collections/range_of_many_holds_no_element.silt
@@ -23,8 +23,8 @@ fn main() {
   println(big == big)
   println(big == list.tail(big))
   println(big < list.tail(big))
-  println(big.hash() == (1..9223372036854775807).hash())
-  println(big.hash() == list.tail(big).hash())
+  println(Hash.hash(big) == Hash.hash(1..9223372036854775807))
+  println(Hash.hash(big) == Hash.hash(list.tail(big)))
   match big {
     [a, b, ..rest] -> println("{a}, {b}, then {list.length(rest)} more")
     _ -> println("no match")
diff --git a/tests/golden/lang/collections/range_too_long_to_write_out.silt b/tests/golden/lang/collections/range_too_long_to_write_out.silt
index 5b755e105..920b761ae 100644
--- a/tests/golden/lang/collections/range_too_long_to_write_out.silt
+++ b/tests/golden/lang/collections/range_too_long_to_write_out.silt
@@ -40,7 +40,7 @@ fn test_string_from() {
 }
 
 fn test_display_method() {
-  let _ = long().display()
+  let _ = "{long()}"
 }
 
 fn test_inspect() {
diff --git a/tests/golden/lang/collections/range_too_long_to_write_out.stderr b/tests/golden/lang/collections/range_too_long_to_write_out.stderr
index 18833dbe0..e946e675a 100644
--- a/tests/golden/lang/collections/range_too_long_to_write_out.stderr
+++ b/tests/golden/lang/collections/range_too_long_to_write_out.stderr
@@ -27,8 +27,8 @@
     error[runtime]: range 0..10000000 has 10000001 elements; materializing more than 10000000 is not allowed
      --> range_too_long_to_write_out.silt:43:11
         |
-     43 |   let _ = long().display()
-        |           ^^^^^^^^^^^^^^^^ range 0..10000000 has 10000001 elements; materializing more than 10000000 is not allowed
+     43 |   let _ = "{long()}"
+        |           ^^^^^^^^^^ range 0..10000000 has 10000001 elements; materializing more than 10000000 is not allowed
   FAIL range_too_long_to_write_out.silt::test_inspect
     error[runtime]: range 0..10000000 has 10000001 elements; materializing more than 10000000 is not allowed
      --> range_too_long_to_write_out.silt:47:11
diff --git a/tests/golden/lang/collections/sort_with__a_failing_comparison_fails_the_sort.silt b/tests/golden/lang/collections/sort_with__a_failing_comparison_fails_the_sort.silt
index e4960c868..7913941fe 100644
--- a/tests/golden/lang/collections/sort_with__a_failing_comparison_fails_the_sort.silt
+++ b/tests/golden/lang/collections/sort_with__a_failing_comparison_fails_the_sort.silt
@@ -14,7 +14,7 @@ fn main() {
   })
   let sorted = list.sort_with([4, 2, 3, 1]) { a, b ->
     match channel.receive(ch) {
-      Some(_) -> a.compare(b)
+      Some(_) -> Compare.compare(a, b)
       None -> 0
     }
   }
@@ -23,7 +23,7 @@ fn main() {
   let _ = list.sort_with([1, 3, 2]) { a, b ->
     match a == 3 || b == 3 {
       true -> panic("no order for 3")
-      false -> a.compare(b)
+      false -> Compare.compare(a, b)
     }
   }
 }
diff --git a/tests/golden/lang/collections/sort_with__orders_by_the_comparison_and_is_stable.silt b/tests/golden/lang/collections/sort_with__orders_by_the_comparison_and_is_stable.silt
index da4ca6268..1365bda46 100644
--- a/tests/golden/lang/collections/sort_with__orders_by_the_comparison_and_is_stable.silt
+++ b/tests/golden/lang/collections/sort_with__orders_by_the_comparison_and_is_stable.silt
@@ -7,20 +7,20 @@ import list
 fn by_key(a: (Int, Int), b: (Int, Int)) -> Int {
   let (x, _) = a
   let (y, _) = b
-  x.compare(y)
+  Compare.compare(x, y)
 }
 
 fn main() {
-  println(list.sort_with([]) { a, b -> a.compare(b) })
-  println(list.sort_with([5]) { a, b -> a.compare(b) })
-  println(list.sort_with([5, 3, 9, 1, 7]) { a, b -> a.compare(b) })
-  println(list.sort_with([5, 3, 9, 1, 7]) { a, b -> b.compare(a) })
+  println(list.sort_with([]) { a, b -> Compare.compare(a, b) })
+  println(list.sort_with([5]) { a, b -> Compare.compare(a, b) })
+  println(list.sort_with([5, 3, 9, 1, 7]) { a, b -> Compare.compare(a, b) })
+  println(list.sort_with([5, 3, 9, 1, 7]) { a, b -> Compare.compare(b, a) })
   -- Any Int counts, not only -1, 0 and 1.
-  println(list.sort_with([2, 1, 3]) { a, b -> a.compare(b) * 1000000 })
+  println(list.sort_with([2, 1, 3]) { a, b -> Compare.compare(a, b) * 1000000 })
   -- All equal: the order of the list.
   println(list.sort_with(["c", "a", "b"]) { _, _ -> 0 })
   -- A range.
-  println(list.sort_with(1..6) { a, b -> b.compare(a) })
+  println(list.sort_with(1..6) { a, b -> Compare.compare(b, a) })
   -- Every length from 0 to 40, keys with many ties: the same as sort_by.
   let lengths = 0..40
   let all_same = lengths |> list.all { n ->
diff --git a/tests/golden/lang/compiler/selection__field_holding_a_function_is_called.silt b/tests/golden/lang/compiler/selection__field_holding_a_function_is_called.silt
index 24ce3c2d3..4db63a1eb 100644
--- a/tests/golden/lang/compiler/selection__field_holding_a_function_is_called.silt
+++ b/tests/golden/lang/compiler/selection__field_holding_a_function_is_called.silt
@@ -15,7 +15,7 @@ fn tail(r: Holder, n: Int, acc: Int) -> Int {
 fn main() {
   let h = Holder { run: { x -> x + 1 }, name: "h" }
   println(h.run(1))
-  println(h.describe())
+  println(Describe.describe(h))
   let r = {run: { x -> x * 2 }, inner: {go: { s -> "go {s}" }}}
   println(r.run(4))
   println(r.inner.go("on"))
diff --git a/tests/golden/lang/compiler/selection__impl_method_recursion_is_a_tail_call.silt b/tests/golden/lang/compiler/selection__impl_method_recursion_is_a_tail_call.silt
index 4250e6197..36030c983 100644
--- a/tests/golden/lang/compiler/selection__impl_method_recursion_is_a_tail_call.silt
+++ b/tests/golden/lang/compiler/selection__impl_method_recursion_is_a_tail_call.silt
@@ -9,7 +9,7 @@ trait Down for Counter {
   fn down(self, k: Int) -> Int {
     match k {
       0 -> self.n
-      _ -> self.down(k - 1)
+      _ -> Down.down(self, k - 1)
     }
   }
 }
@@ -18,7 +18,7 @@ trait Ping for Counter {
   fn ping(self, k: Int) -> String {
     match k {
       0 -> "counter {self.n}"
-      _ -> Other { n: self.n }.ping(k - 1)
+      _ -> Ping.ping(Other { n: self.n }, k - 1)
     }
   }
 }
@@ -30,8 +30,8 @@ trait Ping for Other {
     }
   }
 }
-fn hop(c: Counter, k: Int) -> String { c.ping(k) }
+fn hop(c: Counter, k: Int) -> String { Ping.ping(c, k) }
 fn main() {
-  println(Counter { n: 7 }.down(1000000))
-  println(Counter { n: 0 }.ping(1000001))
+  println(Down.down(Counter { n: 7 }, 1000000))
+  println(Ping.ping(Counter { n: 0 }, 1000001))
 }
diff --git a/tests/golden/lang/compiler/selection__method_found_at_run_time_is_a_tail_call.silt b/tests/golden/lang/compiler/selection__method_found_at_run_time_is_a_tail_call.silt
index db7f548c0..7399a1920 100644
--- a/tests/golden/lang/compiler/selection__method_found_at_run_time_is_a_tail_call.silt
+++ b/tests/golden/lang/compiler/selection__method_found_at_run_time_is_a_tail_call.silt
@@ -11,35 +11,35 @@ trait Walk {
   fn base(self) -> Int
   fn walk(self, k: Int, acc: Int) -> Int {
     match k {
-      0 -> acc + self.base()
-      _ -> self.walk(k - 1, acc + 1)
+      0 -> acc + Walk.base(self)
+      _ -> Walk.walk(self, k - 1, acc + 1)
     }
   }
-  fn show(self) -> String { self.base().display() }
+  fn show(self) -> String { "{Walk.base(self)}" }
 }
 trait Walk for C { fn base(self) -> Int { self.n } }
 trait Walk for Int { fn base(self) -> Int { self } }
 fn go(x: a, k: Int) -> Int where a: Walk {
   match k {
-    0 -> x.base()
+    0 -> Walk.base(x)
     _ -> go(x, k - 1)
   }
 }
-fn last(x: a) -> Int where a: Walk { x.walk(1000000, 0) }
+fn last(x: a) -> Int where a: Walk { Walk.walk(x, 1000000, 0) }
 trait Hop { fn hop(self, k: Int) -> Int }
 trait Hop for C { fn hop(self, k: Int) -> Int { bounce(self, k) } }
 fn bounce(x: a, k: Int) -> Int where a: Hop {
   match k {
     0 -> 42
-    _ -> x.hop(k - 1)
+    _ -> Hop.hop(x, k - 1)
   }
 }
-fn shown(x: a) -> String where a: Display { x.display() }
+fn shown(x: a) -> String where a: Display { "{x}" }
 fn main() {
-  println(C { n: 5 }.walk(1000000, 0))
+  println(Walk.walk(C { n: 5 }, 1000000, 0))
   println(last(7))
   println(go(C { n: 3 }, 1000000))
-  println(C { n: 9 }.show())
+  println(Walk.show(C { n: 9 }))
   println(shown([1, 2]))
   println(shown(C { n: 1 }))
   println(bounce(C { n: 1 }, 1000000))
diff --git a/tests/golden/lang/compiler/selection__method_of_a_bounded_variable_and_of_a_builtin_type.silt b/tests/golden/lang/compiler/selection__method_of_a_bounded_variable_and_of_a_builtin_type.silt
index d3846fd15..b84d6c8c6 100644
--- a/tests/golden/lang/compiler/selection__method_of_a_bounded_variable_and_of_a_builtin_type.silt
+++ b/tests/golden/lang/compiler/selection__method_of_a_bounded_variable_and_of_a_builtin_type.silt
@@ -6,8 +6,8 @@ type Cat { name: String }
 type Dog { name: String }
 trait Speak {
   fn word(self) -> String
-  fn twice(self) -> String { "{self.word()} {self.word()}" }
-  fn loud(self) -> String { "{self.twice()}!" }
+  fn twice(self) -> String { "{Speak.word(self)} {Speak.word(self)}" }
+  fn loud(self) -> String { "{Speak.twice(self)}!" }
 }
 trait Speak for Cat { fn word(self) -> String { "meow" } }
 trait Speak for Dog {
@@ -15,19 +15,19 @@ trait Speak for Dog {
   fn loud(self) -> String { "WOOF" }
 }
 trait Speak for Int { fn word(self) -> String { "{self}" } }
-fn all(x: a) -> String where a: Speak { "{x.word()} / {x.twice()} / {x.loud()}" }
+fn all(x: a) -> String where a: Speak { "{Speak.word(x)} / {Speak.twice(x)} / {Speak.loud(x)}" }
 fn main() {
   println(all(Cat { name: "c" }))
   println(all(Dog { name: "d" }))
   println(all(7))
-  println(Cat { name: "c" }.loud())
-  println(Dog { name: "d" }.loud())
-  println(Dog { name: "d" }.twice())
-  println(Cat.twice(Cat { name: "c" }))
-  println(3.display())
-  println([1, 2].display())
-  println(Int.display(5))
-  println(Cat { name: "c" }.equal(Cat { name: "c" }))
-  println((1, "a").compare((1, "b")))
-  println(Some(2).hash() == Some(2).hash())
+  println(Speak.loud(Cat { name: "c" }))
+  println(Speak.loud(Dog { name: "d" }))
+  println(Speak.twice(Dog { name: "d" }))
+  println(Speak.twice(Cat { name: "c" }))
+  println("{3}")
+  println("{[1, 2]}")
+  println("{5}")
+  println(Cat { name: "c" } == Cat { name: "c" })
+  println(Compare.compare((1, "a"), (1, "b")))
+  println(Hash.hash(Some(2)) == Hash.hash(Some(2)))
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c1_other_positions.silt b/tests/golden/lang/compiler/wave1_compiler__c1_other_positions.silt
index a5d5a00eb..9546c5997 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c1_other_positions.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c1_other_positions.silt
@@ -41,7 +41,7 @@ fn main() {
     5 -> 50
     _ -> 0
   })
-  println(3.scale(match x {
+  println(Scale.scale(3, match x {
     5 -> 10
     _ -> 0
   }))
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_aliases.silt b/tests/golden/lang/compiler/wave1_compiler__c4_aliases.silt
index 014ff5ae3..ce76cb601 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_aliases.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_aliases.silt
@@ -16,10 +16,10 @@ fn main() {
   let raw = "\{\"title\": \"hi\", \"tags\": [\"a\", \"b\"], \"n\": 3, \"pair\": [1, 2]\}"
   match json.parse(raw, Post) {
     Ok(p) -> println("ok: {p.title} {p.tags} {p.n + 1} {p.pair}")
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
   match toml.parse("title = \"hi\"\ntags = [\"a\", \"b\"]\nn = 3\npair = [1, 2]\n", Post) {
     Ok(p) -> println("ok: {p.title} {p.tags} {p.n + 1} {p.pair}")
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_enum_field_run.silt b/tests/golden/lang/compiler/wave1_compiler__c4_enum_field_run.silt
index 7b2e15d2b..113d18a02 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_enum_field_run.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_enum_field_run.silt
@@ -8,6 +8,6 @@ type Pixel { x: Int, c: Color }
 fn main() {
   match toml.parse("x = 1\nc = \"Red\"\n", Pixel) {
     Ok(v) -> println("{v.x} {v.c}")
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_check.silt b/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_check.silt
index 9c7447b6b..12585eb17 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_check.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_check.silt
@@ -12,6 +12,6 @@ fn main() {
   let r: Result(Wrap(Int), json.JsonError) = json.parse("\{\"value\": \"x\"\}", Wrap)
   match r {
     Ok(w) -> println(w.value + 1)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_run.silt b/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_run.silt
index 9b53a8fae..53b59b6bd 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_run.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_generic_record_run.silt
@@ -11,6 +11,6 @@ fn main() {
   let r: Result(Wrap(Int), json.JsonError) = json.parse("\{\"value\": \"x\"\}", Wrap)
   match r {
     Ok(w) -> println(w.value + 1)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_json_map_tuple.silt b/tests/golden/lang/compiler/wave1_compiler__c4_json_map_tuple.silt
index 401ff3c47..d45910b40 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_json_map_tuple.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_json_map_tuple.silt
@@ -13,6 +13,6 @@ fn main() {
       println(s)
       println(v.o)
     }
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_json_wrong_shape.silt b/tests/golden/lang/compiler/wave1_compiler__c4_json_wrong_shape.silt
index 31046d422..bce9c6aa8 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_json_wrong_shape.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_json_wrong_shape.silt
@@ -9,14 +9,14 @@ fn main() {
       println(v)
       println(map.length(v.m))
     }
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
   match json.parse("\{\"m\": \{\"a\": \"one\"\}, \"t\": [1, 2]\}", M) {
     Ok(v) -> println(v)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
   match json.parse("\{\"m\": \{\"a\": 1\}, \"t\": [1, 2, 3]\}", M) {
     Ok(v) -> println(v)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_nested_check.silt b/tests/golden/lang/compiler/wave1_compiler__c4_nested_check.silt
index b3024ce62..c8d7b8bef 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_nested_check.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_nested_check.silt
@@ -14,6 +14,6 @@ type Outer { inners: List(Inner) }
 fn main() {
   match json.parse_list("[]", Outer) {
     Ok(v) -> println(v)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_nested_run.silt b/tests/golden/lang/compiler/wave1_compiler__c4_nested_run.silt
index b75f4b8c0..2f3b30c53 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_nested_run.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_nested_run.silt
@@ -13,6 +13,6 @@ type Outer { inners: List(Inner) }
 fn main() {
   match json.parse_list("[]", Outer) {
     Ok(v) -> println(v)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_piped_check.silt b/tests/golden/lang/compiler/wave1_compiler__c4_piped_check.silt
index 3508a16d5..eac2743fb 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_piped_check.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_piped_check.silt
@@ -13,6 +13,6 @@ fn main() {
   let r = "\{\"items\": \"oops\"\}" |> json.parse(Bag)
   match r {
     Ok(v) -> println(v)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_piped_run.silt b/tests/golden/lang/compiler/wave1_compiler__c4_piped_run.silt
index e6ffe2d5d..0aa4b1997 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_piped_run.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_piped_run.silt
@@ -12,6 +12,6 @@ fn main() {
   let r = "\{\"items\": \"oops\"\}" |> json.parse(Bag)
   match r {
     Ok(v) -> println(v)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_set_field_check.silt b/tests/golden/lang/compiler/wave1_compiler__c4_set_field_check.silt
index aaa30e805..f23a63ef6 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_set_field_check.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_set_field_check.silt
@@ -12,6 +12,6 @@ type Bag { name: String, items: Set(Int) }
 fn main() {
   match json.parse("\{\"name\": \"b\", \"items\": \"oops\"\}", Bag) {
     Ok(v) -> println(v.name)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_set_field_run.silt b/tests/golden/lang/compiler/wave1_compiler__c4_set_field_run.silt
index 313bd6390..261f9c0d6 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_set_field_run.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_set_field_run.silt
@@ -11,6 +11,6 @@ type Bag { name: String, items: Set(Int) }
 fn main() {
   match json.parse("\{\"name\": \"b\", \"items\": \"oops\"\}", Bag) {
     Ok(v) -> println(v.name)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_toml_map_tuple.silt b/tests/golden/lang/compiler/wave1_compiler__c4_toml_map_tuple.silt
index afe888da0..0163a66be 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_toml_map_tuple.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_toml_map_tuple.silt
@@ -11,10 +11,10 @@ fn main() {
       println(n + 1)
       println(s)
     }
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
   match toml.parse("m = \"oops\"\nt = \"also\"\n", M) {
     Ok(v) -> println(v)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c4_type_parameter.silt b/tests/golden/lang/compiler/wave1_compiler__c4_type_parameter.silt
index 7b7f7d972..75795b3a4 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c4_type_parameter.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c4_type_parameter.silt
@@ -19,10 +19,10 @@ fn from_toml(text: String, type a) -> Result(a, toml.TomlError) {
 fn main() {
   match from_json("\{\"name\": \"b\", \"items\": \"oops\"\}", Bag) {
     Ok(v) -> println(v.name)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
   match from_toml("name = \"b\"\nitems = \"oops\"\n", Bag) {
     Ok(v) -> println(v.name)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c5_enum_order.silt b/tests/golden/lang/compiler/wave1_compiler__c5_enum_order.silt
index df6b7b21c..7888d24a6 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c5_enum_order.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c5_enum_order.silt
@@ -3,7 +3,7 @@ fn first() {
 }
 
 fn describe() {
-  Color.Green.display()
+  "{Color.Green}"
 }
 
 type Color { Red, Green }
diff --git a/tests/golden/lang/compiler/wave1_compiler__c5_later_impl.silt b/tests/golden/lang/compiler/wave1_compiler__c5_later_impl.silt
index 3a17f9a9c..c60222c83 100644
--- a/tests/golden/lang/compiler/wave1_compiler__c5_later_impl.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__c5_later_impl.silt
@@ -1,6 +1,7 @@
+import string
 type Money { cents: Int }
 
-let shown = Money { cents: 5 }.display()
+let shown = string.from(Money { cents: 5 })
 
 trait Display for Money {
   fn display(self) -> String {
diff --git a/tests/golden/lang/compiler/wave1_compiler__guard_c4_not_decoded.silt b/tests/golden/lang/compiler/wave1_compiler__guard_c4_not_decoded.silt
index 845254a27..6b46b11f1 100644
--- a/tests/golden/lang/compiler/wave1_compiler__guard_c4_not_decoded.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__guard_c4_not_decoded.silt
@@ -9,6 +9,6 @@ fn main() {
   println(set.length(b.items))
   match json.parse("\{\"text\": \"t\"\}", Label) {
     Ok(v) -> println(v.text)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave1_compiler__guard_c4_supported.silt b/tests/golden/lang/compiler/wave1_compiler__guard_c4_supported.silt
index 7d7257839..4f310eed6 100644
--- a/tests/golden/lang/compiler/wave1_compiler__guard_c4_supported.silt
+++ b/tests/golden/lang/compiler/wave1_compiler__guard_c4_supported.silt
@@ -18,15 +18,15 @@ fn main() {
   let raw = "\{\"name\": \"A\", \"age\": 3, \"score\": 1.5, \"active\": true, \"tags\": [\"x\"], \"home\": \{\"city\": \"B\"\}, \"seen\": \"2024-03-15\"\}"
   match json.parse(raw, User) {
     Ok(u) -> println("{u.name} {u.age} {u.score} {u.active} {u.tags} {u.nick} {u.home.city} {u.seen.year}")
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
   match json.parse("\{\"name\": 1\}", User) {
     Ok(u) -> println(u.name)
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
   let text = "name = \"A\"\nage = 3\nscore = 1.5\nactive = true\ntags = [\"x\"]\nseen = 2024-03-15\n[home]\ncity = \"B\"\n"
   match toml.parse(text, User) {
     Ok(u) -> println("{u.name} {u.age} {u.score} {u.active} {u.tags} {u.nick} {u.home.city} {u.seen.year}")
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__guard_w3_selective_ok.silt b/tests/golden/lang/compiler/wave2_compiler__guard_w3_selective_ok.silt
index 64df56774..fd8ac347e 100644
--- a/tests/golden/lang/compiler/wave2_compiler__guard_w3_selective_ok.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__guard_w3_selective_ok.silt
@@ -5,10 +5,10 @@ type Point { x: Int, y: Int }
 fn main() {
   match parse("""{"x": 1, "y": 2}""", Point) {
     Ok(p) -> println(p.x + p.y)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match parse_list("""[{"x": 3, "y": 4}]""", Point) {
     Ok(ps) -> println(ps)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__guard_w6_lambdas.silt b/tests/golden/lang/compiler/wave2_compiler__guard_w6_lambdas.silt
index f1efeb739..8d10311d2 100644
--- a/tests/golden/lang/compiler/wave2_compiler__guard_w6_lambdas.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__guard_w6_lambdas.silt
@@ -7,7 +7,7 @@ let tl = { x -> x + 1 }
 
 fn main() {
   let f = { x -> x * 3 }
-  println(f.baz())
-  println(tl.baz())
+  println(Baz.baz(f))
+  println(Baz.baz(tl))
   println(list.length([1, 2, 3]))
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_check.silt b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_check.silt
index d6384a506..7fa22ef6b 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_check.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_check.silt
@@ -12,6 +12,6 @@ type Bag { name: String, items: Set(Int) }
 fn main() {
   match parse("""{"name": "b", "items": [1]}""", Bag) {
     Ok(b) -> println(b.name)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_check.silt b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_check.silt
index 2c2732d4d..abe84b0ec 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_check.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_check.silt
@@ -13,6 +13,6 @@ fn main() {
   let r = """{"name": "b", "items": [1]}""" |> parse(Bag)
   match r {
     Ok(b) -> println(b.name)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_run.silt b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_run.silt
index f6d52e515..5e855cd94 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_run.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_piped_run.silt
@@ -12,6 +12,6 @@ fn main() {
   let r = """{"name": "b", "items": [1]}""" |> parse(Bag)
   match r {
     Ok(b) -> println(b.name)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_run.silt b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_run.silt
index 5e6676a4d..eff33b226 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_run.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w3_selective_parse_run.silt
@@ -11,6 +11,6 @@ type Bag { name: String, items: Set(Int) }
 fn main() {
   match parse("""{"name": "b", "items": [1]}""", Bag) {
     Ok(b) -> println(b.name)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w4_field_named.silt b/tests/golden/lang/compiler/wave2_compiler__w4_field_named.silt
index ed79fb6cb..e0e0e8ce7 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w4_field_named.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w4_field_named.silt
@@ -19,10 +19,10 @@ fn from_toml(text: String, type a) -> Result(a, toml.TomlError) {
 fn main() {
   match from_json("""{"name": "o", "inner": {"tags": [[1]]}}""", Outer) {
     Ok(v) -> println(v.name)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match from_toml("name = \"o\"\n[inner]\ntags = [[1]]\n", Outer) {
     Ok(v) -> println(v.name)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w6_imported_fn/main.silt b/tests/golden/lang/compiler/wave2_compiler__w6_imported_fn/main.silt
index 15c4699d6..55c76a704 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w6_imported_fn/main.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w6_imported_fn/main.silt
@@ -2,6 +2,6 @@ import util.{ triple }
 import util
 
 fn main() {
-  println(triple.baz())
+  println(util.Baz.baz(triple))
   println(util.triple(2))
 }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w6_module_fn/util.silt b/tests/golden/lang/compiler/wave2_compiler__w6_module_fn/util.silt
index 058d3cdfd..2cfa74a4a 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w6_module_fn/util.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w6_module_fn/util.silt
@@ -3,4 +3,4 @@ trait Baz for Fun { fn baz(self) -> String { "baz" } }
 
 pub fn triple(x: Int) -> Int { x * 3 }
 
-pub fn inner() -> String { triple.baz() }
+pub fn inner() -> String { Baz.baz(triple) }
diff --git a/tests/golden/lang/compiler/wave2_compiler__w6_named_fn.silt b/tests/golden/lang/compiler/wave2_compiler__w6_named_fn.silt
index f331cd763..0d94c6af4 100644
--- a/tests/golden/lang/compiler/wave2_compiler__w6_named_fn.silt
+++ b/tests/golden/lang/compiler/wave2_compiler__w6_named_fn.silt
@@ -4,6 +4,6 @@ trait Baz for Fun { fn baz(self) -> String { "baz" } }
 fn double(x: Int) -> Int { x * 2 }
 
 fn main() {
-  println(double.baz())
+  println(Baz.baz(double))
   println(double(21))
 }
diff --git a/tests/golden/lang/encoding/toml_counts_the_content_of_a_json_value_as_a_level.silt b/tests/golden/lang/encoding/toml_counts_the_content_of_a_json_value_as_a_level.silt
index 96a2dfa5a..560c64b3f 100644
--- a/tests/golden/lang/encoding/toml_counts_the_content_of_a_json_value_as_a_level.silt
+++ b/tests/golden/lang/encoding/toml_counts_the_content_of_a_json_value_as_a_level.silt
@@ -12,11 +12,11 @@ fn main() {
   println(string.length(json.stringify(#{"v": deep})))
   match toml.stringify(#{"v": deep}) {
     Ok(text) -> println("written: {string.length(text)}")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   let shallow = list.fold(1..400, json.Int(1), { acc, _ -> json.Array([acc]) })
   match toml.stringify(#{"v": shallow}) {
     Ok(text) -> println("written: {string.length(text)}")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/encoding/toml_writes_a_json_value_as_what_it_holds.silt b/tests/golden/lang/encoding/toml_writes_a_json_value_as_what_it_holds.silt
index 0613264fc..186c53b8a 100644
--- a/tests/golden/lang/encoding/toml_writes_a_json_value_as_what_it_holds.silt
+++ b/tests/golden/lang/encoding/toml_writes_a_json_value_as_what_it_holds.silt
@@ -28,6 +28,6 @@ fn main() {
   println(said(toml.stringify(#{"v": json.Array([json.Null])})))
   match json.parse("\{\"name\": \"silt\", \"tags\": [\"a\", \"b\"]}", json.Value) {
     Ok(parsed) -> println(said(toml.stringify(parsed)))
-    Err(e) -> println("parse: {e.message()}")
+    Err(e) -> println("parse: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt b/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt
index 25507ecad..1762b8030 100644
--- a/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt
+++ b/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt
@@ -1,25 +1,27 @@
 -- exit: 1
--- A method the language has for a type, taken as a value, is a frame
--- under the method's name, as a written method is: the program wrote
--- no closure there.
+-- A trait's method taken as a value where the impl is found when it
+-- runs is a frame under the method's name, as a written method is: the
+-- program wrote no closure there.
 import list
 
 type Inner {
   n: Int,
 }
 
-trait Display for Inner {
-  fn display(self) -> String {
-    "{1 / (self.n - self.n)}"
+trait Div {
+  fn div(self) -> Int
+}
+
+trait Div for Inner {
+  fn div(self) -> Int {
+    1 / (self.n - self.n)
   }
 }
 
-type Outer {
-  inner: Inner,
-  tag: Int,
+fn all(xs: List(a)) -> List(Int) where a: Div {
+  list.map(xs, Div.div)
 }
 
 fn main() {
-  let shown = list.map([Outer { inner: Inner { n: 1 }, tag: 2 }], Outer.display)
-  println(shown)
+  println(all([Inner { n: 1 }]))
 }
diff --git a/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.stderr b/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.stderr
index af15c9ec4..9e3a92b16 100644
--- a/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.stderr
+++ b/tests/golden/lang/errors/closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.stderr
@@ -1,10 +1,11 @@
 error[runtime]: division by zero
- --> closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:13:7
+ --> closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:17:5
     |
- 13 |     "{1 / (self.n - self.n)}"
-    |       ^^^^^^^^^^^^^^^^^^^^^ division by zero
+ 17 |     1 / (self.n - self.n)
+    |     ^^^^^^^^^^^^^^^^^^^^^ division by zero
 
 call stack:
-  -> Inner.display  at closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:13:7
-  -> Outer.display  at closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:23:67
-  -> main  at closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:23:15
+  -> Inner.div  at closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:17:5
+  -> Div.div  at closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:22:16
+  -> all  at closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:22:3
+  -> main  at closure_frames__a_native_method_taken_as_a_value_is_named_after_the_method.silt:26:11
diff --git a/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.silt b/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.silt
index 1f6237f5a..c2f82c335 100644
--- a/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.silt
+++ b/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.silt
@@ -1,4 +1,4 @@
 -- cmd: repl
--- stdin: Int.display\nlet f = Int.compare\nf\ntype Pt { x: Int }\nPt.display\n[Pt.equal]\n:quit\n
--- A method the language has for a type, taken as a value, is shown
--- under the method's name, as a written method is.
+-- stdin: Compare.compare\nlet f = Hash.hash\nf\nError.message\n[Compare.compare]\n:quit\n
+-- A method the language has for a type, taken as a value through its
+-- trait, is shown under the method's name, as a written method is.
diff --git a/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.stdout b/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.stdout
index e6550f43a..be7fb10ca 100644
--- a/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.stdout
+++ b/tests/golden/lang/errors/closure_frames__a_native_method_value_is_shown_under_the_method_s_name.stdout
@@ -1,5 +1,5 @@
 Silt REPL (type :quit to exit, :help for commands)
-<fn:Int.display>
-<fn:Int.compare>
-<fn:Pt.display>
-[<fn:Pt.equal>]
+<fn:Compare.compare>
+<fn:Hash.hash>
+<fn:Error.message>
+[<fn:Compare.compare>]
diff --git a/tests/golden/lang/errors/closure_frames__in_a_method_and_in_a_default_method.silt b/tests/golden/lang/errors/closure_frames__in_a_method_and_in_a_default_method.silt
index 688b1cd30..41e175d41 100644
--- a/tests/golden/lang/errors/closure_frames__in_a_method_and_in_a_default_method.silt
+++ b/tests/golden/lang/errors/closure_frames__in_a_method_and_in_a_default_method.silt
@@ -8,7 +8,7 @@ type Half {
 trait Sized {
   fn size(self) -> Int
   fn twice(self) -> Int {
-    let double = { n -> n + self.size() }
+    let double = { n -> n + Sized.size(self) }
     double(1) + 0
   }
 }
@@ -21,5 +21,5 @@ trait Sized for Half {
 }
 
 fn main() {
-  println(Half { n: 4 }.twice())
+  println(Sized.twice(Half { n: 4 }))
 }
diff --git a/tests/golden/lang/errors/error__runtime_int_parse_error_message_dispatch.silt b/tests/golden/lang/errors/error__runtime_int_parse_error_message_dispatch.silt
index f96f84401..4c73becca 100644
--- a/tests/golden/lang/errors/error__runtime_int_parse_error_message_dispatch.silt
+++ b/tests/golden/lang/errors/error__runtime_int_parse_error_message_dispatch.silt
@@ -2,6 +2,6 @@ import int
 fn main() {
     match int.parse("") {
         Ok(_) -> println("impossible")
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
     }
 }
diff --git a/tests/golden/lang/errors/error__type_where_clause_violation.silt b/tests/golden/lang/errors/error__type_where_clause_violation.silt
index 3fb980512..27406c6df 100644
--- a/tests/golden/lang/errors/error__type_where_clause_violation.silt
+++ b/tests/golden/lang/errors/error__type_where_clause_violation.silt
@@ -1,7 +1,7 @@
 -- cmd: check
 -- exit: 1
 -- stderr-contains: not introduced in the function signature
-fn show(x) where x: Display { x.display() }
+fn show(x) where x: Display { "{x}" }
 fn main() {
   show({ -> 1 })
 }
diff --git a/tests/golden/lang/errors/round73f_deferred_fixes__display_equals_message_for_io_error.silt b/tests/golden/lang/errors/round73f_deferred_fixes__display_equals_message_for_io_error.silt
index 9982173e3..2085e83aa 100644
--- a/tests/golden/lang/errors/round73f_deferred_fixes__display_equals_message_for_io_error.silt
+++ b/tests/golden/lang/errors/round73f_deferred_fixes__display_equals_message_for_io_error.silt
@@ -5,7 +5,7 @@ fn main() {
         Ok(_) -> ()
         Err(e) -> {
             let display_form = "{e}"
-            let message_form = e.message()
+            let message_form = Error.message(e)
             match display_form == message_form {
                 true -> println("EQUIV")
                 false -> {
diff --git a/tests/golden/lang/errors/round73f_deferred_fixes__display_method_equals_message_for_io_error.silt b/tests/golden/lang/errors/round73f_deferred_fixes__display_method_equals_message_for_io_error.silt
index 1764dd517..c324cba63 100644
--- a/tests/golden/lang/errors/round73f_deferred_fixes__display_method_equals_message_for_io_error.silt
+++ b/tests/golden/lang/errors/round73f_deferred_fixes__display_method_equals_message_for_io_error.silt
@@ -4,8 +4,8 @@ fn main() {
     match io.read_file("nope_round74_lock_does_not_exist.txt") {
         Ok(_) -> ()
         Err(e) -> {
-            let display_method_form = e.display()
-            let message_form = e.message()
+            let display_method_form = "{e}"
+            let message_form = Error.message(e)
             match display_method_form == message_form {
                 true -> println("EQUIV")
                 false -> {
diff --git a/tests/golden/lang/errors/round92_tuple_index_message__named_method_keeps_generic.silt b/tests/golden/lang/errors/round92_tuple_index_message__named_method_keeps_generic.silt
index 79f6aa4a3..71aea0fa0 100644
--- a/tests/golden/lang/errors/round92_tuple_index_message__named_method_keeps_generic.silt
+++ b/tests/golden/lang/errors/round92_tuple_index_message__named_method_keeps_generic.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: unknown method 'frobnicate'
+-- stderr-contains: type '(Int, Int)' has no field 'frobnicate'
 -- stderr-not-contains: tuple indexing
 fn main() {
   let t = (1, 2)
diff --git a/tests/golden/lang/errors/unknown_method_suggest__list_suggests_close_match.silt b/tests/golden/lang/errors/unknown_method_suggest__list_suggests_close_match.silt
deleted file mode 100644
index a2ef1b8d4..000000000
--- a/tests/golden/lang/errors/unknown_method_suggest__list_suggests_close_match.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'dispaly'
--- stderr-contains: = help: did you mean `display`?
-fn main() {
-  let xs = [1, 2, 3]
-  println(xs.dispaly())
-}
diff --git a/tests/golden/lang/errors/unknown_method_suggest__too_far_omits_suggestion.silt b/tests/golden/lang/errors/unknown_method_suggest__too_far_omits_suggestion.silt
deleted file mode 100644
index c91d4cb2f..000000000
--- a/tests/golden/lang/errors/unknown_method_suggest__too_far_omits_suggestion.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'qqqqqqqq_unrelated'
--- stderr-not-contains: did you mean
-fn main() {
-  let xs = [1, 2, 3]
-  println(xs.qqqqqqqq_unrelated())
-}
diff --git a/tests/golden/lang/errors/unknown_method_suggest__tuple_suggests_close_match.silt b/tests/golden/lang/errors/unknown_method_suggest__tuple_suggests_close_match.silt
deleted file mode 100644
index cdd05028e..000000000
--- a/tests/golden/lang/errors/unknown_method_suggest__tuple_suggests_close_match.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'dispaly' on Tuple
--- stderr-contains: = help: did you mean `display`?
-fn main() {
-  let t = (1, 2)
-  println(t.dispaly())
-}
diff --git a/tests/golden/lang/errors/wave2_sweep__chain_of_1024_method_calls_accepted.silt b/tests/golden/lang/errors/wave2_sweep__chain_of_1024_method_calls_accepted.silt
index c9f03cf62..1b8b5c13c 100644
--- a/tests/golden/lang/errors/wave2_sweep__chain_of_1024_method_calls_accepted.silt
+++ b/tests/golden/lang/errors/wave2_sweep__chain_of_1024_method_calls_accepted.silt
@@ -6,6 +6,6 @@ trait Same for Int {
 }
 fn main() {
   let x = 7
-  let r = x.same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same().same()
+  let r = x |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same |> Same.same
   println(r)
 }
diff --git a/tests/golden/lang/float_display/string_from_a_whole_float.silt b/tests/golden/lang/float_display/string_from_a_whole_float.silt
index 87abe8e30..c2ff05c5d 100644
--- a/tests/golden/lang/float_display/string_from_a_whole_float.silt
+++ b/tests/golden/lang/float_display/string_from_a_whole_float.silt
@@ -5,5 +5,5 @@ fn main() {
   println(string.length(string.from(1.0)))
   println(string.from(1.0) == "1.0")
   println(string.from(-12.0))
-  println(4.0.display())
+  println("{4.0}")
 }
diff --git a/tests/golden/lang/floats/float_parse_rejects_non_finite.silt b/tests/golden/lang/floats/float_parse_rejects_non_finite.silt
index a3317d654..b9c7ade15 100644
--- a/tests/golden/lang/floats/float_parse_rejects_non_finite.silt
+++ b/tests/golden/lang/floats/float_parse_rejects_non_finite.silt
@@ -7,7 +7,7 @@ fn main() {
   |> list.each { s ->
     match float.parse(s) {
       Ok(f) -> println("{s}: Ok({f})")
-      Err(e) -> println("{s}: {e.message()}")
+      Err(e) -> println("{s}: {Error.message(e)}")
     }
   }
 }
diff --git a/tests/golden/lang/fs/fs_walk_stat__glob_malformed_pattern_errs.silt b/tests/golden/lang/fs/fs_walk_stat__glob_malformed_pattern_errs.silt
index dd244d0ff..65a26cdda 100644
--- a/tests/golden/lang/fs/fs_walk_stat__glob_malformed_pattern_errs.silt
+++ b/tests/golden/lang/fs/fs_walk_stat__glob_malformed_pattern_errs.silt
@@ -4,7 +4,7 @@ fn main() {
     match fs.glob("src/[unterminated") {
         Ok(_) -> println("unexpected Ok")
         Err(e) -> {
-            let msg = e.message()
+            let msg = Error.message(e)
             println(string.starts_with(msg, "invalid input"))
         }
     }
diff --git a/tests/golden/lang/fs/fs_walk_stat__stat_missing_path_errs.silt b/tests/golden/lang/fs/fs_walk_stat__stat_missing_path_errs.silt
index eab63051c..d2d542a22 100644
--- a/tests/golden/lang/fs/fs_walk_stat__stat_missing_path_errs.silt
+++ b/tests/golden/lang/fs/fs_walk_stat__stat_missing_path_errs.silt
@@ -2,6 +2,6 @@ import fs
 fn main() {
     match fs.stat("does_not_exist") {
         Ok(_) -> println("unexpected Ok")
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
     }
 }
diff --git a/tests/golden/lang/fs/fs_walk_stat__stat_on_directory.silt b/tests/golden/lang/fs/fs_walk_stat__stat_on_directory.silt
index 013e73058..31201f0a7 100644
--- a/tests/golden/lang/fs/fs_walk_stat__stat_on_directory.silt
+++ b/tests/golden/lang/fs/fs_walk_stat__stat_on_directory.silt
@@ -7,6 +7,6 @@ fn main() {
             println(s.is_symlink)
             println(s.size >= 0)
         }
-        Err(e) -> println("err: {e.message()}")
+        Err(e) -> println("err: {Error.message(e)}")
     }
 }
diff --git a/tests/golden/lang/fs/fs_walk_stat__walk_missing_root_errs.silt b/tests/golden/lang/fs/fs_walk_stat__walk_missing_root_errs.silt
index 0266fc101..61f891a72 100644
--- a/tests/golden/lang/fs/fs_walk_stat__walk_missing_root_errs.silt
+++ b/tests/golden/lang/fs/fs_walk_stat__walk_missing_root_errs.silt
@@ -2,6 +2,6 @@ import fs
 fn main() {
     match fs.walk("nope") {
         Ok(_) -> println("unexpected Ok")
-        Err(e) -> println(e.message())
+        Err(e) -> println(Error.message(e))
     }
 }
diff --git a/tests/golden/lang/imports/feature__import_of_a_module_whose_feature_is_not_built.silt b/tests/golden/lang/imports/feature__import_of_a_module_whose_feature_is_not_built.silt
index 539cc457c..fe5a3cfee 100644
--- a/tests/golden/lang/imports/feature__import_of_a_module_whose_feature_is_not_built.silt
+++ b/tests/golden/lang/imports/feature__import_of_a_module_whose_feature_is_not_built.silt
@@ -9,7 +9,7 @@ import postgres
 fn main() {
   match postgres.connect("postgres://localhost/app") {
     Ok(_) -> println("connected")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   let e = postgres.PostgresError.Connect("nope")
   println(e)
diff --git a/tests/golden/lang/io/hardening__read_write_error_paths.silt b/tests/golden/lang/io/hardening__read_write_error_paths.silt
index 722c15ae5..242c1630a 100644
--- a/tests/golden/lang/io/hardening__read_write_error_paths.silt
+++ b/tests/golden/lang/io/hardening__read_write_error_paths.silt
@@ -7,7 +7,7 @@ fn main() {
   println(match io.read_file("silt_test_nonexistent_file_12345.txt") {
     Ok(_) -> "unexpected success"
     Err(e) -> match {
-      e.message() == "" -> "empty error"
+      Error.message(e) == "" -> "empty error"
       _ -> "has error message"
     }
   })
diff --git a/tests/golden/lang/io/hardening__write_and_read_roundtrip.silt b/tests/golden/lang/io/hardening__write_and_read_roundtrip.silt
index 56b002a33..a28bdf201 100644
--- a/tests/golden/lang/io/hardening__write_and_read_roundtrip.silt
+++ b/tests/golden/lang/io/hardening__write_and_read_roundtrip.silt
@@ -5,7 +5,7 @@ fn main() {
   io.write_file(path, "hello silt")?
   match io.read_file(path) {
     Ok(content) -> println(content)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   fs.remove(path)
 }
diff --git a/tests/golden/lang/json_decode/decode_takes_no_value.silt b/tests/golden/lang/json_decode/decode_takes_no_value.silt
index c61c4cf20..ceb4d44a3 100644
--- a/tests/golden/lang/json_decode/decode_takes_no_value.silt
+++ b/tests/golden/lang/json_decode/decode_takes_no_value.silt
@@ -1,9 +1,9 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: unknown field or method 'decode' on type P
--- `decode` takes no value of the type: it is no method of a call on a
--- value (`p.decode(..)`), only of one through the type, so a program's
--- own `decode` method on a value is not ambiguous with it.
+-- stderr-contains: type 'P' has no field 'decode'
+-- `decode` of json.Decode takes no value of the type: it is called
+-- through the type. A program's own `decode` that takes one is called
+-- through its trait, and a dot after a value is a field.
 import json
 
 type P { x: Int }
@@ -15,7 +15,7 @@ trait Load for String {
 }
 
 fn main() {
-  let _ = "x".decode("y")
+  let _ = Load.decode("x", "y")
   let p = P { x: 1 }
   println(p.decode(json.Null))
 }
diff --git a/tests/golden/lang/json_encode/a_let_that_writes_a_value_needs_what_its_impl_reads.silt b/tests/golden/lang/json_encode/a_let_that_writes_a_value_needs_what_its_impl_reads.silt
index a7c20f5d8..ba83706df 100644
--- a/tests/golden/lang/json_encode/a_let_that_writes_a_value_needs_what_its_impl_reads.silt
+++ b/tests/golden/lang/json_encode/a_let_that_writes_a_value_needs_what_its_impl_reads.silt
@@ -16,7 +16,7 @@ trait json.Encode for T {
 fn send(x: a) -> String where a: json.Encode { json.stringify([x]) }
 
 let s = json.stringify(T { n: 1 })
-let e = T { n: 2 }.encode()
+let e = json.Encode.encode(T { n: 2 })
 let g = send(T { n: 3 })
 let t = toml.stringify(#{"k": T { n: 4 }})
 let m = json.encode(Some(T { n: 5 }))
diff --git a/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/case.stdout b/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/case.stdout
new file mode 100644
index 000000000..195f10c48
--- /dev/null
+++ b/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/case.stdout
@@ -0,0 +1,3 @@
+t1
+t2
+Object(#{"x": Int(3)})
diff --git a/tests/golden/lang/json_encode/its_method_is_seen_where_json_is_imported/codec.silt b/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/codec.silt
similarity index 90%
rename from tests/golden/lang/json_encode/its_method_is_seen_where_json_is_imported/codec.silt
rename to tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/codec.silt
index 45753dc23..496225343 100644
--- a/tests/golden/lang/json_encode/its_method_is_seen_where_json_is_imported/codec.silt
+++ b/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/codec.silt
@@ -13,5 +13,5 @@ trait Codec for T {
 }
 
 pub fn show(t: T) -> String {
-  t.encode()
+  Codec.encode(t)
 }
diff --git a/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/main.silt b/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/main.silt
new file mode 100644
index 000000000..150606c67
--- /dev/null
+++ b/tests/golden/lang/json_encode/a_program_trait_with_an_encode_method/main.silt
@@ -0,0 +1,10 @@
+-- A program's own trait with a method `encode` beside `json.Encode`:
+-- each call names its trait, in a module that imports json too.
+import codec.{ Codec, T, show }
+import json
+
+fn main() {
+  println(show(T { x: 1 }))
+  println(Codec.encode(T { x: 2 }))
+  println(json.Encode.encode(T { x: 3 }))
+}
diff --git a/tests/golden/lang/json_encode/its_method_is_seen_after_any_import_of_json.silt b/tests/golden/lang/json_encode/its_method_is_seen_after_any_import_of_json.silt
index 277657b04..0f1a616f9 100644
--- a/tests/golden/lang/json_encode/its_method_is_seen_after_any_import_of_json.silt
+++ b/tests/golden/lang/json_encode/its_method_is_seen_after_any_import_of_json.silt
@@ -2,12 +2,12 @@
 -- visible, a selective one too, as a `pub` trait of a module is after
 -- `import m.{ mk }`. (Without any import of json there is no `encode`:
 -- its_method_needs_import_json.)
-import json.{ stringify }
+import json.{ stringify, Encode }
 
 type P { x: Int }
 
 fn main() {
   println(stringify(P { x: 1 }))
-  println(P { x: 1 }.encode())
-  println(1.encode())
+  println(Encode.encode(P { x: 1 }))
+  println(Encode.encode(1))
 }
diff --git a/tests/golden/lang/json_encode/its_method_is_seen_where_json_is_imported/main.silt b/tests/golden/lang/json_encode/its_method_is_seen_where_json_is_imported/main.silt
deleted file mode 100644
index 47f99ce4c..000000000
--- a/tests/golden/lang/json_encode/its_method_is_seen_where_json_is_imported/main.silt
+++ /dev/null
@@ -1,15 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: ambiguous method 'encode' on type 'codec.T': provided by traits codec.Codec, json.Encode
--- stderr-contains: --> main.silt:14:11
--- stderr-not-contains: --> codec.silt
--- Every type with `json.Encode` has its method `encode` in a module that
--- imports json, so there a method `encode` of the program's own trait is
--- ambiguous. Where json is not imported (`codec`) it is the only one.
-import codec.{ Codec, T, show }
-import json
-
-fn main() {
-  println(show(T { x: 1 }))
-  println(T { x: 1 }.encode())
-}
diff --git a/tests/golden/lang/json_encode/its_method_needs_import_json.silt b/tests/golden/lang/json_encode/its_method_needs_import_json.silt
deleted file mode 100644
index 2f14eeead..000000000
--- a/tests/golden/lang/json_encode/its_method_needs_import_json.silt
+++ /dev/null
@@ -1,31 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: --> its_method_needs_import_json.silt:23:11
--- stderr-contains: --> its_method_needs_import_json.silt:24:11
--- stderr-contains: --> its_method_needs_import_json.silt:25:11
--- stderr-contains: --> its_method_needs_import_json.silt:26:11
--- stderr-contains: --> its_method_needs_import_json.silt:28:11
--- stderr-contains: --> its_method_needs_import_json.silt:29:11
--- stderr-contains: --> its_method_needs_import_json.silt:30:11
--- stderr-contains: unknown field or method 'encode' on type P
--- `json.Encode` is a trait of the json module: its method `encode` is a
--- value's only in a module that imports json, of a record, an enum, a
--- generic record, an Option, a tuple and an Int alike. (A record's and an
--- enum's were not asked for the import.)
-
-type P { x: Int }
-type E { A, B(Int) }
-type G(a) { v: a }
-
-fn main() {
-  let p = P { x: 1 }
-  let o: Option(Int) = Some(1)
-  println(p.encode())
-  println(B(2).encode())
-  println(A.encode())
-  println(G { v: [1] }.encode())
-  println(o.display())
-  println(o.encode())
-  println((1, 2).encode())
-  println(1.encode())
-}
diff --git a/tests/golden/lang/json_encode/json_encode_is_the_value_of_what_stringify_writes.silt b/tests/golden/lang/json_encode/json_encode_is_the_value_of_what_stringify_writes.silt
index 66f8458d1..200c4b7a8 100644
--- a/tests/golden/lang/json_encode/json_encode_is_the_value_of_what_stringify_writes.silt
+++ b/tests/golden/lang/json_encode/json_encode_is_the_value_of_what_stringify_writes.silt
@@ -24,7 +24,7 @@ trait json.Encode for Pair(a) where a: json.Encode {
 }
 
 fn twice(x: a) -> List(json.Value) where a: json.Encode {
-  [x.encode(), json.encode(x)]
+  [json.Encode.encode(x), json.encode(x)]
 }
 
 fn same(x: a) -> Bool where a: json.Encode {
@@ -41,13 +41,13 @@ fn main() {
   println(json.encode((1, "a")))
   println(json.encode(P { x: 1, total: Money { cents: 5 }, tags: ["t"] }))
   println(json.encode(Pair { left: Money { cents: 1 }, right: Money { cents: 2 } }))
-  println(5.encode())
-  println(Money { cents: 9 }.encode())
+  println(json.Encode.encode(5))
+  println(json.Encode.encode(Money { cents: 9 }))
   println(twice(Money { cents: 3 }))
   println(twice([1, 2]))
   println(json.stringify(json.encode(P { x: 1, total: Money { cents: 5 }, tags: [] })))
   println(json.stringify(P { x: 1, total: Money { cents: 5 }, tags: [] }))
   println([same(1), same(1.0e21), same(-0.5), same("s"), same([Some(1), None]), same(#{"k": 1.5}), same(time.date(2026, 10, 21)), same(P { x: 1, total: Money { cents: 5 }, tags: ["a"] })])
-  let f = Money.encode
+  let f = json.Encode.encode
   println(f(Money { cents: 4 }))
 }
diff --git a/tests/golden/lang/json_encode/the_encode_method_gives_a_json_value.silt b/tests/golden/lang/json_encode/the_encode_method_gives_a_json_value.silt
index 9461421ac..124d884c0 100644
--- a/tests/golden/lang/json_encode/the_encode_method_gives_a_json_value.silt
+++ b/tests/golden/lang/json_encode/the_encode_method_gives_a_json_value.silt
@@ -3,21 +3,21 @@
 -- stderr-contains: --> the_encode_method_gives_a_json_value.silt:16:16
 -- stderr-contains: --> the_encode_method_gives_a_json_value.silt:21:44
 -- stderr-contains: --> the_encode_method_gives_a_json_value.silt:23:10
--- stderr-contains: unknown method 'encode' on type Fn
+-- stderr-contains: has no field 'encode'
 -- stderr-not-contains: :17:
--- `.encode()` of a value whose type has `json.Encode` is a `json.Value`,
--- by a concrete type and through a bound, and a value of a type without
--- the trait has no such method. (It was taken as of any type.)
+-- `json.Encode.encode` of a value whose type has the trait is a
+-- `json.Value`, by a concrete type and through a bound; a dot after a
+-- value is a field. (It was taken as of any type.)
 import json
 
 type Money { cents: Int }
 
 fn main() {
-  let a: Int = 5.encode()
-  let b: json.Value = Money { cents: 1 }.encode()
+  let a: Int = json.Encode.encode(5)
+  let b: json.Value = json.Encode.encode(Money { cents: 1 })
   println(b)
 }
 
-fn via(x: a) -> Int where a: json.Encode { x.encode() }
+fn via(x: a) -> Int where a: json.Encode { json.Encode.encode(x) }
 
 fn f() { { x -> x }.encode() }
diff --git a/tests/golden/lang/limits/stage7_v1__trait_method_256_parameters.silt b/tests/golden/lang/limits/stage7_v1__trait_method_256_parameters.silt
index 6910877cc..386581473 100644
--- a/tests/golden/lang/limits/stage7_v1__trait_method_256_parameters.silt
+++ b/tests/golden/lang/limits/stage7_v1__trait_method_256_parameters.silt
@@ -8,5 +8,5 @@ trait Tr for Int {
   fn go(self, p0: Int, p1: Int, p2: Int, p3: Int, p4: Int, p5: Int, p6: Int, p7: Int, p8: Int, p9: Int, p10: Int, p11: Int, p12: Int, p13: Int, p14: Int, p15: Int, p16: Int, p17: Int, p18: Int, p19: Int, p20: Int, p21: Int, p22: Int, p23: Int, p24: Int, p25: Int, p26: Int, p27: Int, p28: Int, p29: Int, p30: Int, p31: Int, p32: Int, p33: Int, p34: Int, p35: Int, p36: Int, p37: Int, p38: Int, p39: Int, p40: Int, p41: Int, p42: Int, p43: Int, p44: Int, p45: Int, p46: Int, p47: Int, p48: Int, p49: Int, p50: Int, p51: Int, p52: Int, p53: Int, p54: Int, p55: Int, p56: Int, p57: Int, p58: Int, p59: Int, p60: Int, p61: Int, p62: Int, p63: Int, p64: Int, p65: Int, p66: Int, p67: Int, p68: Int, p69: Int, p70: Int, p71: Int, p72: Int, p73: Int, p74: Int, p75: Int, p76: Int, p77: Int, p78: Int, p79: Int, p80: Int, p81: Int, p82: Int, p83: Int, p84: Int, p85: Int, p86: Int, p87: Int, p88: Int, p89: Int, p90: Int, p91: Int, p92: Int, p93: Int, p94: Int, p95: Int, p96: Int, p97: Int, p98: Int, p99: Int, p100: Int, p101: Int, p102: Int, p103: Int, p104: Int, p105: Int, p106: Int, p107: Int, p108: Int, p109: Int, p110: Int, p111: Int, p112: Int, p113: Int, p114: Int, p115: Int, p116: Int, p117: Int, p118: Int, p119: Int, p120: Int, p121: Int, p122: Int, p123: Int, p124: Int, p125: Int, p126: Int, p127: Int, p128: Int, p129: Int, p130: Int, p131: Int, p132: Int, p133: Int, p134: Int, p135: Int, p136: Int, p137: Int, p138: Int, p139: Int, p140: Int, p141: Int, p142: Int, p143: Int, p144: Int, p145: Int, p146: Int, p147: Int, p148: Int, p149: Int, p150: Int, p151: Int, p152: Int, p153: Int, p154: Int, p155: Int, p156: Int, p157: Int, p158: Int, p159: Int, p160: Int, p161: Int, p162: Int, p163: Int, p164: Int, p165: Int, p166: Int, p167: Int, p168: Int, p169: Int, p170: Int, p171: Int, p172: Int, p173: Int, p174: Int, p175: Int, p176: Int, p177: Int, p178: Int, p179: Int, p180: Int, p181: Int, p182: Int, p183: Int, p184: Int, p185: Int, p186: Int, p187: Int, p188: Int, p189: Int, p190: Int, p191: Int, p192: Int, p193: Int, p194: Int, p195: Int, p196: Int, p197: Int, p198: Int, p199: Int, p200: Int, p201: Int, p202: Int, p203: Int, p204: Int, p205: Int, p206: Int, p207: Int, p208: Int, p209: Int, p210: Int, p211: Int, p212: Int, p213: Int, p214: Int, p215: Int, p216: Int, p217: Int, p218: Int, p219: Int, p220: Int, p221: Int, p222: Int, p223: Int, p224: Int, p225: Int, p226: Int, p227: Int, p228: Int, p229: Int, p230: Int, p231: Int, p232: Int, p233: Int, p234: Int, p235: Int, p236: Int, p237: Int, p238: Int, p239: Int, p240: Int, p241: Int, p242: Int, p243: Int, p244: Int, p245: Int, p246: Int, p247: Int, p248: Int, p249: Int, p250: Int, p251: Int, p252: Int, p253: Int, p254: Int) -> Int { self + p0 + p254 * 2 }
 }
 fn main() {
-  println(5.go(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254))
+  println(Tr.go(5, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254))
 }
diff --git a/tests/golden/lang/modules/round94_imported_enum_variant_collision__equality_on_imported_enum_works/main.silt b/tests/golden/lang/modules/round94_imported_enum_variant_collision__equality_on_imported_enum_works/main.silt
index fedd54882..a4f92ff75 100644
--- a/tests/golden/lang/modules/round94_imported_enum_variant_collision__equality_on_imported_enum_works/main.silt
+++ b/tests/golden/lang/modules/round94_imported_enum_variant_collision__equality_on_imported_enum_works/main.silt
@@ -6,5 +6,5 @@ fn main() {
   let y = sb.mkb()
   println(x == sa.mka())
   println(y == sb.mkb())
-  println(x.hash() == sa.mka().hash())
+  println(Hash.hash(x) == Hash.hash(sa.mka()))
 }
diff --git a/tests/golden/lang/modules/round94_module_shadowing__derives_survive_module_named_other/main.silt b/tests/golden/lang/modules/round94_module_shadowing__derives_survive_module_named_other/main.silt
index ed82a96fd..f296958de 100644
--- a/tests/golden/lang/modules/round94_module_shadowing__derives_survive_module_named_other/main.silt
+++ b/tests/golden/lang/modules/round94_module_shadowing__derives_survive_module_named_other/main.silt
@@ -7,6 +7,6 @@ fn main() {
   println(a == P { year: 5 })
   println(a < b)
   println(b < a)
-  println(a.compare(b))
-  println(a.hash() == P { year: 5 }.hash())
+  println(Compare.compare(a, b))
+  println(Hash.hash(a) == Hash.hash(P { year: 5 }))
 }
diff --git a/tests/golden/lang/modules/span_runtime_error_in_module_trait_method/main.silt b/tests/golden/lang/modules/span_runtime_error_in_module_trait_method/main.silt
index 3bd9b88e9..e04f12c9d 100644
--- a/tests/golden/lang/modules/span_runtime_error_in_module_trait_method/main.silt
+++ b/tests/golden/lang/modules/span_runtime_error_in_module_trait_method/main.silt
@@ -1,8 +1,8 @@
 -- exit: 1
 -- A runtime error in a trait method a module defines is shown in the
 -- module, at the method body, not at a line of main.silt.
-import util.{ Box }
+import util.{ Box, Doer }
 fn main() {
   let b = Box { v: 2 }
-  println(b.act())
+  println(Doer.act(b))
 }
diff --git a/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/a.silt b/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/a.silt
index 03c921c39..424555b98 100644
--- a/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/a.silt
+++ b/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/a.silt
@@ -1,4 +1,4 @@
 pub trait Speak { fn speak(self) -> String }
 pub type Dog { name: String }
 trait Speak for Dog { fn speak(self) -> String { "woof" } }
-pub fn talk(x: t) -> String where t: Speak { x.speak() }
+pub fn talk(x: t) -> String where t: Speak { Speak.speak(x) }
diff --git a/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/b.silt b/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/b.silt
index c0898e0b6..018871892 100644
--- a/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/b.silt
+++ b/tests/golden/lang/modules/span_type_error_in_imported_module_declaration/b.silt
@@ -1,4 +1,4 @@
 pub trait Speak { fn speak(self, times: Int) -> Int }
 pub type Cat { name: String }
 trait Speak for Cat { fn speak(self, times: Int) -> Int { times } }
-pub fn talk(x: t) -> Int where t: Speak { x.speak(2) }
+pub fn talk(x: t) -> Int where t: Speak { Speak.speak(x, 2) }
diff --git a/tests/golden/lang/modules/span_type_error_in_imported_module_impl/main.silt b/tests/golden/lang/modules/span_type_error_in_imported_module_impl/main.silt
index 2acf10123..8476b4ae2 100644
--- a/tests/golden/lang/modules/span_type_error_in_imported_module_impl/main.silt
+++ b/tests/golden/lang/modules/span_type_error_in_imported_module_impl/main.silt
@@ -6,5 +6,5 @@
 import b
 fn main() {
   let c = b.Cat { name: "c" }
-  println(c.speak())
+  println(b.Speak.speak(c))
 }
diff --git a/tests/golden/lang/qualified/pub_trait_formats.silt b/tests/golden/lang/qualified/pub_trait_formats.silt
index 054545f2b..0b2ccf493 100644
--- a/tests/golden/lang/qualified/pub_trait_formats.silt
+++ b/tests/golden/lang/qualified/pub_trait_formats.silt
@@ -12,5 +12,5 @@ trait Describe for Int {
 }
 
 fn main() {
-  println(1.describe())
+  println(Describe.describe(1))
 }
diff --git a/tests/golden/lang/qualified/trait_refs/main.silt b/tests/golden/lang/qualified/trait_refs/main.silt
index e1c4a4ebb..25b615fc8 100644
--- a/tests/golden/lang/qualified/trait_refs/main.silt
+++ b/tests/golden/lang/qualified/trait_refs/main.silt
@@ -19,23 +19,23 @@ trait Loud: lib.Describe {
 
 trait Loud for Local {
   fn shout(self) -> String {
-    "{self.describe()}!"
+    "{lib.Describe.describe(self)}!"
   }
 }
 
 trait Loud for lib.Pt {
   fn shout(self) -> String {
-    "{self.describe()}!!"
+    "{lib.Describe.describe(self)}!!"
   }
 }
 
 fn show(a: a) -> String where a: lib.Describe {
-  a.describe()
+  lib.Describe.describe(a)
 }
 
 fn main() {
   println(show(L(1)))
   println(show(lib.Pt { x: 1, y: 2 }))
-  println(L(2).shout())
-  println(lib.Pt { x: 3, y: 4 }.shout())
+  println(Loud.shout(L(2)))
+  println(Loud.shout(lib.Pt { x: 3, y: 4 }))
 }
diff --git a/tests/golden/lang/records/a_record_holds_its_fields_in_declaration_order.silt b/tests/golden/lang/records/a_record_holds_its_fields_in_declaration_order.silt
index 933fe3614..24430ffd0 100644
--- a/tests/golden/lang/records/a_record_holds_its_fields_in_declaration_order.silt
+++ b/tests/golden/lang/records/a_record_holds_its_fields_in_declaration_order.silt
@@ -115,7 +115,7 @@ fn main() {
   println(set.length(set.from_list([a, b, c, d])))
   let seen = map.set(map.set(#{}, a, "first"), c, "second")
   println(map.get(seen, b))
-  println(a.hash() == c.hash())
+  println(Hash.hash(a) == Hash.hash(c))
 
   -- A decoder builds the record its type declares.
   match json.parse("\{\"label\": \"j\", \"build\": 5, \"major\": 4}", Ver) {
diff --git a/tests/golden/lang/records/round73_row_narrowing__annotated_bogus_field_rejected.silt b/tests/golden/lang/records/round73_row_narrowing__annotated_bogus_field_rejected.silt
index 4adb1470f..7489d3061 100644
--- a/tests/golden/lang/records/round73_row_narrowing__annotated_bogus_field_rejected.silt
+++ b/tests/golden/lang/records/round73_row_narrowing__annotated_bogus_field_rejected.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: anon record has no field 'zzznosuchfield'
+-- stderr-contains: has no field 'zzznosuchfield'
 fn pluck(r: {a: Int, b: Int}) { r.zzznosuchfield }
 fn main() {
     let p = {a: 1, b: 2}
diff --git a/tests/golden/lang/resolve/resolve__builtin_trait_method_through_builtin_type.silt b/tests/golden/lang/resolve/resolve__builtin_trait_method_through_builtin_type.silt
index f6b2aeffd..dd2f0beda 100644
--- a/tests/golden/lang/resolve/resolve__builtin_trait_method_through_builtin_type.silt
+++ b/tests/golden/lang/resolve/resolve__builtin_trait_method_through_builtin_type.silt
@@ -2,17 +2,18 @@
 -- The builtin traits' methods of a builtin type are reached through the
 -- type as through a value: `Int.display(1)` is `1.display()`, called or
 -- as a function value.
+import string
 fn main() {
-  println(Int.display(1))
-  println(Int.compare(1, 2))
-  println(Int.equal(1, 1))
-  println(Int.hash(1) == 1.hash())
-  println(Float.compare(1.5, 0.5))
-  println(String.equal("a", "b"))
-  println(Bool.display(true))
-  println(List.display([1, 2]))
-  let show = Int.display
+  println("{1}")
+  println(Compare.compare(1, 2))
+  println(1 == 1)
+  println(Hash.hash(1) == Hash.hash(1))
+  println(Compare.compare(1.5, 0.5))
+  println("a" == "b")
+  println("{true}")
+  println("{[1, 2]}")
+  let show = string.from
   println(show(4))
-  let cmp = String.compare
+  let cmp = Compare.compare
   println(cmp("a", "b"))
 }
diff --git a/tests/golden/lang/resolve/resolve__builtin_type_without_the_method.silt b/tests/golden/lang/resolve/resolve__builtin_type_without_the_method.silt
index 23b5110f3..4563aff90 100644
--- a/tests/golden/lang/resolve/resolve__builtin_type_without_the_method.silt
+++ b/tests/golden/lang/resolve/resolve__builtin_type_without_the_method.silt
@@ -14,5 +14,5 @@ fn main() {
   println(Result.compare(Ok(1), Ok(2)))
   println(Map.compare(1, 2))
   println(time.Weekday.nope(1))
-  println(Option.display(Some(1)))
+  println("{Some(1)}")
 }
diff --git a/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/a.silt b/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/a.silt
index aaa929ea2..5fb69972d 100644
--- a/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/a.silt
+++ b/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/a.silt
@@ -1,3 +1,3 @@
 pub trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "a-int {self}" } }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/b.silt b/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/b.silt
index 2a6dc568c..1cadfcebd 100644
--- a/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/b.silt
+++ b/tests/golden/lang/resolve/resolve__clash_named_in_trait_messages/b.silt
@@ -1,3 +1,3 @@
 pub trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "b-int {self}" } }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/a.silt b/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/a.silt
index 239e93065..2c17b837f 100644
--- a/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/a.silt
+++ b/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/a.silt
@@ -3,4 +3,4 @@ pub trait Conv { type Out
 pub type Pt { x: Int }
 trait Conv for Pt { type Out = Int
   fn conv(self) -> Int { self.x } }
-pub fn run(v: t) -> String where t: Conv { "{v.conv()}" }
+pub fn run(v: t) -> String where t: Conv { "{Conv.conv(v)}" }
diff --git a/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/b.silt b/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/b.silt
index eeb4ae346..98632da1c 100644
--- a/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/b.silt
+++ b/tests/golden/lang/resolve/resolve__clash_named_type_and_trait/b.silt
@@ -3,4 +3,4 @@ pub trait Conv { type Out
 pub type Pt { s: String }
 trait Conv for Pt { type Out = String
   fn cv(self) -> String { self.s } }
-pub fn run(v: t) -> String where t: Conv { "{v.cv()}" }
+pub fn run(v: t) -> String where t: Conv { "{Conv.cv(v)}" }
diff --git a/tests/golden/lang/resolve/resolve__clash_named_unknown_method/main.silt b/tests/golden/lang/resolve/resolve__clash_named_unknown_method/main.silt
index a476ffb86..fa58f3da0 100644
--- a/tests/golden/lang/resolve/resolve__clash_named_unknown_method/main.silt
+++ b/tests/golden/lang/resolve/resolve__clash_named_unknown_method/main.silt
@@ -1,8 +1,8 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: unknown field or method 'area' on type other.Shape
--- other.Shape has no area method; shapes.Shape, imported too, has: the
--- message names the type by its module.
+-- stderr-contains: error[type]: type 'other.Shape' has no field 'area'
+-- other.Shape has no field `area`; shapes.Shape, imported too, has an
+-- `Area` impl: the message names the type by its module.
 import other
 import shapes
 fn main() {
diff --git a/tests/golden/lang/resolve/resolve__error_message_through_builtin_type.silt b/tests/golden/lang/resolve/resolve__error_message_through_builtin_type.silt
index 4222df6c0..40e92c148 100644
--- a/tests/golden/lang/resolve/resolve__error_message_through_builtin_type.silt
+++ b/tests/golden/lang/resolve/resolve__error_message_through_builtin_type.silt
@@ -8,11 +8,11 @@ fn main() {
   match io.read_file("/nonexistent/silt/r5") {
     Ok(_) -> println("ok")
     Err(e) -> {
-      println(io.IoError.message(e) == e.message())
-      println(IoError.message(e) == e.message())
-      println(IoError.display(e) == e.display())
-      let m = io.IoError.message
-      println(m(e) == e.message())
+      println(Error.message(e) == Error.message(e))
+      println(Error.message(e) == Error.message(e))
+      println("{e}" == "{e}")
+      let m = Error.message
+      println(m(e) == Error.message(e))
     }
   }
 }
diff --git a/tests/golden/lang/resolve/resolve__private_trait_method/main.silt b/tests/golden/lang/resolve/resolve__private_trait_method/main.silt
index c7872c13d..051391d34 100644
--- a/tests/golden/lang/resolve/resolve__private_trait_method/main.silt
+++ b/tests/golden/lang/resolve/resolve__private_trait_method/main.silt
@@ -1,13 +1,13 @@
 -- cmd: check
 -- exit: 1
 -- verdict: same
--- stderr-contains: error[type]: method `describe` belongs to trait 'Describe', which is private to module 'shapes'
+-- stderr-contains: error[type]: 'Describe' is private to module 'shapes'
 -- stderr-contains: --> main.silt:12:11
 -- The methods of a trait declared without `pub` can be called only in
--- its module: `shapes.described` may call `describe`, an importer may
--- not, though the type is exported.
+-- its module: `shapes.described` may call `Describe.describe`, an
+-- importer cannot name the trait, though the type is exported.
 import shapes
 fn main() {
   println(shapes.described(shapes.square(2)))
-  println(shapes.square(3).describe())
+  println(shapes.Describe.describe(shapes.square(3)))
 }
diff --git a/tests/golden/lang/resolve/resolve__private_trait_method/shapes.silt b/tests/golden/lang/resolve/resolve__private_trait_method/shapes.silt
index 93517d2f5..76cf0340f 100644
--- a/tests/golden/lang/resolve/resolve__private_trait_method/shapes.silt
+++ b/tests/golden/lang/resolve/resolve__private_trait_method/shapes.silt
@@ -10,4 +10,4 @@ trait Describe for Square {
 
 pub fn square(side: Int) -> Square { Square { side: side } }
 
-pub fn described(s: Square) -> String { s.describe() }
+pub fn described(s: Square) -> String { Describe.describe(s) }
diff --git a/tests/golden/lang/resolve/resolve__private_trait_method_every_path/lib.silt b/tests/golden/lang/resolve/resolve__private_trait_method_every_path/lib.silt
index efee8e3be..f2cd21be9 100644
--- a/tests/golden/lang/resolve/resolve__private_trait_method_every_path/lib.silt
+++ b/tests/golden/lang/resolve/resolve__private_trait_method_every_path/lib.silt
@@ -4,4 +4,4 @@ trait Priv {
 trait Priv for Int {
   fn pm(self) -> Int { self * 10 }
 }
-pub fn via(x: Int) -> Int { x.pm() }
+pub fn via(x: Int) -> Int { Priv.pm(x) }
diff --git a/tests/golden/lang/resolve/resolve__private_trait_method_every_path/main.silt b/tests/golden/lang/resolve/resolve__private_trait_method_every_path/main.silt
index a111a050b..16140c632 100644
--- a/tests/golden/lang/resolve/resolve__private_trait_method_every_path/main.silt
+++ b/tests/golden/lang/resolve/resolve__private_trait_method_every_path/main.silt
@@ -1,16 +1,16 @@
 -- cmd: check
 -- exit: 1
 -- verdict: same
--- stderr-contains: --> main.silt:13:18
+-- stderr-contains: --> main.silt:14:11
 -- stderr-contains: --> main.silt:15:11
+-- stderr-contains: error[type]: 'Priv' is private to module 'lib'
 -- stderr-contains: error[type]: method `pm` belongs to trait 'Priv', which is private to module 'lib'
 -- A private trait's method cannot be called from an importer by any
--- path: on a value, through a lambda whose parameter's type is not yet
--- known, or through the type. `lib.via` may call it.
+-- path: through the trait, which it cannot name, or through the type.
+-- `lib.via` may call it.
 import lib
 fn main() {
   println(lib.via(1))
-  let f = { x -> x.pm() }
-  println(f(3))
+  println(lib.Priv.pm(3))
   println(Int.pm(3))
 }
diff --git a/tests/golden/lang/resolve/resolve__private_trait_not_nameable/lib.silt b/tests/golden/lang/resolve/resolve__private_trait_not_nameable/lib.silt
index ded42c153..8600ce4c5 100644
--- a/tests/golden/lang/resolve/resolve__private_trait_not_nameable/lib.silt
+++ b/tests/golden/lang/resolve/resolve__private_trait_not_nameable/lib.silt
@@ -1,3 +1,3 @@
 trait Hidden { fn hid(self) -> Int }
 trait Hidden for Int { fn hid(self) -> Int { 7 } }
-pub fn seven() -> Int { 7.hid() }
+pub fn seven() -> Int { Hidden.hid(7) }
diff --git a/tests/golden/lang/resolve/resolve__private_type_in_public_signature/lib.silt b/tests/golden/lang/resolve/resolve__private_type_in_public_signature/lib.silt
index 4f2ab6598..b7a29b758 100644
--- a/tests/golden/lang/resolve/resolve__private_type_in_public_signature/lib.silt
+++ b/tests/golden/lang/resolve/resolve__private_type_in_public_signature/lib.silt
@@ -1,6 +1,6 @@
 type Id { Id(Int) }
 trait Greet { fn greet(self) -> String }
 pub fn make(n: Int) -> Id { Id(n) }
-pub fn hello(x: a) -> String where a: Greet { x.greet() }
+pub fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 pub type Holder { id: Id }
 fn private_use(i: Id) -> Int { 1 }
diff --git a/tests/golden/lang/resolve/resolve__pub_trait_method/main.silt b/tests/golden/lang/resolve/resolve__pub_trait_method/main.silt
index 264587e7f..2bcab2199 100644
--- a/tests/golden/lang/resolve/resolve__pub_trait_method/main.silt
+++ b/tests/golden/lang/resolve/resolve__pub_trait_method/main.silt
@@ -3,5 +3,5 @@
 import shapes
 fn main() {
   println(shapes.described(shapes.square(2)))
-  println(shapes.square(3).describe())
+  println(shapes.Describe.describe(shapes.square(3)))
 }
diff --git a/tests/golden/lang/resolve/resolve__pub_trait_method/shapes.silt b/tests/golden/lang/resolve/resolve__pub_trait_method/shapes.silt
index 98381e6bd..7cb615f6d 100644
--- a/tests/golden/lang/resolve/resolve__pub_trait_method/shapes.silt
+++ b/tests/golden/lang/resolve/resolve__pub_trait_method/shapes.silt
@@ -10,4 +10,4 @@ trait Describe for Square {
 
 pub fn square(side: Int) -> Square { Square { side: side } }
 
-pub fn described(s: Square) -> String { s.describe() }
+pub fn described(s: Square) -> String { Describe.describe(s) }
diff --git a/tests/golden/lang/resolve/resolve__qualified_type_method/main.silt b/tests/golden/lang/resolve/resolve__qualified_type_method/main.silt
index 0ea75b5b7..61d0698b5 100644
--- a/tests/golden/lang/resolve/resolve__qualified_type_method/main.silt
+++ b/tests/golden/lang/resolve/resolve__qualified_type_method/main.silt
@@ -13,13 +13,13 @@ trait IntoAppError for io.IoError {
 }
 
 fn load(path: String) -> Result(String, AppError) {
-  let raw = result.map_err(io.read_file(path), io.IoError.into_app_error)?
+  let raw = result.map_err(io.read_file(path), IntoAppError.into_app_error)?
   Ok(raw)
 }
 
 fn main() {
-  println(lib.Shape.describe(lib.Shape.Circle(1)))
-  println(lib.Pt.describe(lib.Pt { x: 2 }))
+  println(lib.Describe.describe(lib.Shape.Circle(1)))
+  println(lib.Describe.describe(lib.Pt { x: 2 }))
   match load("/nonexistent/silt/golden") {
     Ok(_) -> println("ok")
     Err(AppError.IoProblem(_)) -> println("io problem")
diff --git a/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/lib.silt b/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/lib.silt
index ded42c153..8600ce4c5 100644
--- a/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/lib.silt
+++ b/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/lib.silt
@@ -1,3 +1,3 @@
 trait Hidden { fn hid(self) -> Int }
 trait Hidden for Int { fn hid(self) -> Int { 7 } }
-pub fn seven() -> Int { 7.hid() }
+pub fn seven() -> Int { Hidden.hid(7) }
diff --git a/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/main.silt b/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/main.silt
index db496a14d..fc0f0f554 100644
--- a/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/main.silt
+++ b/tests/golden/lang/resolve/resolve__rejected_impl_method_not_reported_again/main.silt
@@ -6,5 +6,5 @@
 import lib
 trait Hidden for String { fn hid(self) -> Int { 1 } }
 fn main() {
-  println("a".hid())
+  println(Hidden.hid("a"))
 }
diff --git a/tests/golden/lang/resolve/resolve__s4_module_trait_beside_local_trait/main.silt b/tests/golden/lang/resolve/resolve__s4_module_trait_beside_local_trait/main.silt
index e0cbeb82d..28ebc275f 100644
--- a/tests/golden/lang/resolve/resolve__s4_module_trait_beside_local_trait/main.silt
+++ b/tests/golden/lang/resolve/resolve__s4_module_trait_beside_local_trait/main.silt
@@ -8,8 +8,8 @@ type X { X(Int) }
 type Y { Y(Int) }
 trait lib.Describe for X { fn describe(self) -> String { "lib" } }
 trait Describe for Y { fn describe(self) -> Int { 7 } }
-fn show(a: a) -> String where a: lib.Describe { a.describe() }
-fn count(a: a) -> Int where a: Describe { a.describe() }
+fn show(a: a) -> String where a: lib.Describe { lib.Describe.describe(a) }
+fn count(a: a) -> Int where a: Describe { Describe.describe(a) }
 fn main() {
   println(show(X(1)))
   println(count(Y(2)) + 1)
diff --git a/tests/golden/lang/resolve/resolve__s4_module_trait_is_not_local_trait/main.silt b/tests/golden/lang/resolve/resolve__s4_module_trait_is_not_local_trait/main.silt
index 54100f956..73ab1ff88 100644
--- a/tests/golden/lang/resolve/resolve__s4_module_trait_is_not_local_trait/main.silt
+++ b/tests/golden/lang/resolve/resolve__s4_module_trait_is_not_local_trait/main.silt
@@ -8,7 +8,7 @@ import lib
 trait Describe { fn describe(self) -> Int }
 type X { X(Int) }
 trait lib.Describe for X { fn describe(self) -> String { "lib" } }
-fn count(a: a) -> Int where a: Describe { a.describe() }
+fn count(a: a) -> Int where a: Describe { Describe.describe(a) }
 fn main() {
   println(count(X(1)))
 }
diff --git a/tests/golden/lang/resolve/resolve__two_modules_one_type_name_with_impls/main.silt b/tests/golden/lang/resolve/resolve__two_modules_one_type_name_with_impls/main.silt
index 38989d5a1..17fc4a2a1 100644
--- a/tests/golden/lang/resolve/resolve__two_modules_one_type_name_with_impls/main.silt
+++ b/tests/golden/lang/resolve/resolve__two_modules_one_type_name_with_impls/main.silt
@@ -7,12 +7,12 @@
 import a
 import b
 fn both(p: a.Pt, q: b.Pt) -> String {
-  "{p.display()} / {q.display()} / {p.x} {q.y}"
+  "{p} / {q} / {p.x} {q.y}"
 }
 fn main() {
-  println(a.mk().display())
-  println(b.mk().display())
-  println(a.Pt.display(a.mk()))
+  println("{a.mk()}")
+  println("{b.mk()}")
+  println("{a.mk()}")
   println(both(a.mk(), b.mk()))
   println(a.mk())
   println(b.mk())
diff --git a/tests/golden/lang/resolve/resolve__type_method_that_is_a_module_function.silt b/tests/golden/lang/resolve/resolve__type_method_that_is_a_module_function.silt
index df38ef449..4871803e9 100644
--- a/tests/golden/lang/resolve/resolve__type_method_that_is_a_module_function.silt
+++ b/tests/golden/lang/resolve/resolve__type_method_that_is_a_module_function.silt
@@ -9,5 +9,5 @@
 -- program is checked, not when it runs.
 fn main() {
   println(Int.parse("3"))
-  println(Int.display(3))
+  println("{3}")
 }
diff --git a/tests/golden/lang/session/stage5_session__poisoned_module_named_like_a_local_type/case.stderr b/tests/golden/lang/session/stage5_session__poisoned_module_named_like_a_local_type/case.stderr
index c2a6c3e50..b61040876 100644
--- a/tests/golden/lang/session/stage5_session__poisoned_module_named_like_a_local_type/case.stderr
+++ b/tests/golden/lang/session/stage5_session__poisoned_module_named_like_a_local_type/case.stderr
@@ -35,8 +35,9 @@ error[parse]: expected declaration, found =
  6 | import Shape
    | ------------ module 'Shape' is imported here
 
-error[type]: unknown field or method 'describe' on type Shape
+error[type]: type 'Shape' has no field 'describe'
  --> main.silt:20:11
     |
  20 |   println(s.describe())
-    |           ^^^^^^^^^^ unknown field or method 'describe' on type Shape
+    |           ^^^^^^^^^^ type 'Shape' has no field 'describe'
+  = help: `describe` is a method of trait `Describe`: call it as `Describe.describe(s)`
diff --git a/tests/golden/lang/session/stage5_session__type_alias_per_module_ab/a.silt b/tests/golden/lang/session/stage5_session__type_alias_per_module_ab/a.silt
index 0dd499815..cde98c207 100644
--- a/tests/golden/lang/session/stage5_session__type_alias_per_module_ab/a.silt
+++ b/tests/golden/lang/session/stage5_session__type_alias_per_module_ab/a.silt
@@ -1,4 +1,4 @@
 type Id = Int
 trait Show2 { fn show2(self) -> String }
 trait Show2 for Id { fn show2(self) -> String { "int-id" } }
-pub fn f(x: Int) -> String { x.show2() }
+pub fn f(x: Int) -> String { Show2.show2(x) }
diff --git a/tests/golden/lang/session/stage5_session__type_alias_per_module_ba/a.silt b/tests/golden/lang/session/stage5_session__type_alias_per_module_ba/a.silt
index 0dd499815..cde98c207 100644
--- a/tests/golden/lang/session/stage5_session__type_alias_per_module_ba/a.silt
+++ b/tests/golden/lang/session/stage5_session__type_alias_per_module_ba/a.silt
@@ -1,4 +1,4 @@
 type Id = Int
 trait Show2 { fn show2(self) -> String }
 trait Show2 for Id { fn show2(self) -> String { "int-id" } }
-pub fn f(x: Int) -> String { x.show2() }
+pub fn f(x: Int) -> String { Show2.show2(x) }
diff --git a/tests/golden/lang/soundness/alias_impl__another_length_or_arity_has_no_impl.silt b/tests/golden/lang/soundness/alias_impl__another_length_or_arity_has_no_impl.silt
index 3c45e636f..75379832a 100644
--- a/tests/golden/lang/soundness/alias_impl__another_length_or_arity_has_no_impl.silt
+++ b/tests/golden/lang/soundness/alias_impl__another_length_or_arity_has_no_impl.silt
@@ -18,8 +18,8 @@ trait T for P2 {
 }
 trait U { fn ap(self) -> Int }
 trait U for Op { fn ap(self) -> Int { self(1) + 1 } }
-fn s(x: a) -> Int where a: T { x.sum() }
-fn u(x: a) -> Int where a: U { x.ap() }
+fn s(x: a) -> Int where a: T { T.sum(x) }
+fn u(x: a) -> Int where a: U { U.ap(x) }
 fn two(a: Int, b: Int) -> Int { a + b }
 fn tag(n: Int) -> Tag { Tag("t") }
 fn main() {
diff --git a/tests/golden/lang/soundness/c2.silt b/tests/golden/lang/soundness/c2.silt
index 05768a29d..d098be07d 100644
--- a/tests/golden/lang/soundness/c2.silt
+++ b/tests/golden/lang/soundness/c2.silt
@@ -2,7 +2,7 @@
 -- exit: 1
 -- stderr-contains: error[type]: type 'Fn' does not implement trait 'Display'
 -- Port of repros/type_soundness/c2.silt, in brace closures.
-fn show(x) { x.display() }
+fn show(x) { "{x}" }
 fn main() {
   let f = { x -> x + 1 }
   println(show(1))
diff --git a/tests/golden/lang/soundness/d06.silt b/tests/golden/lang/soundness/d06.silt
index 8c5b630da..b079ea17d 100644
--- a/tests/golden/lang/soundness/d06.silt
+++ b/tests/golden/lang/soundness/d06.silt
@@ -12,7 +12,7 @@ trait S {
 trait S for F {}
 fn main() {
   let x = F { f: { a -> a } }
-  println(x.s())
-  println(x.e())
-  println(x.c())
+  println(S.s(x))
+  println(S.e(x))
+  println(S.c(x))
 }
diff --git a/tests/golden/lang/soundness/d5.silt b/tests/golden/lang/soundness/d5.silt
index 17941d7aa..109f46a30 100644
--- a/tests/golden/lang/soundness/d5.silt
+++ b/tests/golden/lang/soundness/d5.silt
@@ -1,8 +1,8 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: unknown method 'display' on type Fn
+-- stderr-contains: has no field 'display'
 -- Port of repros/type_soundness/d5.silt, in brace closures.
-fn f(x) { x.display() }
+fn f(x) { "{x}" }
 fn main() {
   let g = { x -> x }
   println(g.display())
diff --git a/tests/golden/lang/soundness/e05.silt b/tests/golden/lang/soundness/e05.silt
index 08903f18b..12b6b7f31 100644
--- a/tests/golden/lang/soundness/e05.silt
+++ b/tests/golden/lang/soundness/e05.silt
@@ -6,6 +6,6 @@
 trait Loud { fn loud(self) -> String }
 trait Loud for Int { fn loud(self) -> String { "INT" } }
 trait Shw { fn shw(self, x: a) -> String }
-trait Shw for Bool { fn shw(self, x: a) -> String where a: Loud { x.loud() } }
-fn call(s: t, v: String) -> String where t: Shw { s.shw(v) }
+trait Shw for Bool { fn shw(self, x: a) -> String where a: Loud { Loud.loud(x) } }
+fn call(s: t, v: String) -> String where t: Shw { Shw.shw(s, v) }
 fn main() { println(call(true, "s")) }
diff --git a/tests/golden/lang/soundness/e12.silt b/tests/golden/lang/soundness/e12.silt
index f6524c021..840b5a86b 100644
--- a/tests/golden/lang/soundness/e12.silt
+++ b/tests/golden/lang/soundness/e12.silt
@@ -5,7 +5,7 @@ trait Greet { fn greet(self) -> String }
 trait Greet for P { fn greet(self) -> String { "p" } }
 fn main() {
   let ps = [P { v: 1 }]
-  let f = { p -> p.greet() }
+  let f = { p -> Greet.greet(p) }
   println(f(P { v: 2 }))
   println(list.map(ps, f))
 }
diff --git a/tests/golden/lang/soundness/e4.silt b/tests/golden/lang/soundness/e4.silt
index 5197e3763..e6e0589fc 100644
--- a/tests/golden/lang/soundness/e4.silt
+++ b/tests/golden/lang/soundness/e4.silt
@@ -1,11 +1,11 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: type mismatch: expected {nonexistent_method: Fn() -> _, ...}, got Int
+-- stderr-contains: type 'Int' has no field 'nonexistent_method'
 -- Port of repros/type_soundness/e4.silt, in brace closures.
 import list
 fn main() {
   let xs = [1, 2, 3]
-  let ys = list.map(xs) { x -> x.display() }
+  let ys = list.map(xs) { x -> "{x}" }
   println(ys)
   let f = { x -> x.nonexistent_method() }
   println(f(1))
diff --git a/tests/golden/lang/soundness/e5.silt b/tests/golden/lang/soundness/e5.silt
index d38e102f2..b8caa24a3 100644
--- a/tests/golden/lang/soundness/e5.silt
+++ b/tests/golden/lang/soundness/e5.silt
@@ -3,7 +3,7 @@
 -- stderr-contains: error[type]: type mismatch: expected Int, got String
 -- Port of repros/type_soundness/e5.silt, in brace closures.
 fn main() {
-  let f = { x -> x.display() }
+  let f = { x -> "{x}" }
   let n: Int = f(1)
   println(n)
 }
diff --git a/tests/golden/lang/soundness/e7.silt b/tests/golden/lang/soundness/e7.silt
index de7878271..4a861c255 100644
--- a/tests/golden/lang/soundness/e7.silt
+++ b/tests/golden/lang/soundness/e7.silt
@@ -2,7 +2,7 @@
 import list
 fn main() {
   let xs = [1, 2, 3]
-  let ys = list.map(xs, { x: Int -> x.display() })
+  let ys = list.map(xs, { x: Int -> "{x}" })
   println(ys)
-  println(1.display())
+  println("{1}")
 }
diff --git a/tests/golden/lang/soundness/every_fn__a_closure_returned_as_a_function_of_a_variant.silt b/tests/golden/lang/soundness/every_fn__a_closure_returned_as_a_function_of_a_variant.silt
index 812f0055d..5e687ad1d 100644
--- a/tests/golden/lang/soundness/every_fn__a_closure_returned_as_a_function_of_a_variant.silt
+++ b/tests/golden/lang/soundness/every_fn__a_closure_returned_as_a_function_of_a_variant.silt
@@ -8,7 +8,7 @@ trait Cast for Fn {
   fn cast(self) -> Fn(Int) -> Solo { self }
 }
 fn main() {
-  let f = { n -> n * 2 }.cast()
+  let f = Cast.cast({ n -> n * 2 })
   match f(21) {
     Solo(s) -> println("got {s}")
   }
diff --git a/tests/golden/lang/soundness/every_fn__not_called_through_the_type.silt b/tests/golden/lang/soundness/every_fn__not_called_through_the_type.silt
index 9dacc0abc..6f1cd4e31 100644
--- a/tests/golden/lang/soundness/every_fn__not_called_through_the_type.silt
+++ b/tests/golden/lang/soundness/every_fn__not_called_through_the_type.silt
@@ -1,9 +1,10 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: method `describe` of the impl for every `Fn` is called on a value: write `x.describe(..)`, not `Fn.describe`
--- stderr-contains: method `describe` of the impl for every `Tuple` is called on a value: write `x.describe(..)`, not `Tuple.describe`
--- The impl for every function is found by the receiver. Written through
--- the type its method would take a `self` of any type: refused.
+-- stderr-contains: type 'Fn' has no method 'describe'
+-- stderr-contains: type 'Tuple' has no method 'describe'
+-- stderr-contains: help: `describe` is a method of trait `D`: call it as `D.describe(x)`
+-- The impl for every function is found by the argument of type Self:
+-- the method is called through its trait, never through the type.
 trait D { fn describe(self) -> String }
 trait D for Fn { fn describe(self) -> String { "fn" } }
 trait D for Tuple { fn describe(self) -> String { "tuple" } }
diff --git a/tests/golden/lang/soundness/every_fn__self_is_not_a_function_of_a_chosen_signature.silt b/tests/golden/lang/soundness/every_fn__self_is_not_a_function_of_a_chosen_signature.silt
index 1aba36076..9a5e4a4ef 100644
--- a/tests/golden/lang/soundness/every_fn__self_is_not_a_function_of_a_chosen_signature.silt
+++ b/tests/golden/lang/soundness/every_fn__self_is_not_a_function_of_a_chosen_signature.silt
@@ -17,10 +17,10 @@ fn show(c: Cents) -> String {
   }
 }
 fn main() {
-  let f = secret.cast()
+  let f = Cast.cast(secret)
   println(show(f(1)))
   let Cents(k) = f(2)
   println("bound: {k}")
-  let g = open.cast()
+  let g = Cast.cast(open)
   println(show(g(1)))
 }
diff --git a/tests/golden/lang/soundness/every_fn__self_returned_as_a_function_of_a_record.silt b/tests/golden/lang/soundness/every_fn__self_returned_as_a_function_of_a_record.silt
index cd843fba3..a6ef76a58 100644
--- a/tests/golden/lang/soundness/every_fn__self_returned_as_a_function_of_a_record.silt
+++ b/tests/golden/lang/soundness/every_fn__self_returned_as_a_function_of_a_record.silt
@@ -10,7 +10,7 @@ trait Cast for Fn {
 }
 fn mk(n: Int) -> Point { Point { x: "px", y: "py" } }
 fn main() {
-  let f = mk.cast()
+  let f = Cast.cast(mk)
   let Wrap(n) = f(1)
   println(n + 1)
 }
diff --git a/tests/golden/lang/soundness/every_tuple__self_is_not_a_tuple_of_chosen_elements.silt b/tests/golden/lang/soundness/every_tuple__self_is_not_a_tuple_of_chosen_elements.silt
index 9f635dd8e..a2f8c4e45 100644
--- a/tests/golden/lang/soundness/every_tuple__self_is_not_a_tuple_of_chosen_elements.silt
+++ b/tests/golden/lang/soundness/every_tuple__self_is_not_a_tuple_of_chosen_elements.silt
@@ -15,7 +15,7 @@ fn len(m: Meters) -> String {
   }
 }
 fn main() {
-  let (m, _) = (Feet { v: 3, unit: "ft" }, 0).cast()
+  let (m, _) = Cast.cast((Feet { v: 3, unit: "ft" }, 0))
   println(len(m))
   let Meters { v, .. } = m
   println(v)
diff --git a/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_record.silt b/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_record.silt
index a7e4c3f0e..4a697cb87 100644
--- a/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_record.silt
+++ b/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_record.silt
@@ -9,6 +9,6 @@ trait Cast for Tuple {
   fn cast(self) -> (Point, Int) { self }
 }
 fn main() {
-  let (Point { x, y }, k) = (Wrap(7), 2).cast()
+  let (Point { x, y }, k) = Cast.cast((Wrap(7), 2))
   println("{x} {y} {k}")
 }
diff --git a/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_variant.silt b/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_variant.silt
index 2a3670441..529928cef 100644
--- a/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_variant.silt
+++ b/tests/golden/lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_variant.silt
@@ -9,6 +9,6 @@ trait Cast for Tuple {
   fn cast(self) -> (Wrap, Int) { self }
 }
 fn main() {
-  let (Wrap(n), k) = (Point { x: "px", y: "py" }, 2).cast()
+  let (Wrap(n), k) = Cast.cast((Point { x: "px", y: "py" }, 2))
   println(n + k)
 }
diff --git a/tests/golden/lang/soundness/every_tuple__self_type_is_the_receivers.silt b/tests/golden/lang/soundness/every_tuple__self_type_is_the_receivers.silt
index 3a9d1b4d8..653f76bcf 100644
--- a/tests/golden/lang/soundness/every_tuple__self_type_is_the_receivers.silt
+++ b/tests/golden/lang/soundness/every_tuple__self_type_is_the_receivers.silt
@@ -9,6 +9,6 @@ trait Same for Tuple {
   fn other(self, o: Self) -> Self { o }
 }
 fn main() {
-  let (Cents(k), _) = (Cents(1), 2).other((Hidden("s3cr3t"), 2, 3))
+  let (Cents(k), _) = Same.other((Cents(1), 2), (Hidden("s3cr3t"), 2, 3))
   println("bound: {k}")
 }
diff --git a/tests/golden/lang/soundness/i5.silt b/tests/golden/lang/soundness/i5.silt
index 73837f8be..c5a2a8747 100644
--- a/tests/golden/lang/soundness/i5.silt
+++ b/tests/golden/lang/soundness/i5.silt
@@ -5,7 +5,7 @@
 type W(a) { W(a) }
 fn main() {
   let w1 = W({ x -> x + 1 })
-  println(w1.display())
+  println("{w1}")
   println("{w1}")
   println(w1)
 }
diff --git a/tests/golden/lang/soundness/i8.silt b/tests/golden/lang/soundness/i8.silt
index fad819ede..e75e002b2 100644
--- a/tests/golden/lang/soundness/i8.silt
+++ b/tests/golden/lang/soundness/i8.silt
@@ -8,7 +8,7 @@ fn main() {
   let u = Node(Node(Leaf, 1, Leaf), 2, Leaf)
   println(t == u)
   println(t < u)
-  println(t.hash() == u.hash())
+  println(Hash.hash(t) == Hash.hash(u))
   println(t)
   let ft = Node(Leaf, { x -> x }, Leaf)
   println(ft == ft)
diff --git a/tests/golden/lang/soundness/se2.silt b/tests/golden/lang/soundness/se2.silt
index 049982381..6a9efe92e 100644
--- a/tests/golden/lang/soundness/se2.silt
+++ b/tests/golden/lang/soundness/se2.silt
@@ -11,7 +11,7 @@ trait Get for P {
   }
 }
 fn main() {
-  println(P { v: 1 }.get())
+  println(Get.get(P { v: 1 }))
   let g = { x -> self }
   println(1)
 }
diff --git a/tests/golden/lang/soundness/t_poly_method.silt b/tests/golden/lang/soundness/t_poly_method.silt
index ae5e4d9c2..22beaed84 100644
--- a/tests/golden/lang/soundness/t_poly_method.silt
+++ b/tests/golden/lang/soundness/t_poly_method.silt
@@ -2,7 +2,7 @@
 -- exit: 1
 -- stderr-contains: error[type]: type 'Fn' does not implement trait 'Display'
 -- Port of repros/typechecker_arch/t_poly_method.silt, in brace closures.
-fn show(x) { x.display() }
+fn show(x) { "{x}" }
 fn main() {
   let f = { y -> y }
   println(show(f) + 1)
diff --git a/tests/golden/lang/soundness/w10.silt b/tests/golden/lang/soundness/w10.silt
index e09d3498b..017774270 100644
--- a/tests/golden/lang/soundness/w10.silt
+++ b/tests/golden/lang/soundness/w10.silt
@@ -5,7 +5,7 @@
 import list
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   println(list.map(["a", "b"], { x -> hello(x) }))
 }
diff --git a/tests/golden/lang/soundness/w5.silt b/tests/golden/lang/soundness/w5.silt
index 133a59364..8be05bc1c 100644
--- a/tests/golden/lang/soundness/w5.silt
+++ b/tests/golden/lang/soundness/w5.silt
@@ -4,7 +4,7 @@
 -- Port of repros/type_soundness/w5.silt, in brace closures.
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   let h = hello
   println(h("s"))
diff --git a/tests/golden/lang/soundness/z1.silt b/tests/golden/lang/soundness/z1.silt
index 60095dd3d..ae8596038 100644
--- a/tests/golden/lang/soundness/z1.silt
+++ b/tests/golden/lang/soundness/z1.silt
@@ -5,7 +5,7 @@
 import channel
 type Box(a) { Box(a) }
 fn show(x) { "{x}" }
-fn show2(x) { x.display() }
+fn show2(x) { "{x}" }
 fn pr(x) { println(x) }
 fn main() {
   let f = { x -> x }
diff --git a/tests/golden/lang/soundness/z2.silt b/tests/golden/lang/soundness/z2.silt
index f940360cd..52ce2a389 100644
--- a/tests/golden/lang/soundness/z2.silt
+++ b/tests/golden/lang/soundness/z2.silt
@@ -4,7 +4,7 @@
 -- Port of repros/type_soundness/z2.silt, in brace closures.
 type Box(a) { Box(a) }
 fn show(x) { "{x}" }
-fn show2(x) { x.display() }
+fn show2(x) { "{x}" }
 fn pr(x) { println(x) }
 fn main() {
   let f = { x -> x }
diff --git a/tests/golden/lang/soundness/z3.silt b/tests/golden/lang/soundness/z3.silt
index 77a08ba29..4cb010c9d 100644
--- a/tests/golden/lang/soundness/z3.silt
+++ b/tests/golden/lang/soundness/z3.silt
@@ -4,7 +4,7 @@
 -- Port of repros/type_soundness/z3.silt, in brace closures.
 type Box(a) { Box(a) }
 fn show(x) { "{x}" }
-fn show2(x) { x.display() }
+fn show2(x) { "{x}" }
 fn pr(x) { println(x) }
 fn main() {
   let f = { x -> x }
diff --git a/tests/golden/lang/stdlib/bytes_module__base64.silt b/tests/golden/lang/stdlib/bytes_module__base64.silt
index 35d8817a7..a3e031c78 100644
--- a/tests/golden/lang/stdlib/bytes_module__base64.silt
+++ b/tests/golden/lang/stdlib/bytes_module__base64.silt
@@ -9,6 +9,6 @@ fn main() {
   println(bytes.to_base64(bytes.from_string("hello")))
   match bytes.from_base64("!!!not base64!!!") {
     Ok(_) -> println("wrong: should error")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/stdlib/bytes_module__concat.silt b/tests/golden/lang/stdlib/bytes_module__concat.silt
index b5180fd08..bfc99931d 100644
--- a/tests/golden/lang/stdlib/bytes_module__concat.silt
+++ b/tests/golden/lang/stdlib/bytes_module__concat.silt
@@ -4,7 +4,7 @@ fn main() {
   let b = bytes.from_string("world")
   match bytes.to_string(bytes.concat(a, b)) {
     Ok(s) -> println(s)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   let h = bytes.from_string("hello")
   println(bytes.concat(h, bytes.empty()) == h)
@@ -16,6 +16,6 @@ fn main() {
   ]
   match bytes.to_string(bytes.concat_all(parts)) {
     Ok(s) -> println(s)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/stdlib/bytes_module__constructors.silt b/tests/golden/lang/stdlib/bytes_module__constructors.silt
index 3d718f0c0..969a6131c 100644
--- a/tests/golden/lang/stdlib/bytes_module__constructors.silt
+++ b/tests/golden/lang/stdlib/bytes_module__constructors.silt
@@ -5,11 +5,11 @@ fn main() {
   -- from_string / to_string round trip, ascii and multibyte
   match bytes.to_string(bytes.from_string("hello")) {
     Ok(s) -> println(s)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match bytes.to_string(bytes.from_string("café 🎉")) {
     Ok(s) -> println(s)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   -- 0xff alone is not valid utf-8
   match bytes.from_list([255]) {
diff --git a/tests/golden/lang/stdlib/bytes_module__hex.silt b/tests/golden/lang/stdlib/bytes_module__hex.silt
index e3d49825e..76659898c 100644
--- a/tests/golden/lang/stdlib/bytes_module__hex.silt
+++ b/tests/golden/lang/stdlib/bytes_module__hex.silt
@@ -2,20 +2,20 @@ import bytes
 fn main() {
   match bytes.from_hex("48656c6c6f") {
     Ok(b) -> println(bytes.to_hex(b))
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   -- uppercase input is accepted, output is lowercase
   match bytes.from_hex("DEADBEEF") {
     Ok(b) -> println(bytes.to_hex(b))
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match bytes.from_hex("abc") {
     Ok(_) -> println("wrong: should error")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match bytes.from_hex("xyzz") {
     Ok(_) -> println("wrong: should error")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   println("[{bytes.to_hex(bytes.empty())}]")
 }
diff --git a/tests/golden/lang/stdlib/bytes_module__length_slice_get.silt b/tests/golden/lang/stdlib/bytes_module__length_slice_get.silt
index eb207b7b1..a3533aa00 100644
--- a/tests/golden/lang/stdlib/bytes_module__length_slice_get.silt
+++ b/tests/golden/lang/stdlib/bytes_module__length_slice_get.silt
@@ -5,7 +5,7 @@ fn main() {
   println([a, b])
   match bytes.to_string(bytes.slice(bytes.from_string("hello world"), 6, 11)) {
     Ok(t) -> println(t)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   println(bytes.length(bytes.slice(bytes.from_string("hello"), 2, 2)))
   -- a start past the end gives nothing; an end past the length is the length
diff --git a/tests/golden/lang/stdlib/bytes_module__list_conversion.silt b/tests/golden/lang/stdlib/bytes_module__list_conversion.silt
index e5d619e9f..b2f8c387a 100644
--- a/tests/golden/lang/stdlib/bytes_module__list_conversion.silt
+++ b/tests/golden/lang/stdlib/bytes_module__list_conversion.silt
@@ -6,10 +6,10 @@ fn main() {
   }
   match bytes.from_list([10, 256, 30]) {
     Ok(_) -> println("wrong: should error")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match bytes.from_list([0, -1, 0]) {
     Ok(_) -> println("wrong: should error")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/stdlib/bytes_module__split.silt b/tests/golden/lang/stdlib/bytes_module__split.silt
index 25f98f736..39d37765b 100644
--- a/tests/golden/lang/stdlib/bytes_module__split.silt
+++ b/tests/golden/lang/stdlib/bytes_module__split.silt
@@ -5,7 +5,7 @@ fn main() {
   println(list.map(parts) { p ->
     match bytes.to_string(p) {
       Ok(s) -> s
-      Err(e) -> e.message()
+      Err(e) -> Error.message(e)
     }
   })
   println(list.length(bytes.split(bytes.from_string("hello"), bytes.from_string(","))))
diff --git a/tests/golden/lang/stdlib/conventions__encoding_crypto_and_uuid_have_typed_errors.silt b/tests/golden/lang/stdlib/conventions__encoding_crypto_and_uuid_have_typed_errors.silt
index 969b42e9e..234e9f5b9 100644
--- a/tests/golden/lang/stdlib/conventions__encoding_crypto_and_uuid_have_typed_errors.silt
+++ b/tests/golden/lang/stdlib/conventions__encoding_crypto_and_uuid_have_typed_errors.silt
@@ -19,7 +19,7 @@ fn main() {
     other -> println(other)
   }
   match encoding.form_decode("%FF=1") {
-    Err(e) -> println("form_decode: {e.message()}")
+    Err(e) -> println("form_decode: {Error.message(e)}")
     Ok(pairs) -> println(pairs)
   }
   match crypto.random_bytes(-1) {
@@ -27,7 +27,7 @@ fn main() {
     _ -> println("something else")
   }
   match crypto.random_bytes(2000000) {
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
     Ok(_) -> println("two million bytes")
   }
   match uuid.parse("not-a-uuid") {
diff --git a/tests/golden/lang/stdlib/conventions__error_enums_are_named_after_their_modules.silt b/tests/golden/lang/stdlib/conventions__error_enums_are_named_after_their_modules.silt
index 512bfda6d..5f4c643f1 100644
--- a/tests/golden/lang/stdlib/conventions__error_enums_are_named_after_their_modules.silt
+++ b/tests/golden/lang/stdlib/conventions__error_enums_are_named_after_their_modules.silt
@@ -13,7 +13,7 @@ import toml
 
 type Point { x: Int }
 
-fn show(e: a) -> String where a: Error { e.message() }
+fn show(e: a) -> String where a: Error { Error.message(e) }
 
 fn main() {
   match io.read_file("no/such/file/anywhere") {
diff --git a/tests/golden/lang/stdlib/crypto_module__hmac_kats.silt b/tests/golden/lang/stdlib/crypto_module__hmac_kats.silt
index d1c92e8e2..7ca9b4eec 100644
--- a/tests/golden/lang/stdlib/crypto_module__hmac_kats.silt
+++ b/tests/golden/lang/stdlib/crypto_module__hmac_kats.silt
@@ -7,7 +7,7 @@ fn main() {
       println(bytes.to_hex(crypto.hmac_sha256(key, bytes.from_string("Hi There"))))
       println(bytes.to_hex(crypto.hmac_sha512(key, bytes.from_string("Hi There"))))
     }
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   println(bytes.length(crypto.hmac_sha256(bytes.from_string("k"), bytes.from_string("m"))))
   println(bytes.length(crypto.hmac_sha512(bytes.from_string("k"), bytes.from_string("m"))))
diff --git a/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.silt b/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.silt
index 5e4e32068..b4c03ecbd 100644
--- a/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.silt
@@ -46,7 +46,7 @@ trait Load for S {
 }
 
 fn via(x: s, type a) -> Result(a, toml.TomlError) where s: Load, a: json.Decode {
-  x.get("n = 1", a)
+  Load.get(x, "n = 1", a)
 }
 
 fn main() {
@@ -56,6 +56,6 @@ fn main() {
   let _ = deep("n = 1", L)
   let _ = both("n = 1", L)
   let _ = tl("n = 1", Set(Int))
-  let _ = S { n: 1 }.get("n = 1", L)
+  let _ = Load.get(S { n: 1 }, "n = 1", L)
   let _ = via(S { n: 1 }, L)
 }
diff --git a/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.stderr b/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.stderr
index 7552edac5..7eeed2c80 100644
--- a/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.stderr
+++ b/tests/golden/lang/stdlib/data_decode__a_bounded_type_another_decoder_refuses_is_one_error.stderr
@@ -47,10 +47,10 @@ error[type]: `toml.parse` cannot decode `Set(Int)`: its type argument must be a
   = help: declare a record type with a field of the type you want, and decode into the record
 
 error[type]: `toml.parse` cannot decode `L`: its type argument must be a record type, an enum type, or a type with a `json.Decode` impl
- --> data_decode__a_bounded_type_another_decoder_refuses_is_one_error.silt:59:35
+ --> data_decode__a_bounded_type_another_decoder_refuses_is_one_error.silt:59:41
     |
- 59 |   let _ = S { n: 1 }.get("n = 1", L)
-    |                                   ^ `toml.parse` cannot decode `L`: its type argument must be a record type, an enum type, or a type with a `json.Decode` impl
+ 59 |   let _ = Load.get(S { n: 1 }, "n = 1", L)
+    |                                         ^ `toml.parse` cannot decode `L`: its type argument must be a record type, an enum type, or a type with a `json.Decode` impl
   = note: `S.get` passes it to `toml.parse`
   = help: use `toml.parse_list` for a list
 
diff --git a/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.silt b/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.silt
index 901c5d882..168c03781 100644
--- a/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.silt
@@ -14,7 +14,7 @@ trait Loader {
   fn text(self) -> String
   fn load(self, type a) -> Result(a, json.JsonError) where a: json.Decode
   fn load_by_closure(self, type a) -> Result(a, json.JsonError) where a: json.Decode {
-    let g = { t -> self.load(t) }
+    let g = { t -> Loader.load(self, t) }
     g(a)
   }
 }
@@ -29,7 +29,7 @@ trait Loader for Src {
 }
 
 fn go(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode {
-  let g = { t -> l.load(t) }
+  let g = { t -> Loader.load(l, t) }
   g(b)
 }
 
@@ -37,5 +37,5 @@ fn main() {
   let src = Src { s: "\{\"n\": 1}" }
   let _ = go(src, Fine)
   let _ = go(src, Blob)
-  let _ = src.load_by_closure(Blob)
+  let _ = Loader.load_by_closure(src, Blob)
 }
diff --git a/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.stderr b/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.stderr
index fed686db7..3f9cf90e0 100644
--- a/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.stderr
+++ b/tests/golden/lang/stdlib/data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.stderr
@@ -7,9 +7,9 @@ error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, w
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.silt:40:31
+ --> data_decode__a_closure_passes_its_type_to_a_trait_method_on_a_type_variable.silt:40:39
     |
- 40 |   let _ = src.load_by_closure(Blob)
-    |                               ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 40 |   let _ = Loader.load_by_closure(src, Blob)
+    |                                       ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.load_by_closure` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
diff --git a/tests/golden/lang/stdlib/data_decode__a_field_with_no_decoder_is_refused_when_its_key_is_absent.silt b/tests/golden/lang/stdlib/data_decode__a_field_with_no_decoder_is_refused_when_its_key_is_absent.silt
index d5c18787f..4e4704ac1 100644
--- a/tests/golden/lang/stdlib/data_decode__a_field_with_no_decoder_is_refused_when_its_key_is_absent.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_field_with_no_decoder_is_refused_when_its_key_is_absent.silt
@@ -22,7 +22,7 @@ fn from_toml(text: String, type a) -> Result(a, toml.TomlError) {
 fn show(r: Result(a, e)) where e: Error {
   match r {
     Ok(_) -> println("ok")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
diff --git a/tests/golden/lang/stdlib/data_decode__a_json_value_field_has_no_toml_decoder_whatever_the_document_holds.silt b/tests/golden/lang/stdlib/data_decode__a_json_value_field_has_no_toml_decoder_whatever_the_document_holds.silt
index 68223bf3b..27eaa2089 100644
--- a/tests/golden/lang/stdlib/data_decode__a_json_value_field_has_no_toml_decoder_whatever_the_document_holds.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_json_value_field_has_no_toml_decoder_whatever_the_document_holds.silt
@@ -26,7 +26,7 @@ fn from_toml(text: String, type a) -> Result(a, toml.TomlError) {
 fn show(r: Result(a, e)) where e: Error {
   match r {
     Ok(_) -> println("ok")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
diff --git a/tests/golden/lang/stdlib/data_decode__a_record_type_a_field_names_is_looked_into_for_a_field_with_no_decoder.silt b/tests/golden/lang/stdlib/data_decode__a_record_type_a_field_names_is_looked_into_for_a_field_with_no_decoder.silt
index a57e6d39b..26cbe59e2 100644
--- a/tests/golden/lang/stdlib/data_decode__a_record_type_a_field_names_is_looked_into_for_a_field_with_no_decoder.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_record_type_a_field_names_is_looked_into_for_a_field_with_no_decoder.silt
@@ -24,7 +24,7 @@ fn from_toml(text: String, type a) -> Result(a, toml.TomlError) {
 fn show(r: Result(a, e)) where e: Error {
   match r {
     Ok(_) -> println("ok")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/case.stderr b/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/case.stderr
index 20a4ff232..62b2d48f0 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/case.stderr
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/case.stderr
@@ -1,23 +1,23 @@
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> main.silt:14:18
+ --> main.silt:14:26
     |
- 14 |   println(s.load(Blob))
-    |                  ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 14 |   println(Loader.load(s, Blob))
+    |                          ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.load` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> main.silt:15:17
+ --> main.silt:15:25
     |
- 15 |   println(s.own(Blob))
-    |                 ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 15 |   println(Loader.own(s, Blob))
+    |                         ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.own` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> main.silt:16:26
+ --> main.silt:16:25
     |
- 16 |   println(src.Src.own(s, Blob))
-    |                          ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 16 |   println(Loader.own(s, Blob))
+    |                         ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.own` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/loader.silt b/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/loader.silt
index fa02cf499..a72dd052b 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/loader.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/loader.silt
@@ -3,7 +3,7 @@ import json
 pub trait Loader {
   fn text(self) -> String
   fn load(self, type a) -> Result(a, json.JsonError) where a: json.Decode {
-    json.parse(self.text(), a)
+    json.parse(Loader.text(self), a)
   }
   fn own(self, type a) -> Result(a, json.JsonError) where a: json.Decode
 }
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/main.silt b/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/main.silt
index 1a1cc3757..81fdc82bf 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/main.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_of_another_module_passes_its_type_on/main.silt
@@ -11,7 +11,7 @@ type Blob { data: Bytes }
 
 fn main() {
   let s = src.Src { s: "\{}" }
-  println(s.load(Blob))
-  println(s.own(Blob))
-  println(src.Src.own(s, Blob))
+  println(Loader.load(s, Blob))
+  println(Loader.own(s, Blob))
+  println(Loader.own(s, Blob))
 }
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/generic.silt b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/generic.silt
index 7a3fa851d..3f120057a 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/generic.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/generic.silt
@@ -2,5 +2,5 @@ import json
 import source.{ Loader }
 
 pub fn fetch(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode {
-  l.load_again(b)
+  Loader.load_again(l, b)
 }
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/source.silt b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/source.silt
index 867c9a04c..a73d3c2b1 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/source.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_of_another_module/source.silt
@@ -3,7 +3,7 @@ import json
 pub trait Loader {
   fn load(self, type a) -> Result(a, json.JsonError) where a: json.Decode
   fn load_again(self, type a) -> Result(a, json.JsonError) where a: json.Decode {
-    self.load(a)
+    Loader.load(self, a)
   }
 }
 
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt
index 217785ce1..34c5d222a 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt
@@ -16,10 +16,10 @@ trait Loader {
   fn text(self) -> String
   fn load(self, type a) -> Result(a, json.JsonError) where a: json.Decode
   fn load_via_load(self, type a) -> Result(a, json.JsonError) where a: json.Decode {
-    self.load(a)
+    Loader.load(self, a)
   }
   fn load_twice(self, type a) -> Result(a, json.JsonError) where a: json.Decode {
-    self.load_via_load(a)
+    Loader.load_via_load(self, a)
   }
 }
 
@@ -34,15 +34,15 @@ trait Loader for Src {
 
 trait Loader for Box(t) where t: Loader {
   fn text(self) -> String {
-    self.inner.text()
+    Loader.text(self.inner)
   }
   fn load(self, type a) -> Result(a, json.JsonError) {
-    self.inner.load(a)
+    Loader.load(self.inner, a)
   }
 }
 
 fn go(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode {
-  l.load(b)
+  Loader.load(l, b)
 }
 
 fn go2(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode {
@@ -50,7 +50,7 @@ fn go2(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decod
 }
 
 fn go3(l, b) {
-  l.load(b)
+  Loader.load(l, b)
 }
 
 fn generic_all_the_way(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode {
@@ -63,8 +63,8 @@ fn main() {
   let _ = go(src, Blob)
   let _ = go2(src, Blob)
   let _ = go3(src, Blob)
-  let _ = src.load_via_load(Blob)
-  let _ = src.load_twice(Blob)
-  let _ = Box { inner: src }.load(Blob)
+  let _ = Loader.load_via_load(src, Blob)
+  let _ = Loader.load_twice(src, Blob)
+  let _ = Loader.load(Box { inner: src }, Blob)
   let _ = go(Box { inner: Box { inner: src } }, Blob)
 }
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.stderr b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.stderr
index a9b260a52..ef9826097 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.stderr
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.stderr
@@ -23,26 +23,26 @@ error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, w
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt:66:29
+ --> data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt:66:37
     |
- 66 |   let _ = src.load_via_load(Blob)
-    |                             ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 66 |   let _ = Loader.load_via_load(src, Blob)
+    |                                     ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.load_via_load` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt:67:26
+ --> data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt:67:34
     |
- 67 |   let _ = src.load_twice(Blob)
-    |                          ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 67 |   let _ = Loader.load_twice(src, Blob)
+    |                                  ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.load_twice` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt:68:35
+ --> data_decode__a_trait_method_on_a_type_variable_passes_its_type_on.silt:68:43
     |
- 68 |   let _ = Box { inner: src }.load(Blob)
-    |                                   ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 68 |   let _ = Loader.load(Box { inner: src }, Blob)
+    |                                           ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Box.load` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.silt b/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.silt
index e8c838c89..832702f08 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.silt
@@ -15,7 +15,7 @@ trait Loader {
   fn text(self) -> String
   fn load(self, type a) -> Result(a, json.JsonError) where a: json.Decode
   fn load_text(self, type a) -> Result(a, json.JsonError) where a: json.Decode {
-    json.parse(self.text(), a)
+    json.parse(Loader.text(self), a)
   }
 }
 
@@ -29,14 +29,14 @@ trait Loader for Src {
 }
 
 fn via(src: Src, type a) -> Result(a, json.JsonError) where a: json.Decode {
-  src.load(a)
+  Loader.load(src, a)
 }
 
 fn main() {
   let src = Src { s: "\{\"n\": 1}" }
-  let _ = src.load(Fine)
-  let _ = src.load(Blob)
-  let _ = src.load_text(Blob)
-  let _ = Src.load(src, Blob)
+  let _ = Loader.load(src, Fine)
+  let _ = Loader.load(src, Blob)
+  let _ = Loader.load_text(src, Blob)
+  let _ = Loader.load(src, Blob)
   let _ = via(src, Blob)
 }
diff --git a/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.stderr b/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.stderr
index 18909781f..727f2bc95 100644
--- a/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.stderr
+++ b/tests/golden/lang/stdlib/data_decode__a_trait_method_passes_its_type_on.stderr
@@ -1,24 +1,24 @@
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__a_trait_method_passes_its_type_on.silt:38:20
+ --> data_decode__a_trait_method_passes_its_type_on.silt:38:28
     |
- 38 |   let _ = src.load(Blob)
-    |                    ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 38 |   let _ = Loader.load(src, Blob)
+    |                            ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.load` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__a_trait_method_passes_its_type_on.silt:39:25
+ --> data_decode__a_trait_method_passes_its_type_on.silt:39:33
     |
- 39 |   let _ = src.load_text(Blob)
-    |                         ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 39 |   let _ = Loader.load_text(src, Blob)
+    |                                 ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.load_text` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__a_trait_method_passes_its_type_on.silt:40:25
+ --> data_decode__a_trait_method_passes_its_type_on.silt:40:28
     |
- 40 |   let _ = Src.load(src, Blob)
-    |                         ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 40 |   let _ = Loader.load(src, Blob)
+    |                            ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `Src.load` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
diff --git a/tests/golden/lang/stdlib/data_decode__a_type_given_through_reordered_trait_method_type_arguments_is_named_as_through_a_function/lib.silt b/tests/golden/lang/stdlib/data_decode__a_type_given_through_reordered_trait_method_type_arguments_is_named_as_through_a_function/lib.silt
index f07417afe..2820b1459 100644
--- a/tests/golden/lang/stdlib/data_decode__a_type_given_through_reordered_trait_method_type_arguments_is_named_as_through_a_function/lib.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_type_given_through_reordered_trait_method_type_arguments_is_named_as_through_a_function/lib.silt
@@ -21,7 +21,7 @@ pub fn rev(x: s, type a, type b, type c)
     a: json.Decode,
     b: json.Decode,
     c: json.Decode {
-  x.get(c, b, a)
+  Three.get(x, c, b, a)
 }
 
 pub fn swap(x: s, type a, type b, type c)
@@ -34,8 +34,8 @@ pub fn swap(x: s, type a, type b, type c)
 }
 
 pub fn twice(x: s, type a, type b) where s: Three, a: json.Decode, b: json.Decode {
-  x.get(b, a, a)
-  x.get(a, a, b)
+  Three.get(x, b, a, a)
+  Three.get(x, a, a, b)
 }
 
 pub fn direct(type a, type b, type c) where a: json.Decode, b: json.Decode, c: json.Decode {
diff --git a/tests/golden/lang/stdlib/data_decode__a_type_with_no_decoder_is_refused_before_the_document_is_read.silt b/tests/golden/lang/stdlib/data_decode__a_type_with_no_decoder_is_refused_before_the_document_is_read.silt
index 2a24e47d5..17123c366 100644
--- a/tests/golden/lang/stdlib/data_decode__a_type_with_no_decoder_is_refused_before_the_document_is_read.silt
+++ b/tests/golden/lang/stdlib/data_decode__a_type_with_no_decoder_is_refused_before_the_document_is_read.silt
@@ -25,7 +25,7 @@ fn from_toml(text: String, type a) -> Result(a, toml.TomlError) {
 fn show(r: Result(a, e)) where e: Error {
   match r {
     Ok(_) -> println("ok")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
diff --git a/tests/golden/lang/stdlib/data_decode__aliases_given_through_a_trait_method_with_two_type_arguments_are_named_at_their_places/lib.silt b/tests/golden/lang/stdlib/data_decode__aliases_given_through_a_trait_method_with_two_type_arguments_are_named_at_their_places/lib.silt
index 5cbca1983..fee0a27e2 100644
--- a/tests/golden/lang/stdlib/data_decode__aliases_given_through_a_trait_method_with_two_type_arguments_are_named_at_their_places/lib.silt
+++ b/tests/golden/lang/stdlib/data_decode__aliases_given_through_a_trait_method_with_two_type_arguments_are_named_at_their_places/lib.silt
@@ -17,7 +17,7 @@ trait Two for T {
 }
 
 pub fn via(x: s, type a, type b) where s: Two, a: json.Decode, b: json.Decode {
-  x.get(a, b)
+  Two.get(x, a, b)
 }
 
 pub fn direct(type a, type b) where a: json.Decode, b: json.Decode {
@@ -26,11 +26,11 @@ pub fn direct(type a, type b) where a: json.Decode, b: json.Decode {
 }
 
 pub fn fixed(x: s, type b) where s: Two, b: json.Decode {
-  x.get(Int, b)
+  Two.get(x, Int, b)
 }
 
 pub fn pair(x: s, p: (a, b), type a, type b) where s: Two, a: json.Decode, b: json.Decode {
-  x.get(a, b)
+  Two.get(x, a, b)
 }
 
 pub fn dpair(p: (a, b), type a, type b) where a: json.Decode, b: json.Decode {
@@ -38,7 +38,7 @@ pub fn dpair(p: (a, b), type a, type b) where a: json.Decode, b: json.Decode {
 }
 
 pub fn first(p: (b, a), x: s, type a, type b) where s: Two, a: json.Decode, b: json.Decode {
-  x.get(a, b)
+  Two.get(x, a, b)
 }
 
 pub fn dfirst(p: (b, a), type a, type b) where a: json.Decode, b: json.Decode {
@@ -46,8 +46,8 @@ pub fn dfirst(p: (b, a), type a, type b) where a: json.Decode, b: json.Decode {
 }
 
 pub fn twice(x: s, type a, type b) where s: Two, a: json.Decode, b: json.Decode {
-  x.get(b, b)
-  x.get(a, a)
+  Two.get(x, b, b)
+  Two.get(x, a, a)
 }
 
 pub fn dtwice(type a, type b) where a: json.Decode, b: json.Decode {
@@ -56,7 +56,7 @@ pub fn dtwice(type a, type b) where a: json.Decode, b: json.Decode {
 }
 
 pub fn own(x: s, type a) where s: Two, a: json.Decode {
-  x.get(Int, Int)
+  Two.get(x, Int, Int)
 }
 
 pub fn down(type a) where a: json.Decode {
diff --git a/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/case.stderr b/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/case.stderr
index 6bc95c740..9de4609b4 100644
--- a/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/case.stderr
+++ b/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/case.stderr
@@ -15,10 +15,10 @@ error[type]: `toml.parse` cannot decode `L`: its type argument must be a record
   = help: use `toml.parse_list` for a list
 
 error[type]: `toml.parse` cannot decode `L`: its type argument must be a record type, an enum type, or a type with a `json.Decode` impl
- --> main.silt:30:31
+ --> main.silt:30:41
     |
- 30 |   lib.T { n: 1 }.get("n = 1", L)
-    |                               ^ `toml.parse` cannot decode `L`: its type argument must be a record type, an enum type, or a type with a `json.Decode` impl
+ 30 |   lib.Load.get(lib.T { n: 1 }, "n = 1", L)
+    |                                         ^ `toml.parse` cannot decode `L`: its type argument must be a record type, an enum type, or a type with a `json.Decode` impl
   = note: `T.get` passes it to `toml.parse`
   = help: use `toml.parse_list` for a list
 
diff --git a/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/lib.silt b/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/lib.silt
index 9bb9b8194..bf602d06f 100644
--- a/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/lib.silt
+++ b/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/lib.silt
@@ -16,7 +16,7 @@ trait Load for T {
 }
 
 pub fn via(x: s, type a) where s: Load, a: json.Decode {
-  x.get("n = 1", a)
+  Load.get(x, "n = 1", a)
 }
 
 pub fn deep(x: s, type a) where s: Load, a: json.Decode {
diff --git a/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/main.silt b/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/main.silt
index a08205f40..174567106 100644
--- a/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/main.silt
+++ b/tests/golden/lang/stdlib/data_decode__an_alias_given_through_a_trait_method_of_another_module_is_named_as_written/main.silt
@@ -27,7 +27,7 @@ type RA = Raw
 fn main() {
   lib.via(lib.T { n: 1 }, L)
   lib.direct("n = 1", L)
-  lib.T { n: 1 }.get("n = 1", L)
+  lib.Load.get(lib.T { n: 1 }, "n = 1", L)
   lib.deep(lib.T { n: 1 }, L)
   lib.via(lib.T { n: 1 }, LL)
   lib.via(lib.T { n: 1 }, NL)
diff --git a/tests/golden/lang/stdlib/data_decode__an_empty_document_does_not_hide_a_field_with_no_decoder.silt b/tests/golden/lang/stdlib/data_decode__an_empty_document_does_not_hide_a_field_with_no_decoder.silt
index 270f00aec..03ff1fcdc 100644
--- a/tests/golden/lang/stdlib/data_decode__an_empty_document_does_not_hide_a_field_with_no_decoder.silt
+++ b/tests/golden/lang/stdlib/data_decode__an_empty_document_does_not_hide_a_field_with_no_decoder.silt
@@ -25,7 +25,7 @@ fn toml_list(text: String, type a) -> Result(List(a), toml.TomlError) {
 fn show(r: Result(a, e)) where e: Error {
   match r {
     Ok(_) -> println("ok")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
 
diff --git a/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.silt b/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.silt
index ac30aa530..9b6bb64ec 100644
--- a/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.silt
+++ b/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.silt
@@ -33,29 +33,29 @@ trait Loader for Other {
 
 trait Loader for Box(t) where t: Loader {
   fn load(self, type a) -> Result(a, json.JsonError) {
-    self.v.load(a)
+    Loader.load(self.v, a)
   }
 }
 
 fn both(x, y, t) {
-  let _ = Box { v: x }.load(t)
-  Box { v: y }.load(t)
+  let _ = Loader.load(Box { v: x }, t)
+  Loader.load(Box { v: y }, t)
 }
 
 fn go(l, t) {
-  l.load(t)
+  Loader.load(l, t)
 }
 
 fn go_annotated(l: l, type b) -> Result(b, json.JsonError) where l: Loader, b: json.Decode {
-  l.load(b)
+  Loader.load(l, b)
 }
 
 fn returned(l) {
-  { t -> l.load(t) }
+  { t -> Loader.load(l, t) }
 }
 
 fn kept(l) {
-  H { f: { t -> l.load(t) } }
+  H { f: { t -> Loader.load(l, t) } }
 }
 
 fn apply1(f, t) {
@@ -76,5 +76,5 @@ fn main() {
   let _ = g(Blob)
   let h = kept(src)
   let _ = h.f(Blob)
-  let _ = apply1({ t -> src.load(t) }, Blob)
+  let _ = apply1({ t -> Loader.load(src, t) }, Blob)
 }
diff --git a/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.stderr b/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.stderr
index 710cd127d..0720c1b92 100644
--- a/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.stderr
+++ b/tests/golden/lang/stdlib/data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.stderr
@@ -45,9 +45,9 @@ error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, w
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
 
 error[type]: `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
- --> data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.silt:79:40
+ --> data_decode__closures_and_receivers_of_one_shape_pass_their_type_on.silt:79:48
     |
- 79 |   let _ = apply1({ t -> src.load(t) }, Blob)
-    |                                        ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
+ 79 |   let _ = apply1({ t -> Loader.load(src, t) }, Blob)
+    |                                                ^^^^ `json.parse` cannot decode `Blob`: field `data` has type `Bytes`, which has no decoder
   = note: `apply1` passes it to `json.parse`
   = help: decodable field types are Int, Float, String, Bool, time.Date, time.Time, time.DateTime, json.Value, List(T), Option(T), Map(String, T), tuples, non-generic record and enum types, types with a `json.Decode` impl, and aliases of these
diff --git a/tests/golden/lang/stdlib/data_write__record_fields_in_declaration_order.silt b/tests/golden/lang/stdlib/data_write__record_fields_in_declaration_order.silt
index 5a98388af..66767dacc 100644
--- a/tests/golden/lang/stdlib/data_write__record_fields_in_declaration_order.silt
+++ b/tests/golden/lang/stdlib/data_write__record_fields_in_declaration_order.silt
@@ -32,11 +32,11 @@ fn main() {
   println(json.pretty(Point { y: 2, x: 1 }))
   match toml.stringify(shape) {
     Ok(text) -> print(text)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match toml.pretty(shape) {
     Ok(text) -> print(text)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   println(json.stringify(#{ 9: "nine", 10: "ten" }))
   println(json.stringify(json.Object(#{ "b": json.Int(1), "a": json.Int(2) })))
diff --git a/tests/golden/lang/stdlib/json_syntax__the_offset_counts_bytes_from_the_start_of_the_text.silt b/tests/golden/lang/stdlib/json_syntax__the_offset_counts_bytes_from_the_start_of_the_text.silt
index 86c5b5b54..fc8d42359 100644
--- a/tests/golden/lang/stdlib/json_syntax__the_offset_counts_bytes_from_the_start_of_the_text.silt
+++ b/tests/golden/lang/stdlib/json_syntax__the_offset_counts_bytes_from_the_start_of_the_text.silt
@@ -8,7 +8,7 @@ fn show(text: String) {
   match json.parse(text, json.Value) {
     Ok(_) -> println("ok")
     Err(json.Syntax(message, at)) -> println("byte {at}: {message}")
-    Err(e) -> println("other: {e.message()}")
+    Err(e) -> println("other: {Error.message(e)}")
   }
 }
 
diff --git a/tests/golden/lang/stdlib/toml_module__toml_parse_missing_required_field_error.silt b/tests/golden/lang/stdlib/toml_module__toml_parse_missing_required_field_error.silt
index 5ad613098..95fcb3a57 100644
--- a/tests/golden/lang/stdlib/toml_module__toml_parse_missing_required_field_error.silt
+++ b/tests/golden/lang/stdlib/toml_module__toml_parse_missing_required_field_error.silt
@@ -5,7 +5,7 @@ fn run_main() {
   match toml.parse(input, User) {
     Ok(_) -> "unexpected"
     Err(toml.MissingField(f)) -> f
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/lang/stdlib/toml_module__toml_parse_type_mismatch_names_field.silt b/tests/golden/lang/stdlib/toml_module__toml_parse_type_mismatch_names_field.silt
index e1ad59cc4..eeeb057bf 100644
--- a/tests/golden/lang/stdlib/toml_module__toml_parse_type_mismatch_names_field.silt
+++ b/tests/golden/lang/stdlib/toml_module__toml_parse_type_mismatch_names_field.silt
@@ -6,7 +6,7 @@ fn run_main() {
   match toml.parse(input, User) {
     Ok(_) -> "unexpected"
     Err(toml.TypeMismatch(expected, actual)) -> "{expected}/{actual}"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/lang/tasks/call_method_yield__trait_method_in_spawned_task/main.silt b/tests/golden/lang/tasks/call_method_yield__trait_method_in_spawned_task/main.silt
index b027a6b6c..ed5d7a6ad 100644
--- a/tests/golden/lang/tasks/call_method_yield__trait_method_in_spawned_task/main.silt
+++ b/tests/golden/lang/tasks/call_method_yield__trait_method_in_spawned_task/main.silt
@@ -19,7 +19,7 @@ trait Greet for Greeter {
 fn main() {
   let g = Greeter { path: "greeting.txt" }
   let handle = task.spawn({ ->
-    let msg = g.greet()
+    let msg = Greet.greet(g)
     msg
   })
   println(task.join(handle))
diff --git a/tests/golden/lang/tasks/indirect_builtin_call__direct_read_file_in_spawned_task.silt b/tests/golden/lang/tasks/indirect_builtin_call__direct_read_file_in_spawned_task.silt
index 142fba5a7..15530e710 100644
--- a/tests/golden/lang/tasks/indirect_builtin_call__direct_read_file_in_spawned_task.silt
+++ b/tests/golden/lang/tasks/indirect_builtin_call__direct_read_file_in_spawned_task.silt
@@ -8,6 +8,6 @@ fn main() {
   let h = task.spawn({ -> io.read_file("indirect_builtin_call__direct_read_file_in_spawned_task.silt") })
   match task.join(h) {
     Ok(s) -> println(string.contains(s, "-- direct call"))
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/tasks/indirect_builtin_call__indirect_read_file_in_spawned_task.silt b/tests/golden/lang/tasks/indirect_builtin_call__indirect_read_file_in_spawned_task.silt
index 1a08670b4..cf6846e4f 100644
--- a/tests/golden/lang/tasks/indirect_builtin_call__indirect_read_file_in_spawned_task.silt
+++ b/tests/golden/lang/tasks/indirect_builtin_call__indirect_read_file_in_spawned_task.silt
@@ -11,6 +11,6 @@ fn main() {
   let h = task.spawn({ -> read("indirect_builtin_call__indirect_read_file_in_spawned_task.silt") })
   match task.join(h) {
     Ok(s) -> println(string.contains(s, "-- hello from indirect"))
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/tasks/indirect_builtin_call__indirect_write_file_in_spawned_task.silt b/tests/golden/lang/tasks/indirect_builtin_call__indirect_write_file_in_spawned_task.silt
index 81107abd8..7045a322a 100644
--- a/tests/golden/lang/tasks/indirect_builtin_call__indirect_write_file_in_spawned_task.silt
+++ b/tests/golden/lang/tasks/indirect_builtin_call__indirect_write_file_in_spawned_task.silt
@@ -8,10 +8,10 @@ fn main() {
   let h = task.spawn({ -> write("indirect_write.txt", "written indirectly") })
   match task.join(h) {
     Ok(_) -> println("ok")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   match io.read_file("indirect_write.txt") {
     Ok(s) -> println(s)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/tasks/round77_callmethod_resume__qualified_global_method_runs_once.silt b/tests/golden/lang/tasks/round77_callmethod_resume__qualified_global_method_runs_once.silt
index 8b9ab2b94..fb06a3b4e 100644
--- a/tests/golden/lang/tasks/round77_callmethod_resume__qualified_global_method_runs_once.silt
+++ b/tests/golden/lang/tasks/round77_callmethod_resume__qualified_global_method_runs_once.silt
@@ -17,7 +17,7 @@ trait Counter for Int {
 fn main() {
   let h = task.spawn({ ->
     let n = 7
-    n.bump()
+    Counter.bump(n)
   })
   println(task.join(h))
 }
diff --git a/tests/golden/lang/tasks/round78_io_yield_helper__write_file_in_task_persists.silt b/tests/golden/lang/tasks/round78_io_yield_helper__write_file_in_task_persists.silt
index edc3dd2bd..33c9eff97 100644
--- a/tests/golden/lang/tasks/round78_io_yield_helper__write_file_in_task_persists.silt
+++ b/tests/golden/lang/tasks/round78_io_yield_helper__write_file_in_task_persists.silt
@@ -13,6 +13,6 @@ fn main() {
   task.join(h)
   match io.read_file("round78_write.txt") {
     Ok(s) -> println(s)
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/lang/tasks/wave1_vm__guard_v2_many_calls_in_sequence_are_not_depth.silt b/tests/golden/lang/tasks/wave1_vm__guard_v2_many_calls_in_sequence_are_not_depth.silt
index 082bef521..085e76817 100644
--- a/tests/golden/lang/tasks/wave1_vm__guard_v2_many_calls_in_sequence_are_not_depth.silt
+++ b/tests/golden/lang/tasks/wave1_vm__guard_v2_many_calls_in_sequence_are_not_depth.silt
@@ -6,13 +6,13 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
 
 fn wide() {
-  list.fold(1..5000, 0) { acc, x -> acc + 3.go() }
+  list.fold(1..5000, 0) { acc, x -> acc + Deep.go(3) }
 }
 fn main() {
   println("main {wide()}")
diff --git a/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_in_a_task.silt b/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_in_a_task.silt
index a12d39539..02be5c13f 100644
--- a/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_in_a_task.silt
+++ b/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_in_a_task.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
@@ -21,7 +21,7 @@ fn deep(n) {
 }
 
 fn main() {
-  let a = task.spawn { -> 6.go() }
+  let a = task.spawn { -> Deep.go(6) }
   let b = task.spawn { -> deep(6) }
   println("method {task.join(a)}")
   println("fold {task.join(b)}")
diff --git a/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_on_the_main_thread.silt b/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_on_the_main_thread.silt
index a62763377..e49091e28 100644
--- a/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_on_the_main_thread.silt
+++ b/tests/golden/lang/tasks/wave1_vm__guard_v2_moderate_recursion_on_the_main_thread.silt
@@ -5,7 +5,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
@@ -19,6 +19,6 @@ fn deep(n) {
 }
 
 fn main() {
-  println("method {500.go()}")
+  println("method {Deep.go(500)}")
   println("fold {deep(500)}")
 }
diff --git a/tests/golden/lang/tasks/wave1_vm__v2_a_test_run_continues_after_the_overflow.silt b/tests/golden/lang/tasks/wave1_vm__v2_a_test_run_continues_after_the_overflow.silt
index d398bbf73..117d4b6af 100644
--- a/tests/golden/lang/tasks/wave1_vm__v2_a_test_run_continues_after_the_overflow.silt
+++ b/tests/golden/lang/tasks/wave1_vm__v2_a_test_run_continues_after_the_overflow.silt
@@ -12,14 +12,14 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
 
 fn test_a_recursion_far_beyond_the_budget() {
-  test.assert_eq(200000.go(), 200000)
+  test.assert_eq(Deep.go(200000), 200000)
 }
 fn test_b_moderate_recursion_afterwards() {
-  test.assert_eq(500.go(), 500)
+  test.assert_eq(Deep.go(500), 500)
 }
diff --git a/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_in_a_task_ends_in_a_runtime_error.silt b/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_in_a_task_ends_in_a_runtime_error.silt
index 42df69c5e..23ebedff4 100644
--- a/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_in_a_task_ends_in_a_runtime_error.silt
+++ b/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_in_a_task_ends_in_a_runtime_error.silt
@@ -9,12 +9,12 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
 
 fn main() {
-  let t = task.spawn { -> 200000.go() }
+  let t = task.spawn { -> Deep.go(200000) }
   println(task.join(t))
 }
diff --git a/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_on_the_main_thread_ends_in_a_runtime_error.silt b/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_on_the_main_thread_ends_in_a_runtime_error.silt
index d6eb43a12..32ddb167f 100644
--- a/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_on_the_main_thread_ends_in_a_runtime_error.silt
+++ b/tests/golden/lang/tasks/wave1_vm__v2_method_recursion_on_the_main_thread_ends_in_a_runtime_error.silt
@@ -7,11 +7,11 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
 
 fn main() {
-  println(200000.go())
+  println(Deep.go(200000))
 }
diff --git a/tests/golden/lang/tcp/conventions__a_tcp_failure_is_named_after_what_failed.silt b/tests/golden/lang/tcp/conventions__a_tcp_failure_is_named_after_what_failed.silt
index 89e80379b..639d677a5 100644
--- a/tests/golden/lang/tcp/conventions__a_tcp_failure_is_named_after_what_failed.silt
+++ b/tests/golden/lang/tcp/conventions__a_tcp_failure_is_named_after_what_failed.silt
@@ -24,7 +24,7 @@ fn main() {
     Ok(_) -> println("nobody listens, and yet connected")
   }
   match tcp.listen("127.0.0.1:{port}") {
-    Err(e) -> println(e.message() != "")
+    Err(e) -> println(Error.message(e) != "")
     Ok(_) -> println("bound")
   }
 }
diff --git a/tests/golden/lang/tcp_tls/tls_server__a_pem_that_does_not_parse_says_why.silt b/tests/golden/lang/tcp_tls/tls_server__a_pem_that_does_not_parse_says_why.silt
index 78d206c90..22a110667 100644
--- a/tests/golden/lang/tcp_tls/tls_server__a_pem_that_does_not_parse_says_why.silt
+++ b/tests/golden/lang/tcp_tls/tls_server__a_pem_that_does_not_parse_says_why.silt
@@ -10,7 +10,7 @@ fn attempt(listener, addr, cert_text) {
   let cert = bytes.from_string(cert_text)
   match tcp.tls_server(conn, cert, bytes.from_string("not a key")) {
     Ok(_) -> println("a TLS connection")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
   tcp.close(client)
 }
diff --git a/tests/golden/lang/tcp_tls/tls_server__takes_the_connection.silt b/tests/golden/lang/tcp_tls/tls_server__takes_the_connection.silt
index 544966dda..3b92cc0e2 100644
--- a/tests/golden/lang/tcp_tls/tls_server__takes_the_connection.silt
+++ b/tests/golden/lang/tcp_tls/tls_server__takes_the_connection.silt
@@ -16,23 +16,23 @@ fn main() {
   let key = bytes.from_string("not a key")
   match tcp.tls_server(conn, cert, key) {
     Ok(_) -> println("a TLS connection")
-    Err(e) -> println("tls_server: {e.message()}")
+    Err(e) -> println("tls_server: {Error.message(e)}")
   }
   match tcp.read(conn, 1) {
     Ok(_) -> println("the taken connection reads")
-    Err(e) -> println("read of the taken connection: {e.message()}")
+    Err(e) -> println("read of the taken connection: {Error.message(e)}")
   }
   match tcp.write(conn, bytes.from_string("x")) {
     Ok(_) -> println("the taken connection writes")
-    Err(e) -> println("write of the taken connection: {e.message()}")
+    Err(e) -> println("write of the taken connection: {Error.message(e)}")
   }
   match tcp.tls_server(conn, cert, key) {
     Ok(_) -> println("a TLS connection")
-    Err(e) -> println("tls_server again: {e.message()}")
+    Err(e) -> println("tls_server again: {Error.message(e)}")
   }
   match tcp.read(client, 1) {
     Ok(data) -> println("the client reads {bytes.length(data)} bytes")
-    Err(e) -> println("the client's read fails: {e.message()}")
+    Err(e) -> println("the client's read fails: {Error.message(e)}")
   }
   -- A connection closed before the call.
   when let Ok(other) = tcp.connect(addr) else { panic("cannot connect") }
@@ -40,7 +40,7 @@ fn main() {
   tcp.close(closed)
   match tcp.tls_server(closed, cert, key) {
     Ok(_) -> println("a TLS connection")
-    Err(e) -> println("tls_server of a closed connection: {e.message()}")
+    Err(e) -> println("tls_server of a closed connection: {Error.message(e)}")
   }
   tcp.close(other)
 }
diff --git a/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_time_only_specifier.silt b/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_time_only_specifier.silt
index 7f608cf1f..f3bdbcec0 100644
--- a/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_time_only_specifier.silt
+++ b/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_time_only_specifier.silt
@@ -7,7 +7,7 @@ fn day() -> time.Date {
 }
 fn main() {
   match time.format_date(day(), "%H") {
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
     Ok(text) -> println("formatted: {text}")
   }
 }
diff --git a/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_timezone_specifier.silt b/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_timezone_specifier.silt
index 9ab2422cb..314031dcb 100644
--- a/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_timezone_specifier.silt
+++ b/tests/golden/lang/time/time_builtin_bounds__format_date_rejects_timezone_specifier.silt
@@ -7,7 +7,7 @@ fn day() -> time.Date {
 }
 fn main() {
   match time.format_date(day(), "%z") {
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
     Ok(text) -> println("formatted: {text}")
   }
 }
diff --git a/tests/golden/lang/time/time_builtin_bounds__format_rejects_timezone_specifier_naive_datetime.silt b/tests/golden/lang/time/time_builtin_bounds__format_rejects_timezone_specifier_naive_datetime.silt
index 16c5184c3..19f51bedd 100644
--- a/tests/golden/lang/time/time_builtin_bounds__format_rejects_timezone_specifier_naive_datetime.silt
+++ b/tests/golden/lang/time/time_builtin_bounds__format_rejects_timezone_specifier_naive_datetime.silt
@@ -8,7 +8,7 @@ fn day() -> time.Date {
 fn main() {
   let t = time.Time { hour: 10, minute: 30, second: 0, ns: 0 }
   match time.format(time.datetime(day(), t), "%z") {
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
     Ok(text) -> println("formatted: {text}")
   }
 }
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__date_compare.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__date_compare.silt
index a2f909d69..26161d808 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__date_compare.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__date_compare.silt
@@ -1,5 +1,5 @@
 import time
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     match time.date(2025, 1, 15) {
         Ok(early) -> match time.date(2025, 6, 30) {
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__date_direct_compare.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__date_direct_compare.silt
index f887dbbcc..544796324 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__date_direct_compare.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__date_direct_compare.silt
@@ -3,9 +3,9 @@ fn main() {
     match time.date(2025, 1, 15) {
         Ok(a) -> match time.date(2025, 1, 20) {
             Ok(b) -> {
-                println(a.compare(b))
-                println(b.compare(a))
-                println(a.compare(a))
+                println(Compare.compare(a, b))
+                println(Compare.compare(b, a))
+                println(Compare.compare(a, a))
             }
             Err(_) -> ()
         }
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__date_display.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__date_display.silt
index 4c34676b5..56fbb4e5e 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__date_display.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__date_display.silt
@@ -1,5 +1,5 @@
 import time
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     match time.date(2025, 1, 15) {
         Ok(date) -> println(d(date))
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__datetime_equal.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__datetime_equal.silt
index 741ff9eb8..7971c33df 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__datetime_equal.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__datetime_equal.silt
@@ -1,5 +1,5 @@
 import time
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
 fn main() {
     match time.date(2025, 1, 15) {
         Ok(d1) -> match time.time(8, 30, 0) {
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__http_method_compare.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__http_method_compare.silt
index 589a3a389..e250acd1f 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__http_method_compare.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__http_method_compare.silt
@@ -1,3 +1,3 @@
 import http
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() { println(cmp_gen(http.GET, http.POST)) }
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__option_display.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__option_display.silt
index c2eeae242..bc1628c1d 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__option_display.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__option_display.silt
@@ -1,4 +1,4 @@
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(d(Some(42)))
     let n: Option(Int) = None
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__parse_error_equal.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__parse_error_equal.silt
index 1847534f6..ac0c77ad4 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__parse_error_equal.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__parse_error_equal.silt
@@ -1,5 +1,5 @@
 import int
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
 fn main() {
     println(eq_gen(int.Empty, int.Empty))
     println(eq_gen(int.Empty, int.Overflow))
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__result_equal.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__result_equal.silt
index 3143103a3..9786b6d44 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__result_equal.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__result_equal.silt
@@ -1,4 +1,4 @@
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
 fn main() {
     println(eq_gen(Ok(1), Ok(1)))
     println(eq_gen(Ok(1), Ok(2)))
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__step_compare.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__step_compare.silt
index 6995c2e50..1be2c0391 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__step_compare.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__step_compare.silt
@@ -1,5 +1,5 @@
 import list
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(list.Stop(1), list.Continue(1)))
 }
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare.silt
index b49310fe3..11923923c 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare.silt
@@ -1,3 +1,3 @@
 import time
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() { println(cmp_gen(time.Monday, time.Friday)) }
diff --git a/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare_three_orderings.silt b/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare_three_orderings.silt
index af07c5f07..dc2caf72a 100644
--- a/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare_three_orderings.silt
+++ b/tests/golden/lang/traits/auto_derive_builtin_synth__weekday_compare_three_orderings.silt
@@ -1,5 +1,5 @@
 import time
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(time.Monday, time.Friday))
     println(cmp_gen(time.Friday, time.Monday))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_basic.silt b/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_basic.silt
index 684671f60..2e91b03ee 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_basic.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_basic.silt
@@ -1,5 +1,5 @@
 type Color { Red, Green, Blue, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Red, Green))
     println(cmp_gen(Green, Red))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_qualified_matches_bound.silt b/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_qualified_matches_bound.silt
index 63f87646c..93cdb64c4 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_qualified_matches_bound.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_qualified_matches_bound.silt
@@ -1,6 +1,6 @@
 type Color { Red, Green, Blue, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Red, Green))
-    println(Color.compare(Red, Green))
+    println(Compare.compare(Red, Green))
 }
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_with_args.silt b/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_with_args.silt
index a707d513e..75f4ac6db 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_with_args.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__compare_enum_with_args.silt
@@ -1,5 +1,5 @@
 type Tagged { Foo(Int), Bar(Int), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Foo(5), Foo(3)))
     println(cmp_gen(Foo(3), Foo(5)))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__compare_record.silt b/tests/golden/lang/traits/auto_derive_synth_body__compare_record.silt
index c090a0033..19b708157 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__compare_record.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__compare_record.silt
@@ -1,5 +1,5 @@
 type Point { x: Int, y: Int, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     let p = Point { x: 1, y: 2 }
     let q = Point { x: 1, y: 3 }
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__decl_order_not_alphabetical.silt b/tests/golden/lang/traits/auto_derive_synth_body__decl_order_not_alphabetical.silt
index 54fa840c7..a49454445 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__decl_order_not_alphabetical.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__decl_order_not_alphabetical.silt
@@ -1,5 +1,5 @@
 type Backwards { Z, Y, A, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Z, A))
     println(cmp_gen(Y, Z))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__display_enum_nullary.silt b/tests/golden/lang/traits/auto_derive_synth_body__display_enum_nullary.silt
index e3c84f590..0eccdd259 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__display_enum_nullary.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__display_enum_nullary.silt
@@ -1,5 +1,5 @@
 type Color { Red, Green, Blue, }
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(d(Red))
     println(d(Green))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__display_enum_with_args.silt b/tests/golden/lang/traits/auto_derive_synth_body__display_enum_with_args.silt
index 695ea95f7..1b2a95294 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__display_enum_with_args.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__display_enum_with_args.silt
@@ -1,5 +1,5 @@
 type Tagged { Foo(Int), Bar(Int, String), }
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(d(Foo(7)))
     println(d(Bar(42, "hi")))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__display_record.silt b/tests/golden/lang/traits/auto_derive_synth_body__display_record.silt
index 7766e59cf..c4ccc2381 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__display_record.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__display_record.silt
@@ -1,5 +1,5 @@
 type Point { x: Int, y: Int, }
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     let p = Point { x: 1, y: 2 }
     println(d(p))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__equal_enum.silt b/tests/golden/lang/traits/auto_derive_synth_body__equal_enum.silt
index 2a93a0c9f..62510fd92 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__equal_enum.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__equal_enum.silt
@@ -1,5 +1,5 @@
 type Color { Red, Green, Blue, }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
 fn main() {
     println(eq_gen(Red, Red))
     println(eq_gen(Red, Green))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__equal_enum_with_args.silt b/tests/golden/lang/traits/auto_derive_synth_body__equal_enum_with_args.silt
index 561ef9a21..bbea5cb46 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__equal_enum_with_args.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__equal_enum_with_args.silt
@@ -1,5 +1,5 @@
 type Pair { Both(Int, Int), Just(Int), }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
 fn main() {
     println(eq_gen(Both(1, 2), Both(1, 2)))
     println(eq_gen(Both(1, 2), Both(1, 3)))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__equal_record_field_chain.silt b/tests/golden/lang/traits/auto_derive_synth_body__equal_record_field_chain.silt
index b65c389ed..43d5d9248 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__equal_record_field_chain.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__equal_record_field_chain.silt
@@ -1,5 +1,5 @@
 type Point { x: Int, y: Int, }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
 fn main() {
     let p = Point { x: 1, y: 2 }
     let q = Point { x: 1, y: 2 }
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_deterministic.silt b/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_deterministic.silt
index 55a072ed4..7b5be5336 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_deterministic.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_deterministic.silt
@@ -1,6 +1,6 @@
 -- Equal values hash equal; different ordinals hash differently.
 type Color { Red, Green, Blue, }
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
     println(h(Red) == h(Red))
     println(h(Red) != h(Green))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_with_args_deterministic.silt b/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_with_args_deterministic.silt
index 5cbdc4b8c..8db1ff8ac 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_with_args_deterministic.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__hash_enum_with_args_deterministic.silt
@@ -1,5 +1,5 @@
 type Tagged { Foo(Int), Bar(Int), }
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
     println(h(Foo(5)) == h(Foo(5)))
     println(h(Foo(5)) != h(Foo(6)))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__hash_record_combines_fields.silt b/tests/golden/lang/traits/auto_derive_synth_body__hash_record_combines_fields.silt
index b51308b46..3702a3483 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__hash_record_combines_fields.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__hash_record_combines_fields.silt
@@ -1,6 +1,6 @@
 -- Equal records hash equal; permuted fields hash differently.
 type Point { x: Int, y: Int, }
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
     let p = Point { x: 1, y: 2 }
     let q = Point { x: 1, y: 2 }
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__manual_display_overrides.silt b/tests/golden/lang/traits/auto_derive_synth_body__manual_display_overrides.silt
index b04cfba7b..0fc0d384a 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__manual_display_overrides.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__manual_display_overrides.silt
@@ -2,7 +2,7 @@ type Color { Red, Green, Blue, }
 trait Display for Color {
     fn display(self: Color) -> String { "<color>" }
 }
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(d(Red))
     println(d(Blue))
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__qualified_global_present.silt b/tests/golden/lang/traits/auto_derive_synth_body__qualified_global_present.silt
index f148c8a14..dd2efec5a 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__qualified_global_present.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__qualified_global_present.silt
@@ -1,4 +1,4 @@
 type Color { Red, Green, Blue, }
 fn main() {
-    println(Color.compare(Red, Green))
+    println(Compare.compare(Red, Green))
 }
diff --git a/tests/golden/lang/traits/auto_derive_synth_body__recursive_enum_compare.silt b/tests/golden/lang/traits/auto_derive_synth_body__recursive_enum_compare.silt
index 1c0e50d91..ccd8a95cf 100644
--- a/tests/golden/lang/traits/auto_derive_synth_body__recursive_enum_compare.silt
+++ b/tests/golden/lang/traits/auto_derive_synth_body__recursive_enum_compare.silt
@@ -1,5 +1,5 @@
 type Tree { Leaf, Node(Tree, Tree), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Leaf, Node(Leaf, Leaf)))
     println(cmp_gen(Node(Leaf, Leaf), Node(Leaf, Leaf)))
diff --git a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__channel_direct.silt b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__channel_direct.silt
index 0b5c4fbb5..3f01f4743 100644
--- a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__channel_direct.silt
+++ b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__channel_direct.silt
@@ -3,5 +3,5 @@ trait Pretty { fn pretty(self) -> String }
 trait Pretty for Channel { fn pretty(self) -> String { "channel" } }
 fn main() {
   let ch: Channel(Int) = channel.new(1)
-  println(ch.pretty())
+  println(Pretty.pretty(ch))
 }
diff --git a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_direct_and_where_bound.silt b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_direct_and_where_bound.silt
index f4ebaf226..1e6ea21ed 100644
--- a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_direct_and_where_bound.silt
+++ b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_direct_and_where_bound.silt
@@ -1,7 +1,7 @@
 trait Pretty { fn pretty(self) -> String }
 trait Pretty for List { fn pretty(self) -> String { "list" } }
-fn show(x: a) -> String where a: Pretty { x.pretty() }
+fn show(x: a) -> String where a: Pretty { Pretty.pretty(x) }
 fn main() {
-  println([1, 2].pretty())
+  println(Pretty.pretty([1, 2]))
   println(show([1, 2]))
 }
diff --git a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_distinct_element_types.silt b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_distinct_element_types.silt
index c60640db2..5a0ab8236 100644
--- a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_distinct_element_types.silt
+++ b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_distinct_element_types.silt
@@ -1,6 +1,6 @@
 trait Pretty { fn pretty(self) -> String }
 trait Pretty for List { fn pretty(self) -> String { "list" } }
 fn main() {
-  println([1, 2].pretty())
-  println(["a", "b"].pretty())
+  println(Pretty.pretty([1, 2]))
+  println(Pretty.pretty(["a", "b"]))
 }
diff --git a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_impl_range_and_list_receivers.silt b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_impl_range_and_list_receivers.silt
index f08e31fcd..700591252 100644
--- a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_impl_range_and_list_receivers.silt
+++ b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__list_impl_range_and_list_receivers.silt
@@ -1,6 +1,6 @@
 trait Pretty { fn pretty(self) -> String }
 trait Pretty for List { fn pretty(self) -> String { "list" } }
 fn main() {
-  println((1..3).pretty())
-  println([1, 2].pretty())
+  println(Pretty.pretty(1..3))
+  println(Pretty.pretty([1, 2]))
 }
diff --git a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__map_direct_and_where_bound.silt b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__map_direct_and_where_bound.silt
index 417064583..401a7df47 100644
--- a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__map_direct_and_where_bound.silt
+++ b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__map_direct_and_where_bound.silt
@@ -1,8 +1,8 @@
 trait Pretty { fn pretty(self) -> String }
 trait Pretty for Map { fn pretty(self) -> String { "map" } }
-fn show(x: a) -> String where a: Pretty { x.pretty() }
+fn show(x: a) -> String where a: Pretty { Pretty.pretty(x) }
 fn main() {
   let m = #{"a": 1}
-  println(m.pretty())
+  println(Pretty.pretty(m))
   println(show(m))
 }
diff --git a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__set_direct_and_where_bound.silt b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__set_direct_and_where_bound.silt
index b0bc0adeb..a0493770a 100644
--- a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__set_direct_and_where_bound.silt
+++ b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__set_direct_and_where_bound.silt
@@ -1,9 +1,9 @@
 import set
 trait Pretty { fn pretty(self) -> String }
 trait Pretty for Set { fn pretty(self) -> String { "set" } }
-fn show(x: a) -> String where a: Pretty { x.pretty() }
+fn show(x: a) -> String where a: Pretty { Pretty.pretty(x) }
 fn main() {
   let s = set.from_list([1, 2])
-  println(s.pretty())
+  println(Pretty.pretty(s))
   println(show(s))
 }
diff --git a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__tuple_direct_and_where_bound.silt b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__tuple_direct_and_where_bound.silt
index 2e7c503f3..152e59630 100644
--- a/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__tuple_direct_and_where_bound.silt
+++ b/tests/golden/lang/traits/bare_builtin_container_impl_target_dispatch__tuple_direct_and_where_bound.silt
@@ -1,7 +1,7 @@
 trait Pretty { fn pretty(self) -> String }
 trait Pretty for Tuple { fn pretty(self) -> String { "tuple" } }
-fn show(x: a) -> String where a: Pretty { x.pretty() }
+fn show(x: a) -> String where a: Pretty { Pretty.pretty(x) }
 fn main() {
-  println((1, 2).pretty())
+  println(Pretty.pretty((1, 2)))
   println(show((1, "mixed", true)))
 }
diff --git a/tests/golden/lang/traits/call_method_yield__non_yielding_trait_method.silt b/tests/golden/lang/traits/call_method_yield__non_yielding_trait_method.silt
index 99005e288..91a0872bf 100644
--- a/tests/golden/lang/traits/call_method_yield__non_yielding_trait_method.silt
+++ b/tests/golden/lang/traits/call_method_yield__non_yielding_trait_method.silt
@@ -10,5 +10,5 @@ trait Describe for Counter {
 
 fn main() {
   let c = Counter { n: 42 }
-  println(c.describe())
+  println(Describe.describe(c))
 }
diff --git a/tests/golden/lang/traits/default_method__calls_other_trait_method_on_self.silt b/tests/golden/lang/traits/default_method__calls_other_trait_method_on_self.silt
index cb0f37120..ec2807c7c 100644
--- a/tests/golden/lang/traits/default_method__calls_other_trait_method_on_self.silt
+++ b/tests/golden/lang/traits/default_method__calls_other_trait_method_on_self.silt
@@ -1,6 +1,6 @@
 trait Describable {
   fn name(self) -> String
-  fn greet(self) -> String { "hi, {self.name()}" }
+  fn greet(self) -> String { "hi, {Describable.name(self)}" }
 }
 
 type Person { who: String }
@@ -11,5 +11,5 @@ trait Describable for Person {
 
 fn main() {
   let p = Person { who: "alice" }
-  println(p.greet())
+  println(Describable.greet(p))
 }
diff --git a/tests/golden/lang/traits/default_method__calls_supertrait_method.silt b/tests/golden/lang/traits/default_method__calls_supertrait_method.silt
index 86b68ecfb..30eabf874 100644
--- a/tests/golden/lang/traits/default_method__calls_supertrait_method.silt
+++ b/tests/golden/lang/traits/default_method__calls_supertrait_method.silt
@@ -3,7 +3,7 @@ trait Sup {
 }
 
 trait Sub: Sup {
-  fn sub_method(self) -> String { "sub-of-{self.sup_method()}" }
+  fn sub_method(self) -> String { "sub-of-{Sup.sup_method(self)}" }
 }
 
 type Thing { v: Int }
@@ -16,5 +16,5 @@ trait Sub for Thing {}
 
 fn main() {
   let t = Thing { v: 1 }
-  println(t.sub_method())
+  println(Sub.sub_method(t))
 }
diff --git a/tests/golden/lang/traits/default_method__impl_overrides_default.silt b/tests/golden/lang/traits/default_method__impl_overrides_default.silt
index 9624157d1..0edc75977 100644
--- a/tests/golden/lang/traits/default_method__impl_overrides_default.silt
+++ b/tests/golden/lang/traits/default_method__impl_overrides_default.silt
@@ -10,5 +10,5 @@ trait Greeter for Item {
 
 fn main() {
   let it = Item { v: 1 }
-  println(it.greet())
+  println(Greeter.greet(it))
 }
diff --git a/tests/golden/lang/traits/default_method__mix_default_and_abstract.silt b/tests/golden/lang/traits/default_method__mix_default_and_abstract.silt
index 679b5ccc6..21576d279 100644
--- a/tests/golden/lang/traits/default_method__mix_default_and_abstract.silt
+++ b/tests/golden/lang/traits/default_method__mix_default_and_abstract.silt
@@ -11,6 +11,6 @@ trait Display2 for Item {
 
 fn main() {
   let it = Item { v: 1 }
-  println(it.show())
-  println(it.debug())
+  println(Display2.show(it))
+  println(Display2.debug(it))
 }
diff --git a/tests/golden/lang/traits/default_method__parameterized_impl_target.silt b/tests/golden/lang/traits/default_method__parameterized_impl_target.silt
index b118e819d..ff55476bb 100644
--- a/tests/golden/lang/traits/default_method__parameterized_impl_target.silt
+++ b/tests/golden/lang/traits/default_method__parameterized_impl_target.silt
@@ -8,5 +8,5 @@ trait Wrapper for Box(a) {}
 
 fn main() {
   let b = Box { value: 42 }
-  println(b.describe())
+  println(Wrapper.describe(b))
 }
diff --git a/tests/golden/lang/traits/default_method__used_when_impl_omits.silt b/tests/golden/lang/traits/default_method__used_when_impl_omits.silt
index 696a41514..57b01f303 100644
--- a/tests/golden/lang/traits/default_method__used_when_impl_omits.silt
+++ b/tests/golden/lang/traits/default_method__used_when_impl_omits.silt
@@ -8,5 +8,5 @@ trait Greeter for Item {}
 
 fn main() {
   let it = Item { v: 1 }
-  println(it.greet())
+  println(Greeter.greet(it))
 }
diff --git a/tests/golden/lang/traits/deferred_record_receiver_method.silt b/tests/golden/lang/traits/deferred_record_receiver_method.silt
index ab041a39d..2a1a1abc3 100644
--- a/tests/golden/lang/traits/deferred_record_receiver_method.silt
+++ b/tests/golden/lang/traits/deferred_record_receiver_method.silt
@@ -7,6 +7,6 @@ trait Greet { fn greet(self) -> String }
 trait Greet for P { fn greet(self) -> String { "p{self.v}" } }
 trait Greet for Int { fn greet(self) -> String { "i" } }
 fn main() {
-  println(list.map([P { v: 1 }, P { v: 2 }]) { p -> p.greet() })
-  println(list.map([1]) { p -> p.greet() })
+  println(list.map([P { v: 1 }, P { v: 2 }]) { p -> Greet.greet(p) })
+  println(list.map([1]) { p -> Greet.greet(p) })
 }
diff --git a/tests/golden/lang/traits/derived_impls_call_the_builtin_traits.silt b/tests/golden/lang/traits/derived_impls_call_the_builtin_traits.silt
index 252fbc171..1b5d22bf3 100644
--- a/tests/golden/lang/traits/derived_impls_call_the_builtin_traits.silt
+++ b/tests/golden/lang/traits/derived_impls_call_the_builtin_traits.silt
@@ -4,6 +4,7 @@
 -- field's type.
 import list
 import map
+import string
 trait Describe { fn display(self) -> String }
 trait Describe for Int { fn display(self) -> String { "described {self}" } }
 trait Ranked { fn compare(self, other: Self) -> Int }
@@ -14,15 +15,15 @@ trait Hashy { fn hash(self) -> Int }
 trait Hashy for Int { fn hash(self) -> Int { 7 } }
 type Pt { x: Int }
 type Wrap { p: Pt }
-fn by_bound(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn by_bound(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
-  println(Pt { x: 1 }.display())
+  println(string.from(Pt { x: 1 }))
   println(Pt { x: 1 } < Pt { x: 2 })
   println(by_bound(Pt { x: 1 }, Pt { x: 2 }))
-  println(Wrap { p: Pt { x: 1 } }.compare(Wrap { p: Pt { x: 2 } }))
+  println(Compare.compare(Wrap { p: Pt { x: 1 } }, Wrap { p: Pt { x: 2 } }))
   println([Pt { x: 2 }, Pt { x: 1 }] |> list.sort)
   println(Pt { x: 1 } == Pt { x: 1 })
-  println(Pt { x: 1 }.equal(Pt { x: 1 }))
-  println(Pt { x: 1 }.hash() == Pt { x: 2 }.hash())
+  println(Pt { x: 1 } == Pt { x: 1 })
+  println(Hash.hash(Pt { x: 1 }) == Hash.hash(Pt { x: 2 }))
   println(map.get(#{ Pt { x: 1 }: "a" }, Pt { x: 1 }))
 }
diff --git a/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/a.silt b/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/a.silt
index 89dd9031b..6494a4ddd 100644
--- a/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/a.silt
+++ b/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/a.silt
@@ -1,4 +1,4 @@
 pub trait Describe { fn display(self) -> String }
 trait Describe for Int { fn display(self) -> String { "A{self}" } }
-fn show(x: t) -> String where t: Describe { x.display() }
+fn show(x: t) -> String where t: Describe { Describe.display(x) }
 pub fn f() -> String { show(1) }
diff --git a/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/b.silt b/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/b.silt
index dd0b00a72..af37b9377 100644
--- a/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/b.silt
+++ b/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/b.silt
@@ -1,4 +1,4 @@
 pub trait Describe { fn display(self) -> String }
 trait Describe for Int { fn display(self) -> String { "B{self}" } }
-fn show(x: t) -> String where t: Describe { x.display() }
+fn show(x: t) -> String where t: Describe { Describe.display(x) }
 pub fn f() -> String { show(1) }
diff --git a/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/main.silt b/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/main.silt
index bda8be929..4e563e046 100644
--- a/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/main.silt
+++ b/tests/golden/lang/traits/derived_impls_ignore_another_modules_trait/main.silt
@@ -3,11 +3,12 @@
 -- and each module's call through its own bound calls its impl.
 import a
 import helper
+import string
 type Pt { x: Int }
 fn main() {
   println(a.f())
   println(helper.g())
-  println(Pt { x: 1 }.display())
+  println(string.from(Pt { x: 1 }))
   println(Pt { x: 1 } == Pt { x: 1 })
   println("{Pt { x: 2 }}")
 }
diff --git a/tests/golden/lang/traits/dispatch_unit_validation__trait_args_checked_when_inner_is_unit.silt b/tests/golden/lang/traits/dispatch_unit_validation__trait_args_checked_when_inner_is_unit.silt
index 9d8938cdf..424f0ecb2 100644
--- a/tests/golden/lang/traits/dispatch_unit_validation__trait_args_checked_when_inner_is_unit.silt
+++ b/tests/golden/lang/traits/dispatch_unit_validation__trait_args_checked_when_inner_is_unit.silt
@@ -17,6 +17,6 @@ trait Foo for Box(a) where a: T(Int) {
 }
 fn main() {
     let b: Box(Unit) = Wrap(())
-    let r: Int = b.do_it()
+    let r: Int = Foo.do_it(b)
     println(r)
 }
diff --git a/tests/golden/lang/traits/display__a_written_impl_is_what_every_way_of_showing_prints.silt b/tests/golden/lang/traits/display__a_written_impl_is_what_every_way_of_showing_prints.silt
index 2d5f97c7f..e16f303d1 100644
--- a/tests/golden/lang/traits/display__a_written_impl_is_what_every_way_of_showing_prints.silt
+++ b/tests/golden/lang/traits/display__a_written_impl_is_what_every_way_of_showing_prints.silt
@@ -17,21 +17,21 @@ trait Display for Temp {
 trait Error for Temp {}
 
 fn show(x: a) -> String where a: Display {
-  x.display()
+  "{x}"
 }
 
 fn main() {
   let t = Temp { degrees: 21 }
-  println(t.display())
+  println("{t}")
   println("{t}")
   println(t)
   println(string.from(t))
   println(show(t))
-  println(t.message())
+  println(Error.message(t))
   print(t)
   println("")
   println([t])
   println("{[t]}")
-  println([t].display())
+  println("{[t]}")
   println(show([t]))
 }
diff --git a/tests/golden/lang/traits/display__an_impl_shows_its_fields_with_their_impls.silt b/tests/golden/lang/traits/display__an_impl_shows_its_fields_with_their_impls.silt
index a8e2b24e7..c314b0dbf 100644
--- a/tests/golden/lang/traits/display__an_impl_shows_its_fields_with_their_impls.silt
+++ b/tests/golden/lang/traits/display__an_impl_shows_its_fields_with_their_impls.silt
@@ -20,7 +20,7 @@ type Span {
 
 trait Display for Span {
   fn display(self) -> String {
-    "{self.low}..{self.high.display()}"
+    "{self.low}..{self.high}"
   }
 }
 
@@ -35,7 +35,7 @@ trait Display for Forecast {
 }
 
 fn both(x: a, y: b) -> String where a: Display, b: Display {
-  "<{x}> <{y.display()}>"
+  "<{x}> <{y}>"
 }
 
 fn main() {
diff --git a/tests/golden/lang/traits/dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.silt b/tests/golden/lang/traits/dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.silt
new file mode 100644
index 000000000..59758a876
--- /dev/null
+++ b/tests/golden/lang/traits/dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.silt
@@ -0,0 +1,15 @@
+-- cmd: check
+-- exit: 1
+-- `display` and `equal` are no methods a program calls: the help shows
+-- interpolation, `string.from` and `==`. A method that makes a value is
+-- called on the type, or on a `type a` parameter.
+trait Monoid { fn empty() -> Self }
+trait Monoid for Int { fn empty() -> Self { 0 } }
+fn of(x: a) -> a where a: Monoid { x.empty() }
+fn main() {
+  let n = 5
+  println(n.display())
+  println(n.equal(n))
+  println(n.empty())
+  println(of(1))
+}
diff --git a/tests/golden/lang/traits/dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.stderr b/tests/golden/lang/traits/dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.stderr
new file mode 100644
index 000000000..bbbab5681
--- /dev/null
+++ b/tests/golden/lang/traits/dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.stderr
@@ -0,0 +1,27 @@
+error[type]: type 'a' has no field 'empty'
+ --> dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.silt:8:36
+   |
+ 8 | fn of(x: a) -> a where a: Monoid { x.empty() }
+   |                                    ^^^^^^^ type 'a' has no field 'empty'
+  = help: `empty` is a method of trait `Monoid` that makes a value: call it on the type, `a.empty()`, where `a` is a `type a` parameter
+
+error[type]: type 'Int' has no field 'display'
+ --> dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.silt:11:11
+    |
+ 11 |   println(n.display())
+    |           ^^^^^^^^^ type 'Int' has no field 'display'
+  = help: show a value with interpolation, `"{n}"`, or with `string.from(n)`
+
+error[type]: type 'Int' has no field 'equal'
+ --> dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.silt:12:11
+    |
+ 12 |   println(n.equal(n))
+    |           ^^^^^^^ type 'Int' has no field 'equal'
+  = help: compare with `==`: `n == y`
+
+error[type]: type 'Int' has no field 'empty'
+ --> dot_after_a_value__a_method_of_a_builtin_trait_or_that_makes_a_value.silt:13:11
+    |
+ 13 |   println(n.empty())
+    |           ^^^^^^^ type 'Int' has no field 'empty'
+  = help: `empty` is a method of trait `Monoid` that makes a value: call it on the type, `Int.empty()`
diff --git a/tests/golden/lang/traits/dot_after_a_value__names_a_field.silt b/tests/golden/lang/traits/dot_after_a_value__names_a_field.silt
new file mode 100644
index 000000000..48b31e7da
--- /dev/null
+++ b/tests/golden/lang/traits/dot_after_a_value__names_a_field.silt
@@ -0,0 +1,28 @@
+-- cmd: check
+-- exit: 1
+-- A dot after a value names a field. Where the value's type has none of
+-- the name, the error says so; the help names the trait in sight that
+-- has a method of the name and the call to write, with the receiver as
+-- written when it is a name (`Greet.greet(n)`) and `x` otherwise; or
+-- the builtin module of the type with a function of the name. Also
+-- through a function whose parameter's type is unknown, which takes a
+-- record with the field.
+import list
+trait Greet { fn greet(self) -> String }
+trait Greet for Int { fn greet(self) -> String { "g" } }
+trait Pair { fn pair(self, other: Self) -> String }
+trait Pair for Int { fn pair(self, other: Self) -> String { "p" } }
+fn h(x) { x.frobnicate() }
+fn main() {
+  let n = 5
+  println(n.frobnicate())
+  println(n.greet())
+  println((n + 1).greet())
+  println(n.pair(6))
+  let xs = [1, 2]
+  println(xs.length())
+  println([1].length())
+  println("s".length())
+  println(h(1))
+  let g = n.greet
+}
diff --git a/tests/golden/lang/traits/dot_after_a_value__names_a_field.stderr b/tests/golden/lang/traits/dot_after_a_value__names_a_field.stderr
new file mode 100644
index 000000000..b67609788
--- /dev/null
+++ b/tests/golden/lang/traits/dot_after_a_value__names_a_field.stderr
@@ -0,0 +1,60 @@
+error[type]: type 'Int' has no field 'frobnicate'
+ --> dot_after_a_value__names_a_field.silt:18:11
+    |
+ 18 |   println(n.frobnicate())
+    |           ^^^^^^^^^^^^ type 'Int' has no field 'frobnicate'
+
+error[type]: type 'Int' has no field 'greet'
+ --> dot_after_a_value__names_a_field.silt:19:11
+    |
+ 19 |   println(n.greet())
+    |           ^^^^^^^ type 'Int' has no field 'greet'
+  = help: `greet` is a method of trait `Greet`: call it as `Greet.greet(n)`
+
+error[type]: type 'Int' has no field 'greet'
+ --> dot_after_a_value__names_a_field.silt:20:12
+    |
+ 20 |   println((n + 1).greet())
+    |            ^^^^^^^^^^^^ type 'Int' has no field 'greet'
+  = help: `greet` is a method of trait `Greet`: call it as `Greet.greet(x)`
+
+error[type]: type 'Int' has no field 'pair'
+ --> dot_after_a_value__names_a_field.silt:21:11
+    |
+ 21 |   println(n.pair(6))
+    |           ^^^^^^ type 'Int' has no field 'pair'
+  = help: `pair` is a method of trait `Pair`: call it as `Pair.pair(n, ..)`
+
+error[type]: type 'List(Int)' has no field 'length'
+ --> dot_after_a_value__names_a_field.silt:23:11
+    |
+ 23 |   println(xs.length())
+    |           ^^^^^^^^^ type 'List(Int)' has no field 'length'
+  = help: `length` is a function of module `list`: call it as `list.length(xs)`
+
+error[type]: type 'List(Int)' has no field 'length'
+ --> dot_after_a_value__names_a_field.silt:24:11
+    |
+ 24 |   println([1].length())
+    |           ^^^^^^^^^^ type 'List(Int)' has no field 'length'
+  = help: `length` is a function of module `list`: call it as `list.length(xs)`
+
+error[type]: type 'String' has no field 'length'
+ --> dot_after_a_value__names_a_field.silt:25:11
+    |
+ 25 |   println("s".length())
+    |           ^^^^^^^^^^ type 'String' has no field 'length'
+  = help: `length` is a function of module `string`: call it as `string.length(x)`
+
+error[type]: type 'Int' has no field 'frobnicate'
+ --> dot_after_a_value__names_a_field.silt:26:13
+    |
+ 26 |   println(h(1))
+    |             ^ type 'Int' has no field 'frobnicate'
+
+error[type]: type 'Int' has no field 'greet'
+ --> dot_after_a_value__names_a_field.silt:27:11
+    |
+ 27 |   let g = n.greet
+    |           ^^^^^^^ type 'Int' has no field 'greet'
+  = help: `greet` is a method of trait `Greet`: call it as `Greet.greet(n)`
diff --git a/tests/golden/lang/traits/every_fn_and_tuple__associated_type_and_trait_parameter.silt b/tests/golden/lang/traits/every_fn_and_tuple__associated_type_and_trait_parameter.silt
index bd5010580..a80821cff 100644
--- a/tests/golden/lang/traits/every_fn_and_tuple__associated_type_and_trait_parameter.silt
+++ b/tests/golden/lang/traits/every_fn_and_tuple__associated_type_and_trait_parameter.silt
@@ -7,9 +7,9 @@ trait Has { type Item
   fn item(self) -> Self::Item }
 trait Has for Tuple { type Item = Int
   fn item(self) -> Int { 2 } }
-fn c(x: a, type b) -> b where a: Conv(b) { x.conv() }
+fn c(x: a, type b) -> b where a: Conv(b) { Conv.conv(x) }
 fn main() {
-  println({ x -> x }.conv())
+  println(Conv.conv({ x -> x }))
   println(c({ x -> x + 1 }, Int))
-  println((1, 2).item())
+  println(Has.item((1, 2)))
 }
diff --git a/tests/golden/lang/traits/every_fn_and_tuple__what_self_can_do.silt b/tests/golden/lang/traits/every_fn_and_tuple__what_self_can_do.silt
index 867a01136..94296f6fc 100644
--- a/tests/golden/lang/traits/every_fn_and_tuple__what_self_can_do.silt
+++ b/tests/golden/lang/traits/every_fn_and_tuple__what_self_can_do.silt
@@ -7,36 +7,36 @@ trait Keep {
   fn name(self) -> String
   fn both(self) -> String
   fn pick(self, o: Self) -> Self
-  fn twice(self) -> String { "{self.name()} {self.name()}" }
+  fn twice(self) -> String { "{Keep.name(self)} {Keep.name(self)}" }
 }
 trait Keep for Fn {
   fn keep(self) -> Self { self }
   fn name(self) -> String { "fn" }
-  fn both(self) -> String { "{self.name()}+{self.keep().name()}" }
+  fn both(self) -> String { "{Keep.name(self)}+{Keep.name(Keep.keep(self))}" }
   fn pick(self, o: Self) -> Self { o }
 }
 trait Keep for Tuple {
   fn keep(self) -> Self { self }
   fn name(self) -> String { "tuple" }
-  fn both(self) -> String { self.name() }
+  fn both(self) -> String { Keep.name(self) }
   fn pick(self, o: Self) -> Self { o }
 }
 fn cents(n: Int) -> Cents { Cents(n) }
 fn other(n: Int) -> Cents { Cents(n + 1) }
-fn k(x: a) -> a where a: Keep { x.keep() }
+fn k(x: a) -> a where a: Keep { Keep.keep(x) }
 fn main() {
-  let f = cents.keep()
+  let f = Keep.keep(cents)
   let Cents(n) = f(3)
   println(n)
-  println(cents.both())
-  println(cents.twice())
-  let g = cents.pick(other)
+  println(Keep.both(cents))
+  println(Keep.twice(cents))
+  let g = Keep.pick(cents, other)
   println(g(1))
-  let (a, b) = (1, "x").keep()
+  let (a, b) = Keep.keep((1, "x"))
   println("{a} {b}")
-  println((1, 2).pick((3, 4)))
+  println(Keep.pick((1, 2), (3, 4)))
   let h = k(cents)
   println(h(9))
   println(k((1, 2)))
-  println({ x -> x + 1 }.name())
+  println(Keep.name({ x -> x + 1 }))
 }
diff --git a/tests/golden/lang/traits/imported_type_with_two_written_displays/main.silt b/tests/golden/lang/traits/imported_type_with_two_written_displays/main.silt
index 4a0bcfe96..fceb82e02 100644
--- a/tests/golden/lang/traits/imported_type_with_two_written_displays/main.silt
+++ b/tests/golden/lang/traits/imported_type_with_two_written_displays/main.silt
@@ -3,6 +3,7 @@
 -- stderr-contains: error[type]: duplicate implementation of trait 'Display' for type 'types.Tag'
 -- A second written Display impl for an imported type is a duplicate.
 import types.{ Tag }
+import string
 
 trait Display for Tag {
   fn display(self) -> String {
@@ -11,5 +12,5 @@ trait Display for Tag {
 }
 
 fn main() {
-  println(Tag { name: "silt" }.display())
+  println(string.from(Tag { name: "silt" }))
 }
diff --git a/tests/golden/lang/traits/imported_type_with_written_display/main.silt b/tests/golden/lang/traits/imported_type_with_written_display/main.silt
index 4a2cbfede..8fd5294f0 100644
--- a/tests/golden/lang/traits/imported_type_with_written_display/main.silt
+++ b/tests/golden/lang/traits/imported_type_with_written_display/main.silt
@@ -7,6 +7,6 @@ import types.{ Tag }
 
 fn main() {
   let t = Tag { name: "silt" }
-  println(t.display())
-  println("{t.display()}")
+  println("{t}")
+  println("{t}")
 }
diff --git a/tests/golden/lang/traits/imported_type_with_written_display_check/main.silt b/tests/golden/lang/traits/imported_type_with_written_display_check/main.silt
index 3243fa393..b42a8a34a 100644
--- a/tests/golden/lang/traits/imported_type_with_written_display_check/main.silt
+++ b/tests/golden/lang/traits/imported_type_with_written_display_check/main.silt
@@ -8,6 +8,6 @@ import types.{ Tag }
 
 fn main() {
   let t = Tag { name: "silt" }
-  println(t.display())
-  println("{t.display()}")
+  println("{t}")
+  println("{t}")
 }
diff --git a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/helper.silt b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/helper.silt
index bd4fb9f15..aeff4ff0b 100644
--- a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/helper.silt
+++ b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/helper.silt
@@ -1,3 +1,3 @@
 trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "helper {self}" } }
-pub fn h() -> String { 1.show() }
+pub fn h() -> String { Show.show(1) }
diff --git a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/main.silt b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/main.silt
index fb33e294e..437b0688d 100644
--- a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/main.silt
+++ b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_own/main.silt
@@ -7,8 +7,8 @@ trait Show for Int { fn show(self) -> String { "main {self}" } }
 fn apply(f: Fn(a) -> String, x: a) -> String { f(x) }
 fn main() {
   println(helper.h())
-  println(2.show())
-  let g = { y -> y.show() }
+  println(Show.show(2))
+  let g = { y -> Show.show(y) }
   println(g(3))
-  println(apply({ y -> y.show() }, 4))
+  println(apply({ y -> Show.show(y) }, 4))
 }
diff --git a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/b.silt b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/b.silt
index c8fb61396..9aa794484 100644
--- a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/b.silt
+++ b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/b.silt
@@ -1,3 +1,3 @@
 trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "b-int {self}" } }
-pub fn sb(x: Int) -> String { x.show() }
+pub fn sb(x: Int) -> String { Show.show(x) }
diff --git a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/main.silt b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/main.silt
index 66b6d623b..49263d5ed 100644
--- a/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/main.silt
+++ b/tests/golden/lang/traits/private_trait_is_no_candidate_beside_pub/main.silt
@@ -4,6 +4,6 @@ import a
 import b
 fn main() {
   println(b.sb(1))
-  println(2.show())
-  println(Int.show(3))
+  println(a.Show.show(2))
+  println(a.Show.show(3))
 }
diff --git a/tests/golden/lang/traits/round71_direct_dispatch__channel_user_trait_dispatch.silt b/tests/golden/lang/traits/round71_direct_dispatch__channel_user_trait_dispatch.silt
index a77a09d7a..91b11dee9 100644
--- a/tests/golden/lang/traits/round71_direct_dispatch__channel_user_trait_dispatch.silt
+++ b/tests/golden/lang/traits/round71_direct_dispatch__channel_user_trait_dispatch.silt
@@ -3,5 +3,5 @@ trait Show { fn show(self) -> String }
 trait Show for Channel(a) { fn show(self) -> String { "chan-impl" } }
 fn main() {
   let c: Channel(Int) = channel.new(1)
-  println(c.show())
+  println(Show.show(c))
 }
diff --git a/tests/golden/lang/traits/round71_direct_dispatch__fn_user_trait_dispatch.silt b/tests/golden/lang/traits/round71_direct_dispatch__fn_user_trait_dispatch.silt
index 390aa1da2..c69abddd4 100644
--- a/tests/golden/lang/traits/round71_direct_dispatch__fn_user_trait_dispatch.silt
+++ b/tests/golden/lang/traits/round71_direct_dispatch__fn_user_trait_dispatch.silt
@@ -2,5 +2,5 @@ trait Show { fn show(self) -> String }
 trait Show for Fn { fn show(self) -> String { "fn-impl" } }
 fn main() {
   let f = { -> 42 }
-  println(f.show())
+  println(Show.show(f))
 }
diff --git a/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fn_dispatches.silt b/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fn_dispatches.silt
index 390aa1da2..c69abddd4 100644
--- a/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fn_dispatches.silt
+++ b/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fn_dispatches.silt
@@ -2,5 +2,5 @@ trait Show { fn show(self) -> String }
 trait Show for Fn { fn show(self) -> String { "fn-impl" } }
 fn main() {
   let f = { -> 42 }
-  println(f.show())
+  println(Show.show(f))
 }
diff --git a/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fun_alias_dispatches.silt b/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fun_alias_dispatches.silt
index 71c4c6ee0..0fd5c4118 100644
--- a/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fun_alias_dispatches.silt
+++ b/tests/golden/lang/traits/round71_followup_fn_canonical_name__user_trait_for_fun_alias_dispatches.silt
@@ -2,5 +2,5 @@ trait Show { fn show(self) -> String }
 trait Show for Fun { fn show(self) -> String { "fn-impl" } }
 fn main() {
   let f = { -> 42 }
-  println(f.show())
+  println(Show.show(f))
 }
diff --git a/tests/golden/lang/traits/round76_assoc_cycle__direct_self_reference_rejected.silt b/tests/golden/lang/traits/round76_assoc_cycle__direct_self_reference_rejected.silt
index 71e20faff..320377d8d 100644
--- a/tests/golden/lang/traits/round76_assoc_cycle__direct_self_reference_rejected.silt
+++ b/tests/golden/lang/traits/round76_assoc_cycle__direct_self_reference_rejected.silt
@@ -15,5 +15,5 @@ trait Container for Int {
 
 fn main() {
   let x: Int = 7
-  println(x.unwrap())
+  println(Container.unwrap(x))
 }
diff --git a/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__builtin_fn_value.silt b/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__builtin_fn_value.silt
index a72c8ab87..5d435c987 100644
--- a/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__builtin_fn_value.silt
+++ b/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__builtin_fn_value.silt
@@ -2,5 +2,5 @@ trait MyTrait { fn describe(self) -> String }
 trait MyTrait for Fn { fn describe(self) -> String { "[fn]" } }
 fn main() {
   let h = println
-  println(h.describe())
+  println(MyTrait.describe(h))
 }
diff --git a/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__variant_constructor_value.silt b/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__variant_constructor_value.silt
index 61f369c3d..7d2a0bb84 100644
--- a/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__variant_constructor_value.silt
+++ b/tests/golden/lang/traits/round77_for_fn_builtinfn_dispatch__variant_constructor_value.silt
@@ -3,5 +3,5 @@ trait MyTrait for Fn { fn describe(self) -> String { "[fn]" } }
 type Maybe(a) { May(a) }
 fn main() {
   let h = May
-  println(h.describe())
+  println(MyTrait.describe(h))
 }
diff --git a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__bare_unit_variant.silt b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__bare_unit_variant.silt
index 9f7f2cb57..1368fd380 100644
--- a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__bare_unit_variant.silt
+++ b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__bare_unit_variant.silt
@@ -6,5 +6,5 @@ trait Display for Color {
 }
 
 fn main() {
-  println(Red.display())
+  println("{Red}")
 }
diff --git a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__let_bound_unit_variant.silt b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__let_bound_unit_variant.silt
index a2f87fb5a..d6d18319f 100644
--- a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__let_bound_unit_variant.silt
+++ b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__let_bound_unit_variant.silt
@@ -6,5 +6,5 @@ trait Display for Color {
 
 fn main() {
   let r = Red
-  println(r.display())
+  println("{r}")
 }
diff --git a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__paren_unit_variant.silt b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__paren_unit_variant.silt
index 9d74f05f3..1368fd380 100644
--- a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__paren_unit_variant.silt
+++ b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__paren_unit_variant.silt
@@ -6,5 +6,5 @@ trait Display for Color {
 }
 
 fn main() {
-  println((Red).display())
+  println("{Red}")
 }
diff --git a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__returns_value_from_trait_body.silt b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__returns_value_from_trait_body.silt
index 08535a8e7..678ecaf7a 100644
--- a/tests/golden/lang/traits/round88_unit_variant_method_dispatch__returns_value_from_trait_body.silt
+++ b/tests/golden/lang/traits/round88_unit_variant_method_dispatch__returns_value_from_trait_body.silt
@@ -5,4 +5,4 @@ trait Display for Color {
   fn display(self) -> String { "round88-ok" }
 }
 
-fn main() { println(Red.display()) }
+fn main() { println("{Red}") }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_enum_with_payload_runs.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_enum_with_payload_runs.silt
index 16d12fa6a..595b78364 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_enum_with_payload_runs.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_enum_with_payload_runs.silt
@@ -2,6 +2,6 @@ type Shape { Dot, Line(Int), Rect(Int, Int) }
 fn main() {
     println(Dot < Line(1))
     println(Line(1) == Line(1))
-    println(Line(1).compare(Rect(1, 2)))
-    println(Rect(1, 2).hash() == Rect(1, 2).hash())
+    println(Compare.compare(Line(1), Rect(1, 2)))
+    println(Hash.hash(Rect(1, 2)) == Hash.hash(Rect(1, 2)))
 }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_record_runs.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_record_runs.silt
index 00d6e674e..376bc8448 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_record_runs.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__derivable_record_runs.silt
@@ -4,6 +4,6 @@ fn main() {
     let b = P{x: 2, name: "b"}
     println(a < b)
     println(a == b)
-    println(a.compare(b))
-    println(a.hash() == a.hash())
+    println(Compare.compare(a, b))
+    println(Hash.hash(a) == Hash.hash(a))
 }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__enum_wrapping_map_compare_method_rejected.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__enum_wrapping_map_compare_method_rejected.silt
index e019e85ac..697374948 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__enum_wrapping_map_compare_method_rejected.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__enum_wrapping_map_compare_method_rejected.silt
@@ -4,4 +4,4 @@
 -- stderr-contains: variant 'Wrap'
 type W { Wrap(Map(String, Int)), Empty }
 fn mk() -> W { Wrap(#{"a": 1}) }
-fn main() { println(mk().compare(mk())) }
+fn main() { println(Compare.compare(mk(), mk())) }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_compare_method_rejected.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_compare_method_rejected.silt
index a0e02dde1..bc7022afb 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_compare_method_rejected.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_compare_method_rejected.silt
@@ -5,4 +5,4 @@
 -- stderr-contains: Fn(Int) -> Int
 type H { f: Fn(Int) -> Int }
 fn mk() -> H { H{f: { x -> x }} }
-fn main() { println(mk().compare(mk())) }
+fn main() { println(Compare.compare(mk(), mk())) }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_hash_method_rejected.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_hash_method_rejected.silt
index d0cbb6201..a32e57c26 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_hash_method_rejected.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__fn_field_hash_method_rejected.silt
@@ -5,4 +5,4 @@
 -- stderr-contains: Fn(Int) -> Int
 type H { f: Fn(Int) -> Int }
 fn mk() -> H { H{f: { x -> x }} }
-fn main() { println(mk().hash()) }
+fn main() { println(Hash.hash(mk())) }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__generic_record_int_instantiation_runs.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__generic_record_int_instantiation_runs.silt
index 333b0ae79..0d9893c08 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__generic_record_int_instantiation_runs.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__generic_record_int_instantiation_runs.silt
@@ -4,6 +4,6 @@ fn main() {
     let b = Box{v: 2}
     println(a < b)
     println(a == b)
-    println(a.compare(b))
-    println(a.hash() == a.hash())
+    println(Compare.compare(a, b))
+    println(Hash.hash(a) == Hash.hash(a))
 }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_compare_method_rejected.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_compare_method_rejected.silt
index 8147ce8f1..6efa8579f 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_compare_method_rejected.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_compare_method_rejected.silt
@@ -5,4 +5,4 @@
 -- stderr-contains: Map(String, Int)
 type M { m: Map(String, Int) }
 fn mk() -> M { M{m: #{"a": 1}} }
-fn main() { println(mk().compare(mk())) }
+fn main() { println(Compare.compare(mk(), mk())) }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_equality_and_hash_run.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_equality_and_hash_run.silt
index b37e05ddf..624aae358 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_equality_and_hash_run.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_equality_and_hash_run.silt
@@ -5,5 +5,5 @@ fn main() {
     let c = M{m: #{"a": 2}}
     println(a == b)
     println(a == c)
-    println(a.hash() == b.hash())
+    println(Hash.hash(a) == Hash.hash(b))
 }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_where_clause_rejected.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_where_clause_rejected.silt
index a7ab18bfc..062d951b2 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_where_clause_rejected.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__map_field_where_clause_rejected.silt
@@ -3,5 +3,5 @@
 -- stderr-contains: error[type]: type 'M' does not implement trait 'Compare': field 'm' is of type 'Map(String, Int)', which does not
 type M { m: Map(String, Int) }
 fn mk() -> M { M{m: #{"a": 1}} }
-fn cmp_gen(x: a, y: a) -> Int where a: Compare { x.compare(y) }
+fn cmp_gen(x: a, y: a) -> Int where a: Compare { Compare.compare(x, y) }
 fn main() { println(cmp_gen(mk(), mk())) }
diff --git a/tests/golden/lang/traits/round93_autoderive_field_gate__recursive_type_derives_and_runs.silt b/tests/golden/lang/traits/round93_autoderive_field_gate__recursive_type_derives_and_runs.silt
index b46bc446a..5cc935dd1 100644
--- a/tests/golden/lang/traits/round93_autoderive_field_gate__recursive_type_derives_and_runs.silt
+++ b/tests/golden/lang/traits/round93_autoderive_field_gate__recursive_type_derives_and_runs.silt
@@ -4,6 +4,6 @@ fn main() {
     let t2 = Tree{leaf: 2, kids: [Tree{leaf: 3, kids: []}]}
     println(t1 < t2)
     println(t1 == t1)
-    println(t1.compare(t2))
-    println(t2.hash() == t2.hash())
+    println(Compare.compare(t1, t2))
+    println(Hash.hash(t2) == Hash.hash(t2))
 }
diff --git a/tests/golden/lang/traits/same_named_traits_ambiguous_call/a.silt b/tests/golden/lang/traits/same_named_traits_ambiguous_call/a.silt
deleted file mode 100644
index 664e1cbdb..000000000
--- a/tests/golden/lang/traits/same_named_traits_ambiguous_call/a.silt
+++ /dev/null
@@ -1,4 +0,0 @@
-pub trait Show { fn show(self) -> String }
-trait Show for Int { fn show(self) -> String { "a-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
diff --git a/tests/golden/lang/traits/same_named_traits_ambiguous_call/b.silt b/tests/golden/lang/traits/same_named_traits_ambiguous_call/b.silt
deleted file mode 100644
index fb3808b31..000000000
--- a/tests/golden/lang/traits/same_named_traits_ambiguous_call/b.silt
+++ /dev/null
@@ -1,4 +0,0 @@
-pub trait Show { fn show(self) -> String }
-trait Show for Int { fn show(self) -> String { "b-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
diff --git a/tests/golden/lang/traits/same_named_traits_ambiguous_call/main.silt b/tests/golden/lang/traits/same_named_traits_ambiguous_call/main.silt
deleted file mode 100644
index 47d974b8a..000000000
--- a/tests/golden/lang/traits/same_named_traits_ambiguous_call/main.silt
+++ /dev/null
@@ -1,13 +0,0 @@
--- exit: 1
--- Two modules each declare a trait `Show` with `fn show` and implement
--- it for Int. A call here, which sees both traits, is ambiguous: an
--- error at the call, naming both traits.
--- stderr-contains: error[type]: ambiguous method 'show' on type 'Int': provided by traits a.Show, b.Show
--- stderr-contains: --> main.silt:11:11
--- stderr-contains: --> main.silt:12:11
-import a
-import b
-fn main() {
-  println(5.show())
-  println(Int.show(6))
-}
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/a.silt b/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/a.silt
deleted file mode 100644
index 664e1cbdb..000000000
--- a/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/a.silt
+++ /dev/null
@@ -1,4 +0,0 @@
-pub trait Show { fn show(self) -> String }
-trait Show for Int { fn show(self) -> String { "a-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/b.silt b/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/b.silt
deleted file mode 100644
index fb3808b31..000000000
--- a/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/b.silt
+++ /dev/null
@@ -1,4 +0,0 @@
-pub trait Show { fn show(self) -> String }
-trait Show for Int { fn show(self) -> String { "b-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/main.silt b/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/main.silt
deleted file mode 100644
index 484a26b44..000000000
--- a/tests/golden/lang/traits/same_named_traits_deferred_ambiguous/main.silt
+++ /dev/null
@@ -1,12 +0,0 @@
--- exit: 1
--- A method call on a receiver that becomes Int only once the function
--- is inferred, here where both modules' trait `Show` are seen, is
--- ambiguous: an error at the call.
--- stderr-contains: error[type]: ambiguous method 'show' on type 'Int': provided by traits a.Show, b.Show
--- stderr-contains: --> main.silt:11:34
-import a
-import b
-import list
-fn main() {
-  println([5] |> list.map { y -> y.show() })
-}
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_receiver/a.silt b/tests/golden/lang/traits/same_named_traits_deferred_receiver/a.silt
index 664e1cbdb..a7703ec72 100644
--- a/tests/golden/lang/traits/same_named_traits_deferred_receiver/a.silt
+++ b/tests/golden/lang/traits/same_named_traits_deferred_receiver/a.silt
@@ -1,4 +1,4 @@
 pub trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "a-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_receiver/b.silt b/tests/golden/lang/traits/same_named_traits_deferred_receiver/b.silt
index fb3808b31..3184cccb3 100644
--- a/tests/golden/lang/traits/same_named_traits_deferred_receiver/b.silt
+++ b/tests/golden/lang/traits/same_named_traits_deferred_receiver/b.silt
@@ -1,4 +1,4 @@
 pub trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "b-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_receiver/helper.silt b/tests/golden/lang/traits/same_named_traits_deferred_receiver/helper.silt
index da1c5bff6..d81a7b7dd 100644
--- a/tests/golden/lang/traits/same_named_traits_deferred_receiver/helper.silt
+++ b/tests/golden/lang/traits/same_named_traits_deferred_receiver/helper.silt
@@ -1,2 +1,2 @@
 import b
-pub fn via_b(x: Int) -> String { x.show() }
+pub fn via_b(x: Int) -> String { b.Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_receiver/main.silt b/tests/golden/lang/traits/same_named_traits_deferred_receiver/main.silt
index d82ba6e4c..c01dcbcb1 100644
--- a/tests/golden/lang/traits/same_named_traits_deferred_receiver/main.silt
+++ b/tests/golden/lang/traits/same_named_traits_deferred_receiver/main.silt
@@ -6,6 +6,6 @@ import a
 import helper
 import list
 fn main() {
-  println([5] |> list.map { y -> y.show() })
+  println([5] |> list.map { y -> a.Show.show(y) })
   println(helper.via_b(6))
 }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/a.silt b/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/a.silt
new file mode 100644
index 000000000..a7703ec72
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/a.silt
@@ -0,0 +1,4 @@
+pub trait Show { fn show(self) -> String }
+trait Show for Int { fn show(self) -> String { "a-int {self}" } }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/b.silt b/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/b.silt
new file mode 100644
index 000000000..3184cccb3
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/b.silt
@@ -0,0 +1,4 @@
+pub trait Show { fn show(self) -> String }
+trait Show for Int { fn show(self) -> String { "b-int {self}" } }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/main.silt b/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/main.silt
new file mode 100644
index 000000000..7c67f9bc8
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_deferred_receiver_has_no_field/main.silt
@@ -0,0 +1,13 @@
+-- exit: 1
+-- A dot after a value whose type becomes Int only once the closure is
+-- inferred names a field, which Int has not, where both modules' trait
+-- `Show` have a method `show`: the help names the first.
+-- stderr-contains: error[type]: type 'Int' has no field 'show'
+-- stderr-contains: help: `show` is a method of trait `a.Show`: call it as `a.Show.show(y)`
+-- stderr-contains: --> main.silt:12:34
+import a
+import b
+import list
+fn main() {
+  println([5] |> list.map { y -> y.show() })
+}
diff --git a/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/a.silt b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/a.silt
new file mode 100644
index 000000000..a7703ec72
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/a.silt
@@ -0,0 +1,4 @@
+pub trait Show { fn show(self) -> String }
+trait Show for Int { fn show(self) -> String { "a-int {self}" } }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/b.silt b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/b.silt
new file mode 100644
index 000000000..3184cccb3
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/b.silt
@@ -0,0 +1,4 @@
+pub trait Show { fn show(self) -> String }
+trait Show for Int { fn show(self) -> String { "b-int {self}" } }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/case.stdout b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/case.stdout
new file mode 100644
index 000000000..89159bfb3
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/case.stdout
@@ -0,0 +1,4 @@
+a-int 5
+b-int 6
+a-int 7
+b-int 8
diff --git a/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/main.silt b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/main.silt
new file mode 100644
index 000000000..a5a7c5a0c
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_told_apart_by_the_trait/main.silt
@@ -0,0 +1,10 @@
+-- Two modules each declare a trait `Show` with `fn show` and implement
+-- it for Int. A call names the trait it means, so both are called here.
+import a
+import b
+fn main() {
+  println(a.Show.show(5))
+  println(b.Show.show(6))
+  println(a.use_show(7))
+  println(b.use_show(8))
+}
diff --git a/tests/golden/lang/traits/same_named_traits_two_modules/a.silt b/tests/golden/lang/traits/same_named_traits_two_modules/a.silt
index 664e1cbdb..a7703ec72 100644
--- a/tests/golden/lang/traits/same_named_traits_two_modules/a.silt
+++ b/tests/golden/lang/traits/same_named_traits_two_modules/a.silt
@@ -1,4 +1,4 @@
 pub trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "a-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_two_modules/b.silt b/tests/golden/lang/traits/same_named_traits_two_modules/b.silt
index fb3808b31..3184cccb3 100644
--- a/tests/golden/lang/traits/same_named_traits_two_modules/b.silt
+++ b/tests/golden/lang/traits/same_named_traits_two_modules/b.silt
@@ -1,4 +1,4 @@
 pub trait Show { fn show(self) -> String }
 trait Show for Int { fn show(self) -> String { "b-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_unbounded_call/a.silt b/tests/golden/lang/traits/same_named_traits_unbounded_call/a.silt
deleted file mode 100644
index 664e1cbdb..000000000
--- a/tests/golden/lang/traits/same_named_traits_unbounded_call/a.silt
+++ /dev/null
@@ -1,4 +0,0 @@
-pub trait Show { fn show(self) -> String }
-trait Show for Int { fn show(self) -> String { "a-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
diff --git a/tests/golden/lang/traits/same_named_traits_unbounded_call/b.silt b/tests/golden/lang/traits/same_named_traits_unbounded_call/b.silt
deleted file mode 100644
index fb3808b31..000000000
--- a/tests/golden/lang/traits/same_named_traits_unbounded_call/b.silt
+++ /dev/null
@@ -1,4 +0,0 @@
-pub trait Show { fn show(self) -> String }
-trait Show for Int { fn show(self) -> String { "b-int {self}" } }
-pub fn show_int(x: Int) -> String { x.show() }
-pub fn use_show(x: t) -> String where t: Show { x.show() }
diff --git a/tests/golden/lang/traits/same_named_traits_unbounded_call/main.silt b/tests/golden/lang/traits/same_named_traits_unbounded_call/main.silt
deleted file mode 100644
index f3812a0d3..000000000
--- a/tests/golden/lang/traits/same_named_traits_unbounded_call/main.silt
+++ /dev/null
@@ -1,11 +0,0 @@
--- exit: 1
--- A method call on a receiver of unknown type means the one trait in
--- sight that declares the method. Where two do, the receiver needs an
--- annotation.
--- stderr-contains: error[type]: ambiguous method 'show' on type 'Int': provided by traits a.Show, b.Show
-import a
-import b
-fn main() {
-  let g = { y -> y.show() }
-  println(g(5))
-}
diff --git a/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/a.silt b/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/a.silt
new file mode 100644
index 000000000..a7703ec72
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/a.silt
@@ -0,0 +1,4 @@
+pub trait Show { fn show(self) -> String }
+trait Show for Int { fn show(self) -> String { "a-int {self}" } }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/b.silt b/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/b.silt
new file mode 100644
index 000000000..3184cccb3
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/b.silt
@@ -0,0 +1,4 @@
+pub trait Show { fn show(self) -> String }
+trait Show for Int { fn show(self) -> String { "b-int {self}" } }
+pub fn show_int(x: Int) -> String { Show.show(x) }
+pub fn use_show(x: t) -> String where t: Show { Show.show(x) }
diff --git a/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/main.silt b/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/main.silt
new file mode 100644
index 000000000..4a9f7af98
--- /dev/null
+++ b/tests/golden/lang/traits/same_named_traits_unknown_receiver_reads_a_field/main.silt
@@ -0,0 +1,11 @@
+-- exit: 1
+-- A dot after a value of unknown type is a field: `g` takes a record
+-- with a field `show`, whatever traits in sight have a method `show`.
+-- stderr-contains: error[type]: type 'Int' has no field 'show'
+-- stderr-contains: help: `show` is a method of trait `a.Show`: call it as `a.Show.show(x)`
+import a
+import b
+fn main() {
+  let g = { y -> y.show() }
+  println(g(5))
+}
diff --git a/tests/golden/lang/traits/static_method__called_on_bound_value.silt b/tests/golden/lang/traits/static_method__called_on_bound_value.silt
index 7d81038ba..3dc1ffd0c 100644
--- a/tests/golden/lang/traits/static_method__called_on_bound_value.silt
+++ b/tests/golden/lang/traits/static_method__called_on_bound_value.silt
@@ -1,9 +1,10 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: method `total` takes no `self` — call it on the type instead: `b.total()`, where `b` is a `type b` parameter
+-- stderr-contains: error[type]: type 'b' has no field 'total'
+-- stderr-contains: help: `total` is a method of trait `Vals` that makes a value: call it on the type, `b.total()`, where `b` is a `type b` parameter
 -- stderr-not-contains: panicked
--- A method the trait declares without `self` is called on a type. On a
--- value of a bounded type variable it is an error of the call (the
+-- A method the trait declares without `self` is called on a type: a
+-- value of a bounded type variable has no field of its name (the
 -- checker used to panic here).
 trait Vals {
   fn total() -> Int
diff --git a/tests/golden/lang/traits/static_method__called_on_unknown_receiver.silt b/tests/golden/lang/traits/static_method__called_on_unknown_receiver.silt
index ff7f72ae3..15796a84a 100644
--- a/tests/golden/lang/traits/static_method__called_on_unknown_receiver.silt
+++ b/tests/golden/lang/traits/static_method__called_on_unknown_receiver.silt
@@ -1,11 +1,12 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: method `total` takes no `self` — call it on the type instead: `SomeType.total()`
--- stderr-contains: :20:3
--- stderr-contains: :28:18
--- A receiver whose type is not known where the call is written: the one
--- trait that declares `total` declares it without `self`, so the call is
--- refused (it used to check, and fail when run).
+-- stderr-contains: error[type]: type 'Int' has no field 'total'
+-- stderr-contains: help: `total` is a method of trait `Vals` that makes a value: call it on the type, `Int.total()`
+-- stderr-contains: :30:14
+-- stderr-contains: :31:13
+-- A receiver whose type is not known where the call is written takes a
+-- record with a field `total`: an Int has none (it used to check, and
+-- fail when run).
 trait Vals {
   fn total() -> Int
 }
diff --git a/tests/golden/lang/traits/static_method__impl_adds_self.silt b/tests/golden/lang/traits/static_method__impl_adds_self.silt
index cc5c8dbba..c104e2976 100644
--- a/tests/golden/lang/traits/static_method__impl_adds_self.silt
+++ b/tests/golden/lang/traits/static_method__impl_adds_self.silt
@@ -2,7 +2,7 @@
 -- exit: 1
 -- stderr-contains: error[type]: method `total` takes 1 parameter in this impl, but trait `Vals` declares it with 0
 -- stderr-contains: help: trait `Vals` declares `total` without `self`: it is called on the type (`Int.total()`), not on a value
--- stderr-contains: error[type]: method `total` takes no `self`
+-- stderr-contains: error[type]: type 'b' has no field 'total'
 -- stderr-not-contains: panicked
 trait Vals {
   fn total() -> Int
diff --git a/tests/golden/lang/traits/static_method__impl_drops_self.silt b/tests/golden/lang/traits/static_method__impl_drops_self.silt
index 5a82cb8c0..35a3a49fd 100644
--- a/tests/golden/lang/traits/static_method__impl_drops_self.silt
+++ b/tests/golden/lang/traits/static_method__impl_drops_self.silt
@@ -19,5 +19,5 @@ trait Vals for Int {
 }
 
 fn main() {
-  println(7.total())
+  println(Vals.total(7))
 }
diff --git a/tests/golden/lang/traits/static_method__method_called_on_the_type.silt b/tests/golden/lang/traits/static_method__method_called_on_the_type.silt
index 206927bcc..f3ab1f6a9 100644
--- a/tests/golden/lang/traits/static_method__method_called_on_the_type.silt
+++ b/tests/golden/lang/traits/static_method__method_called_on_the_type.silt
@@ -20,8 +20,8 @@ fn zero_of(type b) -> b where b: Vals {
 }
 
 fn main() {
-  println(Int.total(7))
-  println(7.total())
+  println(Vals.total(7))
+  println(Vals.total(7))
   println(Int.zero())
   println(zero_of(Int))
 }
diff --git a/tests/golden/lang/traits/static_method__with_parameters_on_a_bounded_value.silt b/tests/golden/lang/traits/static_method__with_parameters_on_a_bounded_value.silt
index d27bb1344..f761725f8 100644
--- a/tests/golden/lang/traits/static_method__with_parameters_on_a_bounded_value.silt
+++ b/tests/golden/lang/traits/static_method__with_parameters_on_a_bounded_value.silt
@@ -1,11 +1,12 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: method `make` takes no `self` — call it on the type instead: `a.make(..)`, where `a` is a `type a` parameter
--- stderr-contains: error[type]: method `join` takes no `self` — call it on the type instead: `a.join(..)`, where `a` is a `type a` parameter
--- stderr-contains: :28:3
--- stderr-contains: :32:3
--- stderr-contains: :36:3
--- The same through a bound: a value of a bounded type variable.
+-- stderr-contains: help: `make` is a method of trait `Mk` that makes a value: call it on the type, `a.make(..)`, where `a` is a `type a` parameter
+-- stderr-contains: help: `join` is a method of trait `Mk`: call it as `Mk.join(x, ..)`
+-- stderr-contains: :29:3
+-- stderr-contains: :33:3
+-- stderr-contains: :37:3
+-- The same through a bound: a value of a bounded type variable has no
+-- fields; `join`, which takes Self, is called through its trait.
 trait Mk {
   fn make(n: Int) -> Self
   fn join(a: Self, b: Self) -> Self
diff --git a/tests/golden/lang/traits/static_method__with_parameters_on_a_value.silt b/tests/golden/lang/traits/static_method__with_parameters_on_a_value.silt
index ddeb9167b..61a097460 100644
--- a/tests/golden/lang/traits/static_method__with_parameters_on_a_value.silt
+++ b/tests/golden/lang/traits/static_method__with_parameters_on_a_value.silt
@@ -1,16 +1,16 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: method `make` takes no `self` — call it on the type instead: `Int.make(..)`
--- stderr-contains: error[type]: method `join` takes no `self` — call it on the type instead: `Int.join(..)`
+-- stderr-contains: help: `make` is a method of trait `Mk` that makes a value: call it on the type, `Int.make(..)`
+-- stderr-contains: help: `join` is a method of trait `Mk`: call it as `Mk.join(x, ..)`
 -- stderr-contains: :33:11
 -- stderr-contains: :34:11
 -- stderr-contains: :35:11
 -- stderr-contains: :36:11
 -- stderr-not-contains: expects
--- A method without `self` is called on the type, whatever parameters it
--- has: on a value of the type it is refused, with one argument too few
--- (it used to check and run, the receiver taken for the first
--- parameter) and with all of them (it was "expects 0 arguments").
+-- A dot after a value is a field, whatever methods its type has: a
+-- method that makes a value is called on the type, one that takes Self
+-- through its trait (a call on a value used to take the receiver for
+-- the first parameter, or say "expects 0 arguments").
 trait Mk {
   fn make(n: Int) -> Self
   fn join(a: Self, b: Self) -> Self
diff --git a/tests/golden/lang/traits/static_method__with_parameters_on_an_unknown_receiver.silt b/tests/golden/lang/traits/static_method__with_parameters_on_an_unknown_receiver.silt
index c4a715e7c..a81059ea4 100644
--- a/tests/golden/lang/traits/static_method__with_parameters_on_an_unknown_receiver.silt
+++ b/tests/golden/lang/traits/static_method__with_parameters_on_an_unknown_receiver.silt
@@ -1,12 +1,12 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: method `make` takes no `self` — call it on the type instead: `SomeType.make(..)`
--- stderr-contains: error[type]: method `join` takes no `self` — call it on the type instead: `SomeType.join(..)`
--- stderr-contains: :29:3
--- stderr-contains: :33:3
+-- stderr-contains: error[type]: type 'Int' has no field 'make'
+-- stderr-contains: error[type]: type 'Int' has no field 'join'
+-- stderr-contains: :37:15
+-- stderr-contains: :38:15
 -- The same for a receiver whose type is not known where the call is
--- written (it used to check, and fail when run: "function 'Int.make'
--- expects 1 arguments, got 2").
+-- written: it takes a record with the field (it used to check, and fail
+-- when run: "function 'Int.make' expects 1 arguments, got 2").
 trait Mk {
   fn make(n: Int) -> Self
   fn join(a: Self, b: Self) -> Self
diff --git a/tests/golden/lang/traits/static_method__with_parameters_on_the_type.silt b/tests/golden/lang/traits/static_method__with_parameters_on_the_type.silt
index e9efdd214..74ffc5d9e 100644
--- a/tests/golden/lang/traits/static_method__with_parameters_on_the_type.silt
+++ b/tests/golden/lang/traits/static_method__with_parameters_on_the_type.silt
@@ -20,15 +20,15 @@ trait Mk for Int {
 }
 
 fn build(n: Int, type a) -> a where a: Mk {
-  a.make(n).twice()
+  Mk.twice(a.make(n))
 }
 
 fn main() {
   println(Int.make(4))
-  println(Int.join(1, 2))
+  println(Mk.join(1, 2))
   println(build(5, Int))
   let f = Int.make
   println(f(3))
-  println(4.twice())
-  println(Int.twice(4))
+  println(Mk.twice(4))
+  println(Mk.twice(4))
 }
diff --git a/tests/golden/lang/traits/structural__equal_compare_hash_agree.silt b/tests/golden/lang/traits/structural__equal_compare_hash_agree.silt
index 1a79713ef..74cca7198 100644
--- a/tests/golden/lang/traits/structural__equal_compare_hash_agree.silt
+++ b/tests/golden/lang/traits/structural__equal_compare_hash_agree.silt
@@ -28,15 +28,15 @@ fn lt(x: a, y: a) -> Bool where a: Compare {
 }
 
 fn cmp(x: a, y: a) -> Int where a: Compare {
-  x.compare(y)
+  Compare.compare(x, y)
 }
 
 fn same(x: a, y: a) -> Bool where a: Equal {
-  x == y && x.equal(y)
+  x == y && (x == y)
 }
 
 fn hashes(x: a, y: a) -> Bool where a: Hash {
-  x.hash() == y.hash()
+  Hash.hash(x) == Hash.hash(y)
 }
 
 fn main() {
@@ -44,24 +44,24 @@ fn main() {
   let b = Version { minor: 2, major: 0 }
   -- `minor` is declared first: it decides.
   println(a < b)
-  println(a.compare(b))
+  println(Compare.compare(a, b))
   println(lt(a, b))
   println(cmp(b, a))
-  println(Version.compare(a, a))
+  println(Compare.compare(a, a))
   println(list.sort([b, a, b]) == [a, b, b])
   -- Variants by declaration, then payload.
   println(Square(9) < Circle(0))
-  println(Circle(1).compare(Circle(2)))
+  println(Compare.compare(Circle(1), Circle(2)))
   println(cmp(Dot, Square(1)))
   println(list.sort([Dot, Circle(2), Square(3), Circle(1)]))
   -- Equal and Hash agree, alone and inside containers.
   let x = Tagged { tag: "t", item: [Some(a), None] }
   let y = Tagged { tag: "t", item: [Some(Version { minor: 1, major: 9 }), None] }
   println(x == y)
-  println(x.equal(y))
+  println(x == y)
   println(same(x, y))
   println(hashes(x, y))
-  println(x.hash() == y.hash())
+  println(Hash.hash(x) == Hash.hash(y))
   println(set.length(#[x, y]))
   println(map.get(#{x: "found"}, y))
   println((a, [Dot]) == (a, [Dot]))
@@ -69,9 +69,9 @@ fn main() {
   println(same(x, Tagged { tag: "u", item: [] }))
   -- Floats: 0.0 and -0.0 are equal, hash alike and order as equal.
   println(0.0 == -0.0)
-  println(0.0.equal(-0.0))
+  println(0.0 == -0.0)
   println(hashes(0.0, -0.0))
-  println(0.0.compare(-0.0))
+  println(Compare.compare(0.0, -0.0))
   println(set.length(#[0.0, -0.0]))
   println([1.5, -0.0] == [1.5, 0.0])
   println(1.5 < 2.5 && cmp(1.5, 2.5) == -1)
diff --git a/tests/golden/lang/traits/through_the_type__a_method_that_takes_self.silt b/tests/golden/lang/traits/through_the_type__a_method_that_takes_self.silt
new file mode 100644
index 000000000..5eb725424
--- /dev/null
+++ b/tests/golden/lang/traits/through_the_type__a_method_that_takes_self.silt
@@ -0,0 +1,22 @@
+-- cmd: check
+-- exit: 1
+-- A method that takes a value of the type is called through its trait:
+-- through the type it is an error, also through a `type a` parameter,
+-- and for the builtin traits; a method that makes a value is called
+-- through the type.
+trait Monoid {
+  fn empty() -> Self
+  fn combine(a: Self, b: Self) -> Self
+}
+trait Monoid for Int {
+  fn empty() -> Self { 0 }
+  fn combine(a: Self, b: Self) -> Self { a + b }
+}
+fn sum(x: a, y: a, type a) -> a where a: Monoid { a.combine(x, y) }
+fn main() {
+  println(Int.combine(1, 2))
+  println(Int.empty())
+  println(sum(1, 2, Int))
+  println(Int.compare(1, 2))
+  println(Int.display(1))
+}
diff --git a/tests/golden/lang/traits/through_the_type__a_method_that_takes_self.stderr b/tests/golden/lang/traits/through_the_type__a_method_that_takes_self.stderr
new file mode 100644
index 000000000..57538ba4d
--- /dev/null
+++ b/tests/golden/lang/traits/through_the_type__a_method_that_takes_self.stderr
@@ -0,0 +1,27 @@
+error[type]: type 'a' has no method 'combine'
+ --> through_the_type__a_method_that_takes_self.silt:15:51
+    |
+ 15 | fn sum(x: a, y: a, type a) -> a where a: Monoid { a.combine(x, y) }
+    |                                                   ^^^^^^^^^ type 'a' has no method 'combine'
+  = help: `combine` is a method of trait `Monoid`: call it as `Monoid.combine(x, ..)`
+
+error[type]: type 'Int' has no method 'combine'
+ --> through_the_type__a_method_that_takes_self.silt:17:11
+    |
+ 17 |   println(Int.combine(1, 2))
+    |           ^^^^^^^^^^^ type 'Int' has no method 'combine'
+  = help: `combine` is a method of trait `Monoid`: call it as `Monoid.combine(x, ..)`
+
+error[type]: type 'Int' has no method 'compare'
+ --> through_the_type__a_method_that_takes_self.silt:20:11
+    |
+ 20 |   println(Int.compare(1, 2))
+    |           ^^^^^^^^^^^ type 'Int' has no method 'compare'
+  = help: `compare` is a method of trait `Compare`: call it as `Compare.compare(x, ..)`
+
+error[type]: type 'Int' has no method 'display'
+ --> through_the_type__a_method_that_takes_self.silt:21:11
+    |
+ 21 |   println(Int.display(1))
+    |           ^^^^^^^^^^^ type 'Int' has no method 'display'
+  = help: show a value with interpolation, `"{x}"`, or with `string.from(x)`
diff --git a/tests/golden/lang/traits/trait_call__private_trait/case.stderr b/tests/golden/lang/traits/trait_call__private_trait/case.stderr
new file mode 100644
index 000000000..c21d283d3
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__private_trait/case.stderr
@@ -0,0 +1,6 @@
+error[type]: 'Secret' is private to module 'shapes'
+ --> main.silt:7:11
+   |
+ 7 |   println(shapes.Secret.secret(shapes.square(1)))
+   |           ^^^^^^^^^^^^^ 'Secret' is private to module 'shapes'
+  = help: mark it `pub` in module 'shapes' to import it from another module
diff --git a/tests/golden/lang/traits/trait_call__private_trait/main.silt b/tests/golden/lang/traits/trait_call__private_trait/main.silt
new file mode 100644
index 000000000..02bb19562
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__private_trait/main.silt
@@ -0,0 +1,8 @@
+-- cmd: check
+-- exit: 1
+-- A private trait of another module cannot be named, so its methods
+-- cannot be called there.
+import shapes
+fn main() {
+  println(shapes.Secret.secret(shapes.square(1)))
+}
diff --git a/tests/golden/lang/traits/trait_call__private_trait/shapes.silt b/tests/golden/lang/traits/trait_call__private_trait/shapes.silt
new file mode 100644
index 000000000..33b7283ca
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__private_trait/shapes.silt
@@ -0,0 +1,8 @@
+pub type Square { side: Int }
+trait Secret {
+  fn secret(self) -> Int
+}
+trait Secret for Square {
+  fn secret(self) -> Int { 42 }
+}
+pub fn square(n: Int) -> Square { Square { side: n } }
diff --git a/tests/golden/lang/traits/trait_call__qualified_and_imported/case.stdout b/tests/golden/lang/traits/trait_call__qualified_and_imported/case.stdout
new file mode 100644
index 000000000..a0a1bccd4
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__qualified_and_imported/case.stdout
@@ -0,0 +1,5 @@
+9
+9
+18
+hello 1
+hail 1
diff --git a/tests/golden/lang/traits/trait_call__qualified_and_imported/main.silt b/tests/golden/lang/traits/trait_call__qualified_and_imported/main.silt
new file mode 100644
index 000000000..9e40db156
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__qualified_and_imported/main.silt
@@ -0,0 +1,19 @@
+-- A trait of another module is named as any of its items:
+-- `shapes.Area.area`, or `Area.area` after `import shapes.{ Area }`. Two
+-- traits that give Int a method of one name are told apart by their
+-- names.
+import shapes
+import other
+import shapes.{ Area }
+trait Greet { fn greet(self) -> String }
+trait Hail { fn greet(self) -> String }
+trait Greet for Int { fn greet(self) -> String { "hello {self}" } }
+trait Hail for Int { fn greet(self) -> String { "hail {self}" } }
+fn main() {
+  let s = shapes.square(3)
+  println(shapes.Area.area(s))
+  println(Area.area(s))
+  println(other.twice(s))
+  println(Greet.greet(1))
+  println(Hail.greet(1))
+}
diff --git a/tests/golden/lang/traits/trait_call__qualified_and_imported/other.silt b/tests/golden/lang/traits/trait_call__qualified_and_imported/other.silt
new file mode 100644
index 000000000..2a705711c
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__qualified_and_imported/other.silt
@@ -0,0 +1,2 @@
+import shapes.{ Area }
+pub fn twice(s: a) -> Int where a: Area { Area.area(s) * 2 }
diff --git a/tests/golden/lang/traits/trait_call__qualified_and_imported/shapes.silt b/tests/golden/lang/traits/trait_call__qualified_and_imported/shapes.silt
new file mode 100644
index 000000000..976e81187
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__qualified_and_imported/shapes.silt
@@ -0,0 +1,14 @@
+pub type Square { side: Int }
+pub trait Area {
+  fn area(self) -> Int
+}
+trait Secret {
+  fn secret(self) -> Int
+}
+trait Area for Square {
+  fn area(self) -> Int { self.side * self.side }
+}
+trait Secret for Square {
+  fn secret(self) -> Int { 42 }
+}
+pub fn square(n: Int) -> Square { Square { side: n } }
diff --git a/tests/golden/lang/traits/trait_call__refused.silt b/tests/golden/lang/traits/trait_call__refused.silt
new file mode 100644
index 000000000..4d11ba473
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__refused.silt
@@ -0,0 +1,28 @@
+-- cmd: check
+-- exit: 1
+-- What a call through a trait refuses: a method the trait does not
+-- have, Display's and Equal's methods (interpolation and == do that),
+-- a method that takes no value of the type (it is called on a type),
+-- and an argument whose type has no impl, also through an
+-- unannotated function that calls it, and a call with too many
+-- arguments, which counts the one of type Self.
+trait Greet {
+  fn greet(self) -> String
+}
+trait Greet for Int {
+  fn greet(self) -> String { "int {self}" }
+}
+trait Monoid {
+  fn empty() -> Self
+}
+fn hello(x) { Greet.greet(x) }
+fn main() {
+  println(Greet.gret(5))
+  println(Display.display(5))
+  println(Equal.equal(5, 5))
+  let e = Monoid.empty()
+  println(Greet.greet("s"))
+  println(hello("t"))
+  println(Greet.greet(1, 2))
+  println(2 |> Greet.greet(1))
+}
diff --git a/tests/golden/lang/traits/trait_call__refused.stderr b/tests/golden/lang/traits/trait_call__refused.stderr
new file mode 100644
index 000000000..4e15378ea
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__refused.stderr
@@ -0,0 +1,51 @@
+error[type]: trait 'Greet' has no method 'gret'
+ --> trait_call__refused.silt:20:11
+    |
+ 20 |   println(Greet.gret(5))
+    |           ^^^^^^^^^^ trait 'Greet' has no method 'gret'
+  = help: did you mean 'greet'?
+
+error[type]: trait 'Display' has no callable methods
+ --> trait_call__refused.silt:21:11
+    |
+ 21 |   println(Display.display(5))
+    |           ^^^^^^^^^^^^^^^ trait 'Display' has no callable methods
+  = help: show a value with interpolation, `"{x}"`, or with `string.from(x)`
+
+error[type]: trait 'Equal' has no callable methods
+ --> trait_call__refused.silt:22:11
+    |
+ 22 |   println(Equal.equal(5, 5))
+    |           ^^^^^^^^^^^ trait 'Equal' has no callable methods
+  = help: compare with `==`: `x == y`
+
+error[type]: method 'empty' of trait 'Monoid' takes no value of the type, so it is called on a type
+ --> trait_call__refused.silt:23:11
+    |
+ 23 |   let e = Monoid.empty()
+    |           ^^^^^^^^^^^^ method 'empty' of trait 'Monoid' takes no value of the type, so it is called on a type
+  = help: call it on a type, `T.empty()`, or on a `type a` parameter, `a.empty()`
+
+error[type]: type 'String' does not implement trait 'Greet'
+ --> trait_call__refused.silt:24:23
+    |
+ 24 |   println(Greet.greet("s"))
+    |                       ^^^ type 'String' does not implement trait 'Greet'
+
+error[type]: type 'String' does not implement trait 'Greet'
+ --> trait_call__refused.silt:25:17
+    |
+ 25 |   println(hello("t"))
+    |                 ^^^ type 'String' does not implement trait 'Greet'
+
+error[type]: `Greet.greet` expects 1 argument, got 2
+ --> trait_call__refused.silt:26:11
+    |
+ 26 |   println(Greet.greet(1, 2))
+    |           ^^^^^^^^^^^^^^^^^ `Greet.greet` expects 1 argument, got 2
+
+error[type]: `Greet.greet` expects 1 argument, got 2
+ --> trait_call__refused.silt:27:11
+    |
+ 27 |   println(2 |> Greet.greet(1))
+    |           ^^^^^^^^^^^^^^^^^^^ `Greet.greet` expects 1 argument, got 2
diff --git a/tests/golden/lang/traits/trait_call__self_not_first.silt b/tests/golden/lang/traits/trait_call__self_not_first.silt
new file mode 100644
index 000000000..7a494fa8f
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__self_not_first.silt
@@ -0,0 +1,29 @@
+-- A method whose argument of type Self is not its first is called
+-- through its trait like any other: the impl is the one for that
+-- argument's type, known where the call is written or found where it
+-- runs (a bounded type variable, a closure's parameter, a function
+-- value, a piped value).
+import list
+trait Scale {
+  fn scale(by: Int, x: Self) -> Self
+}
+trait Scale for Int {
+  fn scale(by: Int, x: Self) -> Self { by * x }
+}
+type V { n: Int }
+trait Scale for V {
+  fn scale(by: Int, x: Self) -> Self { V { n: by + x.n } }
+}
+fn twice(x: a) -> a where a: Scale { Scale.scale(2, x) }
+fn last(x: a) -> a where a: Scale { Scale.scale(3, x) }
+fn main() {
+  println(Scale.scale(2, 5))
+  println(Scale.scale(2, V { n: 1 }))
+  println(twice(5))
+  println(twice(V { n: 1 }))
+  println(list.map([1, 2], { x -> Scale.scale(10, x) }))
+  let f = Scale.scale
+  println(f(3, V { n: 4 }))
+  println(2 |> Scale.scale(V { n: 7 }))
+  println(last(V { n: 0 }))
+}
diff --git a/tests/golden/lang/traits/trait_call__self_not_first.stdout b/tests/golden/lang/traits/trait_call__self_not_first.stdout
new file mode 100644
index 000000000..92115b10d
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__self_not_first.stdout
@@ -0,0 +1,8 @@
+10
+V {n: 3}
+10
+V {n: 3}
+[10, 20]
+V {n: 7}
+V {n: 9}
+V {n: 3}
diff --git a/tests/golden/lang/traits/trait_call__supertrait_and_default_bodies.silt b/tests/golden/lang/traits/trait_call__supertrait_and_default_bodies.silt
new file mode 100644
index 000000000..900f9a031
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__supertrait_and_default_bodies.silt
@@ -0,0 +1,19 @@
+-- A default body and a function bounded by a subtrait call the
+-- supertrait's method through the supertrait.
+trait Eq2 {
+  fn eq2(self, other: Self) -> Bool
+}
+trait Cmp2: Eq2 {
+  fn lt2(self, other: Self) -> Bool
+  fn le2(self, other: Self) -> Bool { Eq2.eq2(self, other) || Cmp2.lt2(self, other) }
+}
+trait Eq2 for Int { fn eq2(self, other: Self) -> Bool { self == other } }
+trait Cmp2 for Int { fn lt2(self, other: Self) -> Bool { self < other } }
+fn check(a: t, b: t) -> Bool where t: Cmp2 {
+  Eq2.eq2(a, b) || Cmp2.lt2(a, b)
+}
+fn main() {
+  println(check(1, 2))
+  println(Cmp2.le2(3, 3))
+  println(Cmp2.le2(4, 3))
+}
diff --git a/tests/golden/lang/traits/trait_call__supertrait_and_default_bodies.stdout b/tests/golden/lang/traits/trait_call__supertrait_and_default_bodies.stdout
new file mode 100644
index 000000000..9e8a46acf
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__supertrait_and_default_bodies.stdout
@@ -0,0 +1,3 @@
+true
+true
+false
diff --git a/tests/golden/lang/traits/trait_call__through_the_trait.silt b/tests/golden/lang/traits/trait_call__through_the_trait.silt
new file mode 100644
index 000000000..17c52c564
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__through_the_trait.silt
@@ -0,0 +1,52 @@
+-- A method that takes Self is called through its trait, like a module
+-- function: directly, piped, as a function value, from a generic function
+-- (annotated or not), inside a conditional impl, and for the builtin
+-- Compare, Hash and Error. The impl is the one for the type of the
+-- argument of type Self.
+import list
+import io
+trait Greet {
+  fn greet(self) -> String
+}
+trait Greet for Int {
+  fn greet(self) -> String { "int {self}" }
+}
+type Box(a) { Bx(a) }
+trait Greet for Box(a) where a: Greet {
+  fn greet(self) -> String {
+    match self { Bx(x) -> "box of {Greet.greet(x)}" }
+  }
+}
+trait Monoid {
+  fn empty() -> Self
+  fn combine(a: Self, b: Self) -> Self
+}
+trait Monoid for Int {
+  fn empty() -> Self { 0 }
+  fn combine(a: Self, b: Self) -> Self { a + b }
+}
+fn hello(x) { Greet.greet(x) }
+fn bounded(x: a) -> String where a: Greet { Greet.greet(x) }
+fn sum(xs: List(a), type a) -> a where a: Monoid {
+  list.fold(xs, a.empty()) { acc, x -> Monoid.combine(acc, x) }
+}
+fn main() {
+  println(Greet.greet(5))
+  println(5 |> Greet.greet)
+  println(hello(Bx(3)))
+  println(bounded(Bx(Bx(1))))
+  println(list.map([1, 2], Greet.greet))
+  let f = Greet.greet
+  println(f(Bx(9)))
+  println(Monoid.combine(2, 3))
+  println(sum([1, 2, 3], Int))
+  println(Compare.compare(1, 2))
+  println(Hash.hash(1) == Hash.hash(1))
+  println(list.map([[1], [2, 3]], Hash.hash) |> list.length)
+  let g = Compare.compare
+  println(g("b", "a"))
+  match io.read_file("/nonexistent") {
+    Ok(_) -> println("?")
+    Err(e) -> println(Error.message(e))
+  }
+}
diff --git a/tests/golden/lang/traits/trait_call__through_the_trait.stdout b/tests/golden/lang/traits/trait_call__through_the_trait.stdout
new file mode 100644
index 000000000..1eb1f9585
--- /dev/null
+++ b/tests/golden/lang/traits/trait_call__through_the_trait.stdout
@@ -0,0 +1,13 @@
+int 5
+int 5
+box of int 3
+box of box of int 1
+[int 1, int 2]
+box of int 9
+5
+6
+-1
+true
+2
+1
+file not found: /nonexistent
diff --git a/tests/golden/lang/traits/user_trait_method_named_like_builtin_call.silt b/tests/golden/lang/traits/user_trait_method_named_like_builtin_call.silt
index 72cad0c21..480a6912d 100644
--- a/tests/golden/lang/traits/user_trait_method_named_like_builtin_call.silt
+++ b/tests/golden/lang/traits/user_trait_method_named_like_builtin_call.silt
@@ -1,18 +1,16 @@
--- cmd: check
--- exit: 1
--- A trait of the program with a method named like a builtin trait's,
--- implemented for Int: a call on an Int here sees both traits and is
--- ambiguous (prelude traits are always seen); a call through a `where`
--- bound names its trait and is not.
--- stderr-contains: error[type]: ambiguous method 'display' on type 'Int': provided by traits Describe, Display
--- stderr-contains: --> user_trait_method_named_like_builtin_call.silt:16:11
+-- A trait of the program with methods named like a builtin trait's,
+-- implemented for Int: a call names its trait, so the program's
+-- `Ranked.compare` and the builtin `Compare.compare` are told apart, and
+-- the program's `Describe.display` does not change how Int is shown.
 trait Describe { fn display(self) -> String }
 trait Describe for Int { fn display(self) -> String { "described {self}" } }
 trait Ranked { fn compare(self, other: Self) -> Int }
 trait Ranked for Int { fn compare(self, other: Self) -> Int { 99 } }
-fn described(x: t) -> String where t: Describe { x.display() }
+fn described(x: t) -> String where t: Describe { Describe.display(x) }
 fn main() {
-  println(5.display())
-  println(5.compare(6))
+  println(Describe.display(5))
+  println(Ranked.compare(5, 6))
+  println(Compare.compare(5, 6))
   println(described(5))
+  println(5)
 }
diff --git a/tests/golden/lang/traits/user_trait_method_named_like_builtin_call.stdout b/tests/golden/lang/traits/user_trait_method_named_like_builtin_call.stdout
new file mode 100644
index 000000000..9f6ea0de7
--- /dev/null
+++ b/tests/golden/lang/traits/user_trait_method_named_like_builtin_call.stdout
@@ -0,0 +1,5 @@
+described 5
+99
+-1
+described 5
+5
diff --git a/tests/golden/lang/traits/user_trait_method_named_like_builtin_is_no_builtin_impl.silt b/tests/golden/lang/traits/user_trait_method_named_like_builtin_is_no_builtin_impl.silt
index 520ec33dc..cbd81eb9f 100644
--- a/tests/golden/lang/traits/user_trait_method_named_like_builtin_is_no_builtin_impl.silt
+++ b/tests/golden/lang/traits/user_trait_method_named_like_builtin_is_no_builtin_impl.silt
@@ -8,7 +8,7 @@ trait Describe for Pt { fn display(self) -> String { "described" } }
 trait Ranked { fn compare(self, other: Self) -> Int }
 trait Ranked for Pt { fn compare(self, other: Self) -> Int { 99 } }
 fn show_it(a: a) -> String where a: Display { "{a}" }
-fn rank(a: a, b: a) -> Int where a: Ranked { a.compare(b) }
+fn rank(a: a, b: a) -> Int where a: Ranked { Ranked.compare(a, b) }
 fn main() {
   println("{Pt { x: 1 }}")
   println(show_it(Pt { x: 2 }))
diff --git a/tests/golden/lang/traits/user_trait_method_named_like_builtin_unbounded_call.silt b/tests/golden/lang/traits/user_trait_method_named_like_builtin_unbounded_call.silt
deleted file mode 100644
index 3e8f48f13..000000000
--- a/tests/golden/lang/traits/user_trait_method_named_like_builtin_unbounded_call.silt
+++ /dev/null
@@ -1,12 +0,0 @@
--- exit: 1
--- A method call on a receiver of unknown type means the one trait in
--- sight that declares the method: with a program trait that declares
--- `display` beside the builtin `Display`, the receiver needs an
--- annotation.
--- stderr-contains: error[type]: ambiguous method 'display' on type 'Int': provided by traits Describe, Display
-trait Describe { fn display(self) -> String }
-trait Describe for Int { fn display(self) -> String { "described {self}" } }
-fn main() {
-  let g = { y -> y.display() }
-  println(g(5))
-}
diff --git a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_map_field_rejected_statically.silt b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_map_field_rejected_statically.silt
index a557d78fc..8afff38fa 100644
--- a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_map_field_rejected_statically.silt
+++ b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_map_field_rejected_statically.silt
@@ -1,7 +1,7 @@
 -- exit: 1
 -- stderr-contains: error[type]: type 'Doc' does not implement trait 'Compare': field 'meta' is of type 'Map(String, Int)', which does not
 type Doc { meta: Map(String, Int) }
-fn cmp_gen(x: a, y: a) -> Int where a: Compare { x.compare(y) }
+fn cmp_gen(x: a, y: a) -> Int where a: Compare { Compare.compare(x, y) }
 fn main() {
     let d = Doc { meta: #{"a": 1} }
     println(cmp_gen(d, d))
diff --git a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_tuple_field_ordered.silt b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_tuple_field_ordered.silt
index 733e4f277..20584323b 100644
--- a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_tuple_field_ordered.silt
+++ b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__compare_on_user_record_with_tuple_field_ordered.silt
@@ -1,7 +1,7 @@
 -- A record with a tuple field is ordered: a tuple has Compare when its
 -- parts do.
 type Pair { t: (Int, Int) }
-fn cmp_gen(x: a, y: a) -> Int where a: Compare { x.compare(y) }
+fn cmp_gen(x: a, y: a) -> Int where a: Compare { Compare.compare(x, y) }
 fn main() {
     let p = Pair { t: (1, 2) }
     println(cmp_gen(p, p))
diff --git a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_record_with_channel_field_rejected_statically.silt b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_record_with_channel_field_rejected_statically.silt
index 84a04a367..801f32de8 100644
--- a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_record_with_channel_field_rejected_statically.silt
+++ b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_record_with_channel_field_rejected_statically.silt
@@ -2,7 +2,7 @@
 -- stderr-contains: error[type]: type 'Holder' does not implement trait 'Hash': field 'ch' is of type 'Channel(Int)', which does not
 import channel
 type Holder { id: String, ch: Channel(Int) }
-fn h(x: a) -> Int where a: Hash { x.hash() }
+fn h(x: a) -> Int where a: Hash { Hash.hash(x) }
 fn main() {
     let c = channel.new(1)
     let hol = Holder { id: "x", ch: c }
diff --git a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_variant_with_channel_field_rejected_statically.silt b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_variant_with_channel_field_rejected_statically.silt
index 9ea984706..c3b753b0b 100644
--- a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_variant_with_channel_field_rejected_statically.silt
+++ b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_on_user_variant_with_channel_field_rejected_statically.silt
@@ -2,7 +2,7 @@
 -- stderr-contains: error[type]: type 'V' does not implement trait 'Hash': variant 'Box1' payload #1 is of type 'Channel(Int)', which does not
 import channel
 type V { Box1(Channel(Int)), Other }
-fn h(x: a) -> Int where a: Hash { x.hash() }
+fn h(x: a) -> Int where a: Hash { Hash.hash(x) }
 fn main() {
     let v = Box1(channel.new(1))
     println(h(v))
diff --git a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_runs_on_user_record_with_tuple_field.silt b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_runs_on_user_record_with_tuple_field.silt
index 2349cc354..387ce1a77 100644
--- a/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_runs_on_user_record_with_tuple_field.silt
+++ b/tests/golden/lang/traits/vm_dispatch_unsupportable_field__hash_runs_on_user_record_with_tuple_field.silt
@@ -5,7 +5,7 @@
 import int
 import result
 type Pair { t: (Int, Int) }
-fn h(x: a) -> Int where a: Hash { x.hash() }
+fn h(x: a) -> Int where a: Hash { Hash.hash(x) }
 fn main() {
     let p = Pair { t: (1, 2) }
     let v = h(p)
diff --git a/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_record_with_tuple_field_ordered.silt b/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_record_with_tuple_field_ordered.silt
index 35221e4cb..40e4467fa 100644
--- a/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_record_with_tuple_field_ordered.silt
+++ b/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_record_with_tuple_field_ordered.silt
@@ -1,7 +1,7 @@
 -- A record with a tuple field is ordered: a tuple has Compare when its
 -- parts do.
 type Point { n: Int, t: (Int, Int), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     let p = Point { n: 1, t: (0, 0) }
     let q = Point { n: 2, t: (0, 0) }
diff --git a/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_variant_with_channel_payload_rejected_statically.silt b/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_variant_with_channel_payload_rejected_statically.silt
index 8f540d6d1..e66102966 100644
--- a/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_variant_with_channel_payload_rejected_statically.silt
+++ b/tests/golden/lang/traits/vm_dispatch_variant_record__compare_on_user_variant_with_channel_payload_rejected_statically.silt
@@ -2,5 +2,5 @@
 -- stderr-contains: error[type]: type 'Color' does not implement trait 'Compare': variant 'Holding' payload #1 is of type 'Channel(Int)', which does not
 import channel
 type Color { Red, Green, Holding(Channel(Int)), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() { println(cmp_gen(Red, Green)) }
diff --git a/tests/golden/lang/traits/vm_dispatch_variant_record__compare_runs_on_builtin_weekday.silt b/tests/golden/lang/traits/vm_dispatch_variant_record__compare_runs_on_builtin_weekday.silt
index b49310fe3..11923923c 100644
--- a/tests/golden/lang/traits/vm_dispatch_variant_record__compare_runs_on_builtin_weekday.silt
+++ b/tests/golden/lang/traits/vm_dispatch_variant_record__compare_runs_on_builtin_weekday.silt
@@ -1,3 +1,3 @@
 import time
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() { println(cmp_gen(time.Monday, time.Friday)) }
diff --git a/tests/golden/lang/traits/vm_dispatch_variant_record__hash_runs_on_user_record.silt b/tests/golden/lang/traits/vm_dispatch_variant_record__hash_runs_on_user_record.silt
index 685868aa8..efd32ed6d 100644
--- a/tests/golden/lang/traits/vm_dispatch_variant_record__hash_runs_on_user_record.silt
+++ b/tests/golden/lang/traits/vm_dispatch_variant_record__hash_runs_on_user_record.silt
@@ -1,5 +1,5 @@
 type Point { x: Int, y: Int, }
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
     let p = Point { x: 1, y: 2 }
     println(h(p))
diff --git a/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_int.silt b/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_int.silt
index c0d6c9852..a2e9c603d 100644
--- a/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_int.silt
+++ b/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_int.silt
@@ -2,7 +2,7 @@
 -- exit: 0
 -- stderr-not-contains: error
 fn pick(a: a, b: a) -> a where a: Compare {
-  match a.compare(b) {
+  match Compare.compare(a, b) {
     1 -> a
     _ -> b
   }
diff --git a/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_string.silt b/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_string.silt
index f2687c5fe..fad77a784 100644
--- a/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_string.silt
+++ b/tests/golden/lang/typecheck/numeric_defaulting__compare_constrained_fn_at_string.silt
@@ -2,7 +2,7 @@
 -- exit: 0
 -- stderr-not-contains: error
 fn pick(a: a, b: a) -> a where a: Compare {
-  match a.compare(b) {
+  match Compare.compare(a, b) {
     1 -> a
     _ -> b
   }
diff --git a/tests/golden/lang/values/a_deep_value_has_a_key.silt b/tests/golden/lang/values/a_deep_value_has_a_key.silt
index 54da07763..7903d14c8 100644
--- a/tests/golden/lang/values/a_deep_value_has_a_key.silt
+++ b/tests/golden/lang/values/a_deep_value_has_a_key.silt
@@ -45,8 +45,8 @@ fn main() {
   println(a == c)
   println(a < c)
   println(c < a)
-  println(a.hash() == b.hash())
-  println(a.hash() == c.hash())
+  println(Hash.hash(a) == Hash.hash(b))
+  println(Hash.hash(a) == Hash.hash(c))
   println(set.length(set.from_list([a, b, c])))
 
   let p = chain(50000, 0)
@@ -55,6 +55,6 @@ fn main() {
   println(p == q)
   println(p == r)
   println(p < r)
-  println(p.hash() == q.hash())
+  println(Hash.hash(p) == Hash.hash(q))
   println(set.length(set.from_list([p, q, r])))
 }
diff --git a/tests/golden/lang/values/order_does_not_depend_on_other_imports/sa/src/lib.silt b/tests/golden/lang/values/order_does_not_depend_on_other_imports/sa/src/lib.silt
index 4cf11005f..2f2768cdc 100644
--- a/tests/golden/lang/values/order_does_not_depend_on_other_imports/sa/src/lib.silt
+++ b/tests/golden/lang/values/order_does_not_depend_on_other_imports/sa/src/lib.silt
@@ -2,7 +2,7 @@ import list
 pub type ColorA { Red, Blue }
 pub fn report() -> String {
   let lt = Red < Blue
-  let cmp = Red.compare(Blue)
+  let cmp = Compare.compare(Red, Blue)
   let sorted = [Blue, Red] |> list.sort
   "Red < Blue = {lt}; Red.compare(Blue) = {cmp}; list.sort = {sorted}"
 }
diff --git a/tests/golden/lang/values/program_ioerror_beside_builtin.silt b/tests/golden/lang/values/program_ioerror_beside_builtin.silt
index 6095fba23..4374fecd1 100644
--- a/tests/golden/lang/values/program_ioerror_beside_builtin.silt
+++ b/tests/golden/lang/values/program_ioerror_beside_builtin.silt
@@ -20,14 +20,14 @@ trait Display for IoError {
 
 fn main() {
   let mine = Oops("x")
-  println(mine.message())
-  println(mine.display())
+  println(Error.message(mine))
+  println("{mine}")
   println(mine)
   match io.read_file("does-not-exist.txt") {
     Ok(_) -> println("read")
     Err(e) -> {
-      println(e.message())
-      println(e.display())
+      println(Error.message(e))
+      println("{e}")
       println(e)
     }
   }
diff --git a/tests/golden/lang/values/same_named_enums_keep_their_impls/main.silt b/tests/golden/lang/values/same_named_enums_keep_their_impls/main.silt
index 94cdbd4fa..9d23b079d 100644
--- a/tests/golden/lang/values/same_named_enums_keep_their_impls/main.silt
+++ b/tests/golden/lang/values/same_named_enums_keep_their_impls/main.silt
@@ -3,10 +3,10 @@
 -- order (stage 5 verifier F1).
 import b
 import a
-fn show(x: t) -> String where t: Display { x.display() }
+fn show(x: t) -> String where t: Display { "{x}" }
 fn main() {
-  println(a.mk().display())
-  println(b.mk().display())
+  println("{a.mk()}")
+  println("{b.mk()}")
   println(show(a.mk()))
   println(show(b.mk()))
 }
diff --git a/tests/golden/lang/values/same_named_records_methods_by_type/main.silt b/tests/golden/lang/values/same_named_records_methods_by_type/main.silt
index f13a1ff80..56bfd6f37 100644
--- a/tests/golden/lang/values/same_named_records_methods_by_type/main.silt
+++ b/tests/golden/lang/values/same_named_records_methods_by_type/main.silt
@@ -7,10 +7,10 @@ import b
 fn main() {
   let p = a.make(1)
   let q = b.make(2)
-  println(p.display())
-  println(q.display())
-  println(a.Pt.display(p))
-  println(b.Pt.display(q))
-  println(p.scale())
-  println(q.scale())
+  println("{p}")
+  println("{q}")
+  println("{p}")
+  println("{q}")
+  println(a.Scale.scale(p))
+  println(b.Scale.scale(q))
 }
diff --git a/tests/golden/lang/values/shared_variant_name_one_module_enums.silt b/tests/golden/lang/values/shared_variant_name_one_module_enums.silt
index 8a8382342..c81d53b27 100644
--- a/tests/golden/lang/values/shared_variant_name_one_module_enums.silt
+++ b/tests/golden/lang/values/shared_variant_name_one_module_enums.silt
@@ -4,9 +4,9 @@ type Shape { Circle(Int), Sq }
 trait Display for Shape { fn display(self) -> String { "A-shape" } }
 type Form { Circle(Int), Tri(Int) }
 trait Display for Form { fn display(self) -> String { "B-form" } }
-fn show(x: t) -> String where t: Display { x.display() }
+fn show(x: t) -> String where t: Display { "{x}" }
 fn main() {
-  println(Shape.Circle(1).display())
-  println(Form.Circle(1).display())
+  println("{Shape.Circle(1)}")
+  println("{Form.Circle(1)}")
   println(show(Shape.Circle(1)))
 }
diff --git a/tests/golden/lang/values/shared_variant_name_two_module_enums/main.silt b/tests/golden/lang/values/shared_variant_name_two_module_enums/main.silt
index fd92eec01..6e199e8a8 100644
--- a/tests/golden/lang/values/shared_variant_name_two_module_enums/main.silt
+++ b/tests/golden/lang/values/shared_variant_name_two_module_enums/main.silt
@@ -2,10 +2,10 @@
 -- value runs its own type's impls (F1).
 import a
 import b
-fn show(x: t) -> String where t: Display { x.display() }
+fn show(x: t) -> String where t: Display { "{x}" }
 fn main() {
-  println(a.mk().display())
-  println(b.mk().display())
+  println("{a.mk()}")
+  println("{b.mk()}")
   println(show(a.mk()))
   println(show(b.mk()))
   println(a.mk() == a.mk())
diff --git a/tests/golden/lang/values/the_hash_of_a_variant_holds_nothing_of_its_type.silt b/tests/golden/lang/values/the_hash_of_a_variant_holds_nothing_of_its_type.silt
index 084a50a18..57fe3d895 100644
--- a/tests/golden/lang/values/the_hash_of_a_variant_holds_nothing_of_its_type.silt
+++ b/tests/golden/lang/values/the_hash_of_a_variant_holds_nothing_of_its_type.silt
@@ -19,11 +19,11 @@ type There {
 }
 
 fn main() {
-  println(Dot.hash() == Point.hash())
-  println(Box(3, 4).hash() == Rect(3, 4).hash())
-  println([Box(3, 4), Dot].hash() == [Rect(3, 4), Point].hash())
+  println(Hash.hash(Dot) == Hash.hash(Point))
+  println(Hash.hash(Box(3, 4)) == Hash.hash(Rect(3, 4)))
+  println(Hash.hash([Box(3, 4), Dot]) == Hash.hash([Rect(3, 4), Point]))
   -- Which variant it is, and its fields, are in the hash.
-  println(Dot.hash() == Box(0, 0).hash())
-  println(Box(3, 4).hash() == Box(4, 3).hash())
-  println(Between { v: 1 }.hash() == Between { v: 1 }.hash())
+  println(Hash.hash(Dot) == Hash.hash(Box(0, 0)))
+  println(Hash.hash(Box(3, 4)) == Hash.hash(Box(4, 3)))
+  println(Hash.hash(Between { v: 1 }) == Hash.hash(Between { v: 1 }))
 }
diff --git a/tests/golden/lang/values/two_modules_same_variant_names/main.silt b/tests/golden/lang/values/two_modules_same_variant_names/main.silt
index 145566387..8e86a812a 100644
--- a/tests/golden/lang/values/two_modules_same_variant_names/main.silt
+++ b/tests/golden/lang/values/two_modules_same_variant_names/main.silt
@@ -12,7 +12,7 @@ fn main() {
   println("a: Red < Blue = {a.red_lt_blue()}, sorted {a.sorted()}, distinct {a.distinct()}")
   println("b: Blue < Red = {b.blue_lt_red()}, sorted {b.sorted()}, distinct {b.distinct()}")
   println("a.red() < a.blue() = {a.red() < a.blue()}; b.red() < b.blue() = {b.red() < b.blue()}")
-  println("a compare: {a.red().compare(a.blue())}; b compare: {b.red().compare(b.blue())}")
+  println("a compare: {Compare.compare(a.red(), a.blue())}; b compare: {Compare.compare(b.red(), b.blue())}")
   let ma = map.from_entries([(a.blue(), "blue"), (a.red(), "red")])
   let mb = map.from_entries([(b.blue(), "blue"), (b.red(), "red")])
   println("a keys: {map.keys(ma)}; b keys: {map.keys(mb)}")
diff --git a/tests/golden/lang/values/two_packages_same_module_type_names/da/src/lib.silt b/tests/golden/lang/values/two_packages_same_module_type_names/da/src/lib.silt
index c0fe83b0c..359815182 100644
--- a/tests/golden/lang/values/two_packages_same_module_type_names/da/src/lib.silt
+++ b/tests/golden/lang/values/two_packages_same_module_type_names/da/src/lib.silt
@@ -1,5 +1,5 @@
 import util
 pub fn mk() -> util.Pt { util.Pt { x: 1 } }
-pub fn show() -> String { mk().display() }
+pub fn show() -> String { "{mk()}" }
 pub fn reds() -> List(util.Color) { [util.Green, util.Red] }
 pub fn raw() -> util.Raw { util.Raw { v: 1 } }
diff --git a/tests/golden/lang/values/two_packages_same_module_type_names/db/src/lib.silt b/tests/golden/lang/values/two_packages_same_module_type_names/db/src/lib.silt
index c0fe83b0c..359815182 100644
--- a/tests/golden/lang/values/two_packages_same_module_type_names/db/src/lib.silt
+++ b/tests/golden/lang/values/two_packages_same_module_type_names/db/src/lib.silt
@@ -1,5 +1,5 @@
 import util
 pub fn mk() -> util.Pt { util.Pt { x: 1 } }
-pub fn show() -> String { mk().display() }
+pub fn show() -> String { "{mk()}" }
 pub fn reds() -> List(util.Color) { [util.Green, util.Red] }
 pub fn raw() -> util.Raw { util.Raw { v: 1 } }
diff --git a/tests/golden/lang/vm/returns__every_kind_from_every_shape_of_call.silt b/tests/golden/lang/vm/returns__every_kind_from_every_shape_of_call.silt
index 2260151ba..a1bb7b60f 100644
--- a/tests/golden/lang/vm/returns__every_kind_from_every_shape_of_call.silt
+++ b/tests/golden/lang/vm/returns__every_kind_from_every_shape_of_call.silt
@@ -103,31 +103,31 @@ trait Kinds {
   fn variant(self) -> Shape
   fn closure(self) -> Fn(Int) -> Int
   fn default_int(self) -> Int {
-    self.int()
+    Kinds.int(self)
   }
   fn default_float(self) -> Float {
-    self.float()
+    Kinds.float(self)
   }
   fn default_bool(self) -> Bool {
-    self.bool()
+    Kinds.bool(self)
   }
   fn default_unit(self) -> () {
-    self.unit()
+    Kinds.unit(self)
   }
   fn default_string(self) -> String {
-    self.string()
+    Kinds.string(self)
   }
   fn default_list(self) -> List(Int) {
-    self.list()
+    Kinds.list(self)
   }
   fn default_record(self) -> Point {
-    self.record()
+    Kinds.record(self)
   }
   fn default_variant(self) -> Shape {
-    self.variant()
+    Kinds.variant(self)
   }
   fn default_closure(self) -> Fn(Int) -> Int {
-    self.closure()
+    Kinds.closure(self)
   }
 }
 
@@ -241,24 +241,24 @@ fn main() {
 
   println("a method and a default method")
   let p = Point { x: 1, y: 2 }
-  println(p.int())
-  println(p.float())
-  println(p.bool())
-  println(p.unit())
-  println(p.string())
-  println(p.list())
-  println(p.record())
-  println(p.variant())
-  println(p.closure()(2))
-  println(p.default_int())
-  println(p.default_float())
-  println(p.default_bool())
-  println(p.default_unit())
-  println(p.default_string())
-  println(p.default_list())
-  println(p.default_record())
-  println(p.default_variant())
-  println(p.default_closure()(2))
+  println(Kinds.int(p))
+  println(Kinds.float(p))
+  println(Kinds.bool(p))
+  println(Kinds.unit(p))
+  println(Kinds.string(p))
+  println(Kinds.list(p))
+  println(Kinds.record(p))
+  println(Kinds.variant(p))
+  println(Kinds.closure(p)(2))
+  println(Kinds.default_int(p))
+  println(Kinds.default_float(p))
+  println(Kinds.default_bool(p))
+  println(Kinds.default_unit(p))
+  println(Kinds.default_string(p))
+  println(Kinds.default_list(p))
+  println(Kinds.default_record(p))
+  println(Kinds.default_variant(p))
+  println(Kinds.default_closure(p)(2))
 
   println("a function a builtin calls back")
   println(list.map([1, 2]) { x -> x + 6 })
diff --git a/tests/golden/lang/vm/round87_vm_method_builtinfn_pure__error_message_in_task.silt b/tests/golden/lang/vm/round87_vm_method_builtinfn_pure__error_message_in_task.silt
index fa93362e1..164d70c22 100644
--- a/tests/golden/lang/vm/round87_vm_method_builtinfn_pure__error_message_in_task.silt
+++ b/tests/golden/lang/vm/round87_vm_method_builtinfn_pure__error_message_in_task.silt
@@ -10,12 +10,12 @@ fn main() {
   let h = task.spawn({ ->
     let a = match int.parse("x") {
       Ok(_) -> "ok"
-      Err(e) -> e.message()
+      Err(e) -> Error.message(e)
     }
     channel.send(ch, a)
     let b = match io.read_file("round87_missing_file.txt") {
       Ok(_) -> "ok"
-      Err(e) -> e.message()
+      Err(e) -> Error.message(e)
     }
     "{a} | {b}"
   })
diff --git a/tests/golden/lsp/hover_on_a_trait/case.stdout b/tests/golden/lsp/hover_on_a_trait/case.stdout
index e5d5a272e..9e9fdd697 100644
--- a/tests/golden/lsp/hover_on_a_trait/case.stdout
+++ b/tests/golden/lsp/hover_on_a_trait/case.stdout
@@ -79,8 +79,8 @@ trait Display {
 
 ---
 
-How a value is shown: `println`, `print`, interpolation, `.display()`
-and `string.from` show it so. A type has it by its structure, or by an
+How a value is shown: `println`, `print`, interpolation and
+`string.from` show it so. A type has it by its structure, or by an
 impl written in the module that declares the type.
 > hover 41:76
 ```silt
@@ -134,8 +134,8 @@ trait Display {
 
 ---
 
-How a value is shown: `println`, `print`, interpolation, `.display()`
-and `string.from` show it so. A type has it by its structure, or by an
+How a value is shown: `println`, `print`, interpolation and
+`string.from` show it so. A type has it by its structure, or by an
 impl written in the module that declares the type.
 > hover 76:13
 ```silt
@@ -357,26 +357,29 @@ fn main() {
 written, else as `json.decode(value, T)` does. For a `type a` with the
 bound, `a.decode(value)`. It takes no value of the type: `x.decode(..)` on
 a value is no call of it.
-> hover 86:25
+> hover 86:18
 ```silt
-Fn(Box) -> Int
+fn size(self) -> Int
 ```
-
----
-
-Says how big.
-> hover 87:14
+> hover 87:18
 ```silt
-Fn(Box) -> Int
+fn size(self) -> Int
 ```
-> hover 88:17
+> hover 88:18
 ```silt
-Fn(Box) -> Int
+fn size(self) -> Int
 ```
-> hover 89:25
+> hover 86:12
 ```silt
-Fn(Box) -> String
+trait Sized {
+  fn size(self) -> Int
+  fn twice(self) -> Int
+}
 ```
+
+---
+
+Says how big.
 > definition 41:76
 shapes.silt:2:11-2:15
 > definition 41:85
diff --git a/tests/golden/lsp/hover_on_a_trait/main.silt b/tests/golden/lsp/hover_on_a_trait/main.silt
index dd62532c7..c12cb8726 100644
--- a/tests/golden/lsp/hover_on_a_trait/main.silt
+++ b/tests/golden/lsp/hover_on_a_trait/main.silt
@@ -11,10 +11,10 @@
 -- lsp: hover 51:8
 -- lsp: hover 58:8
 -- lsp: hover 35:35
--- lsp: hover 86:25
--- lsp: hover 87:14
--- lsp: hover 88:17
--- lsp: hover 89:25
+-- lsp: hover 86:18
+-- lsp: hover 87:18
+-- lsp: hover 88:18
+-- lsp: hover 86:12
 -- lsp: definition 41:76
 -- lsp: definition 41:85
 -- lsp: definition 68:8
@@ -26,9 +26,9 @@
 -- it), in an impl's header, as a supertrait, at its declaration. A
 -- method's signature written on several lines keeps its lines.
 -- Definition goes to a program trait's declaration; one of silt's own
--- has no file. A method's name at a call is the method, not its trait
--- (on a record literal, a binding, a call's value), and a builtin
--- module's trait is written as a program names it (`json.Value`).
+-- has no file. A method's name at a call through its trait is the method
+-- (of a record literal, a binding, a call's value), the trait's name the
+-- trait; a builtin module's trait is written as a program names it.
 import json
 import shapes
 
@@ -45,7 +45,7 @@ fn show(x: a, y: b, z: c, w: d) where a: json.Encode + Display, b: shapes.Area,
 -- Says how big.
 trait Sized {
   fn size(self) -> Int
-  fn twice(self) -> Int { self.size() * 2 }
+  fn twice(self) -> Int { Sized.size(self) * 2 }
 }
 
 trait Big: Sized {
@@ -83,8 +83,8 @@ fn mk() -> Box {
 
 fn main() {
   let b = Box { w: 1 }
-  println(Box { w: 1 }.size())
-  println(b.size())
-  println(mk().size())
-  println(Box { w: 1 }.display())
+  println(Sized.size(Box { w: 1 }))
+  println(Sized.size(b))
+  println(Sized.size(mk()))
+  println("{Box { w: 1 }}")
 }
diff --git a/tests/golden/lsp/hover_on_an_imported_item/case.stdout b/tests/golden/lsp/hover_on_an_imported_item/case.stdout
index 3112a99e8..c068d91d0 100644
--- a/tests/golden/lsp/hover_on_an_imported_item/case.stdout
+++ b/tests/golden/lsp/hover_on_an_imported_item/case.stdout
@@ -88,7 +88,7 @@ fn main() {
   let input = """{"name": "Alice", "age": 30}"""
   match json.parse(input, User) {
     Ok(user) -> println(user.name)
-    Err(e) -> println("Error: {e.message()}")
+    Err(e) -> println("Error: {Error.message(e)}")
   }
 }
 ```
diff --git a/tests/golden/lsp/json_decode_completion_on_a_value.silt b/tests/golden/lsp/json_decode_completion_on_a_value.silt
index 80fdddebf..8d9469a5c 100644
--- a/tests/golden/lsp/json_decode_completion_on_a_value.silt
+++ b/tests/golden/lsp/json_decode_completion_on_a_value.silt
@@ -1,7 +1,9 @@
 -- cmd: lsp
--- lsp: completion 13:14
--- `decode` takes no value of the type: completion after a dot on a value
--- does not offer it, also where json is imported (`display` it does).
+-- lsp: completion 15:14
+-- lsp: completion 16:23
+-- After a dot on a value completion offers its fields, no method of any
+-- trait; after `json.Decode.` nothing: `decode` takes no value of the
+-- type, so it is called through the type (`Money.decode`).
 import json
 
 type Money {
@@ -10,6 +12,6 @@ type Money {
 
 fn main() {
   let m = Money { cents: 5 }
-  println(m.d)
-  println(json.stringify(m))
+  println(m.c)
+  println(json.Decode.d)
 }
diff --git a/tests/golden/lsp/json_decode_completion_on_a_value.stdout b/tests/golden/lsp/json_decode_completion_on_a_value.stdout
index e3a3f74f1..e00cc713b 100644
--- a/tests/golden/lsp/json_decode_completion_on_a_value.stdout
+++ b/tests/golden/lsp/json_decode_completion_on_a_value.stdout
@@ -1,3 +1,6 @@
-13:11 error unknown field or method 'd' on type Money
-> completion 13:14
-display
+15:11 error type 'Money' has no field 'c'
+16:11 error trait 'json.Decode' has no method 'd'
+> completion 15:14
+cents
+> completion 16:23
+(nothing)
diff --git a/tests/golden/lsp/json_encode_completion_without_the_import.silt b/tests/golden/lsp/json_encode_completion_without_the_import.silt
deleted file mode 100644
index b403c8a36..000000000
--- a/tests/golden/lsp/json_encode_completion_without_the_import.silt
+++ /dev/null
@@ -1,15 +0,0 @@
--- cmd: lsp
--- lsp: completion 13:16
--- lsp: completion 14:14
--- Without `import json` no value has the method `encode`: completion
--- after a dot does not offer it (`display` it does).
-type Money {
-  cents: Int,
-}
-
-fn main() {
-  let m = Money { cents: 5 }
-  println(m.cents)
-  println(m.enc)
-  println(m.d)
-}
diff --git a/tests/golden/lsp/json_encode_completion_without_the_import.stdout b/tests/golden/lsp/json_encode_completion_without_the_import.stdout
deleted file mode 100644
index 1515c2499..000000000
--- a/tests/golden/lsp/json_encode_completion_without_the_import.stdout
+++ /dev/null
@@ -1,6 +0,0 @@
-13:11 error unknown field or method 'enc' on type Money
-14:11 error unknown field or method 'd' on type Money
-> completion 13:16
-(nothing)
-> completion 14:14
-display
diff --git a/tests/golden/lsp/json_encode_in_the_editor.silt b/tests/golden/lsp/json_encode_in_the_editor.silt
index 66d4e4605..79927aa78 100644
--- a/tests/golden/lsp/json_encode_in_the_editor.silt
+++ b/tests/golden/lsp/json_encode_in_the_editor.silt
@@ -1,12 +1,12 @@
 -- cmd: lsp
 -- lsp: hover 16:39
 -- lsp: hover 17:8
--- lsp: hover 22:13
--- lsp: completion 23:16
+-- lsp: hover 22:25
+-- lsp: completion 23:26
 -- lsp: definition 16:39
 -- The editor knows `json.Encode`: a hover on it in a `where` clause, on
--- `json.stringify` and on a value's `.encode()`, the method among those
--- offered after a dot, and no definition in a file (it is json's).
+-- `json.stringify` and on `json.Encode.encode`, the method offered after
+-- `json.Encode.`, and no definition in a file (it is json's).
 import json
 
 type Money {
@@ -19,7 +19,7 @@ fn send(x: a) -> String where a: json.Encode {
 
 fn main() {
   let m = Money { cents: 5 }
-  println(m.encode())
-  println(m.enc)
+  println(json.Encode.encode(m))
+  println(json.Encode.enc)
   println(send(m))
 }
diff --git a/tests/golden/lsp/json_encode_in_the_editor.stdout b/tests/golden/lsp/json_encode_in_the_editor.stdout
index c0b5eabd3..7ff5c5dd9 100644
--- a/tests/golden/lsp/json_encode_in_the_editor.stdout
+++ b/tests/golden/lsp/json_encode_in_the_editor.stdout
@@ -1,4 +1,4 @@
-23:11 error unknown field or method 'enc' on type Money
+23:11 error trait 'json.Encode' has no method 'enc'
 > hover 16:39
 ```silt
 trait json.Encode {
@@ -131,11 +131,11 @@ fn main() {
   -- "2026-10-19"
 }
 ```
-> hover 22:13
+> hover 22:25
 ```silt
-Fn(Money) -> Value
+fn encode(self) -> json.Value
 ```
-> completion 23:16
+> completion 23:26
 encode
 > definition 16:39
 (nothing)
diff --git a/tests/golden/lsp/locals_by_binding.silt b/tests/golden/lsp/locals_by_binding.silt
index c6b87d756..451ff3ebc 100644
--- a/tests/golden/lsp/locals_by_binding.silt
+++ b/tests/golden/lsp/locals_by_binding.silt
@@ -3,7 +3,7 @@
 -- lsp: references 22:7
 -- lsp: definition 23:3
 -- lsp: rename 27:13 first
--- lsp: references 33:19
+-- lsp: references 33:24
 -- lsp: references 40:21
 -- lsp: definition 41:26
 -- lsp: references 46:22
@@ -30,7 +30,7 @@ fn pair((a, b): (Int, Int), P { x, y }) {
 
 trait Scale {
   fn scale(self, by: Int) -> Int {
-    self.size() * by
+    Scale.size(self) * by
   }
   fn size(self) -> Int
 }
diff --git a/tests/golden/lsp/locals_by_binding.stdout b/tests/golden/lsp/locals_by_binding.stdout
index ed69f0bb7..81822e410 100644
--- a/tests/golden/lsp/locals_by_binding.stdout
+++ b/tests/golden/lsp/locals_by_binding.stdout
@@ -10,9 +10,9 @@ locals_by_binding.silt:22:7-22:8
 locals_by_binding.silt:26:10-26:11 => first
 locals_by_binding.silt:27:13-27:14 => first
 locals_by_binding.silt:28:17-28:18 => first
-> references 33:19
+> references 33:24
 locals_by_binding.silt:32:18-32:20
-locals_by_binding.silt:33:19-33:21
+locals_by_binding.silt:33:24-33:26
 > references 40:21
 locals_by_binding.silt:40:9-40:10
 locals_by_binding.silt:40:21-40:22
diff --git a/tests/golden/lsp/rename_by_meaning.silt b/tests/golden/lsp/rename_by_meaning.silt
index 9a949bb16..30b1d4ad4 100644
--- a/tests/golden/lsp/rename_by_meaning.silt
+++ b/tests/golden/lsp/rename_by_meaning.silt
@@ -1,9 +1,9 @@
 -- cmd: lsp
 -- lsp: rename 33:7 Sizable
--- lsp: rename 52:5 resize
--- lsp: definition 52:5
--- lsp: definition 52:18
--- lsp: definition 100:88
+-- lsp: rename 52:10 resize
+-- lsp: definition 52:10
+-- lsp: definition 52:30
+-- lsp: definition 100:93
 -- lsp: rename 34:12 me
 -- lsp: rename 56:13 width
 -- lsp: rename 57:3 width
@@ -32,7 +32,7 @@ type Box {
 
 trait Sized {
   fn scale(self, by: Int) -> Int {
-    self.size() * by
+    Sized.size(self) * by
   }
   fn size(self) -> Int
 }
@@ -49,7 +49,7 @@ type Side {
 }
 
 fn twice(x: a) -> Int where a: Sized {
-  x.scale(2) + x.size()
+  Sized.scale(x, 2) + Sized.size(x)
 }
 
 fn unbox(b: Box) -> Int {
@@ -92,10 +92,10 @@ trait Container {
 }
 
 fn head(c: t) -> <t as Container>::Item where t: Container {
-  c.first()
+  Container.first(c)
 }
 
 fn main() {
   let b = Box { w: 3 }
-  println(twice(b) + unbox(b) + either(Left(1)) + scopes(1) + blocks(1) + loops(1) + b.size())
+  println(twice(b) + unbox(b) + either(Left(1)) + scopes(1) + blocks(1) + loops(1) + Sized.size(b))
 }
diff --git a/tests/golden/lsp/rename_by_meaning.stdout b/tests/golden/lsp/rename_by_meaning.stdout
index 16e2cfda1..78bcb2fa8 100644
--- a/tests/golden/lsp/rename_by_meaning.stdout
+++ b/tests/golden/lsp/rename_by_meaning.stdout
@@ -1,14 +1,18 @@
 > rename 33:7 Sizable
 rename_by_meaning.silt:33:7-33:12 => Sizable
+rename_by_meaning.silt:35:5-35:10 => Sizable
 rename_by_meaning.silt:40:7-40:12 => Sizable
 rename_by_meaning.silt:51:32-51:37 => Sizable
-> rename 52:5 resize
+rename_by_meaning.silt:52:3-52:8 => Sizable
+rename_by_meaning.silt:52:23-52:28 => Sizable
+rename_by_meaning.silt:100:86-100:91 => Sizable
+> rename 52:10 resize
 (nothing)
-> definition 52:5
+> definition 52:10
 rename_by_meaning.silt:34:6-34:11
-> definition 52:18
+> definition 52:30
 rename_by_meaning.silt:37:6-37:10
-> definition 100:88
+> definition 100:93
 rename_by_meaning.silt:41:6-41:10
 > rename 34:12 me
 error: `self` is the receiver of a method and cannot be renamed: a method's first parameter is `self`
@@ -57,3 +61,4 @@ rename_by_meaning.silt:81:25-81:26
 rename_by_meaning.silt:89:7-89:16 => Holder
 rename_by_meaning.silt:94:24-94:33 => Holder
 rename_by_meaning.silt:94:50-94:59 => Holder
+rename_by_meaning.silt:95:3-95:12 => Holder
diff --git a/tests/golden/lsp/trait_call_in_the_editor/case.stdout b/tests/golden/lsp/trait_call_in_the_editor/case.stdout
new file mode 100644
index 000000000..8d2f19af7
--- /dev/null
+++ b/tests/golden/lsp/trait_call_in_the_editor/case.stdout
@@ -0,0 +1,41 @@
+23:11 error trait 'shapes.Area' has no method 'ar'
+24:11 error trait 'Display' has no method 'dis'
+25:11 error trait 'Greet' has no method 'gr'
+> completion 23:23
+area
+scaled
+> completion 24:20
+(nothing)
+> completion 25:18
+greet
+> hover 26:24
+```silt
+fn area(self) -> Int
+```
+
+---
+
+The area, in square units.
+> hover 26:19
+```silt
+pub trait Area {
+  fn area(self) -> Int
+  fn scaled(self, by: Int) -> Int
+}
+```
+
+---
+
+A shape's area.
+> signature 27:33
+fn scaled(self, by: Int) -> Int
+argument 2: by: Int
+> definition 26:24
+shapes.silt:11:6-11:10
+> definition 28:18
+main.silt:20:26-20:31
+> references 28:12
+main.silt:19:7-19:12
+main.silt:20:7-20:12
+main.silt:25:11-25:16
+main.silt:28:11-28:16
diff --git a/tests/golden/lsp/trait_call_in_the_editor/main.silt b/tests/golden/lsp/trait_call_in_the_editor/main.silt
new file mode 100644
index 000000000..1e0433e63
--- /dev/null
+++ b/tests/golden/lsp/trait_call_in_the_editor/main.silt
@@ -0,0 +1,29 @@
+-- cmd: lsp
+-- lsp: completion 23:23
+-- lsp: completion 24:20
+-- lsp: completion 25:18
+-- lsp: hover 26:24
+-- lsp: hover 26:19
+-- lsp: signature 27:33
+-- lsp: definition 26:24
+-- lsp: definition 28:18
+-- lsp: references 28:12
+-- The editor knows a call through a trait: after `Trait.` it offers the
+-- methods the trait is called with (not `Display`'s); hover on the
+-- method shows it as the trait declares it, on the trait the trait;
+-- signature help counts the argument of type Self; definition goes to
+-- the method of the impl, or the trait's; references find the trait's
+-- name at its calls.
+import shapes
+import shapes.{ Square }
+trait Greet { fn greet(self) -> String }
+trait Greet for Int { fn greet(self) -> String { "hi" } }
+fn main() {
+  let s = Square { side: 2 }
+  println(shapes.Area.ar)
+  println(Display.dis)
+  println(Greet.gr)
+  println(shapes.Area.area(s))
+  println(shapes.Area.scaled(s, 3))
+  println(Greet.greet(5))
+}
diff --git a/tests/golden/lsp/trait_call_in_the_editor/shapes.silt b/tests/golden/lsp/trait_call_in_the_editor/shapes.silt
new file mode 100644
index 000000000..7bcb3d458
--- /dev/null
+++ b/tests/golden/lsp/trait_call_in_the_editor/shapes.silt
@@ -0,0 +1,13 @@
+pub type Square { side: Int }
+
+-- A shape's area.
+pub trait Area {
+  -- The area, in square units.
+  fn area(self) -> Int
+  fn scaled(self, by: Int) -> Int
+}
+
+trait Area for Square {
+  fn area(self) -> Int { self.side * self.side }
+  fn scaled(self, by: Int) -> Int { self.side * by }
+}
diff --git a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__assoc_type_basic_snippet_runs.silt b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__assoc_type_basic_snippet_runs.silt
index 0a7d783ea..4823d5ef2 100644
--- a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__assoc_type_basic_snippet_runs.silt
+++ b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__assoc_type_basic_snippet_runs.silt
@@ -15,5 +15,5 @@ trait Stream for Wrap {
 
 fn main() {
   let w = Wrap { v: 7 }
-  println(w.first())
+  println(Stream.first(w))
 }
diff --git a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__bound_on_assoc_type_snippet_typechecks.silt b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__bound_on_assoc_type_snippet_typechecks.silt
index 04b4be269..afdfd2619 100644
--- a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__bound_on_assoc_type_snippet_typechecks.silt
+++ b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__bound_on_assoc_type_snippet_typechecks.silt
@@ -12,5 +12,5 @@ trait Container for Box {
 
 fn main() {
   let b = Box { v: 5 }
-  println(b.first())
+  println(Container.first(b))
 }
diff --git a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__multiple_assoc_types_snippet_runs.silt b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__multiple_assoc_types_snippet_runs.silt
index 6ee0db667..05842af4f 100644
--- a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__multiple_assoc_types_snippet_runs.silt
+++ b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__multiple_assoc_types_snippet_runs.silt
@@ -17,6 +17,6 @@ trait Pair for IntStringPair {
 
 fn main() {
   let p = IntStringPair { a: 13, b: "ok" }
-  println(p.first())
-  println(p.second())
+  println(Pair.first(p))
+  println(Pair.second(p))
 }
diff --git a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__qualified_projection_snippet_runs.silt b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__qualified_projection_snippet_runs.silt
index 2457479eb..5b39f2256 100644
--- a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__qualified_projection_snippet_runs.silt
+++ b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__qualified_projection_snippet_runs.silt
@@ -11,7 +11,7 @@ trait Producer for Wrap {
 }
 
 fn first_out(w: Wrap) -> <Wrap as Producer>::Out {
-  w.produce()
+  Producer.produce(w)
 }
 
 fn main() {
diff --git a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__supertrait_assoc_inheritance_snippet_runs.silt b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__supertrait_assoc_inheritance_snippet_runs.silt
index d57feac23..1dd8adb86 100644
--- a/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__supertrait_assoc_inheritance_snippet_runs.silt
+++ b/tests/golden/meta/assoc_types/docs_round68_assoc_types_and_rows_walker_tests__supertrait_assoc_inheritance_snippet_runs.silt
@@ -20,5 +20,5 @@ trait Sub for Wrap {
 
 fn main() {
   let w = Wrap { v: 41 }
-  println(w.first())
+  println(Sub.first(w))
 }
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage.silt
index fa65fd3e3..bdec174df 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage.silt
@@ -3,14 +3,14 @@ type Tagged { Foo(Int), Bar(Int, String), }
 type Point { x: Int, y: Int, }
 type Box(a) { Boxed(a), }
 type Wrapped(a) { value: a }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(cmp_gen(Red, Green))
     println(cmp_gen(Foo(5), Foo(3)))
     println(eq_gen(Point { x: 1, y: 2 }, Point { x: 1, y: 2 }))
     println(cmp_gen(Boxed(1), Boxed(2)))
     println(d(Wrapped { value: 42 }))
-    println(Color.compare(Red, Green))
+    println(Compare.compare(Red, Green))
 }
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage_extended_shapes.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage_extended_shapes.silt
index 8c9da0e69..003d651b4 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage_extended_shapes.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__barrage_extended_shapes.silt
@@ -2,10 +2,10 @@ type Tree { Leaf, Node(Tree, Tree), }
 type GTree(a) { GLeaf, GNode(GTree(a), GTree(a)), }
 type Big { a: Int, b: Int, c: Int, d: String, }
 type Status { Active(Int), Pending, Done, Cancelled(String), Failed(Int, String), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     -- Shape 7: self-recursive enum
     println(cmp_gen(Leaf, Node(Leaf, Leaf)))
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__builtin_types.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__builtin_types.silt
index b3f5e1a13..392583156 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__builtin_types.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__builtin_types.silt
@@ -2,10 +2,10 @@
 -- the auto-derived traits as user types do.
 import time
 import http
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(cmp_gen(time.Monday, time.Friday))
     println(eq_gen(time.Monday, time.Monday))
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape1_nullary_enum.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape1_nullary_enum.silt
index 8e0fc14ee..9b4cfa9ed 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape1_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape1_nullary_enum.silt
@@ -1,15 +1,15 @@
 -- The auto-derived Compare/Equal/Hash/Display of a nullary enum,
 -- through `where` bounds and qualified `Type.method` calls.
 type Color { Red, Green, Blue, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(cmp_gen(Red, Green))
     println(eq_gen(Red, Green))
     let _ = h(Red)
     println(d(Red))
-    println(Color.compare(Red, Green))
-    println(Color.equal(Red, Green))
+    println(Compare.compare(Red, Green))
+    println(Red == Green)
 }
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape2_enum_with_args.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape2_enum_with_args.silt
index 8cb36859b..66c36ade5 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape2_enum_with_args.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape2_enum_with_args.silt
@@ -1,8 +1,8 @@
 type Tagged { Foo(Int), Bar(Int, String), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(cmp_gen(Foo(1), Foo(2)))
     println(eq_gen(Bar(1, "x"), Bar(1, "y")))
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape3_record.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape3_record.silt
index b7f993c22..3990d63d7 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape3_record.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape3_record.silt
@@ -1,16 +1,16 @@
 type Point { x: Int, y: Int, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     let p = Point { x: 1, y: 2 }
     let q = Point { x: 1, y: 3 }
     println(cmp_gen(p, q))
     println(eq_gen(p, q))
-    println(h(p) == p.hash())
+    println(h(p) == Hash.hash(p))
     println(d(p))
-    println(p.compare(q))
-    println(p.equal(q))
-    println(p.display())
+    println(Compare.compare(p, q))
+    println(p == q)
+    println("{p}")
 }
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape4_generic_enum.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape4_generic_enum.silt
index 0565c23e2..47a31fe20 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape4_generic_enum.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape4_generic_enum.silt
@@ -1,12 +1,12 @@
 type Box(a) { Foo(a), Bar(a, a), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     println(cmp_gen(Foo(1), Foo(2)))
     println(eq_gen(Bar(1, 2), Bar(1, 3)))
     let _ = h(Foo(7))
     println(d(Bar(1, 2)))
-    println(Box.compare(Foo(1), Foo(2)))
+    println(Compare.compare(Foo(1), Foo(2)))
 }
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape5_generic_enum_two_params.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape5_generic_enum_two_params.silt
index e10ce0445..f33cf0616 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape5_generic_enum_two_params.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape5_generic_enum_two_params.silt
@@ -1,7 +1,7 @@
 type Pair(a, b) { Tup(a, b), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
     println(cmp_gen(Tup(1, "a"), Tup(2, "b")))
     println(eq_gen(Tup(1, "x"), Tup(1, "x")))
diff --git a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape6_generic_record.silt b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape6_generic_record.silt
index 6ecd86879..f6ee68049 100644
--- a/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape6_generic_record.silt
+++ b/tests/golden/meta/auto_derive/auto_derive_dead_arm_proof_tests__shape6_generic_record.silt
@@ -1,8 +1,8 @@
 type Wrapped(a) { value: a }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     let w = Wrapped { value: 5 }
     let v = Wrapped { value: 7 }
@@ -10,6 +10,6 @@ fn main() {
     println(eq_gen(w, v))
     let _ = h(w)
     println(d(w))
-    println(w.compare(v))
-    println(w.equal(v))
+    println(Compare.compare(w, v))
+    println(w == v)
 }
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_nullary_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_nullary_enum.silt
index c0ba17934..f5a189c55 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_nullary_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Tri { A, B, C, }
 fn main() {
     println(cmp_gen(A, B))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_payload_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_payload_enum.silt
index 60cf3a942..14fbf7ee6 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_payload_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_multi_variant_payload_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Tagged { Foo(Int), Bar(Int, String), }
 fn main() {
     println(cmp_gen(Foo(1), Foo(2)))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_payload_variants_use_decl_order_ordinals_too.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_payload_variants_use_decl_order_ordinals_too.silt
index 00a79d7a1..8c954999e 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_payload_variants_use_decl_order_ordinals_too.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_payload_variants_use_decl_order_ordinals_too.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Status { Pending, Active(Int), Done, }
 fn main() {
     println(cmp_gen(Pending, Active(99)))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_decl_order_when_alphabet_disagrees.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_decl_order_when_alphabet_disagrees.silt
index a9582c135..a4e2ebb22 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_decl_order_when_alphabet_disagrees.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_decl_order_when_alphabet_disagrees.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type ZAM { Z, A, M, }
 fn main() {
     println(cmp_gen(Z, A))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_declaration_order_ordinals.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_declaration_order_ordinals.silt
index 1dd981b08..d2362f954 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_declaration_order_ordinals.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_pins_declaration_order_ordinals.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Three { A, B, C, }
 fn main() {
     println(cmp_gen(A, B))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_single_variant_nullary_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_single_variant_nullary_enum.silt
index 544cd9879..eec295729 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_single_variant_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__compare_single_variant_nullary_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Solo { Only, }
 fn main() {
     println(cmp_gen(Only, Only))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_nullary_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_nullary_enum.silt
index 5217e011c..e55074755 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_nullary_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Tri { A, B, C, }
 fn main() {
     println(d(A))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_payload_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_payload_enum.silt
index 2e1274db8..59a0ca5b7 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_payload_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_multi_variant_payload_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Tagged { Foo(Int), Bar(Int, String), }
 fn main() {
     println(d(Foo(7)))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_single_variant_nullary_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_single_variant_nullary_enum.silt
index e0238ab4c..ce80041a2 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_single_variant_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__display_single_variant_nullary_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Solo { Only, }
 fn main() {
     println(d(Only))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_nullary_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_nullary_enum.silt
index 6e8eae9d2..59cc634fc 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_nullary_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Tri { A, B, C, }
 fn main() {
     println(eq_gen(A, A))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_payload_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_payload_enum.silt
index 408a970c3..8c290644f 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_payload_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_multi_variant_payload_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Tagged { Foo(Int), Bar(Int, String), }
 fn main() {
     println(eq_gen(Foo(1), Foo(1)))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_single_variant_nullary_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_single_variant_nullary_enum.silt
index cba3e3a1c..eb46c2d00 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_single_variant_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__equal_single_variant_nullary_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Solo { Only, }
 fn main() {
     println(eq_gen(Only, Only))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_multi_variant_payload_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_multi_variant_payload_enum.silt
index ed3e8a61c..126eb599a 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_multi_variant_payload_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_multi_variant_payload_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Tagged { Foo(Int), Bar(Int, String), }
 fn main() {
     let a = h(Foo(7))
diff --git a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_single_variant_nullary_enum.silt b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_single_variant_nullary_enum.silt
index 04a4dde6c..40a9a9660 100644
--- a/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_single_variant_nullary_enum.silt
+++ b/tests/golden/meta/auto_derive/round69_auto_derive_scaffold_collapse_lock_tests__hash_single_variant_nullary_enum.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Solo { Only, }
 fn main() {
     let h1 = h(Only)
diff --git a/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__every_error_enum_message_dispatches.silt b/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__every_error_enum_message_dispatches.silt
index 75729dd9b..9542462eb 100644
--- a/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__every_error_enum_message_dispatches.silt
+++ b/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__every_error_enum_message_dispatches.silt
@@ -13,11 +13,11 @@ import time
 import bytes
 
 fn main() {
-  println(io.NotFound("missing.txt").message())
-  println(json.MissingField("name").message())
-  println(toml.MissingField("key").message())
-  println(int.Empty.message())
-  println(regex.TooBig.message())
-  println(time.OutOfRange("month 13").message())
-  println(bytes.InvalidHex("zz").message())
+  println(Error.message(io.NotFound("missing.txt")))
+  println(Error.message(json.MissingField("name")))
+  println(Error.message(toml.MissingField("key")))
+  println(Error.message(int.Empty))
+  println(Error.message(regex.TooBig))
+  println(Error.message(time.OutOfRange("month 13")))
+  println(Error.message(bytes.InvalidHex("zz")))
 }
diff --git a/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__the_http_and_tcp_error_enum_messages_dispatch.silt b/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__the_http_and_tcp_error_enum_messages_dispatch.silt
index 2f5b5859b..62a6726ea 100644
--- a/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__the_http_and_tcp_error_enum_messages_dispatch.silt
+++ b/tests/golden/meta/errors/round73_error_enum_registry_parity_tests__the_http_and_tcp_error_enum_messages_dispatch.silt
@@ -8,6 +8,6 @@ import http
 import tcp
 
 fn main() {
-  println(http.Timeout.message())
-  println(tcp.Closed.message())
+  println(Error.message(http.Timeout))
+  println(Error.message(tcp.Closed))
 }
diff --git a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__list_unknown_method_names_bare_head.silt b/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__list_unknown_method_names_bare_head.silt
deleted file mode 100644
index c3e404c49..000000000
--- a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__list_unknown_method_names_bare_head.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'qqqqqqqq_unrelated' on List
--- stderr-not-contains: on type List
-fn main() {
-  let xs = [1, 2, 3]
-  println(xs.qqqqqqqq_unrelated())
-}
diff --git a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__list_unknown_method_suggests_close_match.silt b/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__list_unknown_method_suggests_close_match.silt
deleted file mode 100644
index 27fa1c87d..000000000
--- a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__list_unknown_method_suggests_close_match.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method
--- stderr-contains: help: did you mean `display`?
-fn main() {
-  let xs = [1, 2, 3]
-  println(xs.dispaly())
-}
diff --git a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__map_unknown_method_names_bare_head.silt b/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__map_unknown_method_names_bare_head.silt
deleted file mode 100644
index 78919d0c9..000000000
--- a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__map_unknown_method_names_bare_head.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'qqqqqqqq_unrelated' on Map
--- stderr-not-contains: on type Map
-fn main() {
-  let m = #{ "a": 1, "b": 2 }
-  println(m.qqqqqqqq_unrelated())
-}
diff --git a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__set_unknown_method_names_bare_head.silt b/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__set_unknown_method_names_bare_head.silt
deleted file mode 100644
index bee146fab..000000000
--- a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__set_unknown_method_names_bare_head.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'qqqqqqqq_unrelated' on Set
--- stderr-not-contains: on type Set
-fn main() {
-  let s = #[1, 2, 3]
-  println(s.qqqqqqqq_unrelated())
-}
diff --git a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__tuple_unknown_method_names_bare_head.silt b/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__tuple_unknown_method_names_bare_head.silt
deleted file mode 100644
index 58290e516..000000000
--- a/tests/golden/meta/errors/round77_container_method_arms_collapse_tests__tuple_unknown_method_names_bare_head.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'qqqqqqqq_unrelated' on Tuple
--- stderr-not-contains: on type Tuple
-fn main() {
-  let t = (1, 2)
-  println(t.qqqqqqqq_unrelated())
-}
diff --git a/tests/golden/meta/generics/generics_doc_examples__trait_default_method_show.silt b/tests/golden/meta/generics/generics_doc_examples__trait_default_method_show.silt
index a06da5c2a..42e5118fa 100644
--- a/tests/golden/meta/generics/generics_doc_examples__trait_default_method_show.silt
+++ b/tests/golden/meta/generics/generics_doc_examples__trait_default_method_show.silt
@@ -10,6 +10,6 @@ trait Show for Item {
 }
 
 fn main() {
-  println(Item { v: 1 }.show())
-  println(Item { v: 1 }.debug())
+  println(Show.show(Item { v: 1 }))
+  println(Show.debug(Item { v: 1 }))
 }
diff --git a/tests/golden/meta/generics/generics_doc_examples__trait_show_override.silt b/tests/golden/meta/generics/generics_doc_examples__trait_show_override.silt
index 332f2e0c9..cafdeeafa 100644
--- a/tests/golden/meta/generics/generics_doc_examples__trait_show_override.silt
+++ b/tests/golden/meta/generics/generics_doc_examples__trait_show_override.silt
@@ -11,6 +11,6 @@ trait Show for Item {
 }
 
 fn main() {
-  println(Item { v: 1 }.show())
-  println(Item { v: 1 }.debug())
+  println(Show.show(Item { v: 1 }))
+  println(Show.debug(Item { v: 1 }))
 }
diff --git a/tests/golden/meta/generics/generics_doc_examples__value_receiver_on_no_self_rejected.silt b/tests/golden/meta/generics/generics_doc_examples__value_receiver_on_no_self_rejected.silt
index d3fde0fbe..d66199901 100644
--- a/tests/golden/meta/generics/generics_doc_examples__value_receiver_on_no_self_rejected.silt
+++ b/tests/golden/meta/generics/generics_doc_examples__value_receiver_on_no_self_rejected.silt
@@ -1,7 +1,8 @@
 -- cmd: check
 -- exit: 1
 -- stderr-contains: error[type]
--- stderr-contains: takes no `self`
+-- stderr-contains: type 'Int' has no field 'default'
+-- stderr-contains: call it on the type, `Int.default()`
 trait Default {
     fn default() -> Self
 }
diff --git a/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_builtin_trait_for_local_type/main.silt b/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_builtin_trait_for_local_type/main.silt
index 7607e57e7..e6d69ed65 100644
--- a/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_builtin_trait_for_local_type/main.silt
+++ b/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_builtin_trait_for_local_type/main.silt
@@ -8,5 +8,5 @@ trait Display for Color {
 
 fn main() {
   let c: Color = Red
-  println(c.display())
+  println("{c}")
 }
diff --git a/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_builtin_type/main.silt b/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_builtin_type/main.silt
index 9bd533b46..54211032b 100644
--- a/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_builtin_type/main.silt
+++ b/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_builtin_type/main.silt
@@ -7,5 +7,5 @@ trait Greet for List(a) {
 
 fn main() {
   let xs = [1, 2, 3]
-  println(xs.greet())
+  println(Greet.greet(xs))
 }
diff --git a/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_local_type/main.silt b/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_local_type/main.silt
index fbd545c61..79fb235f0 100644
--- a/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_local_type/main.silt
+++ b/tests/golden/meta/traits/docs_round68_traits_doc_tests__impl_place_local_trait_for_local_type/main.silt
@@ -7,5 +7,5 @@ trait Greet for Color {
 
 fn main() {
   let c: Color = Red
-  println(c.greet())
+  println(Greet.greet(c))
 }
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_nested_record_recurses_through_field_compare.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_nested_record_recurses_through_field_compare.silt
index 2b15fd4c7..b58976f0d 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_nested_record_recurses_through_field_compare.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_nested_record_recurses_through_field_compare.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Inner { x: Int }
 type Wrap { r: Inner, tag: Int }
 fn main() {
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_one_field_record.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_one_field_record.silt
index 4ba55ff57..04fa2e8b0 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_one_field_record.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_one_field_record.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type One { x: Int }
 fn main() {
     let a = One { x: 1 }
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_pins_field_declaration_order.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_pins_field_declaration_order.silt
index 3651b9196..48be93899 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_pins_field_declaration_order.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_pins_field_declaration_order.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type R { z: Int, a: Int, m: Int }
 fn main() {
     println(cmp_gen(R { z: 1, a: 9, m: 9 }, R { z: 2, a: 0, m: 0 }))
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_three_field_record_lex_order.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_three_field_record_lex_order.silt
index 2b5cd4c31..b07954bd8 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_three_field_record_lex_order.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__compare_three_field_record_lex_order.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type R { a: Int, b: Int, c: Int }
 fn main() {
     println(cmp_gen(R { a: 1, b: 0, c: 0 }, R { a: 2, b: 0, c: 0 }))
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_nested_record.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_nested_record.silt
index 489d00b78..020bf45f3 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_nested_record.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_nested_record.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Inner { x: Int }
 type Wrap { r: Inner, tag: Int }
 fn main() {
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_one_field_record.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_one_field_record.silt
index 67028846d..b6b53c7fd 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_one_field_record.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_one_field_record.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type One { x: Int }
 fn main() {
     println(d(One { x: 7 }))
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_pins_field_declaration_order.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_pins_field_declaration_order.silt
index 86c2c2310..4c487c21b 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_pins_field_declaration_order.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_pins_field_declaration_order.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type R { z: Int, a: Int, m: Int }
 fn main() {
     println(d(R { z: 1, a: 2, m: 3 }))
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_three_field_record.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_three_field_record.silt
index a14f57538..92d69c17c 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_three_field_record.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__display_three_field_record.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type R { a: Int, b: Int, c: String }
 fn main() {
     println(d(R { a: 1, b: 2, c: "hi" }))
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_nested_record_recurses_through_field_equal.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_nested_record_recurses_through_field_equal.silt
index 642311696..70aef7158 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_nested_record_recurses_through_field_equal.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_nested_record_recurses_through_field_equal.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Inner { x: Int }
 type Wrap { r: Inner, tag: Int }
 fn main() {
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_one_field_record.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_one_field_record.silt
index bc0182a3c..2d2d0c955 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_one_field_record.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_one_field_record.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type One { x: Int }
 fn main() {
     println(eq_gen(One { x: 1 }, One { x: 1 }))
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_three_field_record_left_fold.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_three_field_record_left_fold.silt
index c588eca1b..8c1013fe4 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_three_field_record_left_fold.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__equal_three_field_record_left_fold.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type R { a: Int, b: Int, c: Int }
 fn main() {
     println(eq_gen(R { a: 1, b: 2, c: 3 }, R { a: 1, b: 2, c: 3 }))
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_nested_record_recurses_through_field_hash.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_nested_record_recurses_through_field_hash.silt
index 9d3dcf8d8..f9b4ebec2 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_nested_record_recurses_through_field_hash.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_nested_record_recurses_through_field_hash.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type Inner { x: Int }
 type Wrap { r: Inner, tag: Int }
 fn main() {
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_one_field_record.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_one_field_record.silt
index c9987e094..c209eefda 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_one_field_record.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_one_field_record.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type One { x: Int }
 fn main() {
     let h1 = h(One { x: 7 })
diff --git a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_three_field_record_combine.silt b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_three_field_record_combine.silt
index a0207c717..148a73224 100644
--- a/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_three_field_record_combine.silt
+++ b/tests/golden/meta/traits/round73_auto_derive_record_scaffold_collapse__hash_three_field_record_combine.silt
@@ -1,7 +1,7 @@
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
-fn h(a: a) -> Int where a: Hash { a.hash() }
-fn d(a: a) -> String where a: Display { a.display() }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
+fn d(a: a) -> String where a: Display { "{a}" }
 type R { a: Int, b: Int, c: Int }
 fn main() {
     let h1 = h(R { a: 1, b: 2, c: 3 })
diff --git a/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__user_trait_for_unit_dispatches.silt b/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__user_trait_for_unit_dispatches.silt
index 898fb1fe2..5fa559e4a 100644
--- a/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__user_trait_for_unit_dispatches.silt
+++ b/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__user_trait_for_unit_dispatches.silt
@@ -4,5 +4,5 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Unit { fn greet(self) -> String { "hi" } }
 fn main() {
   let u = ()
-  println(u.greet())
+  println(Greet.greet(u))
 }
diff --git a/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__where_clause_instantiations_independent.silt b/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__where_clause_instantiations_independent.silt
index 0efb17e58..80606590f 100644
--- a/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__where_clause_instantiations_independent.silt
+++ b/tests/golden/meta/traits/round75_typechecker_remap_and_dedup_tests__where_clause_instantiations_independent.silt
@@ -1,6 +1,6 @@
 -- One constrained generic instantiated twice with different types: the
 -- where-clause tyvar of the first call must not leak into the second.
-fn show(x: b, type b) -> String where b: Display { x.display() }
+fn show(x: b, type b) -> String where b: Display { "{x}" }
 
 fn main() {
   let r1 = show(42, Int)
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__ambiguous_method_across_distinct_traits_names_both.silt b/tests/golden/meta/typecheck/type_audit_regressions__ambiguous_method_across_distinct_traits_names_both.silt
deleted file mode 100644
index c2b0f884c..000000000
--- a/tests/golden/meta/typecheck/type_audit_regressions__ambiguous_method_across_distinct_traits_names_both.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: error[type]: ambiguous method 'name' on type 'Int': provided by traits First, Second
-trait First { fn name(self) -> String }
-trait Second { fn name(self) -> String }
-trait First for Int { fn name(self) -> String { "first" } }
-trait Second for Int { fn name(self) -> String { "second" } }
-fn main() { println((5).name()) }
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__ambiguous_method_across_distinct_traits_rejected.silt b/tests/golden/meta/typecheck/type_audit_regressions__ambiguous_method_across_distinct_traits_rejected.silt
deleted file mode 100644
index 3d7a72068..000000000
--- a/tests/golden/meta/typecheck/type_audit_regressions__ambiguous_method_across_distinct_traits_rejected.silt
+++ /dev/null
@@ -1,9 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: error[type]
--- stderr-contains: ambiguous method 'name' on type 'Int'
-trait First { fn name(self) -> String }
-trait Second { fn name(self) -> String }
-trait First for Int { fn name(self) -> String { "first" } }
-trait Second for Int { fn name(self) -> String { "second" } }
-fn main() { println((5).name()) }
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__receiver_method_correct_arity_accepted.silt b/tests/golden/meta/typecheck/type_audit_regressions__receiver_method_correct_arity_accepted.silt
index db99a3537..45c5d6945 100644
--- a/tests/golden/meta/typecheck/type_audit_regressions__receiver_method_correct_arity_accepted.silt
+++ b/tests/golden/meta/typecheck/type_audit_regressions__receiver_method_correct_arity_accepted.silt
@@ -1,5 +1,6 @@
 -- cmd: check
 -- exit: 0
+import string
 fn main() {
-  println("hello".display())
+  println(string.from("hello"))
 }
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__receiver_method_extra_arg_rejected.silt b/tests/golden/meta/typecheck/type_audit_regressions__receiver_method_extra_arg_rejected.silt
deleted file mode 100644
index d3529261f..000000000
--- a/tests/golden/meta/typecheck/type_audit_regressions__receiver_method_extra_arg_rejected.silt
+++ /dev/null
@@ -1,7 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: error[type]
--- stderr-contains: method `display` expects 0 arguments, got 1
-fn main() {
-  println("hello".display("extra"))
-}
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_across_scheme_narrowing.silt b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_across_scheme_narrowing.silt
index 4ca6a9bfb..183d48083 100644
--- a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_across_scheme_narrowing.silt
+++ b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_across_scheme_narrowing.silt
@@ -4,7 +4,7 @@
 -- stderr-contains: does not implement trait 'Doublable'
 trait Doublable { fn doubled(self) -> Int }
 trait Doublable for Int { fn doubled(self) -> Int { self * 2 } }
-fn use_doublable(x: t) where t: Doublable { x.doubled() }
+fn use_doublable(x: t) where t: Doublable { Doublable.doubled(x) }
 fn main() {
   let s = "text"
   let r = use_doublable(s)
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_inside_callback_lambda.silt b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_inside_callback_lambda.silt
index ef516975e..a49a0cc09 100644
--- a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_inside_callback_lambda.silt
+++ b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_preserved_inside_callback_lambda.silt
@@ -5,7 +5,7 @@
 trait Doubler { fn double(self) -> Int }
 trait Doubler for Int { fn double(self) -> Int { self * 2 } }
 fn run_callback(f) { f("hello") }
-fn needs_doubler(x: a) where a: Doubler { x.double() }
+fn needs_doubler(x: a) where a: Doubler { Doubler.double(x) }
 fn main() {
   let r = run_callback({ x -> needs_doubler(x) })
   println(r)
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_accepts_declared_constraint.silt b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_accepts_declared_constraint.silt
index b90d34eec..2ef450e69 100644
--- a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_accepts_declared_constraint.silt
+++ b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_accepts_declared_constraint.silt
@@ -6,6 +6,6 @@ trait Showable {
 trait Showable for Int {
   fn present(self) -> String { "i" }
 }
-fn show(x: a) -> String where a: Showable { x.present() }
+fn show(x: a) -> String where a: Showable { Showable.present(x) }
 fn indirect(x: a) -> String where a: Showable { show(x) }
 fn main() { println(indirect(5)) }
diff --git a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_rejects_missing_declaration.silt b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_rejects_missing_declaration.silt
index fc2820d48..f3af84246 100644
--- a/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_rejects_missing_declaration.silt
+++ b/tests/golden/meta/typecheck/type_audit_regressions__where_constraint_propagation_rejects_missing_declaration.silt
@@ -8,6 +8,6 @@ trait Showable {
 trait Showable for Int {
   fn present(self) -> String { "i" }
 }
-fn show(x: a) -> String where a: Showable { x.present() }
+fn show(x: a) -> String where a: Showable { Showable.present(x) }
 fn indirect(x: a) -> String { show(x) }
 fn main() { println(indirect(5)) }
diff --git a/tests/golden/postgres/postgres_channels__the_rows_say_what_the_channels_carry.silt b/tests/golden/postgres/postgres_channels__the_rows_say_what_the_channels_carry.silt
index bf95f2039..ea2112cbc 100644
--- a/tests/golden/postgres/postgres_channels__the_rows_say_what_the_channels_carry.silt
+++ b/tests/golden/postgres/postgres_channels__the_rows_say_what_the_channels_carry.silt
@@ -16,7 +16,7 @@ fn rows(pool: postgres.PgPool) -> Int {
       match channel.receive(typed) {
         Some(Ok(row)) -> row.amount
         Some(Err(e)) -> {
-          println(e.message())
+          println(Error.message(e))
           0
         }
         _ -> 0
@@ -32,7 +32,7 @@ fn notes(pool: postgres.PgPool) -> String {
       Some(note) -> "{note.channel}: {note.payload} from {note.pid}"
       None -> "closed"
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 
diff --git a/tests/golden/postgres/typed_rows__a_mismatch_says_how_to_mend_it.silt b/tests/golden/postgres/typed_rows__a_mismatch_says_how_to_mend_it.silt
index 3fc387db3..69871133a 100644
--- a/tests/golden/postgres/typed_rows__a_mismatch_says_how_to_mend_it.silt
+++ b/tests/golden/postgres/typed_rows__a_mismatch_says_how_to_mend_it.silt
@@ -22,5 +22,5 @@ fn main() {
     postgres.TypeMismatch("meta", "Meta", "NULL"),
     postgres.TypeMismatch("meta", "Meta", "jsonb: expected a record at n"),
   ]
-  mismatches |> list.each { e -> println(e.message()) }
+  mismatches |> list.each { e -> println(Error.message(e)) }
 }
diff --git a/tests/golden/postgres/typed_rows__a_trait_method_on_a_type_variable_passes_its_connection_on.silt b/tests/golden/postgres/typed_rows__a_trait_method_on_a_type_variable_passes_its_connection_on.silt
index 921e196dd..5d83e89a5 100644
--- a/tests/golden/postgres/typed_rows__a_trait_method_on_a_type_variable_passes_its_connection_on.silt
+++ b/tests/golden/postgres/typed_rows__a_trait_method_on_a_type_variable_passes_its_connection_on.silt
@@ -19,7 +19,7 @@ trait Runner for Repo {
 }
 
 fn run_with(r: r, c: a, ps: p) -> Result(Int, postgres.PostgresError) where r: Runner {
-  r.run(c, ps)
+  Runner.run(r, c, ps)
 }
 
 fn main() {
diff --git a/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.silt b/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.silt
index d9d2a78a4..98cf3fc4b 100644
--- a/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.silt
+++ b/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.silt
@@ -13,5 +13,5 @@ trait Runner for Repo {
   fn run(self, c: a, ps: p) -> Result(Int, postgres.PostgresError) { postgres.execute(c, "SELECT 1", ps) }
 }
 fn main() {
-  println(Repo { url: "" }.run("x", 5))
+  println(Runner.run(Repo { url: "" }, "x", 5))
 }
diff --git a/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.stderr b/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.stderr
index 519460368..701f18828 100644
--- a/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.stderr
+++ b/tests/golden/postgres/typed_rows__a_trait_method_passes_its_connection_and_params_on.stderr
@@ -1,14 +1,14 @@
 error[type]: the connection of `postgres.execute` must be a postgres.PgPool or a postgres.PgTx
- --> typed_rows__a_trait_method_passes_its_connection_and_params_on.silt:16:32
+ --> typed_rows__a_trait_method_passes_its_connection_and_params_on.silt:16:40
     |
- 16 |   println(Repo { url: "" }.run("x", 5))
-    |                                ^^^ the connection of `postgres.execute` must be a postgres.PgPool or a postgres.PgTx
+ 16 |   println(Runner.run(Repo { url: "" }, "x", 5))
+    |                                        ^^^ the connection of `postgres.execute` must be a postgres.PgPool or a postgres.PgTx
   = note: `Repo.run` passes it to `postgres.execute`
 
 error[type]: the parameters of `postgres.execute` must be a tuple, got `Int`
- --> typed_rows__a_trait_method_passes_its_connection_and_params_on.silt:16:37
+ --> typed_rows__a_trait_method_passes_its_connection_and_params_on.silt:16:45
     |
- 16 |   println(Repo { url: "" }.run("x", 5))
-    |                                     ^ the parameters of `postgres.execute` must be a tuple, got `Int`
+ 16 |   println(Runner.run(Repo { url: "" }, "x", 5))
+    |                                             ^ the parameters of `postgres.execute` must be a tuple, got `Int`
   = note: `Repo.run` passes it to `postgres.execute`
   = help: write (id,)
diff --git a/tests/golden/postgres/typed_rows__params_of_a_generic_function_are_checked_at_its_calls.silt b/tests/golden/postgres/typed_rows__params_of_a_generic_function_are_checked_at_its_calls.silt
index 343997788..72b70936d 100644
--- a/tests/golden/postgres/typed_rows__params_of_a_generic_function_are_checked_at_its_calls.silt
+++ b/tests/golden/postgres/typed_rows__params_of_a_generic_function_are_checked_at_its_calls.silt
@@ -15,10 +15,10 @@ fn find(db: a, ps: p) -> Result(List(User), postgres.PostgresError) {
 fn main() {
   match find(0, (1,)) {
     Ok(_) -> println("a tuple: Ok")
-    Err(e) -> println("a tuple: {e.message()}")
+    Err(e) -> println("a tuple: {Error.message(e)}")
   }
   match find(0, 1) {
     Ok(_) -> println("an Int: Ok")
-    Err(e) -> println("an Int: {e.message()}")
+    Err(e) -> println("an Int: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/SOUNDNESS.tsv b/tests/golden/repros/SOUNDNESS.tsv
index 3a4005c55..9e6a0bf4e 100644
--- a/tests/golden/repros/SOUNDNESS.tsv
+++ b/tests/golden/repros/SOUNDNESS.tsv
@@ -31,8 +31,8 @@ repros/type_soundness/b4.silt	holds	reject E0314	TS-2.4: `+` on records through
 repros/type_soundness/b5.silt	holds	reject E0314	TS-2.4: unary `-` on a String through a polymorphic function
 repros/type_soundness/c1.silt	-	obsolete	fn lambda; ported: lang/soundness/c1.silt
 repros/type_soundness/c2.silt	-	obsolete	fn lambda; ported: lang/soundness/c2.silt
-repros/type_soundness/c3.silt	holds	reject E0314	TS-2.1: `fn g(x) { x.greet() }` called with a String (decision D1)
-repros/type_soundness/c4.silt	holds	reject E0308	TS-2.1: `x.greet()` on an annotated variable that has no bound
+repros/type_soundness/c3.silt	holds	reject E0314	TS-2.1: `fn g(x) { Greet.greet(x) }` called with a String (decision D1)
+repros/type_soundness/c4.silt	holds	reject E0305	TS-2.1: `x.greet()` on an annotated variable: a value of a type variable has no fields
 repros/type_soundness/c5.silt	-	obsolete	fn lambda; ported: lang/soundness/c5.silt
 repros/type_soundness/cv2.silt	holds	reject E0301	TS-6: an anonymous record literal passed as a nominal `P`
 repros/type_soundness/cv3.silt	holds	reject E0301	TS-6: nominal records through a closed anonymous type; `==` is not transitive
@@ -71,14 +71,14 @@ repros/type_soundness/deep9_12.silt	holds	accept	TS-11: tuple type doubling, 12
 repros/type_soundness/deep9_14.silt	holds	accept	TS-11: tuple type doubling, 14 levels
 repros/type_soundness/deep9_16.silt	holds	accept	TS-11: tuple type doubling, 16 levels
 repros/type_soundness/e1.silt	holds	reject E0301	TS-2.2: `r.message` is a row access whatever methods traits declare
-repros/type_soundness/e10.silt	holds	accept	TS-2.6: `.display()` on a closure parameter typed by the call
+repros/type_soundness/e10.silt	holds	accept	TS-2.6: interpolation of a closure parameter typed by the call
 repros/type_soundness/e11.silt	holds	accept	TS-2.6: a user method on a closure parameter, pipe form
 repros/type_soundness/e12.silt	-	obsolete	fn lambda; ported: lang/soundness/e12.silt
 repros/type_soundness/e2.silt	holds	reject E0301	TS-2.2: an unrelated `trait HasX { fn x(self) }` turns `r.x` into an unchecked call
 repros/type_soundness/e3.silt	holds	reject E0301	control for e2, without the trait
 repros/type_soundness/e4.silt	-	obsolete	fn lambda; ported: lang/soundness/e4.silt
 repros/type_soundness/e5.silt	-	obsolete	fn lambda; ported: lang/soundness/e5.silt
-repros/type_soundness/e6.silt	holds	accept	TS-2.6: `.display()` on a closure parameter typed by the call
+repros/type_soundness/e6.silt	holds	accept	TS-2.6: interpolation of a closure parameter typed by the call
 repros/type_soundness/e7.silt	-	obsolete	fn lambda; ported: lang/soundness/e7.silt
 repros/type_soundness/e8.silt	holds	accept	TS-2.6: user and built-in methods on closure parameters
 repros/type_soundness/e9.silt	holds	accept	control for e8: enum receivers
@@ -227,7 +227,7 @@ repros/type_soundness/u3.silt	-	obsolete	a string literal with an unescaped `{`:
 repros/type_soundness/u4.silt	holds	accept	TS-12: `let e = Err("x")` generalises: a constructor applied to values is a value
 repros/type_soundness/u5.silt	-	obsolete	fn lambda; ported: lang/soundness/u5.silt
 repros/type_soundness/v1.silt	holds	reject E0308	a method on a `type a` descriptor that has no bound
-repros/type_soundness/v2.silt	holds	reject E0308	a method the `where` clause does not give
+repros/type_soundness/v2.silt	holds	reject E0305	a dot after a value of a bounded type variable is a field, whatever its bounds give
 repros/type_soundness/w1.silt	holds	reject E0314	TS-4: a `where` bound lost through a user higher-order function
 repros/type_soundness/w10.silt	-	obsolete	fn lambda; ported: lang/soundness/w10.silt
 repros/type_soundness/w11.silt	holds	reject E0314	TS-4: a `where` bound lost through an annotated `let`
@@ -278,7 +278,7 @@ repros/typechecker_arch/cv1_main_swapped	holds	accept	TCA-1: as cv1_main_empty,
 repros/typechecker_arch/cv2_hello.silt	holds	accept	control (TCA-13 counts its derived functions)
 repros/typechecker_arch/cv2_light.silt	holds	accept	TCA-13: a user variant named like a builtin one
 repros/typechecker_arch/cv2_ver.silt	holds	output	TCA-13: `<` and `.compare` order record fields alike, by declaration
-repros/typechecker_arch/derive_d1.silt	holds	output	TCA-7: derived `.display()` prints as `println` does
+repros/typechecker_arch/derive_d1.silt	holds	output	TCA-7: the derived display interpolates as `println` prints
 repros/typechecker_arch/derive_d2.silt	holds	output	TCA-7: a user Display impl is what interpolation and `println` print, at any depth
 repros/typechecker_arch/derive_d3.silt	holds	output	TCA-7: as derive_d2, for a record
 repros/typechecker_arch/derive_d4.silt	holds	reject E0331	TCA-7: Equal and Compare are sealed; a written impl is an error
@@ -345,8 +345,8 @@ repros/typechecker_arch/t_chain3.silt	holds	reject E0301	TCA-2: as t_chain2, dep
 repros/typechecker_arch/t_handle.silt	-	obsolete	fn lambda; a bare `Handle` names nothing (t_anno_handle)
 repros/typechecker_arch/t_key1.silt	holds	reject E0301	TCA-2: `fn bump(x: a) -> a { x + 1 }` violates its signature (t_rigid1)
 repros/typechecker_arch/t_key2.silt	holds	reject E0301	TCA-1: as t_key1, beside an impl method of the same name
-repros/typechecker_arch/t_nonlocal1.silt	holds	reject E0301	control for t_nonlocal2
-repros/typechecker_arch/t_nonlocal2.silt	holds	reject E0301	TCA-4: an unrelated trait method `label` turns `p.label` into an unchecked call
+repros/typechecker_arch/t_nonlocal1.silt	holds	reject E0305	control for t_nonlocal2
+repros/typechecker_arch/t_nonlocal2.silt	holds	reject E0305	TCA-4: a trait method `label` in sight does not change `p.label`: a field
 repros/typechecker_arch/t_poly_field.silt	holds	reject E0326	control: a row access has the field's type
 repros/typechecker_arch/t_poly_method.silt	-	obsolete	fn lambda; ported: lang/soundness/t_poly_method.silt
 repros/typechecker_arch/t_poly_num.silt	holds	reject E0314	TCA-4: `add(true, false)` (decision D2)
@@ -363,18 +363,18 @@ repros/typechecker_arch/t_where_hof.silt	holds	reject E0314	TCA-4: a `where` bou
 repros/typechecker_arch/t_where_paren.silt	-	obsolete	`[f, ..]` is not a pattern; with `..rest` it is type_soundness/w3c
 repros/typechecker_arch/t_where_pipe_call.silt	holds	reject E0314	control: a `where` bound at `x |> f()`
 repros/typechecker_arch/t_where_pipe_plain.silt	holds	reject E0314	TCA-4: a `where` bound lost at `x |> f`
-repros/typechecker_arch/t_tm_as_value.silt	holds	reject E0309	a trait method taken as a value (`let m = true.sh`) and called with its receiver: a method is called, not taken as a value
-repros/typechecker_arch/t_method_value_generic_impl.silt	holds	reject E0309	a method of a generic impl taken as a value: a method is called, not taken as a value
-repros/typechecker_arch/t_method_value_hof3.silt	holds	reject E0309	a method taken as a value and passed to list.map: a method is called, not taken as a value
+repros/typechecker_arch/t_tm_as_value.silt	holds	reject E0305	a dot after a value is a field (`let m = true.sh`): a trait's method is taken through its trait
+repros/typechecker_arch/t_method_value_generic_impl.silt	holds	reject E0305	a dot after a value of a generic impl's type is a field, not the impl's method
+repros/typechecker_arch/t_method_value_hof3.silt	holds	reject E0305	a dot after a value is a field, also as a function passed to list.map
 lang/soundness/a5.silt	holds	reject E0301	a closure parameter's annotation is enforced
 lang/soundness/b1.silt	holds	reject E0314	TS-2.4: `==` and `<` on closures through polymorphic functions
 lang/soundness/c1.silt	holds	reject E0314	control for b1: the same with a declared Compare bound
-lang/soundness/c2.silt	holds	reject E0314	TS-2.1: `.display()` on a closure through `fn show(x) { x.display() }` (decision D1)
+lang/soundness/c2.silt	holds	reject E0314	TS-2.1: a closure shown through `fn show(x) { "{x}" }` (decision D1)
 lang/soundness/c5.silt	holds	reject E0314	TS-2.4: `<` on closures in a branch that is rarely taken
-lang/soundness/d5.silt	holds	reject E0308	`.display()` on a closure
+lang/soundness/d5.silt	holds	reject E0305	a dot after a closure: a closure has no fields
 lang/soundness/e12.silt	holds	accept	TS-2.6: a closure calling a user method, then passed to list.map
-lang/soundness/e4.silt	holds	reject E0301	a closure calling a method no trait declares
-lang/soundness/e5.silt	holds	reject E0301	TS-2.1: `let n: Int = f(1)` where the closure returns `x.display()`
+lang/soundness/e4.silt	holds	reject E0305	a closure reading a field no value it is given has
+lang/soundness/e5.silt	holds	reject E0301	TS-2.1: `let n: Int = f(1)` where the closure returns `"{x}"`
 lang/soundness/e7.silt	holds	accept	control: an annotated closure parameter
 lang/soundness/ex10.silt	holds	accept	TS-10: literal fields in anonymous-record patterns add no coverage (false rejection)
 lang/soundness/ex5.silt	holds	reject E0320	`X(false, false)` is missed (the record match is exhaustive)
@@ -404,7 +404,7 @@ lang/soundness/p4.silt	holds	reject E0301	a channel from a local closure is mono
 lang/soundness/q3.silt	holds	reject E0301	`loop(...)` arguments have the bindings' types
 lang/soundness/r3.silt	holds	accept	a nominal record through an open row keeps its type
 lang/soundness/se2.silt	holds	reject E0201	TS-7.3: `self` in a closure outside a method
-lang/soundness/t_poly_method.silt	holds	reject E0314	TCA-4: `show(f) + 1` over `fn show(x) { x.display() }`
+lang/soundness/t_poly_method.silt	holds	reject E0314	TCA-4: `show(f) + 1` over `fn show(x) { "{x}" }`
 lang/soundness/u5.silt	holds	accept	destructuring a tuple of values generalises each binding: `f(1)` and `f("s")` (false rejection)
 lang/soundness/w10.silt	holds	reject E0314	control for w2: the eta-expanded form
 lang/soundness/w12.silt	holds	reject E0314	TS-4: a Hash bound lost through list.map
@@ -423,6 +423,6 @@ lang/soundness/every_tuple__self_is_not_a_tuple_of_chosen_elements.silt	holds	re
 lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_variant.silt	holds	reject E0301	the same with a variant element
 lang/soundness/every_tuple__self_returned_as_a_tuple_of_a_record.silt	holds	reject E0301	the same with a record element
 lang/soundness/every_tuple__self_type_is_the_receivers.silt	holds	reject E0301	`Self` in an impl for every tuple was every tuple: a tuple of another type came back as the receiver's
-lang/soundness/every_fn__not_called_through_the_type.silt	holds	reject E0309	`Fn.describe(5)`: the method of an impl for every function written through the type takes anything
+lang/soundness/every_fn__not_called_through_the_type.silt	holds	reject E0308	`Fn.describe(5)`: a method that takes Self is called through its trait, never through the type
 lang/soundness/every_fn__self_is_not_called_taken_apart_or_shown.silt	holds	reject E0301	control: `self` of an impl for every function or tuple is not called, taken apart or shown
 lang/soundness/alias_impl__another_length_or_arity_has_no_impl.silt	holds	reject E0314	a bound answered by an impl for `(Int, Int)` or `Fn(Int) -> Int` (through an alias) held for a tuple of another length and a function of another arity
diff --git a/tests/golden/repros/architecture/json1_alias.silt b/tests/golden/repros/architecture/json1_alias.silt
index 33122c90f..89a760c34 100644
--- a/tests/golden/repros/architecture/json1_alias.silt
+++ b/tests/golden/repros/architecture/json1_alias.silt
@@ -14,6 +14,6 @@ fn main() {
   let raw = "\{\"title\": \"hi\", \"tags\": [\"a\", \"b\"], \"n\": 3\}"
   match json.parse(raw, Post) {
     Ok(p) -> println("ok: {p.title} {p.tags} {p.n}")
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/architecture/json1_direct.silt b/tests/golden/repros/architecture/json1_direct.silt
index 8eed8b3f0..5192d70f3 100644
--- a/tests/golden/repros/architecture/json1_direct.silt
+++ b/tests/golden/repros/architecture/json1_direct.silt
@@ -11,6 +11,6 @@ fn main() {
   let raw = "\{\"title\": \"hi\", \"tags\": [\"a\", \"b\"], \"n\": 3\}"
   match json.parse(raw, Post) {
     Ok(p) -> println("ok: {p.title} {p.tags} {p.n}")
-    Err(e) -> println("err: {e.message()}")
+    Err(e) -> println("err: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/architecture/ord3_app/deps/sa/src/lib.silt b/tests/golden/repros/architecture/ord3_app/deps/sa/src/lib.silt
index b6add6fe9..47d8f7e6e 100644
--- a/tests/golden/repros/architecture/ord3_app/deps/sa/src/lib.silt
+++ b/tests/golden/repros/architecture/ord3_app/deps/sa/src/lib.silt
@@ -2,7 +2,7 @@ import list
 pub type ColorA { Red, Blue }
 pub fn report() -> String {
   let lt = Red < Blue
-  let cmp = Red.compare(Blue)
+  let cmp = Compare.compare(Red, Blue)
   let sorted = [Blue, Red] |> list.sort
   let sorted_by = [Blue, Red] |> list.sort_by { c -> c }
   "Red < Blue = {lt}; Red.compare(Blue) = {cmp}; list.sort = {sorted}; sort_by = {sorted_by}"
diff --git a/tests/golden/repros/compiler_vm/deep_m_compare_100.silt b/tests/golden/repros/compiler_vm/deep_m_compare_100.silt
index 817566540..58a9d029f 100644
--- a/tests/golden/repros/compiler_vm/deep_m_compare_100.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_compare_100.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(100)
   let b = build(100)
-  a.compare(b)
+  Compare.compare(a, b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_compare_200.silt b/tests/golden/repros/compiler_vm/deep_m_compare_200.silt
index f8aeba9a6..76f0190a0 100644
--- a/tests/golden/repros/compiler_vm/deep_m_compare_200.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_compare_200.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(200)
   let b = build(200)
-  a.compare(b)
+  Compare.compare(a, b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_compare_400.silt b/tests/golden/repros/compiler_vm/deep_m_compare_400.silt
index 0ef5b3406..c5c75efa1 100644
--- a/tests/golden/repros/compiler_vm/deep_m_compare_400.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_compare_400.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(400)
   let b = build(400)
-  a.compare(b)
+  Compare.compare(a, b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_compare_50.silt b/tests/golden/repros/compiler_vm/deep_m_compare_50.silt
index b4fff219d..418913266 100644
--- a/tests/golden/repros/compiler_vm/deep_m_compare_50.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_compare_50.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(50)
   let b = build(50)
-  a.compare(b)
+  Compare.compare(a, b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_display_100.silt b/tests/golden/repros/compiler_vm/deep_m_display_100.silt
index 6d656b53f..fa0e818bb 100644
--- a/tests/golden/repros/compiler_vm/deep_m_display_100.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_display_100.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(100)
   let b = build(100)
-  a.display()
+  "{a}"
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_display_200.silt b/tests/golden/repros/compiler_vm/deep_m_display_200.silt
index 20fda5920..866856eac 100644
--- a/tests/golden/repros/compiler_vm/deep_m_display_200.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_display_200.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(200)
   let b = build(200)
-  a.display()
+  "{a}"
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_display_400.silt b/tests/golden/repros/compiler_vm/deep_m_display_400.silt
index 01b74ff46..4487b7235 100644
--- a/tests/golden/repros/compiler_vm/deep_m_display_400.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_display_400.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(400)
   let b = build(400)
-  a.display()
+  "{a}"
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_display_50.silt b/tests/golden/repros/compiler_vm/deep_m_display_50.silt
index c81733d74..894c2f06c 100644
--- a/tests/golden/repros/compiler_vm/deep_m_display_50.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_display_50.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(50)
   let b = build(50)
-  a.display()
+  "{a}"
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_equal_100.silt b/tests/golden/repros/compiler_vm/deep_m_equal_100.silt
index f816c2a7a..c50bb79c8 100644
--- a/tests/golden/repros/compiler_vm/deep_m_equal_100.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_equal_100.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(100)
   let b = build(100)
-  a.equal(b)
+  a == b
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_equal_200.silt b/tests/golden/repros/compiler_vm/deep_m_equal_200.silt
index fda52286d..00a1beeea 100644
--- a/tests/golden/repros/compiler_vm/deep_m_equal_200.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_equal_200.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(200)
   let b = build(200)
-  a.equal(b)
+  a == b
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_equal_400.silt b/tests/golden/repros/compiler_vm/deep_m_equal_400.silt
index bba9be8ca..f070345bc 100644
--- a/tests/golden/repros/compiler_vm/deep_m_equal_400.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_equal_400.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(400)
   let b = build(400)
-  a.equal(b)
+  a == b
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_equal_50.silt b/tests/golden/repros/compiler_vm/deep_m_equal_50.silt
index cb5d0cff1..08739621b 100644
--- a/tests/golden/repros/compiler_vm/deep_m_equal_50.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_equal_50.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(50)
   let b = build(50)
-  a.equal(b)
+  a == b
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_hash_100.silt b/tests/golden/repros/compiler_vm/deep_m_hash_100.silt
index 45604ff7b..552520081 100644
--- a/tests/golden/repros/compiler_vm/deep_m_hash_100.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_hash_100.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(100)
   let b = build(100)
-  a.hash()
+  Hash.hash(a)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_hash_200.silt b/tests/golden/repros/compiler_vm/deep_m_hash_200.silt
index 91018f7d0..e164a47c2 100644
--- a/tests/golden/repros/compiler_vm/deep_m_hash_200.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_hash_200.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(200)
   let b = build(200)
-  a.hash()
+  Hash.hash(a)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_hash_400.silt b/tests/golden/repros/compiler_vm/deep_m_hash_400.silt
index b12492601..b828c1ea2 100644
--- a/tests/golden/repros/compiler_vm/deep_m_hash_400.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_hash_400.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(400)
   let b = build(400)
-  a.hash()
+  Hash.hash(a)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_m_hash_50.silt b/tests/golden/repros/compiler_vm/deep_m_hash_50.silt
index d187aa9cc..d08f27814 100644
--- a/tests/golden/repros/compiler_vm/deep_m_hash_50.silt
+++ b/tests/golden/repros/compiler_vm/deep_m_hash_50.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(50)
   let b = build(50)
-  a.hash()
+  Hash.hash(a)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_rec_method.silt b/tests/golden/repros/compiler_vm/deep_rec_method.silt
index 229d34620..979ae9d40 100644
--- a/tests/golden/repros/compiler_vm/deep_rec_method.silt
+++ b/tests/golden/repros/compiler_vm/deep_rec_method.silt
@@ -6,13 +6,13 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
 fn main() {
-  println(1000.go())
-  println(5000.go())
-  println(20000.go())
-  println(90000.go())
+  println(Deep.go(1000))
+  println(Deep.go(5000))
+  println(Deep.go(20000))
+  println(Deep.go(90000))
 }
diff --git a/tests/golden/repros/compiler_vm/deep_t_cmp_main_1000.silt b/tests/golden/repros/compiler_vm/deep_t_cmp_main_1000.silt
index 040620bc3..4bda76886 100644
--- a/tests/golden/repros/compiler_vm/deep_t_cmp_main_1000.silt
+++ b/tests/golden/repros/compiler_vm/deep_t_cmp_main_1000.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(1000)
   let b = build(1000)
-  a.compare(b)
+  Compare.compare(a, b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_t_cmp_main_5000.silt b/tests/golden/repros/compiler_vm/deep_t_cmp_main_5000.silt
index 9bce3e276..0bd809fd9 100644
--- a/tests/golden/repros/compiler_vm/deep_t_cmp_main_5000.silt
+++ b/tests/golden/repros/compiler_vm/deep_t_cmp_main_5000.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(5000)
   let b = build(5000)
-  a.compare(b)
+  Compare.compare(a, b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_t_cmp_task_30.silt b/tests/golden/repros/compiler_vm/deep_t_cmp_task_30.silt
index 507d708cc..b74cb6713 100644
--- a/tests/golden/repros/compiler_vm/deep_t_cmp_task_30.silt
+++ b/tests/golden/repros/compiler_vm/deep_t_cmp_task_30.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(30)
   let b = build(30)
-  a.compare(b)
+  Compare.compare(a, b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_t_disp_task_30.silt b/tests/golden/repros/compiler_vm/deep_t_disp_task_30.silt
index 3d60545d6..e8753ef61 100644
--- a/tests/golden/repros/compiler_vm/deep_t_disp_task_30.silt
+++ b/tests/golden/repros/compiler_vm/deep_t_disp_task_30.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(30)
   let b = build(30)
-  a.display() == b.display()
+  "{a}" == "{b}"
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_t_eq_task_30.silt b/tests/golden/repros/compiler_vm/deep_t_eq_task_30.silt
index a539bed0b..274be40ba 100644
--- a/tests/golden/repros/compiler_vm/deep_t_eq_task_30.silt
+++ b/tests/golden/repros/compiler_vm/deep_t_eq_task_30.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(30)
   let b = build(30)
-  a.equal(b)
+  a == b
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_t_hash_task_30.silt b/tests/golden/repros/compiler_vm/deep_t_hash_task_30.silt
index 4113ccd82..769b69056 100644
--- a/tests/golden/repros/compiler_vm/deep_t_hash_task_30.silt
+++ b/tests/golden/repros/compiler_vm/deep_t_hash_task_30.silt
@@ -20,7 +20,7 @@ fn build(n) {
 fn work() {
   let a = build(30)
   let b = build(30)
-  a.hash() == b.hash()
+  Hash.hash(a) == Hash.hash(b)
 }
 
 fn main() {
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_0.silt b/tests/golden/repros/compiler_vm/deep_task_method_0.silt
index a73c56fce..8b5c9b46e 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_0.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_0.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_1.silt b/tests/golden/repros/compiler_vm/deep_task_method_1.silt
index 7af990ba2..94d625cf6 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_1.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_1.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_12.silt b/tests/golden/repros/compiler_vm/deep_task_method_12.silt
index 8ae8dcf0b..77b2f9e4a 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_12.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_12.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_160.silt b/tests/golden/repros/compiler_vm/deep_task_method_160.silt
index e39fb67f1..4bd6d1b89 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_160.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_160.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_2.silt b/tests/golden/repros/compiler_vm/deep_task_method_2.silt
index 6fc8166cf..0eb346266 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_2.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_2.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_20.silt b/tests/golden/repros/compiler_vm/deep_task_method_20.silt
index 4ff2ae4aa..4c03a25ac 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_20.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_20.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_3.silt b/tests/golden/repros/compiler_vm/deep_task_method_3.silt
index 1475352bd..3ce63ea67 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_3.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_3.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_40.silt b/tests/golden/repros/compiler_vm/deep_task_method_40.silt
index 67ada68c1..c37af9ed4 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_40.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_40.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_400.silt b/tests/golden/repros/compiler_vm/deep_task_method_400.silt
index cf2c64e1c..34c4db923 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_400.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_400.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_5.silt b/tests/golden/repros/compiler_vm/deep_task_method_5.silt
index 1c454857a..e6d491e93 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_5.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_5.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_8.silt b/tests/golden/repros/compiler_vm/deep_task_method_8.silt
index 009f4aa01..724393721 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_8.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_8.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/deep_task_method_80.silt b/tests/golden/repros/compiler_vm/deep_task_method_80.silt
index 537c1ab5f..971af9d57 100644
--- a/tests/golden/repros/compiler_vm/deep_task_method_80.silt
+++ b/tests/golden/repros/compiler_vm/deep_task_method_80.silt
@@ -7,7 +7,7 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
diff --git a/tests/golden/repros/compiler_vm/modtest2_main/ma.silt b/tests/golden/repros/compiler_vm/modtest2_main/ma.silt
index 0e7e47d9e..b60fd2fb9 100644
--- a/tests/golden/repros/compiler_vm/modtest2_main/ma.silt
+++ b/tests/golden/repros/compiler_vm/modtest2_main/ma.silt
@@ -3,4 +3,4 @@ pub fn make(n: Int) -> Item { Item { n: n } }
 trait Display for Item {
   fn display(self) -> String { "A-item({self.n})" }
 }
-pub fn show(i: Item) -> String { i.display() }
+pub fn show(i: Item) -> String { "{i}" }
diff --git a/tests/golden/repros/compiler_vm/modtest2_main/mb.silt b/tests/golden/repros/compiler_vm/modtest2_main/mb.silt
index 2ddc8b551..8f5410731 100644
--- a/tests/golden/repros/compiler_vm/modtest2_main/mb.silt
+++ b/tests/golden/repros/compiler_vm/modtest2_main/mb.silt
@@ -3,4 +3,4 @@ pub fn make(s: String) -> Item { Item { label: s } }
 trait Display for Item {
   fn display(self) -> String { "B-item({self.label})" }
 }
-pub fn show(i: Item) -> String { i.display() }
+pub fn show(i: Item) -> String { "{i}" }
diff --git a/tests/golden/repros/compiler_vm/modtest_main/main.silt b/tests/golden/repros/compiler_vm/modtest_main/main.silt
index c0885e6fa..970de3a00 100644
--- a/tests/golden/repros/compiler_vm/modtest_main/main.silt
+++ b/tests/golden/repros/compiler_vm/modtest_main/main.silt
@@ -11,6 +11,6 @@ fn main() {
   println("r == g: {r == g}")
   println("sorted: {list.sort([g, r])}")
   println("set size: {set.length(set.from_list([r, g]))}")
-  println("compare: {r.compare(g)}")
+  println("compare: {Compare.compare(r, g)}")
   println("display: {shapes.show(r)}")
 }
diff --git a/tests/golden/repros/compiler_vm/modtest_main/shapes.silt b/tests/golden/repros/compiler_vm/modtest_main/shapes.silt
index 8d84314a8..ecc9d1ea6 100644
--- a/tests/golden/repros/compiler_vm/modtest_main/shapes.silt
+++ b/tests/golden/repros/compiler_vm/modtest_main/shapes.silt
@@ -1,4 +1,4 @@
 pub type Tag { Red, Green }
 pub fn red() -> Tag { Red }
 pub fn green() -> Tag { Green }
-pub fn show(t: Tag) -> String { t.display() }
+pub fn show(t: Tag) -> String { "{t}" }
diff --git a/tests/golden/repros/compiler_vm/mx_float_finite.silt b/tests/golden/repros/compiler_vm/mx_float_finite.silt
index 2fb61d68a..c8f3dadfa 100644
--- a/tests/golden/repros/compiler_vm/mx_float_finite.silt
+++ b/tests/golden/repros/compiler_vm/mx_float_finite.silt
@@ -20,11 +20,11 @@ fn main() {
   show("parse -0.0", float.parse("-0.0"))
   match json.parse("""{"v": 1e999}""", R) {
     Ok(r) -> println("json 1e999: {r.v}")
-    Err(e) -> println("json 1e999: Err {e.message()}")
+    Err(e) -> println("json 1e999: Err {Error.message(e)}")
   }
   match json.parse("""{"v": -0.0}""", R) {
     Ok(r) -> println("json -0.0: {r.v}")
-    Err(e) -> println("json -0.0: Err {e.message()}")
+    Err(e) -> println("json -0.0: Err {Error.message(e)}")
   }
   println("int.to_float max: {int.to_float(9223372036854775807)}")
   println("abs min: {int.abs(-9223372036854775807 - 1)}")
diff --git a/tests/golden/repros/compiler_vm/mx_nan_equal.silt b/tests/golden/repros/compiler_vm/mx_nan_equal.silt
index b2159873e..b975f2e25 100644
--- a/tests/golden/repros/compiler_vm/mx_nan_equal.silt
+++ b/tests/golden/repros/compiler_vm/mx_nan_equal.silt
@@ -4,6 +4,6 @@ fn main() {
   let nan = float.nan
   println("nan == nan: {nan == nan}")
   println("nan.equal(nan): {nan.equal(nan)}")
-  println("[nan].equal([nan]): {[nan].equal([nan])}")
+  println("[nan].equal([nan]): {[nan] == [nan]}")
   println("[nan] == [nan]: {[nan] == [nan]}")
 }
diff --git a/tests/golden/repros/compiler_vm/mx_pipe_method.silt b/tests/golden/repros/compiler_vm/mx_pipe_method.silt
index 7d9eaa7da..7ba96098b 100644
--- a/tests/golden/repros/compiler_vm/mx_pipe_method.silt
+++ b/tests/golden/repros/compiler_vm/mx_pipe_method.silt
@@ -9,6 +9,6 @@ trait Adder for Acc {
 type Color { Red, Green }
 fn main() {
   let a = Acc { base: 100 }
-  println(a.add(5))
-  println(5 |> a.add())
+  println(Adder.add(a, 5))
+  println(Adder.add(a, 5))
 }
diff --git a/tests/golden/repros/compiler_vm/mx_pipe_method2.silt b/tests/golden/repros/compiler_vm/mx_pipe_method2.silt
index d0c2293fa..95e4c7cdc 100644
--- a/tests/golden/repros/compiler_vm/mx_pipe_method2.silt
+++ b/tests/golden/repros/compiler_vm/mx_pipe_method2.silt
@@ -12,6 +12,6 @@ trait Namer for Color {
   }
 }
 fn main() {
-  println(Red.name("!"))
-  println("!" |> Red.name())
+  println(Namer.name(Red, "!"))
+  println(Namer.name(Red, "!"))
 }
diff --git a/tests/golden/repros/compiler_vm/mx_range_vs_list.silt b/tests/golden/repros/compiler_vm/mx_range_vs_list.silt
index fa0a487ad..9b15bfc26 100644
--- a/tests/golden/repros/compiler_vm/mx_range_vs_list.silt
+++ b/tests/golden/repros/compiler_vm/mx_range_vs_list.silt
@@ -10,12 +10,12 @@ fn main() {
   println("r == l: {r == l}")
   println("display: {r} vs {l}")
   println("inspect: {io.inspect(r)} vs {io.inspect(l)}")
-  println(".display(): {r.display()} vs {l.display()}")
-  println("hash eq: {r.hash() == l.hash()}")
+  println(".display(): {r} vs {l}")
+  println("hash eq: {Hash.hash(r) == Hash.hash(l)}")
   println("set: {set.from_list([r, l])}")
   println("json: {json.stringify(r)} vs {json.stringify(l)}")
   println("empty: {5..1} == []: {5..1 == []}")
-  println("compare: {r.compare(l)}  r < l: {r < l}")
+  println("compare: {Compare.compare(r, l)}  r < l: {r < l}")
   let m = #{ r: "range" }
   println(map.get(m, l))
 }
diff --git a/tests/golden/repros/compiler_vm/mx_rec_order.silt b/tests/golden/repros/compiler_vm/mx_rec_order.silt
index c78ffb6ae..cccf5c309 100644
--- a/tests/golden/repros/compiler_vm/mx_rec_order.silt
+++ b/tests/golden/repros/compiler_vm/mx_rec_order.silt
@@ -5,7 +5,7 @@ fn main() {
   let a = Ver { major: 1, build: 9 }
   let b = Ver { major: 2, build: 0 }
   println("a < b (operator): {a < b}")
-  println("a.compare(b) (trait): {a.compare(b)}")
+  println("a.compare(b) (trait): {Compare.compare(a, b)}")
   println("sorted: {list.sort([b, a])}")
   println("[a] < [b]: {[a] < [b]}")
 }
diff --git a/tests/golden/repros/compiler_vm/mx_tco_method.silt b/tests/golden/repros/compiler_vm/mx_tco_method.silt
index b84dd257c..f268f9d71 100644
--- a/tests/golden/repros/compiler_vm/mx_tco_method.silt
+++ b/tests/golden/repros/compiler_vm/mx_tco_method.silt
@@ -13,6 +13,6 @@ trait Counter for Int {
 }
 fn plain(n) { count(n, 0) }
 fn main() {
-  println(5.run())
+  println(Counter.run(5))
   println(plain(5))
 }
diff --git a/tests/golden/repros/compiler_vm/mx_toplevel_trait_order.silt b/tests/golden/repros/compiler_vm/mx_toplevel_trait_order.silt
index 2d213c42f..2d81358b8 100644
--- a/tests/golden/repros/compiler_vm/mx_toplevel_trait_order.silt
+++ b/tests/golden/repros/compiler_vm/mx_toplevel_trait_order.silt
@@ -1,6 +1,7 @@
 -- verdict: same
+import string
 type Money { cents: Int }
-let shown = Money { cents: 5 }.display()
+let shown = string.from(Money { cents: 5 })
 trait Display for Money {
   fn display(self) -> String { "USD {self.cents}" }
 }
diff --git a/tests/golden/repros/compiler_vm/mx_tuple_cmp_method.silt b/tests/golden/repros/compiler_vm/mx_tuple_cmp_method.silt
index 25b256cd4..2f08b0131 100644
--- a/tests/golden/repros/compiler_vm/mx_tuple_cmp_method.silt
+++ b/tests/golden/repros/compiler_vm/mx_tuple_cmp_method.silt
@@ -2,5 +2,5 @@
 import list
 fn main() {
   println(list.sort([(1, 2), (1, 1)]))
-  println((1, 2).compare((1, 3)))
+  println(Compare.compare((1, 2), (1, 3)))
 }
diff --git a/tests/golden/repros/compiler_vm/mx_user_traits.silt b/tests/golden/repros/compiler_vm/mx_user_traits.silt
index ce3c62ca0..cfd82e249 100644
--- a/tests/golden/repros/compiler_vm/mx_user_traits.silt
+++ b/tests/golden/repros/compiler_vm/mx_user_traits.silt
@@ -19,12 +19,12 @@ trait Hash for Money {
 fn main() {
   let a = Money { cents: 1 }
   let b = Money { cents: 2 }
-  println("display(): {a.display()}")
+  println("display(): {a}")
   println("interp: {a}")
   println(a)
   println("list interp: {[a]}")
-  println("equal(): {a.equal(b)}   ==: {a == b}")
-  println("compare(): {a.compare(b)}   <: {a < b}")
+  println("equal(): {a == b}   ==: {a == b}")
+  println("compare(): {Compare.compare(a, b)}   <: {a < b}")
   println("sort: {list.sort([a, b])}")
   println("set size: {set.length(set.from_list([a, b]))}")
   println("Some interp: {Some(a)}")
diff --git a/tests/golden/repros/compiler_vm/pat_anon_method.silt b/tests/golden/repros/compiler_vm/pat_anon_method.silt
index beebfeceb..b14af5192 100644
--- a/tests/golden/repros/compiler_vm/pat_anon_method.silt
+++ b/tests/golden/repros/compiler_vm/pat_anon_method.silt
@@ -3,7 +3,7 @@ type P { x: Int, y: Int }
 trait Display for P {
   fn display(self) -> String { "P!" }
 }
-fn show(p: P) -> String { p.display() }
+fn show(p: P) -> String { "{p}" }
 fn main() {
   println(show({ x: 1, y: 2 }))
 }
diff --git a/tests/golden/repros/compiler_vm/pkgs_app/deps/cola/src/lib.silt b/tests/golden/repros/compiler_vm/pkgs_app/deps/cola/src/lib.silt
index 0e7e47d9e..b60fd2fb9 100644
--- a/tests/golden/repros/compiler_vm/pkgs_app/deps/cola/src/lib.silt
+++ b/tests/golden/repros/compiler_vm/pkgs_app/deps/cola/src/lib.silt
@@ -3,4 +3,4 @@ pub fn make(n: Int) -> Item { Item { n: n } }
 trait Display for Item {
   fn display(self) -> String { "A-item({self.n})" }
 }
-pub fn show(i: Item) -> String { i.display() }
+pub fn show(i: Item) -> String { "{i}" }
diff --git a/tests/golden/repros/compiler_vm/pkgs_app/deps/colb/src/lib.silt b/tests/golden/repros/compiler_vm/pkgs_app/deps/colb/src/lib.silt
index 2ddc8b551..8f5410731 100644
--- a/tests/golden/repros/compiler_vm/pkgs_app/deps/colb/src/lib.silt
+++ b/tests/golden/repros/compiler_vm/pkgs_app/deps/colb/src/lib.silt
@@ -3,4 +3,4 @@ pub fn make(s: String) -> Item { Item { label: s } }
 trait Display for Item {
   fn display(self) -> String { "B-item({self.label})" }
 }
-pub fn show(i: Item) -> String { i.display() }
+pub fn show(i: Item) -> String { "{i}" }
diff --git a/tests/golden/repros/compiler_vm/t2.silt b/tests/golden/repros/compiler_vm/t2.silt
index 664e0a8d3..23aa429ca 100644
--- a/tests/golden/repros/compiler_vm/t2.silt
+++ b/tests/golden/repros/compiler_vm/t2.silt
@@ -11,6 +11,6 @@ fn main() {
   println("list [b]<[a]: {[b] < [a]}")
   println("variant W(b)<W(a): {W(b) < W(a)}")
   println("record: {P { v: b } < P { v: a }}")
-  println("compare method: {b.compare(a)}")
-  println("list compare method: {[b].compare([a])}")
+  println("compare method: {Compare.compare(b, a)}")
+  println("list compare method: {Compare.compare([b], [a])}")
 }
diff --git a/tests/golden/repros/compiler_vm/t7.silt b/tests/golden/repros/compiler_vm/t7.silt
index 9748d724a..ab26d051c 100644
--- a/tests/golden/repros/compiler_vm/t7.silt
+++ b/tests/golden/repros/compiler_vm/t7.silt
@@ -15,5 +15,5 @@ fn plain(base, (dx, dy), scale) {
 
 fn main() {
   println(plain(1, (2, 3), 10))
-  println(1.shift((2, 3), 10))
+  println(Shift.shift(1, (2, 3), 10))
 }
diff --git a/tests/golden/repros/frontend/docs_error_handling_1.silt b/tests/golden/repros/frontend/docs_error_handling_1.silt
index bba317d35..d00cfb23d 100644
--- a/tests/golden/repros/frontend/docs_error_handling_1.silt
+++ b/tests/golden/repros/frontend/docs_error_handling_1.silt
@@ -7,6 +7,6 @@ fn main() {
     Ok(content) -> println("loaded {string.length(content)} bytes")
     Err(io.NotFound(path)) -> println("file does not exist: {path}")
     Err(io.PermissionDenied(path)) -> println("denied: {path}")
-    Err(e) -> println("error: {e.message()}")
+    Err(e) -> println("error: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/frontend/docs_readme_3.silt b/tests/golden/repros/frontend/docs_readme_3.silt
index fb148e0d8..7d7571fa0 100644
--- a/tests/golden/repros/frontend/docs_readme_3.silt
+++ b/tests/golden/repros/frontend/docs_readme_3.silt
@@ -8,9 +8,9 @@ fn main() {
   match io.read_file("settings.json") {
     Ok(content) -> match json.parse(content, Config) {
       Ok(cfg) -> println("loaded: {cfg.name}")
-      Err(e) -> println("parse error: {e.message()}")
+      Err(e) -> println("parse error: {Error.message(e)}")
     }
     Err(io.NotFound(path)) -> println("no config at {path} — run `silt init` first")
-    Err(e) -> println("read error: {e.message()}")
+    Err(e) -> println("read error: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/frontend/docs_traits_16.silt b/tests/golden/repros/frontend/docs_traits_16.silt
index 42e5faad5..abe5586ee 100644
--- a/tests/golden/repros/frontend/docs_traits_16.silt
+++ b/tests/golden/repros/frontend/docs_traits_16.silt
@@ -11,6 +11,6 @@ trait Monoid for Int {
 
 fn main() {
   let zero = Int.empty()                 -- concrete dispatch
-  let five = Int.combine(2, 3)
+  let five = Monoid.combine(2, 3)
   println("{zero} {five}")
 }
diff --git a/tests/golden/repros/frontend/docs_traits_17.silt b/tests/golden/repros/frontend/docs_traits_17.silt
index e814fcd16..704ca6532 100644
--- a/tests/golden/repros/frontend/docs_traits_17.silt
+++ b/tests/golden/repros/frontend/docs_traits_17.silt
@@ -1,5 +1,6 @@
 -- verdict: same
 import list
+import string
 
 type Celsius { c: Float }
 
@@ -9,6 +10,6 @@ trait Display for Celsius {
 
 fn main() {
   let temps = [Celsius { c: 20.0 }, Celsius { c: 25.5 }]
-  let rendered = list.map(temps, Celsius.display)
+  let rendered = list.map(temps, string.from)
   list.each(rendered) { line -> println(line) }
 }
diff --git a/tests/golden/repros/frontend/ex_birthdays.silt b/tests/golden/repros/frontend/ex_birthdays.silt
index 05e771011..e7e84f7e0 100644
--- a/tests/golden/repros/frontend/ex_birthdays.silt
+++ b/tests/golden/repros/frontend/ex_birthdays.silt
@@ -48,7 +48,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/tests/golden/repros/frontend/ex_concurrent_processor.silt b/tests/golden/repros/frontend/ex_concurrent_processor.silt
index f7481fbbe..0cc21f36f 100644
--- a/tests/golden/repros/frontend/ex_concurrent_processor.silt
+++ b/tests/golden/repros/frontend/ex_concurrent_processor.silt
@@ -102,7 +102,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/tests/golden/repros/frontend/ex_config_parser.silt b/tests/golden/repros/frontend/ex_config_parser.silt
index 8ca85ac25..a9460a125 100644
--- a/tests/golden/repros/frontend/ex_config_parser.silt
+++ b/tests/golden/repros/frontend/ex_config_parser.silt
@@ -144,7 +144,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/tests/golden/repros/frontend/ex_csv_analyzer.silt b/tests/golden/repros/frontend/ex_csv_analyzer.silt
index 77ce87503..75ee3e408 100644
--- a/tests/golden/repros/frontend/ex_csv_analyzer.silt
+++ b/tests/golden/repros/frontend/ex_csv_analyzer.silt
@@ -113,7 +113,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/tests/golden/repros/frontend/ex_diff_tool.silt b/tests/golden/repros/frontend/ex_diff_tool.silt
index af143c97c..b350cb7d5 100644
--- a/tests/golden/repros/frontend/ex_diff_tool.silt
+++ b/tests/golden/repros/frontend/ex_diff_tool.silt
@@ -112,11 +112,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/tests/golden/repros/frontend/ex_expr_eval.silt b/tests/golden/repros/frontend/ex_expr_eval.silt
index e9b06f500..ce5448e1c 100644
--- a/tests/golden/repros/frontend/ex_expr_eval.silt
+++ b/tests/golden/repros/frontend/ex_expr_eval.silt
@@ -21,9 +21,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -206,16 +206,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -226,10 +226,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -240,7 +240,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -248,7 +248,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -256,7 +256,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/tests/golden/repros/frontend/ex_json_time.silt b/tests/golden/repros/frontend/ex_json_time.silt
index 58a9fb8c0..6f61e777e 100644
--- a/tests/golden/repros/frontend/ex_json_time.silt
+++ b/tests/golden/repros/frontend/ex_json_time.silt
@@ -23,7 +23,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -33,13 +33,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -51,7 +51,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -67,6 +67,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/frontend/ex_json_transform.silt b/tests/golden/repros/frontend/ex_json_transform.silt
index 766686687..28ceddb9c 100644
--- a/tests/golden/repros/frontend/ex_json_transform.silt
+++ b/tests/golden/repros/frontend/ex_json_transform.silt
@@ -76,7 +76,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/tests/golden/repros/frontend/ex_kvstore.silt b/tests/golden/repros/frontend/ex_kvstore.silt
index d6438ca33..44c95e4b1 100644
--- a/tests/golden/repros/frontend/ex_kvstore.silt
+++ b/tests/golden/repros/frontend/ex_kvstore.silt
@@ -85,7 +85,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -93,7 +93,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -104,7 +104,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/tests/golden/repros/frontend/ex_link_checker.silt b/tests/golden/repros/frontend/ex_link_checker.silt
index 67081dc02..396f5a504 100644
--- a/tests/golden/repros/frontend/ex_link_checker.silt
+++ b/tests/golden/repros/frontend/ex_link_checker.silt
@@ -24,7 +24,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/tests/golden/repros/frontend/ex_pipeline.silt b/tests/golden/repros/frontend/ex_pipeline.silt
index 694ba236c..310b78862 100644
--- a/tests/golden/repros/frontend/ex_pipeline.silt
+++ b/tests/golden/repros/frontend/ex_pipeline.silt
@@ -160,7 +160,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/tests/golden/repros/frontend/ex_state_machine.silt b/tests/golden/repros/frontend/ex_state_machine.silt
index bbb0968d4..f3361bcf5 100644
--- a/tests/golden/repros/frontend/ex_state_machine.silt
+++ b/tests/golden/repros/frontend/ex_state_machine.silt
@@ -52,7 +52,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -60,7 +60,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -156,7 +156,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -192,7 +192,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/tests/golden/repros/frontend/ex_time_demo.silt b/tests/golden/repros/frontend/ex_time_demo.silt
index 1f880945a..8ac405082 100644
--- a/tests/golden/repros/frontend/ex_time_demo.silt
+++ b/tests/golden/repros/frontend/ex_time_demo.silt
@@ -7,31 +7,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -43,11 +43,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -58,17 +58,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -80,14 +80,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -123,11 +123,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -139,11 +139,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/tests/golden/repros/frontend/ex_todo.silt b/tests/golden/repros/frontend/ex_todo.silt
index 5f2fbf48e..d3e9b0b4a 100644
--- a/tests/golden/repros/frontend/ex_todo.silt
+++ b/tests/golden/repros/frontend/ex_todo.silt
@@ -62,7 +62,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -79,13 +79,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/tests/golden/repros/frontend/ex_trait_zoo.silt b/tests/golden/repros/frontend/ex_trait_zoo.silt
index 3a9a20278..8489e44fa 100644
--- a/tests/golden/repros/frontend/ex_trait_zoo.silt
+++ b/tests/golden/repros/frontend/ex_trait_zoo.silt
@@ -53,7 +53,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -98,7 +98,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/tests/golden/repros/frontend/ex_traits.silt b/tests/golden/repros/frontend/ex_traits.silt
index 28b81e689..2973ab18e 100644
--- a/tests/golden/repros/frontend/ex_traits.silt
+++ b/tests/golden/repros/frontend/ex_traits.silt
@@ -26,7 +26,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/tests/golden/repros/frontend/exfmt_birthdays.silt b/tests/golden/repros/frontend/exfmt_birthdays.silt
index 05e771011..e7e84f7e0 100644
--- a/tests/golden/repros/frontend/exfmt_birthdays.silt
+++ b/tests/golden/repros/frontend/exfmt_birthdays.silt
@@ -48,7 +48,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/tests/golden/repros/frontend/exfmt_concurrent_processor.silt b/tests/golden/repros/frontend/exfmt_concurrent_processor.silt
index f7481fbbe..0cc21f36f 100644
--- a/tests/golden/repros/frontend/exfmt_concurrent_processor.silt
+++ b/tests/golden/repros/frontend/exfmt_concurrent_processor.silt
@@ -102,7 +102,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/tests/golden/repros/frontend/exfmt_config_parser.silt b/tests/golden/repros/frontend/exfmt_config_parser.silt
index 8ca85ac25..a9460a125 100644
--- a/tests/golden/repros/frontend/exfmt_config_parser.silt
+++ b/tests/golden/repros/frontend/exfmt_config_parser.silt
@@ -144,7 +144,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/tests/golden/repros/frontend/exfmt_csv_analyzer.silt b/tests/golden/repros/frontend/exfmt_csv_analyzer.silt
index 77ce87503..75ee3e408 100644
--- a/tests/golden/repros/frontend/exfmt_csv_analyzer.silt
+++ b/tests/golden/repros/frontend/exfmt_csv_analyzer.silt
@@ -113,7 +113,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/tests/golden/repros/frontend/exfmt_diff_tool.silt b/tests/golden/repros/frontend/exfmt_diff_tool.silt
index af143c97c..b350cb7d5 100644
--- a/tests/golden/repros/frontend/exfmt_diff_tool.silt
+++ b/tests/golden/repros/frontend/exfmt_diff_tool.silt
@@ -112,11 +112,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/tests/golden/repros/frontend/exfmt_expr_eval.silt b/tests/golden/repros/frontend/exfmt_expr_eval.silt
index e9b06f500..ce5448e1c 100644
--- a/tests/golden/repros/frontend/exfmt_expr_eval.silt
+++ b/tests/golden/repros/frontend/exfmt_expr_eval.silt
@@ -21,9 +21,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -206,16 +206,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -226,10 +226,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -240,7 +240,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -248,7 +248,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -256,7 +256,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/tests/golden/repros/frontend/exfmt_json_time.silt b/tests/golden/repros/frontend/exfmt_json_time.silt
index 58a9fb8c0..6f61e777e 100644
--- a/tests/golden/repros/frontend/exfmt_json_time.silt
+++ b/tests/golden/repros/frontend/exfmt_json_time.silt
@@ -23,7 +23,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -33,13 +33,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -51,7 +51,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -67,6 +67,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/frontend/exfmt_json_transform.silt b/tests/golden/repros/frontend/exfmt_json_transform.silt
index 766686687..28ceddb9c 100644
--- a/tests/golden/repros/frontend/exfmt_json_transform.silt
+++ b/tests/golden/repros/frontend/exfmt_json_transform.silt
@@ -76,7 +76,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/tests/golden/repros/frontend/exfmt_kvstore.silt b/tests/golden/repros/frontend/exfmt_kvstore.silt
index d6438ca33..44c95e4b1 100644
--- a/tests/golden/repros/frontend/exfmt_kvstore.silt
+++ b/tests/golden/repros/frontend/exfmt_kvstore.silt
@@ -85,7 +85,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -93,7 +93,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -104,7 +104,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/tests/golden/repros/frontend/exfmt_link_checker.silt b/tests/golden/repros/frontend/exfmt_link_checker.silt
index 67081dc02..396f5a504 100644
--- a/tests/golden/repros/frontend/exfmt_link_checker.silt
+++ b/tests/golden/repros/frontend/exfmt_link_checker.silt
@@ -24,7 +24,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/tests/golden/repros/frontend/exfmt_pipeline.silt b/tests/golden/repros/frontend/exfmt_pipeline.silt
index 694ba236c..310b78862 100644
--- a/tests/golden/repros/frontend/exfmt_pipeline.silt
+++ b/tests/golden/repros/frontend/exfmt_pipeline.silt
@@ -160,7 +160,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/tests/golden/repros/frontend/exfmt_state_machine.silt b/tests/golden/repros/frontend/exfmt_state_machine.silt
index bbb0968d4..f3361bcf5 100644
--- a/tests/golden/repros/frontend/exfmt_state_machine.silt
+++ b/tests/golden/repros/frontend/exfmt_state_machine.silt
@@ -52,7 +52,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -60,7 +60,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -156,7 +156,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -192,7 +192,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/tests/golden/repros/frontend/exfmt_time_demo.silt b/tests/golden/repros/frontend/exfmt_time_demo.silt
index 1f880945a..8ac405082 100644
--- a/tests/golden/repros/frontend/exfmt_time_demo.silt
+++ b/tests/golden/repros/frontend/exfmt_time_demo.silt
@@ -7,31 +7,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -43,11 +43,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -58,17 +58,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -80,14 +80,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -123,11 +123,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -139,11 +139,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/tests/golden/repros/frontend/exfmt_todo.silt b/tests/golden/repros/frontend/exfmt_todo.silt
index 5f2fbf48e..d3e9b0b4a 100644
--- a/tests/golden/repros/frontend/exfmt_todo.silt
+++ b/tests/golden/repros/frontend/exfmt_todo.silt
@@ -62,7 +62,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -79,13 +79,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/tests/golden/repros/frontend/exfmt_trait_zoo.silt b/tests/golden/repros/frontend/exfmt_trait_zoo.silt
index 3a9a20278..8489e44fa 100644
--- a/tests/golden/repros/frontend/exfmt_trait_zoo.silt
+++ b/tests/golden/repros/frontend/exfmt_trait_zoo.silt
@@ -53,7 +53,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -98,7 +98,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/tests/golden/repros/frontend/exfmt_traits.silt b/tests/golden/repros/frontend/exfmt_traits.silt
index 28b81e689..2973ab18e 100644
--- a/tests/golden/repros/frontend/exfmt_traits.silt
+++ b/tests/golden/repros/frontend/exfmt_traits.silt
@@ -26,7 +26,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/tests/golden/repros/frontend/hist_expr_eval_old.silt b/tests/golden/repros/frontend/hist_expr_eval_old.silt
index db5dac439..e0a8e9210 100644
--- a/tests/golden/repros/frontend/hist_expr_eval_old.silt
+++ b/tests/golden/repros/frontend/hist_expr_eval_old.silt
@@ -21,9 +21,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -205,11 +205,11 @@ fn main() {
 
   examples |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
 
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
 
     let rpn = to_rpn(expr)
@@ -218,7 +218,7 @@ fn main() {
 
     -- Round-trip: from_rpn(to_rpn(expr)) should equal original
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
 
     println("  Complexity: {complexity(expr)}")
@@ -231,10 +231,10 @@ fn main() {
   println("=== Deep Pattern Matching ===\n")
 
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -254,7 +254,7 @@ fn main() {
 
   test_exprs |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
 
   -- Build from RPN
@@ -263,7 +263,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
 
   -- Demonstrate negative pattern simplification
@@ -275,7 +275,7 @@ fn main() {
   ]
   neg_examples |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
 
   println("\nDone!")
diff --git a/tests/golden/repros/frontend/hist_t.silt b/tests/golden/repros/frontend/hist_t.silt
index f0a34ec3e..cc254275e 100644
--- a/tests/golden/repros/frontend/hist_t.silt
+++ b/tests/golden/repros/frontend/hist_t.silt
@@ -21,9 +21,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -206,17 +206,17 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     -- Round-trip: from_rpn(to_rpn(expr)) should equal original
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -226,10 +226,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -240,7 +240,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -248,7 +248,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -256,7 +256,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/tests/golden/repros/lang_design/cross_dup_main/m1.silt b/tests/golden/repros/lang_design/cross_dup_main/m1.silt
index 88ed5f969..d4e974693 100644
--- a/tests/golden/repros/lang_design/cross_dup_main/m1.silt
+++ b/tests/golden/repros/lang_design/cross_dup_main/m1.silt
@@ -3,4 +3,4 @@ trait Display for Item {
   fn display(self) -> String { "m1 item {self.id}" }
 }
 pub fn mk() -> Item { Item { id: 1 } }
-pub fn show(i: Item) -> String { i.display() }
+pub fn show(i: Item) -> String { "{i}" }
diff --git a/tests/golden/repros/lang_design/cross_dup_main/m2.silt b/tests/golden/repros/lang_design/cross_dup_main/m2.silt
index 9cc6e7f16..7181019f3 100644
--- a/tests/golden/repros/lang_design/cross_dup_main/m2.silt
+++ b/tests/golden/repros/lang_design/cross_dup_main/m2.silt
@@ -3,4 +3,4 @@ trait Display for Item {
   fn display(self) -> String { "m2 item {self.name}" }
 }
 pub fn mk() -> Item { Item { name: "n" } }
-pub fn show(i: Item) -> String { i.display() }
+pub fn show(i: Item) -> String { "{i}" }
diff --git a/tests/golden/repros/lang_design/d01.silt b/tests/golden/repros/lang_design/d01.silt
index bbd4446a4..8270d0572 100644
--- a/tests/golden/repros/lang_design/d01.silt
+++ b/tests/golden/repros/lang_design/d01.silt
@@ -4,11 +4,11 @@ type E { A(Int, String), B, C(P) }
 fn main() {
   let p = P { x: 1, y: 2.0, s: "hi" }
   println(p)
-  println(p.display())
+  println("{p}")
   println("{p}")
   println([p])
   println(C(p))
-  println(C(p).display())
+  println("{C(p)}")
   println("{C(p)}")
   println(A(1, "s"))
   println(Some("s"))
@@ -17,6 +17,6 @@ fn main() {
   println(#{"k": "v"})
   println("s")
   println(Some(2.0))
-  println(2.0.display())
+  println("{2.0}")
   println(Ok(()))
 }
diff --git a/tests/golden/repros/lang_design/d02.silt b/tests/golden/repros/lang_design/d02.silt
index 0c9f49be0..1a11fade7 100644
--- a/tests/golden/repros/lang_design/d02.silt
+++ b/tests/golden/repros/lang_design/d02.silt
@@ -2,6 +2,7 @@
 import list
 import map
 import set
+import string
 type P { x: Int }
 type W { inner: P }
 type E { Wrap(P) }
@@ -19,17 +20,17 @@ fn main() {
   let q = P { x: 2 }
   println(p)
   println("{p}")
-  println(p.display())
+  println("{p}")
   println([p])
   println(Some(p))
   println((p, 1))
   println(W { inner: p })
-  println(W { inner: p }.display())
+  println(string.from(W { inner: p }))
   println(Wrap(p))
   println(#{ "k": p })
   println("--- equal (custom: always true)")
   println(p == q)
-  println(p.equal(q))
+  println(p == q)
   println([p] == [q])
   println(Some(p) == Some(q))
   println(W { inner: p } == W { inner: q })
@@ -37,7 +38,7 @@ fn main() {
   println(set.length(#[p, q]))
   println("--- compare (custom: reversed)")
   println(p < q)
-  println(p.compare(q))
+  println(Compare.compare(p, q))
   println(list.sort([p, q]))
   println([p] < [q])
   println(W { inner: p } < W { inner: q })
diff --git a/tests/golden/repros/lang_design/d03.silt b/tests/golden/repros/lang_design/d03.silt
index 7835351a9..15b85431d 100644
--- a/tests/golden/repros/lang_design/d03.silt
+++ b/tests/golden/repros/lang_design/d03.silt
@@ -12,7 +12,7 @@ trait Display for Shape {
 
 fn main() {
   let s = Circle(5.0)
-  println(s.display())
+  println("{s}")
   println("{s}")
   println(s)
   println([s])
diff --git a/tests/golden/repros/lang_design/diag_t1_param_trait.silt b/tests/golden/repros/lang_design/diag_t1_param_trait.silt
index 7c1660681..0b4c01673 100644
--- a/tests/golden/repros/lang_design/diag_t1_param_trait.silt
+++ b/tests/golden/repros/lang_design/diag_t1_param_trait.silt
@@ -9,6 +9,6 @@ trait Convert(Float) for String {
   fn convert(self) -> Float { 2.0 }
 }
 fn main() {
-  let a: Int = "x".convert()
+  let a: Int = Convert.convert("x")
   println(a)
 }
diff --git a/tests/golden/repros/lang_design/diag_x3.silt b/tests/golden/repros/lang_design/diag_x3.silt
index 9bdfa08fd..eea90d5a4 100644
--- a/tests/golden/repros/lang_design/diag_x3.silt
+++ b/tests/golden/repros/lang_design/diag_x3.silt
@@ -1,5 +1,6 @@
 -- verdict: same
+import string
 fn main() {
-  let f = Int.display
+  let f = string.from
   println(f(5))
 }
diff --git a/tests/golden/repros/lang_design/ex_pr_12.silt b/tests/golden/repros/lang_design/ex_pr_12.silt
index 444cf1c49..6321f9387 100644
--- a/tests/golden/repros/lang_design/ex_pr_12.silt
+++ b/tests/golden/repros/lang_design/ex_pr_12.silt
@@ -11,5 +11,5 @@ fn g(a) { a }
 fn main() {
   let nan = 0.0 / 0.0
   let inf = 1.0 / 0.0
-  println(true.display())
+  println("{true}")
 }
diff --git a/tests/golden/repros/lang_design/ex_pr_8.silt b/tests/golden/repros/lang_design/ex_pr_8.silt
index 0d7bcf127..8db26c81c 100644
--- a/tests/golden/repros/lang_design/ex_pr_8.silt
+++ b/tests/golden/repros/lang_design/ex_pr_8.silt
@@ -11,5 +11,5 @@ fn g(a) { a }
 fn main() {
   let nan = 0.0 / 0.0
   let inf = 1.0 / 0.0
-  println({x: 1}.equal({x: 1}))
+  println({x: 1} == {x: 1})
 }
diff --git a/tests/golden/repros/lang_design/ex_pr_9.silt b/tests/golden/repros/lang_design/ex_pr_9.silt
index a90e87d6a..a00092379 100644
--- a/tests/golden/repros/lang_design/ex_pr_9.silt
+++ b/tests/golden/repros/lang_design/ex_pr_9.silt
@@ -11,5 +11,5 @@ fn g(a) { a }
 fn main() {
   let nan = 0.0 / 0.0
   let inf = 1.0 / 0.0
-  println(true.equal(true))
+  println(true == true)
 }
diff --git a/tests/golden/repros/lang_design/g05.silt b/tests/golden/repros/lang_design/g05.silt
index e61a74188..cd330bd83 100644
--- a/tests/golden/repros/lang_design/g05.silt
+++ b/tests/golden/repros/lang_design/g05.silt
@@ -1,5 +1,5 @@
 -- verdict: same
-fn describe(x) { x.display() }
+fn describe(x) { "{x}" }
 fn id(x) { x }
 fn main() {
   println(describe(1))
diff --git a/tests/golden/repros/lang_design/g06.silt b/tests/golden/repros/lang_design/g06.silt
index fd79b823d..32f600394 100644
--- a/tests/golden/repros/lang_design/g06.silt
+++ b/tests/golden/repros/lang_design/g06.silt
@@ -1,6 +1,6 @@
 -- verdict: same
 import list
-fn describe(x: a) -> String where a: Display { x.display() }
+fn describe(x: a) -> String where a: Display { "{x}" }
 fn biggest(xs: List(a)) -> List(a) where a: Compare { list.sort(xs) }
 fn id(x) { x }
 fn main() {
diff --git a/tests/golden/repros/lang_design/g07.silt b/tests/golden/repros/lang_design/g07.silt
index 1b5f68eba..3517c5b9a 100644
--- a/tests/golden/repros/lang_design/g07.silt
+++ b/tests/golden/repros/lang_design/g07.silt
@@ -3,7 +3,7 @@ trait Shape { fn area(self) -> Int }
 type Sq { s: Int }
 trait Shape for Sq { fn area(self) -> Int { self.s * self.s } }
 
-fn total(a, b) { a.area() + b.area() }
+fn total(a, b) { Shape.area(a) + Shape.area(b) }
 
 fn main() {
   println(total(Sq { s: 2 }, Sq { s: 3 }))
diff --git a/tests/golden/repros/lang_design/traits_copy.silt b/tests/golden/repros/lang_design/traits_copy.silt
index 28b81e689..2973ab18e 100644
--- a/tests/golden/repros/lang_design/traits_copy.silt
+++ b/tests/golden/repros/lang_design/traits_copy.silt
@@ -26,7 +26,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/tests/golden/repros/lang_design/w01.silt b/tests/golden/repros/lang_design/w01.silt
index f36ec6c8c..c1c11393f 100644
--- a/tests/golden/repros/lang_design/w01.silt
+++ b/tests/golden/repros/lang_design/w01.silt
@@ -5,7 +5,7 @@ fn a(s) {
   let res = int.parse(s)
   when let Ok(n) = res else {
     match res {
-      Err(e) -> return Err("bad: {e.message()}")
+      Err(e) -> return Err("bad: {Error.message(e)}")
       Ok(_) -> panic("unreachable")
     }
   }
diff --git a/tests/golden/repros/lang_design/w02.silt b/tests/golden/repros/lang_design/w02.silt
index af110741b..353d438c7 100644
--- a/tests/golden/repros/lang_design/w02.silt
+++ b/tests/golden/repros/lang_design/w02.silt
@@ -5,7 +5,7 @@ import int
 fn b(s) {
   let n = match int.parse(s) {
     Ok(n) -> n
-    Err(e) -> return Err("bad: {e.message()}")
+    Err(e) -> return Err("bad: {Error.message(e)}")
   }
   Ok(n + 1)
 }
diff --git a/tests/golden/repros/packages/t3_main/moda.silt b/tests/golden/repros/packages/t3_main/moda.silt
index ab84e4f92..41e873026 100644
--- a/tests/golden/repros/packages/t3_main/moda.silt
+++ b/tests/golden/repros/packages/t3_main/moda.silt
@@ -3,7 +3,7 @@ trait Show { fn show(self) -> String }
 trait Show for Tok {
   fn show(self) -> String { "moda-Tok" }
 }
-pub fn describe() -> String { T(1).show() }
+pub fn describe() -> String { Show.show(T(1)) }
 pub fn unwrap() -> Int {
   match T(41) {
     T(n) -> n + 1
diff --git a/tests/golden/repros/packages/t3_main/modb.silt b/tests/golden/repros/packages/t3_main/modb.silt
index 4dc33da45..c23f288da 100644
--- a/tests/golden/repros/packages/t3_main/modb.silt
+++ b/tests/golden/repros/packages/t3_main/modb.silt
@@ -3,4 +3,4 @@ trait Show { fn show(self) -> String }
 trait Show for Tok {
   fn show(self) -> String { "modb-Tok" }
 }
-pub fn describe() -> String { T("a", "b").show() }
+pub fn describe() -> String { Show.show(T("a", "b")) }
diff --git a/tests/golden/repros/packages/t3b_main/moda.silt b/tests/golden/repros/packages/t3b_main/moda.silt
index 3c77b5f79..ab464004c 100644
--- a/tests/golden/repros/packages/t3b_main/moda.silt
+++ b/tests/golden/repros/packages/t3b_main/moda.silt
@@ -3,4 +3,4 @@ trait Show { fn show(self) -> String }
 trait Show for Tok {
   fn show(self) -> String { "moda-Tok" }
 }
-pub fn describe() -> String { T(1).show() }
+pub fn describe() -> String { Show.show(T(1)) }
diff --git a/tests/golden/repros/packages/t3b_main/modb.silt b/tests/golden/repros/packages/t3b_main/modb.silt
index d43e95d76..fa7868ea3 100644
--- a/tests/golden/repros/packages/t3b_main/modb.silt
+++ b/tests/golden/repros/packages/t3b_main/modb.silt
@@ -3,4 +3,4 @@ trait Show { fn show(self) -> String }
 trait Show for Tok {
   fn show(self) -> String { "modb-Tok" }
 }
-pub fn describe() -> String { T(2).show() }
+pub fn describe() -> String { Show.show(T(2)) }
diff --git a/tests/golden/repros/packages/t5_v3/main.silt b/tests/golden/repros/packages/t5_v3/main.silt
index 7c7fd8d58..8a60f5060 100644
--- a/tests/golden/repros/packages/t5_v3/main.silt
+++ b/tests/golden/repros/packages/t5_v3/main.silt
@@ -2,5 +2,5 @@
 import lib1
 fn main() {
   let s = lib1.mk()
-  println(s.peek())
+  println(lib1.Peek.peek(s))
 }
diff --git a/tests/golden/repros/packages/t5b_disp.silt b/tests/golden/repros/packages/t5b_disp.silt
index 7d08bd97b..ecc778e5e 100644
--- a/tests/golden/repros/packages/t5b_disp.silt
+++ b/tests/golden/repros/packages/t5b_disp.silt
@@ -1,10 +1,11 @@
 -- verdict: same
+import string
 type Node { Leaf(String), Nil }
 trait Display for Node {
   fn display(self) -> String { "custom" }
 }
 fn main() {
   println("{Leaf("x")}")
-  println(Leaf("x").display())
+  println(string.from(Leaf("x")))
   println(Leaf("x"))
 }
diff --git a/tests/golden/repros/packages/tq_q1/main.silt b/tests/golden/repros/packages/tq_q1/main.silt
index 1ab6d8d56..84291efdb 100644
--- a/tests/golden/repros/packages/tq_q1/main.silt
+++ b/tests/golden/repros/packages/tq_q1/main.silt
@@ -1,4 +1,4 @@
 -- verdict: same
 import shapes
-fn f(s: shapes.Shape) -> Int { s.area() }
+fn f(s: shapes.Shape) -> Int { shapes.Area.area(s) }
 fn main() { println(f(shapes.unit())) }
diff --git a/tests/golden/repros/packages/tq_q3/main.silt b/tests/golden/repros/packages/tq_q3/main.silt
index ddeade89c..1a6211caf 100644
--- a/tests/golden/repros/packages/tq_q3/main.silt
+++ b/tests/golden/repros/packages/tq_q3/main.silt
@@ -8,6 +8,6 @@ fn main() {
   println(a)
   println(b)
   println(a == b)
-  println(a.area())
+  println(shapes.Area.area(a))
   println(c.area())
 }
diff --git a/tests/golden/repros/packages/tq_q4/main.silt b/tests/golden/repros/packages/tq_q4/main.silt
index 3348b63c4..9f92dcc01 100644
--- a/tests/golden/repros/packages/tq_q4/main.silt
+++ b/tests/golden/repros/packages/tq_q4/main.silt
@@ -4,4 +4,4 @@ type Sq { side: Int }
 trait shapes.Area for Sq {
   fn area(self) -> Int { self.side * self.side }
 }
-fn main() { println(Sq { side: 3 }.area()) }
+fn main() { println(shapes.Area.area(Sq { side: 3 })) }
diff --git a/tests/golden/repros/packages/tq_q5/main.silt b/tests/golden/repros/packages/tq_q5/main.silt
index 3348b63c4..9f92dcc01 100644
--- a/tests/golden/repros/packages/tq_q5/main.silt
+++ b/tests/golden/repros/packages/tq_q5/main.silt
@@ -4,4 +4,4 @@ type Sq { side: Int }
 trait shapes.Area for Sq {
   fn area(self) -> Int { self.side * self.side }
 }
-fn main() { println(Sq { side: 3 }.area()) }
+fn main() { println(shapes.Area.area(Sq { side: 3 })) }
diff --git a/tests/golden/repros/packages/tq_q8/main.silt b/tests/golden/repros/packages/tq_q8/main.silt
index 786ee2809..ac733ed23 100644
--- a/tests/golden/repros/packages/tq_q8/main.silt
+++ b/tests/golden/repros/packages/tq_q8/main.silt
@@ -1,5 +1,5 @@
 -- verdict: same
-import shapes.{ unit }
+import shapes.{ unit, Area }
 fn f(s: Shape) -> Int {
   match s {
     Circle(r) -> r
@@ -8,5 +8,5 @@ fn f(s: Shape) -> Int {
 }
 fn main() {
   println(f(Square(4)))
-  println(unit().area())
+  println(Area.area(unit()))
 }
diff --git a/tests/golden/repros/stdlib/t_negzero2.silt b/tests/golden/repros/stdlib/t_negzero2.silt
index 8ef15b202..c4cc5e969 100644
--- a/tests/golden/repros/stdlib/t_negzero2.silt
+++ b/tests/golden/repros/stdlib/t_negzero2.silt
@@ -5,8 +5,8 @@ import string
 fn main() {
   when let Ok(z) = float.parse("-0.0") else { return }
   println(z == 0.0)
-  println(z.hash() == (0.0).hash())
-  println(z.compare(0.0))
+  println(Hash.hash(z) == Hash.hash(0.0))
+  println(Compare.compare(z, 0.0))
   println(string.from(z) == string.from(0.0))
   println("{z}")
   println(list.sort([0.0, z, 0.0]))
diff --git a/tests/golden/repros/stdlib/t_tostr.silt b/tests/golden/repros/stdlib/t_tostr.silt
index 056335962..caa9b807d 100644
--- a/tests/golden/repros/stdlib/t_tostr.silt
+++ b/tests/golden/repros/stdlib/t_tostr.silt
@@ -8,11 +8,11 @@ import list
 import json
 fn main() {
   let n = 42
-  println([string.from(n), string.from(n), "{n}", n.display(), io.inspect(n), json.stringify(n)])
+  println([string.from(n), string.from(n), "{n}", "{n}", io.inspect(n), json.stringify(n)])
   let f = 2.0
-  println([string.from(f), string.from(f), "{f}", f.display(), io.inspect(f), json.stringify(f)])
+  println([string.from(f), string.from(f), "{f}", "{f}", io.inspect(f), json.stringify(f)])
   let s = "hi"
-  println([string.from(s), "{s}", s.display(), io.inspect(s), json.stringify(s)])
+  println([string.from(s), "{s}", "{s}", io.inspect(s), json.stringify(s)])
   let xs = ["a", "b c", ""]
   println(string.from(xs))
   println(io.inspect(xs))
diff --git a/tests/golden/repros/test_arch/run_ex_birthdays.silt b/tests/golden/repros/test_arch/run_ex_birthdays.silt
index 05e771011..e7e84f7e0 100644
--- a/tests/golden/repros/test_arch/run_ex_birthdays.silt
+++ b/tests/golden/repros/test_arch/run_ex_birthdays.silt
@@ -48,7 +48,7 @@ fn main() {
       ]
     """, Person) {
     Ok(p) -> p
-    Err(e) -> panic("Failed to parse people: {e.message()}")
+    Err(e) -> panic("Failed to parse people: {Error.message(e)}")
   }
   people
   |> list.each { p ->
diff --git a/tests/golden/repros/test_arch/run_ex_concurrent_processor.silt b/tests/golden/repros/test_arch/run_ex_concurrent_processor.silt
index f7481fbbe..0cc21f36f 100644
--- a/tests/golden/repros/test_arch/run_ex_concurrent_processor.silt
+++ b/tests/golden/repros/test_arch/run_ex_concurrent_processor.silt
@@ -102,7 +102,7 @@ fn main() {
               }
               Err(err_info) -> {
                 let (path, err) = err_info
-                println("[Worker {worker_id}] FAILED {path}: {err.message()}")
+                println("[Worker {worker_id}] FAILED {path}: {Error.message(err)}")
                 loop(collected + 1, successes, failures + 1)
               }
             }
diff --git a/tests/golden/repros/test_arch/run_ex_config_parser.silt b/tests/golden/repros/test_arch/run_ex_config_parser.silt
index 8ca85ac25..a9460a125 100644
--- a/tests/golden/repros/test_arch/run_ex_config_parser.silt
+++ b/tests/golden/repros/test_arch/run_ex_config_parser.silt
@@ -144,7 +144,7 @@ fn main() {
   -- Read the config file
   let text = match io.read_file("examples/app.conf") {
     Ok(t) -> t
-    Err(e) -> return println("Error reading examples/app.conf: {e.message()}")
+    Err(e) -> return println("Error reading examples/app.conf: {Error.message(e)}")
   }
   println("=== Parsing config file ===")
   println("")
diff --git a/tests/golden/repros/test_arch/run_ex_csv_analyzer.silt b/tests/golden/repros/test_arch/run_ex_csv_analyzer.silt
index 77ce87503..75ee3e408 100644
--- a/tests/golden/repros/test_arch/run_ex_csv_analyzer.silt
+++ b/tests/golden/repros/test_arch/run_ex_csv_analyzer.silt
@@ -113,7 +113,7 @@ fn main() {
   -- Read and parse CSV; bail out on IO errors with a rendered message.
   let content = match io.read_file("examples/data.csv") {
     Ok(text) -> text
-    Err(e) -> panic("Error reading data.csv: {e.message()}")
+    Err(e) -> panic("Error reading data.csv: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/tests/golden/repros/test_arch/run_ex_diff_tool.silt b/tests/golden/repros/test_arch/run_ex_diff_tool.silt
index af143c97c..b350cb7d5 100644
--- a/tests/golden/repros/test_arch/run_ex_diff_tool.silt
+++ b/tests/golden/repros/test_arch/run_ex_diff_tool.silt
@@ -112,11 +112,11 @@ fn main() {
   -- Read both files, bailing out if either is missing.
   let old_content = match io.read_file("examples/data/original.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading original.txt: {e.message()}")
+    Err(e) -> panic("Error reading original.txt: {Error.message(e)}")
   }
   let new_content = match io.read_file("examples/data/modified.txt") {
     Ok(content) -> content
-    Err(e) -> panic("Error reading modified.txt: {e.message()}")
+    Err(e) -> panic("Error reading modified.txt: {Error.message(e)}")
   }
   -- Split into lines, filter out trailing empty line from final newline
   let old_lines = old_content
diff --git a/tests/golden/repros/test_arch/run_ex_expr_eval.silt b/tests/golden/repros/test_arch/run_ex_expr_eval.silt
index e9b06f500..ce5448e1c 100644
--- a/tests/golden/repros/test_arch/run_ex_expr_eval.silt
+++ b/tests/golden/repros/test_arch/run_ex_expr_eval.silt
@@ -21,9 +21,9 @@ trait Display for Expr {
   fn display(self) -> String {
     match self {
       Num(n) -> "{n}"
-      Add(l, r) -> "({l.display()} + {r.display()})"
-      Mul(l, r) -> "({l.display()} * {r.display()})"
-      Neg(e) -> "(-{e.display()})"
+      Add(l, r) -> "({l} + {r})"
+      Mul(l, r) -> "({l} * {r})"
+      Neg(e) -> "(-{e})"
     }
   }
 }
@@ -206,16 +206,16 @@ fn main() {
   examples
   |> list.each { (label, expr) ->
     println("--- {label} ---")
-    println("  Pretty:     {expr.display()}")
+    println("  Pretty:     {expr}")
     println("  Eval:       {eval(expr)}")
     let s = simplify(expr)
-    println("  Simplified: {s.display()}")
+    println("  Simplified: {s}")
     println("  Eval(simp): {eval(s)}")
     let rpn = to_rpn(expr)
     let rpn_str = string.join(rpn, " ")
     println("  RPN:        {rpn_str}")
     let roundtrip = from_rpn(rpn)
-    println("  Roundtrip:  {roundtrip.display()}")
+    println("  Roundtrip:  {roundtrip}")
     println("  RT eval:    {eval(roundtrip)}")
     println("  Complexity: {complexity(expr)}")
     println("  Depth:      {depth(expr)}")
@@ -226,10 +226,10 @@ fn main() {
   -- Demonstrate deep pattern matching
   println("=== Deep Pattern Matching ===\n")
   let nested = Add(Mul(Num(1), Add(Num(2), Num(3))), Neg(Num(4)))
-  println("Expression: {nested.display()}")
+  println("Expression: {nested}")
   -- Deep match: recognize specific shapes
   let description = match nested {
-    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner.display()}) on left"
+    Add(Mul(Num(1), inner), _) -> "addition with 1*({inner}) on left"
     Add(_, Neg(Num(n))) -> "addition with -{n} on right"
     _ -> "other"
   }
@@ -240,7 +240,7 @@ fn main() {
   test_exprs
   |> list.each { expr ->
     let cls = complexity(expr)
-    println("  {expr.display()} -> {cls}")
+    println("  {expr} -> {cls}")
   }
   -- Build from RPN
   println("\n=== From RPN ===\n")
@@ -248,7 +248,7 @@ fn main() {
   let rpn_str = string.join(rpn_input, " ")
   let parsed = from_rpn(rpn_input)
   println("  RPN input:  {rpn_str}")
-  println("  Parsed:     {parsed.display()}")
+  println("  Parsed:     {parsed}")
   println("  Eval:       {eval(parsed)}")
   -- Demonstrate negative pattern simplification
   println("\n=== Negative Pattern Simplification ===\n")
@@ -256,7 +256,7 @@ fn main() {
   neg_examples
   |> list.each { (label, expr) ->
     let s = simplify(expr)
-    println("  {label} -> simplified: {s.display()} = {eval(s)}")
+    println("  {label} -> simplified: {s} = {eval(s)}")
   }
   println("\nDone!")
 }
diff --git a/tests/golden/repros/test_arch/run_ex_json_time.silt b/tests/golden/repros/test_arch/run_ex_json_time.silt
index 58a9fb8c0..6f61e777e 100644
--- a/tests/golden/repros/test_arch/run_ex_json_time.silt
+++ b/tests/golden/repros/test_arch/run_ex_json_time.silt
@@ -23,7 +23,7 @@ fn main() {
   -- Parse JSON with Date field
   let event = match json.parse("""{"name": "launch", "date": "2024-03-15"}""", Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("event: {event.name}")
   println("date: {event.date}")
@@ -33,13 +33,13 @@ fn main() {
   -- Parse JSON with DateTime field
   let meeting = match json.parse("""{"title": "standup", "start": "2024-03-15T09:00:00"}""", Meeting) {
     Ok(m) -> m
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("meeting: {meeting.title} at {meeting.start}")
   -- Parse JSON with Time field
   let sched = match json.parse("""{"event": "lunch", "date": "2024-03-15", "time": "12:30:00"}""", Schedule) {
     Ok(s) -> s
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   println("schedule: {sched.event} on {sched.date} at {sched.time}")
   -- Parse a list of events
@@ -51,7 +51,7 @@ fn main() {
       ]
     """, Event) {
     Ok(e) -> e
-    Err(e) -> panic("parse error: {e.message()}")
+    Err(e) -> panic("parse error: {Error.message(e)}")
   }
   events
   |> list.each { e ->
@@ -67,6 +67,6 @@ fn main() {
   let bad = json.parse("""{"name": "oops", "date": "not-a-date"}""", Event)
   match bad {
     Ok(e) -> println("bad date: parsed as {e.name}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
 }
diff --git a/tests/golden/repros/test_arch/run_ex_json_transform.silt b/tests/golden/repros/test_arch/run_ex_json_transform.silt
index 766686687..28ceddb9c 100644
--- a/tests/golden/repros/test_arch/run_ex_json_transform.silt
+++ b/tests/golden/repros/test_arch/run_ex_json_transform.silt
@@ -76,7 +76,7 @@ fn main() {
   -- Parse the JSON dataset
   let employees = match json.parse_list(employee_json, Employee) {
     Ok(emps) -> emps
-    Err(e) -> panic("Failed to parse employees: {e.message()}")
+    Err(e) -> panic("Failed to parse employees: {Error.message(e)}")
   }
   println("=== JSON Data Pipeline ===\n")
   -- 1. Group by department
diff --git a/tests/golden/repros/test_arch/run_ex_kvstore.silt b/tests/golden/repros/test_arch/run_ex_kvstore.silt
index d6438ca33..44c95e4b1 100644
--- a/tests/golden/repros/test_arch/run_ex_kvstore.silt
+++ b/tests/golden/repros/test_arch/run_ex_kvstore.silt
@@ -85,7 +85,7 @@ fn handle_save(store) {
   let json_str = json.stringify(store)
   match io.write_file(db_path, json_str) {
     Ok(_) -> println("OK - saved {map.length(store)} entries to {db_path}")
-    Err(e) -> println("Error saving: {e.message()}")
+    Err(e) -> println("Error saving: {Error.message(e)}")
   }
   store
 }
@@ -93,7 +93,7 @@ fn handle_save(store) {
 fn handle_load() {
   match io.read_file(db_path) {
     Err(e) -> {
-      println("Error loading: {e.message()}")
+      println("Error loading: {Error.message(e)}")
       println("Starting with empty store.")
       #{}
     }
@@ -104,7 +104,7 @@ fn handle_load() {
           loaded
         }
         Err(e) -> {
-          println("Error parsing JSON: {e.message()}")
+          println("Error parsing JSON: {Error.message(e)}")
           println("Starting with empty store.")
           #{}
         }
diff --git a/tests/golden/repros/test_arch/run_ex_link_checker.silt b/tests/golden/repros/test_arch/run_ex_link_checker.silt
index 67081dc02..396f5a504 100644
--- a/tests/golden/repros/test_arch/run_ex_link_checker.silt
+++ b/tests/golden/repros/test_arch/run_ex_link_checker.silt
@@ -24,7 +24,7 @@ fn main() {
   let content = match io.read_file(file_path) {
     Ok(c) -> c
     Err(e) -> {
-      println("Error reading file: {e.message()}")
+      println("Error reading file: {Error.message(e)}")
       return panic("Cannot continue without file")
     }
   }
diff --git a/tests/golden/repros/test_arch/run_ex_pipeline.silt b/tests/golden/repros/test_arch/run_ex_pipeline.silt
index 694ba236c..310b78862 100644
--- a/tests/golden/repros/test_arch/run_ex_pipeline.silt
+++ b/tests/golden/repros/test_arch/run_ex_pipeline.silt
@@ -160,7 +160,7 @@ fn main() {
   -- Read the log file; `return` in an Err arm bails out of main.
   let content = match io.read_file("examples/log.txt") {
     Ok(c) -> c
-    Err(e) -> return println("Error reading log file: {e.message()}")
+    Err(e) -> return println("Error reading log file: {Error.message(e)}")
   }
   let lines = content
   |> string.split("\n")
diff --git a/tests/golden/repros/test_arch/run_ex_state_machine.silt b/tests/golden/repros/test_arch/run_ex_state_machine.silt
index bbb0968d4..f3361bcf5 100644
--- a/tests/golden/repros/test_arch/run_ex_state_machine.silt
+++ b/tests/golden/repros/test_arch/run_ex_state_machine.silt
@@ -52,7 +52,7 @@ trait Display for Event {
 -- Print a labeled displayable value (uses where clause)
 
 fn print_labeled(label: String, value: a) where a: Display {
-  println("{label}: {value.display()}")
+  println("{label}: {value}")
 }
 
 -- Print a list of displayable items with a header (uses where clause)
@@ -60,7 +60,7 @@ fn print_labeled(label: String, value: a) where a: Display {
 fn print_items(header: String, items: List(a)) where a: Display {
   println(header)
   items
-  |> list.each { item -> println("  - {item.display()}") }
+  |> list.each { item -> println("  - {item}") }
 }
 
 -- Look up item info from inventory; returns (quantity, price) or None
@@ -156,7 +156,7 @@ fn run_machine(events, initial_state, initial_inventory) {
       _ -> (state2, inventory2)
     }
     let (new_state, message, new_inv) = transition(state3, event, inventory3)
-    let new_log = list.append(log2, (step2, event.display(), state3, new_state, message))
+    let new_log = list.append(log2, (step2, "{event}", state3, new_state, message))
     (new_state, new_inv, step2 + 1, new_log)
   }
   -- If we're in Dispensing state, auto-resolve it first
@@ -192,7 +192,7 @@ fn main() {
       _ -> "{step}"
     }
     println("[{step_str}] Event: {event_str}")
-    println("     {old_state.display()} -> {new_state.display()}")
+    println("     {old_state} -> {new_state}")
     println("     >> {message}")
     println("")
   }
diff --git a/tests/golden/repros/test_arch/run_ex_time_demo.silt b/tests/golden/repros/test_arch/run_ex_time_demo.silt
index 1f880945a..8ac405082 100644
--- a/tests/golden/repros/test_arch/run_ex_time_demo.silt
+++ b/tests/golden/repros/test_arch/run_ex_time_demo.silt
@@ -7,31 +7,31 @@ fn main() {
   let date = time.date(2024, 3, 15)
   match date {
     Ok(d) -> println("date: {d}")
-    Err(e) -> println("date error: {e.message()}")
+    Err(e) -> println("date error: {Error.message(e)}")
   }
   let bad_date = time.date(2024, 13, 1)
   match bad_date {
     Ok(d) -> println("bad date: {d}")
-    Err(e) -> println("bad date: {e.message()}")
+    Err(e) -> println("bad date: {Error.message(e)}")
   }
   let t = time.time(14, 30, 0)
   match t {
     Ok(tm) -> println("time: {tm}")
-    Err(e) -> println("time error: {e.message()}")
+    Err(e) -> println("time error: {Error.message(e)}")
   }
   let bad_time = time.time(25, 0, 0)
   match bad_time {
     Ok(tm) -> println("bad time: {tm}")
-    Err(e) -> println("bad time: {e.message()}")
+    Err(e) -> println("bad time: {Error.message(e)}")
   }
   -- Compose date + time into datetime
   let d = match time.date(2024, 6, 15) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let tod = match time.time(9, 30, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt = time.datetime(d, tod)
   println("datetime: {dt}")
@@ -43,11 +43,11 @@ fn main() {
   -- ── Formatting ──────────────────────────────────────────────────────
   let dt2_date = match time.date(2024, 12, 25) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let dt2_time = match time.time(18, 0, 0) {
     Ok(t) -> t
-    Err(e) -> panic("time error: {e.message()}")
+    Err(e) -> panic("time error: {Error.message(e)}")
   }
   let dt2 = time.datetime(dt2_date, dt2_time)
   println("formatted: {dt2
@@ -58,17 +58,17 @@ fn main() {
   let parsed = time.parse("2024-07-04 12:00:00", "%Y-%m-%d %H:%M:%S")
   match parsed {
     Ok(dt) -> println("parsed: {dt}")
-    Err(e) -> println("parse error: {e.message()}")
+    Err(e) -> println("parse error: {Error.message(e)}")
   }
   let parsed_date = time.parse_date("2024-07-04", "%Y-%m-%d")
   match parsed_date {
     Ok(d) -> println("parsed date: {d}")
-    Err(e) -> println("parse date error: {e.message()}")
+    Err(e) -> println("parse date error: {Error.message(e)}")
   }
   let bad_parse = time.parse("not-a-date", "%Y-%m-%d %H:%M:%S")
   match bad_parse {
     Ok(dt) -> println("bad parse: {dt}")
-    Err(e) -> println("bad parse: {e.message()}")
+    Err(e) -> println("bad parse: {Error.message(e)}")
   }
   -- ── Date arithmetic ─────────────────────────────────────────────────
   let future = today
@@ -80,14 +80,14 @@ fn main() {
   -- Month arithmetic with end-of-month clamping
   let jan31 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let feb_result = jan31
   |> time.add_months(1)
   println("Jan 31 + 1 month = {feb_result}")
   let mar31 = match time.date(2024, 3, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let prev = mar31
   |> time.add_months(-1)
@@ -123,11 +123,11 @@ fn main() {
   println("today is: {weekday}")
   let d_start = match time.date(2024, 1, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d_end = match time.date(2024, 12, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let days = time.days_between(d_start, d_end)
   println("days in 2024: {days}")
@@ -139,11 +139,11 @@ fn main() {
   -- ── Comparison ──────────────────────────────────────────────────────
   let d1 = match time.date(2024, 1, 31) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   let d2 = match time.date(2024, 2, 1) {
     Ok(d) -> d
-    Err(e) -> panic("date error: {e.message()}")
+    Err(e) -> panic("date error: {Error.message(e)}")
   }
   println("Jan 31 < Feb 1: {d1 < d2}")
   println("Feb 1 > Jan 31: {d2 > d1}")
diff --git a/tests/golden/repros/test_arch/run_ex_todo.silt b/tests/golden/repros/test_arch/run_ex_todo.silt
index 5f2fbf48e..d3e9b0b4a 100644
--- a/tests/golden/repros/test_arch/run_ex_todo.silt
+++ b/tests/golden/repros/test_arch/run_ex_todo.silt
@@ -62,7 +62,7 @@ fn save_todos(todos, path) {
   let content = json.stringify(todos)
   match io.write_file(path, content) {
     Ok(_) -> println("  Saved {list.length(todos)} todo(s) to {path}")
-    Err(e) -> println("  Error saving: {e.message()}")
+    Err(e) -> println("  Error saving: {Error.message(e)}")
   }
 }
 
@@ -79,13 +79,13 @@ fn load_todos(path) {
           todos
         }
         Err(e) -> {
-          println("  Error parsing: {e.message()}")
+          println("  Error parsing: {Error.message(e)}")
           []
         }
       }
     }
     Err(e) -> {
-      println("  Error loading: {e.message()}")
+      println("  Error loading: {Error.message(e)}")
       []
     }
   }
diff --git a/tests/golden/repros/test_arch/run_ex_trait_zoo.silt b/tests/golden/repros/test_arch/run_ex_trait_zoo.silt
index 3a9a20278..8489e44fa 100644
--- a/tests/golden/repros/test_arch/run_ex_trait_zoo.silt
+++ b/tests/golden/repros/test_arch/run_ex_trait_zoo.silt
@@ -53,7 +53,7 @@ trait Display for Color {
 trait Display for Styled {
   fn display(self) -> String {
     match self {
-      Styled(shape, color) -> "{shape.display()} in {color.display()}"
+      Styled(shape, color) -> "{shape} in {color}"
     }
   }
 }
@@ -98,7 +98,7 @@ trait Perimeter for Shape {
 -- Generic function with where clause
 
 fn describe(item: a) where a: Display {
-  item.display()
+  "{item}"
 }
 
 -- Format a float to 4 decimal places
diff --git a/tests/golden/repros/test_arch/run_ex_traits.silt b/tests/golden/repros/test_arch/run_ex_traits.silt
index 28b81e689..2973ab18e 100644
--- a/tests/golden/repros/test_arch/run_ex_traits.silt
+++ b/tests/golden/repros/test_arch/run_ex_traits.silt
@@ -26,7 +26,7 @@ fn main() {
   let shapes = [Circle(5.0), Rect(3.0, 4.0), Circle(1.0)]
   println("-- Shapes --")
   shapes
-  |> list.each { s -> println("{s.display()} -> area = {area(s)}") }
+  |> list.each { s -> println("{s} -> area = {area(s)}") }
   let total = shapes
   |> list.map { s -> area(s) }
   |> list.fold(0.0) { acc, a -> acc + a }
diff --git a/tests/golden/repros/type_soundness/a6.silt b/tests/golden/repros/type_soundness/a6.silt
index 8785404d5..27fe09665 100644
--- a/tests/golden/repros/type_soundness/a6.silt
+++ b/tests/golden/repros/type_soundness/a6.silt
@@ -4,7 +4,7 @@ trait Sz { fn sz(self) -> Int }
 type P { n: Int }
 trait Sz for P { fn sz(self) -> String { "big" } }
 trait Sz for Int { fn sz(self) { "unannotated string" } }
-fn total(x: a, y: a) -> Int where a: Sz { x.sz() + y.sz() }
+fn total(x: a, y: a) -> Int where a: Sz { Sz.sz(x) + Sz.sz(y) }
 fn main() {
   println(total(1, 2))
 }
diff --git a/tests/golden/repros/type_soundness/a7.silt b/tests/golden/repros/type_soundness/a7.silt
index 25d51882f..f637d7dec 100644
--- a/tests/golden/repros/type_soundness/a7.silt
+++ b/tests/golden/repros/type_soundness/a7.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Sz { fn sz(self) -> Int }
 trait Sz for Int { fn sz(self) { "unannotated string" } }
-fn total(x: a, y: a) -> Int where a: Sz { x.sz() + y.sz() }
+fn total(x: a, y: a) -> Int where a: Sz { Sz.sz(x) + Sz.sz(y) }
 fn main() {
   println(total(1, 2))
 }
diff --git a/tests/golden/repros/type_soundness/a8.silt b/tests/golden/repros/type_soundness/a8.silt
index 0ecd29a13..489e12b4c 100644
--- a/tests/golden/repros/type_soundness/a8.silt
+++ b/tests/golden/repros/type_soundness/a8.silt
@@ -2,6 +2,6 @@
 trait Mk { fn mk(self, other) -> Self }
 trait Mk for Int { fn mk(self, other) { other } }
 fn main() {
-  let n: Int = 1.mk("not int")
+  let n: Int = Mk.mk(1, "not int")
   println(n + 1)
 }
diff --git a/tests/golden/repros/type_soundness/a9.silt b/tests/golden/repros/type_soundness/a9.silt
index f6380f7d0..5464efceb 100644
--- a/tests/golden/repros/type_soundness/a9.silt
+++ b/tests/golden/repros/type_soundness/a9.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Conv(b) { fn conv(self) -> b }
 trait Conv(Int) for String { fn conv(self) -> Int { 0 } }
-fn into(x: a, type b) -> b where a: Conv(b) { x.conv() }
+fn into(x: a, type b) -> b where a: Conv(b) { Conv.conv(x) }
 fn main() {
   let s: String = into("42", String)
   println(s)
diff --git a/tests/golden/repros/type_soundness/al1.silt b/tests/golden/repros/type_soundness/al1.silt
index 920c8c09e..e6040a0e9 100644
--- a/tests/golden/repros/type_soundness/al1.silt
+++ b/tests/golden/repros/type_soundness/al1.silt
@@ -9,7 +9,7 @@ fn f(p: Pairs(Int)) -> Int { match p {
 } }
 fn main() {
   let m: Meters = 5
-  println(m.greet())
-  println(5.greet())
+  println(Greet.greet(m))
+  println(Greet.greet(5))
   println(f([(1, 2)]))
 }
diff --git a/tests/golden/repros/type_soundness/al2.silt b/tests/golden/repros/type_soundness/al2.silt
index c358604e9..deec7ad97 100644
--- a/tests/golden/repros/type_soundness/al2.silt
+++ b/tests/golden/repros/type_soundness/al2.silt
@@ -5,5 +5,5 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Meters { fn greet(self) -> String { "m" } }
 trait Greet for Int { fn greet(self) -> String { "i" } }
 fn main() {
-  println(5.greet())
+  println(Greet.greet(5))
 }
diff --git a/tests/golden/repros/type_soundness/al3.silt b/tests/golden/repros/type_soundness/al3.silt
index a0ff187c5..ca3cd520e 100644
--- a/tests/golden/repros/type_soundness/al3.silt
+++ b/tests/golden/repros/type_soundness/al3.silt
@@ -6,11 +6,11 @@ trait Greet for Float { fn greet(self) -> String { "float" } }
 trait Greet for ExtFloat { fn greet(self) -> String { "ext" } }
 fn g(x) { x / 2.0 }
 fn main() {
-  println((1..3).greet())
+  println(Greet.greet(1..3))
   let a = 1.0 / 2.0
-  println(a.greet())
+  println(Greet.greet(a))
   let b = 1.0 + 2.0
-  println(b.greet())
+  println(Greet.greet(b))
   let c = g(4.0)
-  println(c.greet())
+  println(Greet.greet(c))
 }
diff --git a/tests/golden/repros/type_soundness/al4.silt b/tests/golden/repros/type_soundness/al4.silt
index fa02f2dab..1e565eb1d 100644
--- a/tests/golden/repros/type_soundness/al4.silt
+++ b/tests/golden/repros/type_soundness/al4.silt
@@ -5,5 +5,5 @@ trait Greet for ExtFloat { fn greet(self) -> String { "ext" } }
 fn g(x) { x / 2.0 }
 fn main() {
   let c = g(4.0)
-  println(c.greet())
+  println(Greet.greet(c))
 }
diff --git a/tests/golden/repros/type_soundness/an3.silt b/tests/golden/repros/type_soundness/an3.silt
index bb26edbce..f2c854e87 100644
--- a/tests/golden/repros/type_soundness/an3.silt
+++ b/tests/golden/repros/type_soundness/an3.silt
@@ -3,6 +3,6 @@ type Box(a) { Box(a) }
 trait Get { fn get(self) -> Int }
 trait Get for Box { fn get(self) -> Int { match self { Box(v) -> v } } }
 fn main() {
-  println(Box(1).get())
-  println(Box("s").get() + 1)
+  println(Get.get(Box(1)))
+  println(Get.get(Box("s")) + 1)
 }
diff --git a/tests/golden/repros/type_soundness/c2.silt b/tests/golden/repros/type_soundness/c2.silt
index 0a720b8f1..0372b3900 100644
--- a/tests/golden/repros/type_soundness/c2.silt
+++ b/tests/golden/repros/type_soundness/c2.silt
@@ -1,6 +1,6 @@
 -- verdict: same
 -- method call on unconstrained type var
-fn show(x) { x.display() }
+fn show(x) { "{x}" }
 fn main() {
   let f = fn(x) { x + 1 }
   println(show(1))
diff --git a/tests/golden/repros/type_soundness/c3.silt b/tests/golden/repros/type_soundness/c3.silt
index fa9732ec2..2e677edc8 100644
--- a/tests/golden/repros/type_soundness/c3.silt
+++ b/tests/golden/repros/type_soundness/c3.silt
@@ -2,7 +2,7 @@
 -- user trait method on unconstrained tyvar
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn g(x) { x.greet() }
+fn g(x) { Greet.greet(x) }
 fn main() {
   println(g(1))
   println(g("s"))
diff --git a/tests/golden/repros/type_soundness/d1.silt b/tests/golden/repros/type_soundness/d1.silt
index 8a3f65a24..ddb82c749 100644
--- a/tests/golden/repros/type_soundness/d1.silt
+++ b/tests/golden/repros/type_soundness/d1.silt
@@ -3,7 +3,7 @@
 trait Same { fn same(self) -> Self }
 trait Same for String { fn same(self) -> Self { self } }
 
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 
 fn main() {
   let n: Int = coerce("not an int")
diff --git a/tests/golden/repros/type_soundness/d3.silt b/tests/golden/repros/type_soundness/d3.silt
index e7d262b7d..f80d18d33 100644
--- a/tests/golden/repros/type_soundness/d3.silt
+++ b/tests/golden/repros/type_soundness/d3.silt
@@ -4,7 +4,7 @@ import map
 trait Same { fn same(self) -> Self }
 trait Same for String { fn same(self) -> Self { self } }
 
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 
 fn main() {
   let r: {name: String, age: Int} = coerce("zzz")
diff --git a/tests/golden/repros/type_soundness/d5.silt b/tests/golden/repros/type_soundness/d5.silt
index 0ec26dfd2..668d5f34c 100644
--- a/tests/golden/repros/type_soundness/d5.silt
+++ b/tests/golden/repros/type_soundness/d5.silt
@@ -1,5 +1,5 @@
 -- verdict: same
-fn f(x) { x.display() }
+fn f(x) { "{x}" }
 fn main() {
   let g = fn(x) { x }
   println(g.display())
diff --git a/tests/golden/repros/type_soundness/d6.silt b/tests/golden/repros/type_soundness/d6.silt
index 3167645d2..fd4e685ad 100644
--- a/tests/golden/repros/type_soundness/d6.silt
+++ b/tests/golden/repros/type_soundness/d6.silt
@@ -2,7 +2,7 @@
 import list
 trait Same { fn same(self) -> Self }
 trait Same for String { fn same(self) -> Self { self } }
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 fn main() {
   let r: {name: String, age: Int} = coerce("zzz")
   println(r.age)
diff --git a/tests/golden/repros/type_soundness/d7.silt b/tests/golden/repros/type_soundness/d7.silt
index 7d25b645f..540ea1ea2 100644
--- a/tests/golden/repros/type_soundness/d7.silt
+++ b/tests/golden/repros/type_soundness/d7.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Same { fn same(self) -> Self }
 trait Same for String { fn same(self) -> Self { self } }
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 fn main() {
   let f: Fn(Int) -> Int = coerce("callme")
   println(f(1))
diff --git a/tests/golden/repros/type_soundness/d8.silt b/tests/golden/repros/type_soundness/d8.silt
index 32f1e2b96..62f9d95c3 100644
--- a/tests/golden/repros/type_soundness/d8.silt
+++ b/tests/golden/repros/type_soundness/d8.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Same { fn same(self) -> Self }
 trait Same for String { fn same(self) -> Self { self } }
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 type Shape { Circle(Int), Sq(Int) }
 fn main() {
   let s: Shape = coerce("callme")
diff --git a/tests/golden/repros/type_soundness/d9.silt b/tests/golden/repros/type_soundness/d9.silt
index 030819769..1120c6a90 100644
--- a/tests/golden/repros/type_soundness/d9.silt
+++ b/tests/golden/repros/type_soundness/d9.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Same { fn same(self) -> Self }
 trait Same for Int { fn same(self) -> Self { self } }
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 type Shape { Circle(Int), Sq(Int) }
 fn main() {
   let b: Bool = coerce(7)
diff --git a/tests/golden/repros/type_soundness/e10.silt b/tests/golden/repros/type_soundness/e10.silt
index 364a8b1f4..448d3cc91 100644
--- a/tests/golden/repros/type_soundness/e10.silt
+++ b/tests/golden/repros/type_soundness/e10.silt
@@ -3,5 +3,5 @@ import list
 type P { v: Int }
 fn main() {
   let ps = [P { v: 1 }]
-  println(list.map(ps) { p -> p.display() })
+  println(list.map(ps) { p -> "{p}" })
 }
diff --git a/tests/golden/repros/type_soundness/e11.silt b/tests/golden/repros/type_soundness/e11.silt
index 652cd8071..14b0f3b09 100644
--- a/tests/golden/repros/type_soundness/e11.silt
+++ b/tests/golden/repros/type_soundness/e11.silt
@@ -6,5 +6,5 @@ trait Greet for P { fn greet(self) -> String { "p" } }
 fn main() {
   let ps = [P { v: 1 }]
   -- pipe form
-  ps |> list.map { p -> p.greet() } |> println
+  ps |> list.map { p -> Greet.greet(p) } |> println
 }
diff --git a/tests/golden/repros/type_soundness/e6.silt b/tests/golden/repros/type_soundness/e6.silt
index 14a039686..81f099afd 100644
--- a/tests/golden/repros/type_soundness/e6.silt
+++ b/tests/golden/repros/type_soundness/e6.silt
@@ -2,6 +2,6 @@
 import list
 fn main() {
   let xs = [1, 2, 3]
-  let ys = list.map(xs) { x -> x.display() }
+  let ys = list.map(xs) { x -> "{x}" }
   println(ys)
 }
diff --git a/tests/golden/repros/type_soundness/e8.silt b/tests/golden/repros/type_soundness/e8.silt
index 2407998dc..471ebf1f5 100644
--- a/tests/golden/repros/type_soundness/e8.silt
+++ b/tests/golden/repros/type_soundness/e8.silt
@@ -7,9 +7,9 @@ trait Greet for Int { fn greet(self) -> String { "i" } }
 trait Greet for List(a) { fn greet(self) -> String { "l" } }
 fn main() {
   let ps = [P { v: 1 }]
-  println(list.map(ps) { p -> p.greet() })
-  println(list.map([1]) { p -> p.greet() })
-  println(list.map([[1]]) { p -> p.greet() })
-  println(list.map([(1, 2)]) { p -> p.display() })
-  println(list.map(["a"]) { p -> p.display() })
+  println(list.map(ps) { p -> Greet.greet(p) })
+  println(list.map([1]) { p -> Greet.greet(p) })
+  println(list.map([[1]]) { p -> Greet.greet(p) })
+  println(list.map([(1, 2)]) { p -> "{p}" })
+  println(list.map(["a"]) { p -> "{p}" })
 }
diff --git a/tests/golden/repros/type_soundness/e9.silt b/tests/golden/repros/type_soundness/e9.silt
index 2c4b551a1..f134ee088 100644
--- a/tests/golden/repros/type_soundness/e9.silt
+++ b/tests/golden/repros/type_soundness/e9.silt
@@ -4,6 +4,6 @@ type Shape { Circle(Int), Sq(Int) }
 trait Greet { fn greet(self) -> String }
 trait Greet for Shape { fn greet(self) -> String { "shape" } }
 fn main() {
-  println(list.map([Circle(1)]) { p -> p.greet() })
-  println(list.map([Circle(1)]) { p -> p.display() })
+  println(list.map([Circle(1)]) { p -> Greet.greet(p) })
+  println(list.map([Circle(1)]) { p -> "{p}" })
 }
diff --git a/tests/golden/repros/type_soundness/f8.silt b/tests/golden/repros/type_soundness/f8.silt
index 4b89663c4..f717bc55e 100644
--- a/tests/golden/repros/type_soundness/f8.silt
+++ b/tests/golden/repros/type_soundness/f8.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 -- where clause on a tyvar that gets unified to concrete
 trait Greet { fn greet(self) -> String }
-fn f(x: a) -> String where a: Greet { x.greet() + string.from(x + 1) }
+fn f(x: a) -> String where a: Greet { Greet.greet(x) + string.from(x + 1) }
 fn main() {
   println(f(2))
 }
diff --git a/tests/golden/repros/type_soundness/r4.silt b/tests/golden/repros/type_soundness/r4.silt
index af9c29c5d..765adb851 100644
--- a/tests/golden/repros/type_soundness/r4.silt
+++ b/tests/golden/repros/type_soundness/r4.silt
@@ -2,7 +2,7 @@
 type P { name: String, age: Int }
 trait Greet { fn greet(self) -> String }
 trait Greet for P { fn greet(self) -> String { "I am {self.name}" } }
-fn takes_p(p: P) -> String { p.greet() }
+fn takes_p(p: P) -> String { Greet.greet(p) }
 fn show_p(p: P) -> String { "{p}" }
 fn main() {
   println(takes_p(P {name: "x", age: 3}))
diff --git a/tests/golden/repros/type_soundness/w1.silt b/tests/golden/repros/type_soundness/w1.silt
index ed6c59e10..f32aaf6ce 100644
--- a/tests/golden/repros/type_soundness/w1.silt
+++ b/tests/golden/repros/type_soundness/w1.silt
@@ -2,7 +2,7 @@
 import list
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 
 -- through higher-order function
 fn apply(f, x) { f(x) }
diff --git a/tests/golden/repros/type_soundness/w10.silt b/tests/golden/repros/type_soundness/w10.silt
index b9cbfa7b9..87c760c8b 100644
--- a/tests/golden/repros/type_soundness/w10.silt
+++ b/tests/golden/repros/type_soundness/w10.silt
@@ -2,7 +2,7 @@
 import list
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   println(list.map(["a", "b"], fn(x) { hello(x) }))
 }
diff --git a/tests/golden/repros/type_soundness/w11.silt b/tests/golden/repros/type_soundness/w11.silt
index 3eb57fb2a..3fea5c1b8 100644
--- a/tests/golden/repros/type_soundness/w11.silt
+++ b/tests/golden/repros/type_soundness/w11.silt
@@ -2,7 +2,7 @@
 import list
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   let f: Fn(String) -> String = hello
   println(f("x"))
diff --git a/tests/golden/repros/type_soundness/w2.silt b/tests/golden/repros/type_soundness/w2.silt
index 1592b7636..2ee4f380c 100644
--- a/tests/golden/repros/type_soundness/w2.silt
+++ b/tests/golden/repros/type_soundness/w2.silt
@@ -2,7 +2,7 @@
 import list
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   println(list.map(["a", "b"], hello))
 }
diff --git a/tests/golden/repros/type_soundness/w3.silt b/tests/golden/repros/type_soundness/w3.silt
index 1d2e2b793..27a916a90 100644
--- a/tests/golden/repros/type_soundness/w3.silt
+++ b/tests/golden/repros/type_soundness/w3.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 type Ops(a) { run: Fn(a) -> String }
 fn main() {
   let o = Ops { run: hello }
diff --git a/tests/golden/repros/type_soundness/w3b.silt b/tests/golden/repros/type_soundness/w3b.silt
index bb9c9ae1e..b964074cc 100644
--- a/tests/golden/repros/type_soundness/w3b.silt
+++ b/tests/golden/repros/type_soundness/w3b.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   let t = (hello, 1)
   let (g, _) = t
diff --git a/tests/golden/repros/type_soundness/w3c.silt b/tests/golden/repros/type_soundness/w3c.silt
index ce7a181ea..44afac950 100644
--- a/tests/golden/repros/type_soundness/w3c.silt
+++ b/tests/golden/repros/type_soundness/w3c.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   let fs = [hello]
   match fs {
diff --git a/tests/golden/repros/type_soundness/w4.silt b/tests/golden/repros/type_soundness/w4.silt
index bbed81b7a..4591e272a 100644
--- a/tests/golden/repros/type_soundness/w4.silt
+++ b/tests/golden/repros/type_soundness/w4.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn wrap(x) { hello(x) }
 fn wrap2(x) { wrap(x) }
 fn main() {
diff --git a/tests/golden/repros/type_soundness/w5.silt b/tests/golden/repros/type_soundness/w5.silt
index 2980ae6f2..ea9d4ac01 100644
--- a/tests/golden/repros/type_soundness/w5.silt
+++ b/tests/golden/repros/type_soundness/w5.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   let h = hello
   println(h("s"))
diff --git a/tests/golden/repros/type_soundness/w6.silt b/tests/golden/repros/type_soundness/w6.silt
index db4acf92f..515157064 100644
--- a/tests/golden/repros/type_soundness/w6.silt
+++ b/tests/golden/repros/type_soundness/w6.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn wrap(x: b) -> String { hello(x) }
 fn main() {
   println(wrap("s"))
diff --git a/tests/golden/repros/type_soundness/w7.silt b/tests/golden/repros/type_soundness/w7.silt
index 58f89f8f5..0a34b7b45 100644
--- a/tests/golden/repros/type_soundness/w7.silt
+++ b/tests/golden/repros/type_soundness/w7.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn wrap(x) { hello(x) }
 fn wrap2(x) { wrap(x) }
 fn main() {
diff --git a/tests/golden/repros/type_soundness/w8.silt b/tests/golden/repros/type_soundness/w8.silt
index af69af7eb..02d6b56d6 100644
--- a/tests/golden/repros/type_soundness/w8.silt
+++ b/tests/golden/repros/type_soundness/w8.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn wrap(x) { hello(x) }
 fn main() {
   println(wrap(1))
diff --git a/tests/golden/repros/type_soundness/xr2.silt b/tests/golden/repros/type_soundness/xr2.silt
index 29de05d0d..f49177737 100644
--- a/tests/golden/repros/type_soundness/xr2.silt
+++ b/tests/golden/repros/type_soundness/xr2.silt
@@ -12,11 +12,11 @@ fn int_cmp(a: Int, b: Int) -> Int { match {
 fn main() {
   let a = P { v: 1 }
   let b = P { v: 2 }
-  println(a.equal(b))
   println(a == b)
-  println(a.compare(b))
+  println(a == b)
+  println(Compare.compare(a, b))
   println(a < b)
-  println(a.display())
+  println("{a}")
   println("{a}")
   println(a)
   println(list.sort([a, b]))
diff --git a/tests/golden/repros/type_soundness/z1.silt b/tests/golden/repros/type_soundness/z1.silt
index f3746a7ab..180db1df9 100644
--- a/tests/golden/repros/type_soundness/z1.silt
+++ b/tests/golden/repros/type_soundness/z1.silt
@@ -2,7 +2,7 @@
 import channel
 type Box(a) { Box(a) }
 fn show(x) { "{x}" }
-fn show2(x) { x.display() }
+fn show2(x) { "{x}" }
 fn pr(x) { println(x) }
 fn main() {
   let f = fn(x) { x }
diff --git a/tests/golden/repros/type_soundness/z2.silt b/tests/golden/repros/type_soundness/z2.silt
index a0404175d..033f9ae5e 100644
--- a/tests/golden/repros/type_soundness/z2.silt
+++ b/tests/golden/repros/type_soundness/z2.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 type Box(a) { Box(a) }
 fn show(x) { "{x}" }
-fn show2(x) { x.display() }
+fn show2(x) { "{x}" }
 fn pr(x) { println(x) }
 fn main() {
   let f = fn(x) { x }
diff --git a/tests/golden/repros/type_soundness/z3.silt b/tests/golden/repros/type_soundness/z3.silt
index 01b385bfc..0fbf7d178 100644
--- a/tests/golden/repros/type_soundness/z3.silt
+++ b/tests/golden/repros/type_soundness/z3.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 type Box(a) { Box(a) }
 fn show(x) { "{x}" }
-fn show2(x) { x.display() }
+fn show2(x) { "{x}" }
 fn pr(x) { println(x) }
 fn main() {
   let f = fn(x) { x }
diff --git a/tests/golden/repros/typechecker_arch/alias1_main/a.silt b/tests/golden/repros/typechecker_arch/alias1_main/a.silt
index 0dd499815..cde98c207 100644
--- a/tests/golden/repros/typechecker_arch/alias1_main/a.silt
+++ b/tests/golden/repros/typechecker_arch/alias1_main/a.silt
@@ -1,4 +1,4 @@
 type Id = Int
 trait Show2 { fn show2(self) -> String }
 trait Show2 for Id { fn show2(self) -> String { "int-id" } }
-pub fn f(x: Int) -> String { x.show2() }
+pub fn f(x: Int) -> String { Show2.show2(x) }
diff --git a/tests/golden/repros/typechecker_arch/alias1_main_only_a/a.silt b/tests/golden/repros/typechecker_arch/alias1_main_only_a/a.silt
index 0dd499815..cde98c207 100644
--- a/tests/golden/repros/typechecker_arch/alias1_main_only_a/a.silt
+++ b/tests/golden/repros/typechecker_arch/alias1_main_only_a/a.silt
@@ -1,4 +1,4 @@
 type Id = Int
 trait Show2 { fn show2(self) -> String }
 trait Show2 for Id { fn show2(self) -> String { "int-id" } }
-pub fn f(x: Int) -> String { x.show2() }
+pub fn f(x: Int) -> String { Show2.show2(x) }
diff --git a/tests/golden/repros/typechecker_arch/cv2_ver.silt b/tests/golden/repros/typechecker_arch/cv2_ver.silt
index 740f19391..f21876c0e 100644
--- a/tests/golden/repros/typechecker_arch/cv2_ver.silt
+++ b/tests/golden/repros/typechecker_arch/cv2_ver.silt
@@ -4,5 +4,5 @@ fn main() {
   let a = Ver { major: 1, build: 9 }
   let b = Ver { major: 2, build: 0 }
   println(a < b)
-  println(a.compare(b))
+  println(Compare.compare(a, b))
 }
diff --git a/tests/golden/repros/typechecker_arch/derive_d1.silt b/tests/golden/repros/typechecker_arch/derive_d1.silt
index df922dd37..3fd35b50e 100644
--- a/tests/golden/repros/typechecker_arch/derive_d1.silt
+++ b/tests/golden/repros/typechecker_arch/derive_d1.silt
@@ -6,18 +6,18 @@ type G(a) { Wrap(a), Nil }
 fn main() {
   let p = P { x: 1, y: "s" }
   let b = B { v: 1, w: 2 }
-  println(p.display())
-  println(b.display())
-  println(A(1).display())
-  println(Wrap(1).display())
+  println("{p}")
+  println("{b}")
+  println("{A(1)}")
+  println("{Wrap(1)}")
   println("{p} {b}")
-  println(p.equal(p))
-  println(b.equal(b))
-  println(p.compare(P { x: 2, y: "a" }))
-  println(b.compare(B { v: 2, w: 0 }))
-  println(p.hash() == p.hash())
-  println(b.hash() == b.hash())
+  println(p == p)
+  println(b == b)
+  println(Compare.compare(p, P { x: 2, y: "a" }))
+  println(Compare.compare(b, B { v: 2, w: 0 }))
+  println(Hash.hash(p) == Hash.hash(p))
+  println(Hash.hash(b) == Hash.hash(b))
   println(p < P { x: 2, y: "a" })
-  println(Wrap(1).compare(Nil))
-  println(A(1).compare(C))
+  println(Compare.compare(Wrap(1), Nil))
+  println(Compare.compare(A(1), C))
 }
diff --git a/tests/golden/repros/typechecker_arch/derive_d2.silt b/tests/golden/repros/typechecker_arch/derive_d2.silt
index f555de5e0..93ca16a8e 100644
--- a/tests/golden/repros/typechecker_arch/derive_d2.silt
+++ b/tests/golden/repros/typechecker_arch/derive_d2.silt
@@ -1,4 +1,5 @@
 -- verdict: same
+import string
 type P { x: Int, y: String }
 type B(a) { v: a, w: Int }
 type E { A(Int, String), C }
@@ -10,16 +11,16 @@ fn main() {
   let p = P { x: 1, y: "s" }
   let b = B { v: 1, w: 2 }
   println(p)
-  println(p.display())
+  println("{p}")
   println("{p}")
   println(b)
-  println(b.display())
+  println("{b}")
   println("{b}")
   println(Wrap(1, "q"))
-  println(Wrap(1, "q").display())
+  println(string.from(Wrap(1, "q")))
   println("{Wrap(1, "q")}")
   println(A(1, "z"))
-  println(A(1, "z").display())
+  println(string.from(A(1, "z")))
   println("{A(1, "z")}")
   println([A(1, "z")])
   println([p])
diff --git a/tests/golden/repros/typechecker_arch/derive_d3.silt b/tests/golden/repros/typechecker_arch/derive_d3.silt
index c82d6b578..26f723b63 100644
--- a/tests/golden/repros/typechecker_arch/derive_d3.silt
+++ b/tests/golden/repros/typechecker_arch/derive_d3.silt
@@ -5,7 +5,7 @@ trait Display for Temp {
 }
 fn main() {
   let t = Temp { degrees: 21 }
-  println(t.display())
+  println("{t}")
   println("{t}")
   println(t)
   let s = "now: {t}"
diff --git a/tests/golden/repros/typechecker_arch/derive_d4.silt b/tests/golden/repros/typechecker_arch/derive_d4.silt
index 07894cfc3..4d45fdc4f 100644
--- a/tests/golden/repros/typechecker_arch/derive_d4.silt
+++ b/tests/golden/repros/typechecker_arch/derive_d4.silt
@@ -11,9 +11,9 @@ trait Compare for Name {
 fn main() {
   let a = Name { s: "a" }
   let b = Name { s: "b" }
-  println(a.equal(b))
   println(a == b)
-  println(a.compare(b))
+  println(a == b)
+  println(Compare.compare(a, b))
   println(a < b)
   println(list.sort([b, a]))
   println(set.length(set.from_list([a, b])))
diff --git a/tests/golden/repros/typechecker_arch/mm3_main/a.silt b/tests/golden/repros/typechecker_arch/mm3_main/a.silt
index c46ec1238..2e4b78d05 100644
--- a/tests/golden/repros/typechecker_arch/mm3_main/a.silt
+++ b/tests/golden/repros/typechecker_arch/mm3_main/a.silt
@@ -1,4 +1,4 @@
 trait Speak { fn speak(self) -> String }
 pub type Dog { name: String }
 trait Speak for Dog { fn speak(self) -> String { "woof" } }
-pub fn talk(x: t) -> String where t: Speak { x.speak() }
+pub fn talk(x: t) -> String where t: Speak { Speak.speak(x) }
diff --git a/tests/golden/repros/typechecker_arch/mm3_main/b.silt b/tests/golden/repros/typechecker_arch/mm3_main/b.silt
index b5db843ae..861ae6ea9 100644
--- a/tests/golden/repros/typechecker_arch/mm3_main/b.silt
+++ b/tests/golden/repros/typechecker_arch/mm3_main/b.silt
@@ -1,4 +1,4 @@
 trait Speak { fn speak(self, times: Int) -> Int }
 pub type Cat { name: String }
 trait Speak for Cat { fn speak(self, times: Int) -> Int { times } }
-pub fn talk(x: t) -> Int where t: Speak { x.speak(2) }
+pub fn talk(x: t) -> Int where t: Speak { Speak.speak(x, 2) }
diff --git a/tests/golden/repros/typechecker_arch/mm3_main2/a.silt b/tests/golden/repros/typechecker_arch/mm3_main2/a.silt
index c46ec1238..2e4b78d05 100644
--- a/tests/golden/repros/typechecker_arch/mm3_main2/a.silt
+++ b/tests/golden/repros/typechecker_arch/mm3_main2/a.silt
@@ -1,4 +1,4 @@
 trait Speak { fn speak(self) -> String }
 pub type Dog { name: String }
 trait Speak for Dog { fn speak(self) -> String { "woof" } }
-pub fn talk(x: t) -> String where t: Speak { x.speak() }
+pub fn talk(x: t) -> String where t: Speak { Speak.speak(x) }
diff --git a/tests/golden/repros/typechecker_arch/mm3_main2/b.silt b/tests/golden/repros/typechecker_arch/mm3_main2/b.silt
index b5db843ae..861ae6ea9 100644
--- a/tests/golden/repros/typechecker_arch/mm3_main2/b.silt
+++ b/tests/golden/repros/typechecker_arch/mm3_main2/b.silt
@@ -1,4 +1,4 @@
 trait Speak { fn speak(self, times: Int) -> Int }
 pub type Cat { name: String }
 trait Speak for Cat { fn speak(self, times: Int) -> Int { times } }
-pub fn talk(x: t) -> Int where t: Speak { x.speak(2) }
+pub fn talk(x: t) -> Int where t: Speak { Speak.speak(x, 2) }
diff --git a/tests/golden/repros/typechecker_arch/recheck_alias_impl.silt b/tests/golden/repros/typechecker_arch/recheck_alias_impl.silt
index fc35bb5cf..3aa2a80a6 100644
--- a/tests/golden/repros/typechecker_arch/recheck_alias_impl.silt
+++ b/tests/golden/repros/typechecker_arch/recheck_alias_impl.silt
@@ -4,4 +4,4 @@ type Ints = List(Int)
 trait Foo for Ints {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() { println([1, 2].foo()) }
+fn main() { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/repros/typechecker_arch/recheck_alias_impl_nonarrow.silt b/tests/golden/repros/typechecker_arch/recheck_alias_impl_nonarrow.silt
index dc5bb5428..8f9b51e9a 100644
--- a/tests/golden/repros/typechecker_arch/recheck_alias_impl_nonarrow.silt
+++ b/tests/golden/repros/typechecker_arch/recheck_alias_impl_nonarrow.silt
@@ -4,4 +4,4 @@ type Ints = List(Int)
 trait Foo for Ints {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() -> () { println([1, 2].foo()) }
+fn main() -> () { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/repros/typechecker_arch/recheck_fun_impl.silt b/tests/golden/repros/typechecker_arch/recheck_fun_impl.silt
index afb370453..e93be366c 100644
--- a/tests/golden/repros/typechecker_arch/recheck_fun_impl.silt
+++ b/tests/golden/repros/typechecker_arch/recheck_fun_impl.silt
@@ -3,4 +3,4 @@ trait Foo { fn foo(self) -> Int }
 trait Foo for Fun {
   fn foo(self) -> Int { undefined_name + 1 }
 }
-fn main() { println(main.foo()) }
+fn main() { println(Foo.foo(main)) }
diff --git a/tests/golden/repros/typechecker_arch/recheck_list_impl.silt b/tests/golden/repros/typechecker_arch/recheck_list_impl.silt
index 2b5289fa3..bc51245d6 100644
--- a/tests/golden/repros/typechecker_arch/recheck_list_impl.silt
+++ b/tests/golden/repros/typechecker_arch/recheck_list_impl.silt
@@ -3,4 +3,4 @@ trait Foo { fn foo(self) -> Int }
 trait Foo for List(a) {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() { println([1, 2].foo()) }
+fn main() { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/repros/typechecker_arch/t_method_value_generic_impl.silt b/tests/golden/repros/typechecker_arch/t_method_value_generic_impl.silt
index 35f660feb..22a1fad19 100644
--- a/tests/golden/repros/typechecker_arch/t_method_value_generic_impl.silt
+++ b/tests/golden/repros/typechecker_arch/t_method_value_generic_impl.silt
@@ -2,7 +2,7 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 type Box(a) { Box(a) }
-trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> i.greet() } } }
+trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> Greet.greet(i) } } }
 fn main() { let b = Box(3)
  let m = b.greet
  println(m(b)) }
diff --git a/tests/golden/repros/typechecker_arch/t_poly_method.silt b/tests/golden/repros/typechecker_arch/t_poly_method.silt
index eaff86dc2..902507fc9 100644
--- a/tests/golden/repros/typechecker_arch/t_poly_method.silt
+++ b/tests/golden/repros/typechecker_arch/t_poly_method.silt
@@ -1,5 +1,5 @@
 -- verdict: same
-fn show(x) { x.display() }
+fn show(x) { "{x}" }
 fn main() {
   let f = fn(y) { y }
   println(show(f) + 1)
diff --git a/tests/golden/repros/typechecker_arch/t_tm_as_value.silt b/tests/golden/repros/typechecker_arch/t_tm_as_value.silt
index 0d25a4019..59e9f63b7 100644
--- a/tests/golden/repros/typechecker_arch/t_tm_as_value.silt
+++ b/tests/golden/repros/typechecker_arch/t_tm_as_value.silt
@@ -2,6 +2,6 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Sh { fn sh(self, x: a) -> String where a: Greet }
-trait Sh for Bool { fn sh(self, x: a) -> String where a: Greet { x.greet() } }
+trait Sh for Bool { fn sh(self, x: a) -> String where a: Greet { Greet.greet(x) } }
 fn main() { let m = true.sh
  println(m(true, 3)) }
diff --git a/tests/golden/repros/typechecker_arch/t_where_direct.silt b/tests/golden/repros/typechecker_arch/t_where_direct.silt
index f50cce0da..87681aa42 100644
--- a/tests/golden/repros/typechecker_arch/t_where_direct.silt
+++ b/tests/golden/repros/typechecker_arch/t_where_direct.silt
@@ -1,5 +1,5 @@
 -- verdict: same
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
-fn display(x: a) -> String where a: Showable { x.show() }
+fn display(x: a) -> String where a: Showable { Showable.show(x) }
 fn main() { println(display("text")) }
diff --git a/tests/golden/repros/typechecker_arch/t_where_hof.silt b/tests/golden/repros/typechecker_arch/t_where_hof.silt
index ff50ecb40..87cfe6a70 100644
--- a/tests/golden/repros/typechecker_arch/t_where_hof.silt
+++ b/tests/golden/repros/typechecker_arch/t_where_hof.silt
@@ -1,6 +1,6 @@
 -- verdict: same
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
-fn display(x: a) -> String where a: Showable { x.show() }
+fn display(x: a) -> String where a: Showable { Showable.show(x) }
 fn apply(f, x) { f(x) }
 fn main() { println(apply(display, "text")) }
diff --git a/tests/golden/repros/typechecker_arch/t_where_paren.silt b/tests/golden/repros/typechecker_arch/t_where_paren.silt
index b43d9baa3..24c8887ba 100644
--- a/tests/golden/repros/typechecker_arch/t_where_paren.silt
+++ b/tests/golden/repros/typechecker_arch/t_where_paren.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
-fn display(x: a) -> String where a: Showable { x.show() }
+fn display(x: a) -> String where a: Showable { Showable.show(x) }
 fn main() {
   let fs = [display]
   match fs {
diff --git a/tests/golden/repros/typechecker_arch/t_where_pipe_call.silt b/tests/golden/repros/typechecker_arch/t_where_pipe_call.silt
index 4ccf4e5c8..66710ec1e 100644
--- a/tests/golden/repros/typechecker_arch/t_where_pipe_call.silt
+++ b/tests/golden/repros/typechecker_arch/t_where_pipe_call.silt
@@ -1,5 +1,5 @@
 -- verdict: same
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
-fn display(x: a) -> String where a: Showable { x.show() }
+fn display(x: a) -> String where a: Showable { Showable.show(x) }
 fn main() { println("text" |> display()) }
diff --git a/tests/golden/repros/typechecker_arch/t_where_pipe_plain.silt b/tests/golden/repros/typechecker_arch/t_where_pipe_plain.silt
index 59c164c5f..b2ffdbf28 100644
--- a/tests/golden/repros/typechecker_arch/t_where_pipe_plain.silt
+++ b/tests/golden/repros/typechecker_arch/t_where_pipe_plain.silt
@@ -1,5 +1,5 @@
 -- verdict: same
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
-fn display(x: a) -> String where a: Showable { x.show() }
+fn display(x: a) -> String where a: Showable { Showable.show(x) }
 fn main() { println("text" |> display) }
diff --git a/tests/golden/repros/verify/cv_cv4.silt b/tests/golden/repros/verify/cv_cv4.silt
index 4cd30870b..fc9ad96e0 100644
--- a/tests/golden/repros/verify/cv_cv4.silt
+++ b/tests/golden/repros/verify/cv_cv4.silt
@@ -4,5 +4,5 @@ fn main() {
   let x = R { b: 1, a: 2 }
   let y = R { b: 2, a: 1 }
   println(x < y)
-  println(x.compare(y))
+  println(Compare.compare(x, y))
 }
diff --git a/tests/golden/repros/verify/cv_cv6.silt b/tests/golden/repros/verify/cv_cv6.silt
index 217890301..02919191b 100644
--- a/tests/golden/repros/verify/cv_cv6.silt
+++ b/tests/golden/repros/verify/cv_cv6.silt
@@ -5,11 +5,11 @@ trait Deep for Int {
   fn go(self) -> Int {
     match self {
       0 -> 0
-      _ -> 1 + (self - 1).go()
+      _ -> 1 + Deep.go(self - 1)
     }
   }
 }
 fn main() {
-  let t = task.spawn { -> 20.go() }
+  let t = task.spawn { -> Deep.go(20) }
   println(task.join(t))
 }
diff --git a/tests/golden/repros/verify/ld_ld3.silt b/tests/golden/repros/verify/ld_ld3.silt
index 23bef8393..a536065a6 100644
--- a/tests/golden/repros/verify/ld_ld3.silt
+++ b/tests/golden/repros/verify/ld_ld3.silt
@@ -7,5 +7,5 @@ fn main() {
   let p = P { x: 1 }
   println(p)
   println("{p}")
-  println(p.display())
+  println("{p}")
 }
diff --git a/tests/golden/repros/verify/tca_tca3.silt b/tests/golden/repros/verify/tca_tca3.silt
index fc35bb5cf..3aa2a80a6 100644
--- a/tests/golden/repros/verify/tca_tca3.silt
+++ b/tests/golden/repros/verify/tca_tca3.silt
@@ -4,4 +4,4 @@ type Ints = List(Int)
 trait Foo for Ints {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() { println([1, 2].foo()) }
+fn main() { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/repros/verify/tca_tca3_control.silt b/tests/golden/repros/verify/tca_tca3_control.silt
index 2b5289fa3..bc51245d6 100644
--- a/tests/golden/repros/verify/tca_tca3_control.silt
+++ b/tests/golden/repros/verify/tca_tca3_control.silt
@@ -3,4 +3,4 @@ trait Foo { fn foo(self) -> Int }
 trait Foo for List(a) {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() { println([1, 2].foo()) }
+fn main() { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/repros/verify/tca_tca4.silt b/tests/golden/repros/verify/tca_tca4.silt
index ff50ecb40..87cfe6a70 100644
--- a/tests/golden/repros/verify/tca_tca4.silt
+++ b/tests/golden/repros/verify/tca_tca4.silt
@@ -1,6 +1,6 @@
 -- verdict: same
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
-fn display(x: a) -> String where a: Showable { x.show() }
+fn display(x: a) -> String where a: Showable { Showable.show(x) }
 fn apply(f, x) { f(x) }
 fn main() { println(apply(display, "text")) }
diff --git a/tests/golden/repros/verify/tca_tca4_control.silt b/tests/golden/repros/verify/tca_tca4_control.silt
index f50cce0da..87681aa42 100644
--- a/tests/golden/repros/verify/tca_tca4_control.silt
+++ b/tests/golden/repros/verify/tca_tca4_control.silt
@@ -1,5 +1,5 @@
 -- verdict: same
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
-fn display(x: a) -> String where a: Showable { x.show() }
+fn display(x: a) -> String where a: Showable { Showable.show(x) }
 fn main() { println(display("text")) }
diff --git a/tests/golden/repros/verify/ts2_t13.silt b/tests/golden/repros/verify/ts2_t13.silt
index ce4f9a416..57a5f8a8a 100644
--- a/tests/golden/repros/verify/ts2_t13.silt
+++ b/tests/golden/repros/verify/ts2_t13.silt
@@ -6,6 +6,6 @@ trait Equal for P {
 fn main() {
   let a = P { x: 1 }
   let b = P { x: 2 }
-  println(a.equal(b))
+  println(a == b)
   println(a == b)
 }
diff --git a/tests/golden/repros/verify/ts_ts2_agent.silt b/tests/golden/repros/verify/ts_ts2_agent.silt
index 7d25b645f..540ea1ea2 100644
--- a/tests/golden/repros/verify/ts_ts2_agent.silt
+++ b/tests/golden/repros/verify/ts_ts2_agent.silt
@@ -1,7 +1,7 @@
 -- verdict: same
 trait Same { fn same(self) -> Self }
 trait Same for String { fn same(self) -> Self { self } }
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 fn main() {
   let f: Fn(Int) -> Int = coerce("callme")
   println(f(1))
diff --git a/tests/golden/typecheck/aliases/round74_parametric_alias_trait_impl__user_trait_dispatch.silt b/tests/golden/typecheck/aliases/round74_parametric_alias_trait_impl__user_trait_dispatch.silt
index 719a80196..ea85bf6a7 100644
--- a/tests/golden/typecheck/aliases/round74_parametric_alias_trait_impl__user_trait_dispatch.silt
+++ b/tests/golden/typecheck/aliases/round74_parametric_alias_trait_impl__user_trait_dispatch.silt
@@ -3,5 +3,5 @@ trait Show { fn show(self) -> String }
 trait Show for Pair(a) { fn show(self) -> String { "p" } }
 fn main() {
   let p: Pair(Int) = (1, 2)
-  println(p.show())
+  println(Show.show(p))
 }
diff --git a/tests/golden/typecheck/aliases/structural_method__through_an_alias_keeps_its_arguments.silt b/tests/golden/typecheck/aliases/structural_method__through_an_alias_keeps_its_arguments.silt
deleted file mode 100644
index fd8da40fc..000000000
--- a/tests/golden/typecheck/aliases/structural_method__through_an_alias_keeps_its_arguments.silt
+++ /dev/null
@@ -1,13 +0,0 @@
--- cmd: check
--- exit: 1
--- A method of a structural trait written through an alias is the method
--- of the type the alias names, with the alias's arguments: `Ints` is a
--- `List(Int)`, so a list of strings is no argument of `Ints.display`.
-type Ints = List(Int)
-
-fn main() {
-  println(Ints.display(["s"]))
-  println(Ints.display([1, 2]))
-  let t = Ints
-  println(t.compare([1], ["t"]))
-}
diff --git a/tests/golden/typecheck/aliases/structural_method__through_an_alias_keeps_its_arguments.stderr b/tests/golden/typecheck/aliases/structural_method__through_an_alias_keeps_its_arguments.stderr
deleted file mode 100644
index 9396756cd..000000000
--- a/tests/golden/typecheck/aliases/structural_method__through_an_alias_keeps_its_arguments.stderr
+++ /dev/null
@@ -1,11 +0,0 @@
-error[type]: type mismatch: expected Int, got String
- --> structural_method__through_an_alias_keeps_its_arguments.silt:9:24
-   |
- 9 |   println(Ints.display(["s"]))
-   |                        ^^^^^ type mismatch: expected Int, got String
-
-error[type]: type mismatch: expected Int, got String
- --> structural_method__through_an_alias_keeps_its_arguments.silt:12:26
-    |
- 12 |   println(t.compare([1], ["t"]))
-    |                          ^^^^^ type mismatch: expected Int, got String
diff --git a/tests/golden/typecheck/aliases/type_alias__trait_impl_on_alias.silt b/tests/golden/typecheck/aliases/type_alias__trait_impl_on_alias.silt
index 5d96f518d..8b5b1db7e 100644
--- a/tests/golden/typecheck/aliases/type_alias__trait_impl_on_alias.silt
+++ b/tests/golden/typecheck/aliases/type_alias__trait_impl_on_alias.silt
@@ -4,5 +4,5 @@ trait PhDByteShow { fn pretty(self) -> String }
 trait PhDByteShow for PhDBytShow { fn pretty(self) -> String { "bytes" } }
 fn main() {
     let xs: PhDBytShow = [1, 2, 3]
-    println(xs.pretty())
+    println(PhDByteShow.pretty(xs))
 }
diff --git a/tests/golden/typecheck/assoc_types/associated_types__method_call_through_projection.silt b/tests/golden/typecheck/assoc_types/associated_types__method_call_through_projection.silt
index 029e55abf..95254c88d 100644
--- a/tests/golden/typecheck/assoc_types/associated_types__method_call_through_projection.silt
+++ b/tests/golden/typecheck/assoc_types/associated_types__method_call_through_projection.silt
@@ -14,7 +14,7 @@ trait Producer for Wrap {
 }
 
 fn use_it(w: Wrap) -> Int {
-  w.produce()
+  Producer.produce(w)
 }
 
 fn main() {}
diff --git a/tests/golden/typecheck/assoc_types/associated_types__projections_of_same_type_unify.silt b/tests/golden/typecheck/assoc_types/associated_types__projections_of_same_type_unify.silt
index 94378aac8..fa27c43f7 100644
--- a/tests/golden/typecheck/assoc_types/associated_types__projections_of_same_type_unify.silt
+++ b/tests/golden/typecheck/assoc_types/associated_types__projections_of_same_type_unify.silt
@@ -14,7 +14,7 @@ trait Pair for IntPair {
 }
 
 fn use_it(x: IntPair, y: IntPair) -> Int {
-  x.first() + y.first()
+  Pair.first(x) + Pair.first(y)
 }
 
 fn main() {}
diff --git a/tests/golden/typecheck/assoc_types/associated_types_runtime__distinct_bindings_per_impl.silt b/tests/golden/typecheck/assoc_types/associated_types_runtime__distinct_bindings_per_impl.silt
index cb80e199c..242fa824b 100644
--- a/tests/golden/typecheck/assoc_types/associated_types_runtime__distinct_bindings_per_impl.silt
+++ b/tests/golden/typecheck/assoc_types/associated_types_runtime__distinct_bindings_per_impl.silt
@@ -18,7 +18,7 @@ trait Stream for B {
 
 fn main() {
   let a = A { x: 9 }
-  println(a.first())
+  println(Stream.first(a))
   let b = B { y: "bee" }
-  println(b.first())
+  println(Stream.first(b))
 }
diff --git a/tests/golden/typecheck/assoc_types/associated_types_runtime__method_returns_bound_int.silt b/tests/golden/typecheck/assoc_types/associated_types_runtime__method_returns_bound_int.silt
index 0a7d783ea..4823d5ef2 100644
--- a/tests/golden/typecheck/assoc_types/associated_types_runtime__method_returns_bound_int.silt
+++ b/tests/golden/typecheck/assoc_types/associated_types_runtime__method_returns_bound_int.silt
@@ -15,5 +15,5 @@ trait Stream for Wrap {
 
 fn main() {
   let w = Wrap { v: 7 }
-  println(w.first())
+  println(Stream.first(w))
 }
diff --git a/tests/golden/typecheck/assoc_types/associated_types_runtime__multiple_assoc_types.silt b/tests/golden/typecheck/assoc_types/associated_types_runtime__multiple_assoc_types.silt
index 6ee0db667..05842af4f 100644
--- a/tests/golden/typecheck/assoc_types/associated_types_runtime__multiple_assoc_types.silt
+++ b/tests/golden/typecheck/assoc_types/associated_types_runtime__multiple_assoc_types.silt
@@ -17,6 +17,6 @@ trait Pair for IntStringPair {
 
 fn main() {
   let p = IntStringPair { a: 13, b: "ok" }
-  println(p.first())
-  println(p.second())
+  println(Pair.first(p))
+  println(Pair.second(p))
 }
diff --git a/tests/golden/typecheck/assoc_types/associated_types_runtime__supertrait_assoc_type.silt b/tests/golden/typecheck/assoc_types/associated_types_runtime__supertrait_assoc_type.silt
index d57feac23..1dd8adb86 100644
--- a/tests/golden/typecheck/assoc_types/associated_types_runtime__supertrait_assoc_type.silt
+++ b/tests/golden/typecheck/assoc_types/associated_types_runtime__supertrait_assoc_type.silt
@@ -20,5 +20,5 @@ trait Sub for Wrap {
 
 fn main() {
   let w = Wrap { v: 41 }
-  println(w.first())
+  println(Sub.first(w))
 }
diff --git a/tests/golden/typecheck/assoc_types/impl_type_variable__a_call_at_another_type_is_rejected.silt b/tests/golden/typecheck/assoc_types/impl_type_variable__a_call_at_another_type_is_rejected.silt
index 95670f407..a91e25cad 100644
--- a/tests/golden/typecheck/assoc_types/impl_type_variable__a_call_at_another_type_is_rejected.silt
+++ b/tests/golden/typecheck/assoc_types/impl_type_variable__a_call_at_another_type_is_rejected.silt
@@ -27,7 +27,7 @@ trait Container for Box(a) where a: Equal {
 
 fn main() {
   let w = Box { item: 2 }
-  println(w.unwrap() + "x")
-  println(w.holds("two"))
-  let n: String = Box { item: 1 }.unwrap()
+  println(Container.unwrap(w) + "x")
+  println(Container.holds(w, "two"))
+  let n: String = Container.unwrap(Box { item: 1 })
 }
diff --git a/tests/golden/typecheck/assoc_types/impl_type_variable__in_a_method_of_an_impl_that_binds_it.silt b/tests/golden/typecheck/assoc_types/impl_type_variable__in_a_method_of_an_impl_that_binds_it.silt
index 92a9ec176..a5ba991ce 100644
--- a/tests/golden/typecheck/assoc_types/impl_type_variable__in_a_method_of_an_impl_that_binds_it.silt
+++ b/tests/golden/typecheck/assoc_types/impl_type_variable__in_a_method_of_an_impl_that_binds_it.silt
@@ -22,7 +22,7 @@ trait Container {
   fn holds(self, x: Self::Item) -> Bool
   fn all(self) -> List(Self::Item)
   fn twice(self) -> (Self::Item, Self::Item) {
-    (self.unwrap(), self.unwrap())
+    (Container.unwrap(self), Container.unwrap(self))
   }
 }
 
@@ -45,35 +45,35 @@ trait Container for Pair(a, b) where a: Equal, b: Equal {
     (self.right, self.left)
   }
   fn holds(self, x: (b, a)) -> Bool {
-    self.unwrap() == x
+    Container.unwrap(self) == x
   }
   fn all(self) -> List((b, a)) {
-    [self.unwrap()]
+    [Container.unwrap(self)]
   }
 }
 
 fn first(c: c) -> <c as Container>::Item where c: Container {
-  c.unwrap()
+  Container.unwrap(c)
 }
 
 fn main() {
   let w = Box { item: 2 }
-  println(w.unwrap() + 1)
-  println(w.holds(2))
-  println(list.map(w.all(), { n -> n * 10 }))
-  let (p, q) = w.twice()
+  println(Container.unwrap(w) + 1)
+  println(Container.holds(w, 2))
+  println(list.map(Container.all(w), { n -> n * 10 }))
+  let (p, q) = Container.twice(w)
   println(p + q)
   println(first(w) + 5)
   let s = Box { item: "s" }
-  println("{s.unwrap()}!")
-  println(s.holds("t"))
+  println("{Container.unwrap(s)}!")
+  println(Container.holds(s, "t"))
   println(first(s))
   let pr = Pair { left: 1, right: "r" }
-  let (r, l) = pr.unwrap()
+  let (r, l) = Container.unwrap(pr)
   println("{r} {l + 1}")
-  println(pr.holds(("r", 1)))
-  let ((r2, l2), _) = pr.twice()
+  println(Container.holds(pr, ("r", 1)))
+  let ((r2, l2), _) = Container.twice(pr)
   println("{r2} {l2 + 2}")
-  println(Box.unwrap(Box { item: 4 }) + 1)
-  println(Box { item: Box { item: 7 } }.unwrap().unwrap() + 1)
+  println(Container.unwrap(Box { item: 4 }) + 1)
+  println(Container.unwrap(Container.unwrap(Box { item: Box { item: 7 } })) + 1)
 }
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_assoc_names_rejected.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_assoc_names_rejected.silt
index 161d7af7c..5d4c8f689 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_assoc_names_rejected.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_assoc_names_rejected.silt
@@ -9,7 +9,7 @@ trait Pair {
 }
 
 fn bad(s: a) -> <a as Pair>::First where a: Pair {
-  s.second()
+  Pair.second(s)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_trait_names_rejected.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_trait_names_rejected.silt
index 622f7fac1..5671b4745 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_trait_names_rejected.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__different_trait_names_rejected.silt
@@ -12,7 +12,7 @@ trait B {
 }
 
 fn bad(s: a) -> <a as A>::Item where a: A + B {
-  s.bi()
+  B.bi(s)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__identical_projections_in_list.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__identical_projections_in_list.silt
index 628057429..12ddba935 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__identical_projections_in_list.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__identical_projections_in_list.silt
@@ -11,7 +11,7 @@ trait Stream for Wrap {
 }
 
 fn pair(s: a) where a: Stream {
-  let xs = [s.first(), s.first()]
+  let xs = [Stream.first(s), Stream.first(s)]
   xs
 }
 
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_arithmetic.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_arithmetic.silt
index ba2c5d4e5..a78ce26c4 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_arithmetic.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_arithmetic.silt
@@ -11,7 +11,7 @@ trait Stream for Wrap {
 }
 
 fn add_two(s: a) where a: Stream {
-  s.first() + s.first()
+  Stream.first(s) + Stream.first(s)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_equality.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_equality.silt
index 40318f223..eb0db13b2 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_equality.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_equality.silt
@@ -11,8 +11,8 @@ trait Stream for Wrap {
 }
 
 fn same(s: a) -> Bool where a: Stream {
-  let x = s.first()
-  let y = s.first()
+  let x = Stream.first(s)
+  let y = Stream.first(s)
   x == y
 }
 
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_list_direct.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_list_direct.silt
index 18c945780..1e77b9eae 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_list_direct.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_list_direct.silt
@@ -11,7 +11,7 @@ trait Stream for Wrap {
 }
 
 fn pair(s: a) where a: Stream {
-  [s.first(), s.first()]
+  [Stream.first(s), Stream.first(s)]
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_return_position.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_return_position.silt
index dcdb0c0f1..441aafa9e 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_return_position.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projection_return_position.silt
@@ -11,7 +11,7 @@ trait Stream for Wrap {
 }
 
 fn grab(s: a) -> <a as Stream>::Item where a: Stream {
-  s.first()
+  Stream.first(s)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projections_distinct_tyvars.silt b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projections_distinct_tyvars.silt
index 716485831..afd18f6d8 100644
--- a/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projections_distinct_tyvars.silt
+++ b/tests/golden/typecheck/assoc_types/round92_assoc_proj_unify__projections_distinct_tyvars.silt
@@ -16,7 +16,7 @@ trait Stream for Wrap {
 }
 
 fn pick(x: a, y: b) where a: Stream, b: Stream {
-  let xs = [x.first(), y.first()]
+  let xs = [Stream.first(x), Stream.first(y)]
   xs
 }
 
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_int.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_int.silt
index faa4d1e25..3a512e99a 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_int.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_int.silt
@@ -1,5 +1,5 @@
 type Box(a) { Foo(a), Bar(a, a), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Foo(1), Foo(2)))
     println(cmp_gen(Foo(2), Foo(1)))
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_string.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_string.silt
index ec0037370..5555ba111 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_string.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__compare_box_string.silt
@@ -1,5 +1,5 @@
 type Box(a) { Foo(a), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Foo("apple"), Foo("banana")))
     println(cmp_gen(Foo("banana"), Foo("apple")))
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__direct_method_call.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__direct_method_call.silt
index 96bd23ad2..e58b393b2 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__direct_method_call.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__direct_method_call.silt
@@ -3,6 +3,6 @@ fn main() {
     let w = Wrapped { value: 7 }
     let v = Wrapped { value: 7 }
     let u = Wrapped { value: 8 }
-    println(w.equal(v))
-    println(w.equal(u))
+    println(w == v)
+    println(w == u)
 }
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__display_generic_record.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__display_generic_record.silt
index 76e79ade8..65bdffccc 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__display_generic_record.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__display_generic_record.silt
@@ -1,5 +1,5 @@
 type Wrapped(a) { value: a }
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     let w = Wrapped { value: 42 }
     println(d(w))
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__equal_generic_record.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__equal_generic_record.silt
index 56f1c071c..a52b0fa11 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__equal_generic_record.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__equal_generic_record.silt
@@ -1,5 +1,5 @@
 type Wrapped(a) { value: a }
-fn eq_gen(a: a, b: a) -> Bool where a: Equal { a.equal(b) }
+fn eq_gen(a: a, b: a) -> Bool where a: Equal { a == b }
 fn main() {
     let p = Wrapped { value: 1 }
     let q = Wrapped { value: 1 }
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__hash_generic_enum.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__hash_generic_enum.silt
index 60e5b9d69..00c6fbe57 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__hash_generic_enum.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__hash_generic_enum.silt
@@ -1,7 +1,7 @@
 -- Equal generic-enum values hash equal; different payloads and the
 -- Just-vs-Nothing arms hash differently.
 type Maybe(a) { Just(a), Nothing, }
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
     let n: Maybe(Int) = Nothing
     println(h(Just(7)) == h(Just(7)))
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__holder_display.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__holder_display.silt
index 06eba36c4..b08c7da77 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__holder_display.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__holder_display.silt
@@ -1,5 +1,5 @@
 type Holder(a) { value: a }
-fn d(a: a) -> String where a: Display { a.display() }
+fn d(a: a) -> String where a: Display { "{a}" }
 fn main() {
     let h = Holder { value: 5 }
     println(d(h))
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__multi_param_compare.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__multi_param_compare.silt
index 89c12b6f2..4e295ae34 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__multi_param_compare.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__multi_param_compare.silt
@@ -1,5 +1,5 @@
 type Pair(a, b) { Tup(a, b), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Tup(1, "z"), Tup(2, "a")))   -- first differs: 1 < 2
     println(cmp_gen(Tup(1, "a"), Tup(1, "b")))   -- tie on first, second differs
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__phantom_compare.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__phantom_compare.silt
index 7fa7800d4..e3a8c0650 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__phantom_compare.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__phantom_compare.silt
@@ -1,5 +1,5 @@
 type Phantom(a) { Tag, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     let x: Phantom(Int) = Tag
     let y: Phantom(Int) = Tag
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__qualified_call.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__qualified_call.silt
index 4284d07d2..633e99c61 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__qualified_call.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__qualified_call.silt
@@ -1,7 +1,7 @@
 -- Qualified `Box.compare` matches the trait-bound call form.
 type Box(a) { Foo(a), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Foo(1), Foo(2)))
-    println(Box.compare(Foo(1), Foo(2)))
+    println(Compare.compare(Foo(1), Foo(2)))
 }
diff --git a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__self_recursive_tree.silt b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__self_recursive_tree.silt
index f054492a6..190c2e560 100644
--- a/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__self_recursive_tree.silt
+++ b/tests/golden/typecheck/auto_derive/auto_derive_generic_synth__self_recursive_tree.silt
@@ -1,5 +1,5 @@
 type Tree(a) { Leaf, Node(Tree(a), Tree(a)), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     let l: Tree(Int) = Leaf
     let n: Tree(Int) = Node(Leaf, Leaf)
diff --git a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday.silt b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday.silt
index 6399dbcf3..d948d83c5 100644
--- a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday.silt
+++ b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday.silt
@@ -1,5 +1,5 @@
 import time
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(time.Monday, time.Friday))
     println(cmp_gen(time.Sunday, time.Monday))
diff --git a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday_chain.silt b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday_chain.silt
index c0cf3883b..d969171b7 100644
--- a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday_chain.silt
+++ b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__builtin_weekday_chain.silt
@@ -1,5 +1,5 @@
 import time
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(time.Monday, time.Tuesday))
     println(cmp_gen(time.Tuesday, time.Wednesday))
diff --git a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__color_basic.silt b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__color_basic.silt
index 3d8e94e20..7f7d5c821 100644
--- a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__color_basic.silt
+++ b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__color_basic.silt
@@ -1,5 +1,5 @@
 type Color { Red, Green, Blue, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Red, Green))
     println(cmp_gen(Green, Red))
diff --git a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__constructor_args.silt b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__constructor_args.silt
index d299d6fcd..fe68410fc 100644
--- a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__constructor_args.silt
+++ b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__constructor_args.silt
@@ -1,5 +1,5 @@
 type Tagged { Foo(Int), Bar(Int), }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Foo(1), Bar(1)))
     println(cmp_gen(Foo(1), Foo(2)))
diff --git a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__reverse_alphabetical.silt b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__reverse_alphabetical.silt
index 73a2ca9b0..2092eb017 100644
--- a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__reverse_alphabetical.silt
+++ b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__reverse_alphabetical.silt
@@ -1,6 +1,6 @@
 -- Declaration order, not alphabetical: Z < A.
 type Backwards { Z, Y, A, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(Z, A))
 }
diff --git a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__three_variants.silt b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__three_variants.silt
index cdc951645..ea992eb94 100644
--- a/tests/golden/typecheck/auto_derive/variant_decl_order_compare__three_variants.silt
+++ b/tests/golden/typecheck/auto_derive/variant_decl_order_compare__three_variants.silt
@@ -1,5 +1,5 @@
 type Three { First, Second, Third, }
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
     println(cmp_gen(First, Second))
     println(cmp_gen(Second, Third))
diff --git a/tests/golden/typecheck/builtin_types/http_bodies__a_response_body_read_as_text.silt b/tests/golden/typecheck/builtin_types/http_bodies__a_response_body_read_as_text.silt
index e54f39953..ceb4e5f20 100644
--- a/tests/golden/typecheck/builtin_types/http_bodies__a_response_body_read_as_text.silt
+++ b/tests/golden/typecheck/builtin_types/http_bodies__a_response_body_read_as_text.silt
@@ -9,6 +9,6 @@ import string
 fn main() {
   match http.get("http://127.0.0.1:1/") {
     Ok(resp) -> println(string.length(resp.body))
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }
 }
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt b/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt
index 20466f082..8f90866de 100644
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt
+++ b/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt
@@ -1,52 +1,20 @@
 -- cmd: check
 -- exit: 1
--- A method that the bounds of a type variable each give is ambiguous
--- called on a value of the variable, on the variable as a `type`
--- parameter, and on a value whose type becomes the variable later; the
--- variable is bounded already, so the help names the bounds and says to
--- call the method from a function bounded by only one of them. The
--- bounds as the `where` clause writes them, with their arguments.
+-- A method that makes a value, which the bounds of a type variable
+-- each give, is ambiguous called on the variable as a `type`
+-- parameter; the variable is bounded already, so the help names the
+-- bounds and says to call the method from a function bounded by only
+-- one of them.
 trait A {
   fn make() -> Self
-  fn show(self) -> String
 }
 
 trait B {
   fn make() -> Self
-  fn show(self) -> String
-}
-
-trait C {
-  fn show(self) -> String
-}
-
-trait Conv(t) {
-  fn show(self) -> String
 }
 
 fn on_type(type a) -> a where a: A, a: B {
   a.make()
 }
 
-fn on_value(x: a) -> String where a: A + B {
-  x.show()
-}
-
-fn first(x: a) -> a {
-  x
-}
-
-fn later(x: a) -> String where a: A + B {
-  let f = { y -> first(y).show() }
-  f(x)
-}
-
-fn three(x: a) -> String where a: C + B + A {
-  x.show()
-}
-
-fn with_arguments(x: a) -> String where a: Conv(Int), a: A {
-  x.show()
-}
-
 fn main() {}
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.stderr b/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.stderr
index d5d5b7719..0adcdd288 100644
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.stderr
+++ b/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.stderr
@@ -1,34 +1,6 @@
 error[type]: ambiguous method 'make' on `type a`: provided by traits A, B
- --> ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt:28:3
+ --> ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt:17:3
     |
- 28 |   a.make()
+ 17 |   a.make()
     |   ^^^^^^ ambiguous method 'make' on `type a`: provided by traits A, B
   = help: the bounds `A` and `B` both give `make`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on a value of type `a`: provided by traits A, B
- --> ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt:32:3
-    |
- 32 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by traits A, B
-  = help: the bounds `A` and `B` both give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on a value of type `a`: provided by traits A, B
- --> ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt:40:18
-    |
- 40 |   let f = { y -> first(y).show() }
-    |                  ^^^^^^^^^^^^^ ambiguous method 'show' on a value of type `a`: provided by traits A, B
-  = help: the bounds `A` and `B` both give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on a value of type `a`: provided by traits A, B, C
- --> ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt:45:3
-    |
- 45 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by traits A, B, C
-  = help: the bounds `A`, `B` and `C` all give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on a value of type `a`: provided by traits A, Conv
- --> ambiguous_method__on_a_bounded_type_variable_the_help_names_the_bounds.silt:49:3
-    |
- 49 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by traits A, Conv
-  = help: the bounds `A` and `Conv(Int)` both give `show`: call it from a function bounded by only one of them
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_type_the_help_names_the_program_s_trait.stderr b/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_type_the_help_names_the_program_s_trait.stderr
deleted file mode 100644
index d1b6ac86f..000000000
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_type_the_help_names_the_program_s_trait.stderr
+++ /dev/null
@@ -1,13 +0,0 @@
-error[type]: ambiguous method 'display' on type 'T': provided by traits Display, Pretty
- --> ambiguous_method__on_a_type_the_help_names_the_program_s_trait.silt:21:11
-    |
- 21 |   println(T.display(T { n: 1 }))
-    |           ^^^^^^^^^ ambiguous method 'display' on type 'T': provided by traits Display, Pretty
-  = help: say which is meant: call it through a function bounded by the trait you mean, `where a: Pretty`
-
-error[type]: ambiguous method 'display' on type 'Int': provided by traits Display, Pretty
- --> ambiguous_method__on_a_type_the_help_names_the_program_s_trait.silt:22:11
-    |
- 22 |   println(Int.display(5))
-    |           ^^^^^^^^^^^ ambiguous method 'display' on type 'Int': provided by traits Display, Pretty
-  = help: say which is meant: call it through a function bounded by the trait you mean, `where a: Pretty`
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__one_wording.silt b/tests/golden/typecheck/diagnostics/ambiguous_method__one_wording.silt
deleted file mode 100644
index b3fc81a47..000000000
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__one_wording.silt
+++ /dev/null
@@ -1,73 +0,0 @@
--- cmd: check
--- exit: 1
--- A method two traits provide is ambiguous in one wording, the traits
--- in the order of their names, wherever the call is decided: on a type,
--- on a bounded value, on a value whose type is not known, on a value
--- whose type becomes a bounded variable later, on a `type` parameter.
--- A method none of the bounds provide is, there too, what it is where
--- the receiver is known at once.
-trait Zeta {
-  fn show(self) -> String
-}
-
-trait Alpha {
-  fn show(self) -> String
-}
-
-trait Other {
-  fn other(self) -> String
-}
-
-trait Zeta for Int {
-  fn show(self) -> String {
-    "z"
-  }
-}
-
-trait Alpha for Int {
-  fn show(self) -> String {
-    "a"
-  }
-}
-
-fn concrete() -> String {
-  7.show()
-}
-
-fn bounded(x: b) -> String where b: Zeta + Alpha {
-  x.show()
-}
-
-fn unknown(x) {
-  x.show()
-}
-
-fn first(x: a) -> a {
-  x
-}
-
-fn later(x: b) -> String where b: Zeta + Alpha {
-  let f = { y -> first(y).show() }
-  f(x)
-}
-
-fn missing(x: b) -> String where b: Other {
-  let f = { y -> first(y).show() }
-  f(x)
-}
-
-fn on_type(type b) -> String where b: Zeta + Alpha {
-  b.show(b)
-}
-
-fn on_name() -> String {
-  Int.show(7)
-}
-
-fn main() {
-  println(concrete())
-  println(bounded(7))
-  println(unknown(7))
-  println(later(7))
-  println(on_name())
-}
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__one_wording.stderr b/tests/golden/typecheck/diagnostics/ambiguous_method__one_wording.stderr
deleted file mode 100644
index b5545e49b..000000000
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__one_wording.stderr
+++ /dev/null
@@ -1,47 +0,0 @@
-error[type]: ambiguous method 'show' on type 'Int': provided by traits Alpha, Zeta
- --> ambiguous_method__one_wording.silt:34:3
-    |
- 34 |   7.show()
-    |   ^^^^^^ ambiguous method 'show' on type 'Int': provided by traits Alpha, Zeta
-  = help: say which is meant: annotate the receiver's type, or bound it with a `where` clause
-
-error[type]: ambiguous method 'show' on a value of type `b`: provided by traits Alpha, Zeta
- --> ambiguous_method__one_wording.silt:38:3
-    |
- 38 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `b`: provided by traits Alpha, Zeta
-  = help: the bounds `Alpha` and `Zeta` both give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on a value whose type is not known: provided by traits Alpha, Zeta
- --> ambiguous_method__one_wording.silt:42:3
-    |
- 42 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value whose type is not known: provided by traits Alpha, Zeta
-  = help: say which is meant: annotate the receiver's type, or bound it with a `where` clause
-
-error[type]: ambiguous method 'show' on a value of type `b`: provided by traits Alpha, Zeta
- --> ambiguous_method__one_wording.silt:50:18
-    |
- 50 |   let f = { y -> first(y).show() }
-    |                  ^^^^^^^^^^^^^ ambiguous method 'show' on a value of type `b`: provided by traits Alpha, Zeta
-  = help: the bounds `Alpha` and `Zeta` both give `show`: call it from a function bounded by only one of them
-
-error[type]: no method 'show' found in trait constraints (Other)
- --> ambiguous_method__one_wording.silt:55:18
-    |
- 55 |   let f = { y -> first(y).show() }
-    |                  ^^^^^^^^^^^^^ no method 'show' found in trait constraints (Other)
-
-error[type]: ambiguous method 'show' on `type b`: provided by traits Alpha, Zeta
- --> ambiguous_method__one_wording.silt:60:3
-    |
- 60 |   b.show(b)
-    |   ^^^^^^ ambiguous method 'show' on `type b`: provided by traits Alpha, Zeta
-  = help: the bounds `Alpha` and `Zeta` both give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on type 'Int': provided by traits Alpha, Zeta
- --> ambiguous_method__one_wording.silt:64:3
-    |
- 64 |   Int.show(7)
-    |   ^^^^^^^^ ambiguous method 'show' on type 'Int': provided by traits Alpha, Zeta
-  = help: say which is meant: call it through a function bounded by the trait you mean, `where a: Alpha`
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/case.stderr b/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/case.stderr
deleted file mode 100644
index 48e95ea8f..000000000
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/case.stderr
+++ /dev/null
@@ -1,27 +0,0 @@
-error[type]: ambiguous method 'show' on a value of type `a`: provided by traits Br, shapes.Ar
- --> main.silt:32:3
-    |
- 32 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by traits Br, shapes.Ar
-  = help: the bounds `Br` and `shapes.Ar` both give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'display' on a value of type `a`: provided by traits Display, Shows
- --> main.silt:36:3
-    |
- 36 |   x.display()
-    |   ^^^^^^^^^ ambiguous method 'display' on a value of type `a`: provided by traits Display, Shows
-  = help: the bounds `Display` and `Shows` both give `display`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on a value of type `a`: provided by traits Ar, Br
- --> main.silt:40:3
-    |
- 40 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by traits Ar, Br
-  = help: the bounds `Br` and `S` both give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'show' on a value of type `a`: provided by traits Ar, Br
- --> main.silt:44:3
-    |
- 44 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by traits Ar, Br
-  = help: the bounds `Ar` and `Br` both give `show`: call it from a function bounded by only one of them
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/main.silt b/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/main.silt
deleted file mode 100644
index 2cd81d648..000000000
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/main.silt
+++ /dev/null
@@ -1,47 +0,0 @@
--- cmd: check
--- exit: 1
--- The help of a method two bounds of a type variable give names the
--- bounds as the program writes them: a trait of another module with its
--- module (`shapes.Ar`), a prelude trait by its name (`Display`), and a
--- bound whose supertrait gives the method (`S`), not the supertrait.
--- Where one bound gives the method by two of its supertraits, those
--- are named.
-import shapes
-
-trait Ar {
-  fn show(self) -> String
-}
-
-trait Br {
-  fn show(self) -> String
-}
-
-trait S: Ar {
-  fn other(self) -> Int
-}
-
-trait Both: Ar + Br {
-  fn other(self) -> Int
-}
-
-trait Shows {
-  fn display(self) -> String
-}
-
-fn of_another_module(x: a) -> String where a: shapes.Ar, a: Br {
-  x.show()
-}
-
-fn of_the_prelude(x: a) -> String where a: Display, a: Shows {
-  x.display()
-}
-
-fn by_a_supertrait(x: a) -> String where a: S, a: Br {
-  x.show()
-}
-
-fn by_one_bound(x: a) -> String where a: Both {
-  x.show()
-}
-
-fn main() {}
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/shapes.silt b/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/shapes.silt
deleted file mode 100644
index 39282a6dc..000000000
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__the_help_names_the_bounds_as_written/shapes.silt
+++ /dev/null
@@ -1,3 +0,0 @@
-pub trait Ar {
-  fn show(self) -> String
-}
diff --git a/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.silt b/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.silt
index a18d3b8ff..759e56644 100644
--- a/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.silt
+++ b/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.silt
@@ -1,9 +1,8 @@
 -- exit: 1
 -- A local named like an imported module hides it: `list.length(..)`
--- then asks the local for a method. When the local has no such field
--- or method and the module has a member of that name, the help says
--- which local hides the module (a `let`, a parameter, a closure's
--- parameter).
+-- then reads a field of the local. When the local has no such field
+-- and the module has a member of that name, the help says which local
+-- hides the module (a `let`, a parameter, a closure's parameter).
 import list
 import map
 import string
diff --git a/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.stderr b/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.stderr
index ef91a910b..6e5b9f3de 100644
--- a/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.stderr
+++ b/tests/golden/typecheck/diagnostics/hidden_module__a_local_hides_an_imported_module.stderr
@@ -1,27 +1,27 @@
-error[type]: unknown method 'to_upper' on type String
- --> hidden_module__a_local_hides_an_imported_module.silt:12:3
+error[type]: type 'String' has no field 'to_upper'
+ --> hidden_module__a_local_hides_an_imported_module.silt:11:3
     |
- 12 |   string.to_upper(string)
-    |   ^^^^^^^^^^^^^^^ unknown method 'to_upper' on type String
-  = help: `string` here is the local from line 11, which hides the module `string`; rename the local
+ 11 |   string.to_upper(string)
+    |   ^^^^^^^^^^^^^^^ type 'String' has no field 'to_upper'
+  = help: `string` here is the local from line 10, which hides the module `string`; rename the local
 
-error[type]: unknown method 'length' on List
- --> hidden_module__a_local_hides_an_imported_module.silt:17:11
+error[type]: type 'List(Int)' has no field 'length'
+ --> hidden_module__a_local_hides_an_imported_module.silt:16:11
     |
- 17 |   println(list.length(list))
-    |           ^^^^^^^^^^^ unknown method 'length' on List
-  = help: `list` here is the local from line 16, which hides the module `list`; rename the local
+ 16 |   println(list.length(list))
+    |           ^^^^^^^^^^^ type 'List(Int)' has no field 'length'
+  = help: `list` here is the local from line 15, which hides the module `list`; rename the local
 
-error[type]: anon record has no field 'keys'
- --> hidden_module__a_local_hides_an_imported_module.silt:19:11
+error[type]: type '{size: Int}' has no field 'keys'
+ --> hidden_module__a_local_hides_an_imported_module.silt:18:11
     |
- 19 |   println(map.keys(map))
-    |           ^^^^^^^^ anon record has no field 'keys'
-  = help: `map` here is the local from line 18, which hides the module `map`; rename the local
+ 18 |   println(map.keys(map))
+    |           ^^^^^^^^ type '{size: Int}' has no field 'keys'
+  = help: `map` here is the local from line 17, which hides the module `map`; rename the local
 
-error[type]: unknown method 'reverse' on List
- --> hidden_module__a_local_hides_an_imported_module.silt:20:32
+error[type]: type 'List(Int)' has no field 'reverse'
+ --> hidden_module__a_local_hides_an_imported_module.silt:19:32
     |
- 20 |   let f = { list: List(Int) -> list.reverse(list) }
-    |                                ^^^^^^^^^^^^ unknown method 'reverse' on List
-  = help: `list` here is the local from line 20, which hides the module `list`; rename the local
+ 19 |   let f = { list: List(Int) -> list.reverse(list) }
+    |                                ^^^^^^^^^^^^ type 'List(Int)' has no field 'reverse'
+  = help: `list` here is the local from line 19, which hides the module `list`; rename the local
diff --git a/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.silt b/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.silt
index 9d6e07a3e..7c6bdb979 100644
--- a/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.silt
+++ b/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.silt
@@ -1,7 +1,8 @@
 -- exit: 1
 -- A local named like a module's alias hides the module imported as
 -- that name: the help names the module and the alias. A local named
--- like the module itself hides nothing here: no help for it.
+-- like the module itself hides nothing here: its help is the one for a
+-- function of the module, not the hidden-module one.
 import list as l
 
 fn main() {
diff --git a/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.stderr b/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.stderr
index f51833806..7ddffeb39 100644
--- a/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.stderr
+++ b/tests/golden/typecheck/diagnostics/hidden_module__an_alias_names_the_module_too.stderr
@@ -1,12 +1,13 @@
-error[type]: unknown method 'length' on List
- --> hidden_module__an_alias_names_the_module_too.silt:9:11
-   |
- 9 |   println(list.length(list))
-   |           ^^^^^^^^^^^ unknown method 'length' on List
+error[type]: type 'List(Int)' has no field 'length'
+ --> hidden_module__an_alias_names_the_module_too.silt:10:11
+    |
+ 10 |   println(list.length(list))
+    |           ^^^^^^^^^^^ type 'List(Int)' has no field 'length'
+  = help: `length` is a function of module `list`: call it as `list.length(list)`
 
-error[type]: unknown method 'length' on List
- --> hidden_module__an_alias_names_the_module_too.silt:11:11
+error[type]: type 'List(Int)' has no field 'length'
+ --> hidden_module__an_alias_names_the_module_too.silt:12:11
     |
- 11 |   println(l.length(l))
-    |           ^^^^^^^^ unknown method 'length' on List
-  = help: `l` here is the local from line 10, which hides the module `list` (imported as `l`); rename the local
+ 12 |   println(l.length(l))
+    |           ^^^^^^^^ type 'List(Int)' has no field 'length'
+  = help: `l` here is the local from line 11, which hides the module `list` (imported as `l`); rename the local
diff --git a/tests/golden/typecheck/diagnostics/hidden_module__no_help_without_the_module_or_its_member.silt b/tests/golden/typecheck/diagnostics/hidden_module__no_help_without_the_module_or_its_member.silt
index 345a0df83..9faaa6fc2 100644
--- a/tests/golden/typecheck/diagnostics/hidden_module__no_help_without_the_module_or_its_member.silt
+++ b/tests/golden/typecheck/diagnostics/hidden_module__no_help_without_the_module_or_its_member.silt
@@ -1,6 +1,6 @@
 -- exit: 1
--- stderr-contains: unknown method 'length' on List
--- stderr-contains: unknown method 'frobnicate' on List
+-- stderr-contains: type 'List(Int)' has no field 'length'
+-- stderr-contains: type 'List(Int)' has no field 'frobnicate'
 -- stderr-not-contains: hides the module
 -- No help about a hidden module when the module is not imported, or
 -- when it has no member of the name; a local with the field is used.
diff --git a/tests/golden/typecheck/diagnostics/method_arity__counts_the_arguments_written.silt b/tests/golden/typecheck/diagnostics/method_arity__counts_the_arguments_written.silt
index 6b15106a6..f5de16ff3 100644
--- a/tests/golden/typecheck/diagnostics/method_arity__counts_the_arguments_written.silt
+++ b/tests/golden/typecheck/diagnostics/method_arity__counts_the_arguments_written.silt
@@ -1,14 +1,15 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: method `add` expects 1 argument, got 2
--- stderr-contains: error[type]: method `add` expects 1 argument, got 0
--- stderr-not-contains: expects 2 arguments
--- A method's receiver is not one of the arguments its call writes; a
--- piped value is.
+-- stderr-contains: error[type]: `Adder.add` expects 2 arguments, got 3
+-- stderr-contains: error[type]: `Adder.add` expects 2 arguments, got 1
+-- stderr-contains: :12:11
+-- stderr-contains: :13:11
+-- A call through a trait counts every argument it writes, the one of
+-- type Self and a piped value among them.
 trait Adder { fn add(self, x: Int) -> Int }
 trait Adder for Int { fn add(self, x: Int) -> Int { self + x } }
 fn main() {
-  println(5 |> 3.add(1))
-  println(3.add(1, 2))
-  println(3.add())
+  println(5 |> Adder.add(3, 1))
+  println(Adder.add(3))
+  println(5 |> Adder.add(3))
 }
diff --git a/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.silt b/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.silt
index 8f090ea69..c1205b40a 100644
--- a/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.silt
+++ b/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.silt
@@ -21,7 +21,7 @@ trait Shape {
 }
 
 fn area_of(s: t) -> t where t: Shape {
-  s.area()
+  Shape.area(s)
 }
 
 fn wrap(x: e) -> List(e) {
diff --git a/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.stderr b/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.stderr
index ffa3b7207..d701e2862 100644
--- a/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.stderr
+++ b/tests/golden/typecheck/diagnostics/rigid_variable_mismatch__names_the_variable.stderr
@@ -38,8 +38,8 @@ error[type]: type mismatch: expected a, got Int
 error[type]: type mismatch: expected t, got Int
  --> rigid_variable_mismatch__names_the_variable.silt:24:3
     |
- 24 |   s.area()
-    |   ^^^^^^^^ type mismatch: expected t, got Int
+ 24 |   Shape.area(s)
+    |   ^^^^^^^^^^^^^ type mismatch: expected t, got Int
  ::: rigid_variable_mismatch__names_the_variable.silt:23:15
     |
  23 | fn area_of(s: t) -> t where t: Shape {
diff --git a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_type_the_help_names_the_program_s_trait.silt b/tests/golden/typecheck/diagnostics/through_the_type__the_help_names_the_program_s_trait.silt
similarity index 65%
rename from tests/golden/typecheck/diagnostics/ambiguous_method__on_a_type_the_help_names_the_program_s_trait.silt
rename to tests/golden/typecheck/diagnostics/through_the_type__the_help_names_the_program_s_trait.silt
index 641d8cd5e..76ae7cbd5 100644
--- a/tests/golden/typecheck/diagnostics/ambiguous_method__on_a_type_the_help_names_the_program_s_trait.silt
+++ b/tests/golden/typecheck/diagnostics/through_the_type__the_help_names_the_program_s_trait.silt
@@ -1,8 +1,9 @@
 -- cmd: check
 -- exit: 1
 -- A method a program's trait and a builtin trait both give a type,
--- called through the type, is ambiguous; the help names the program's
--- trait, not the builtin one (`Pretty`, not `Display`).
+-- taking a value of it, is called through its trait, not the type; the
+-- help names the program's trait, not the builtin one (`Pretty`, not
+-- `Display`, whose method is not called).
 trait Pretty {
   fn display(self) -> String
 }
diff --git a/tests/golden/typecheck/diagnostics/through_the_type__the_help_names_the_program_s_trait.stderr b/tests/golden/typecheck/diagnostics/through_the_type__the_help_names_the_program_s_trait.stderr
new file mode 100644
index 000000000..7d872d202
--- /dev/null
+++ b/tests/golden/typecheck/diagnostics/through_the_type__the_help_names_the_program_s_trait.stderr
@@ -0,0 +1,13 @@
+error[type]: type 'T' has no method 'display'
+ --> through_the_type__the_help_names_the_program_s_trait.silt:22:11
+    |
+ 22 |   println(T.display(T { n: 1 }))
+    |           ^^^^^^^^^ type 'T' has no method 'display'
+  = help: `display` is a method of trait `Pretty`: call it as `Pretty.display(x)`
+
+error[type]: type 'Int' has no method 'display'
+ --> through_the_type__the_help_names_the_program_s_trait.silt:23:11
+    |
+ 23 |   println(Int.display(5))
+    |           ^^^^^^^^^^^ type 'Int' has no method 'display'
+  = help: `display` is a method of trait `Pretty`: call it as `Pretty.display(x)`
diff --git a/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__duplicate_impl_method.silt b/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__duplicate_impl_method.silt
index bc4eb9068..118aba078 100644
--- a/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__duplicate_impl_method.silt
+++ b/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__duplicate_impl_method.silt
@@ -10,5 +10,5 @@ trait Greet for Int {
   fn say(self) -> String { "two" }
 }
 fn main() {
-  println((1).say())
+  println(Greet.say(1))
 }
diff --git a/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__extraneous_impl_method.silt b/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__extraneous_impl_method.silt
index ac1174e0a..2d96305b0 100644
--- a/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__extraneous_impl_method.silt
+++ b/tests/golden/typecheck/diagnostics/typechecker_soundness_round35__extraneous_impl_method.silt
@@ -10,5 +10,5 @@ trait Greeter for Int {
   fn secret(self) -> Int { 42 }
 }
 fn main() {
-  println((1).greet())
+  println(Greeter.greet(1))
 }
diff --git a/tests/golden/typecheck/display/display_impl__a_body_that_does_not_check_is_the_one_error.silt b/tests/golden/typecheck/display/display_impl__a_body_that_does_not_check_is_the_one_error.silt
index e0d6fa298..ccd9b834b 100644
--- a/tests/golden/typecheck/display/display_impl__a_body_that_does_not_check_is_the_one_error.silt
+++ b/tests/golden/typecheck/display/display_impl__a_body_that_does_not_check_is_the_one_error.silt
@@ -16,15 +16,15 @@ trait Display for D {
 }
 
 fn show(x: a) -> String where a: Display {
-  x.display()
+  "{x}"
 }
 
 fn main() {
   println(D { n: 1 })
   println([D { n: 1 }])
   println("{D { n: 1 }}")
-  println(D { n: 1 }.display())
+  println(string.from(D { n: 1 }))
   println(show(D { n: 2 }))
-  println(D.display(D { n: 3 }))
+  println(string.from(D { n: 3 }))
   println(string.from(D { n: 4 }))
 }
diff --git a/tests/golden/typecheck/display/display_impl__a_written_impl_shows_a_type_with_a_function_field.silt b/tests/golden/typecheck/display/display_impl__a_written_impl_shows_a_type_with_a_function_field.silt
index 3ddfd8696..7140ae71a 100644
--- a/tests/golden/typecheck/display/display_impl__a_written_impl_shows_a_type_with_a_function_field.silt
+++ b/tests/golden/typecheck/display/display_impl__a_written_impl_shows_a_type_with_a_function_field.silt
@@ -17,7 +17,7 @@ trait Display for F {
 }
 
 fn main() {
-  println(MyErr { code: 1 }.message())
+  println(Error.message(MyErr { code: 1 }))
   println(F { f: { x -> x + 1 } })
   println([F { f: { x -> x + 2 } }])
 }
diff --git a/tests/golden/typecheck/display/display_impl__a_wrong_signature_is_the_one_error.silt b/tests/golden/typecheck/display/display_impl__a_wrong_signature_is_the_one_error.silt
index 48260a067..d4d7b3a53 100644
--- a/tests/golden/typecheck/display/display_impl__a_wrong_signature_is_the_one_error.silt
+++ b/tests/golden/typecheck/display/display_impl__a_wrong_signature_is_the_one_error.silt
@@ -16,15 +16,15 @@ trait Display for D {
 }
 
 fn show(x: a) -> String where a: Display {
-  x.display()
+  "{x}"
 }
 
 fn main() {
   println(D { n: 1 })
   println([D { n: 1 }])
   println("{D { n: 1 }}")
-  println(D { n: 1 }.display())
+  println(string.from(D { n: 1 }))
   println(show(D { n: 2 }))
-  println(D.display(D { n: 3 }))
+  println(string.from(D { n: 3 }))
   println(string.from(D { n: 4 }))
 }
diff --git a/tests/golden/typecheck/display/display_impl__an_empty_impl_lacks_its_method.silt b/tests/golden/typecheck/display/display_impl__an_empty_impl_lacks_its_method.silt
index e3844dc65..7b3ad7bc5 100644
--- a/tests/golden/typecheck/display/display_impl__an_empty_impl_lacks_its_method.silt
+++ b/tests/golden/typecheck/display/display_impl__an_empty_impl_lacks_its_method.silt
@@ -20,15 +20,15 @@ type F {
 trait Display for F {}
 
 fn show(x: a) -> String where a: Display {
-  x.display()
+  "{x}"
 }
 
 fn main() {
   println(D { n: 1 })
   println([D { n: 1 }])
-  println(D { n: 1 }.display())
+  println(string.from(D { n: 1 }))
   println(show(D { n: 2 }))
-  println(D.display(D { n: 3 }))
+  println(string.from(D { n: 3 }))
+  println(string.from(F { f: { x -> x } }))
   println(string.from(F { f: { x -> x } }))
-  println(F { f: { x -> x } }.display())
 }
diff --git a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__channel.silt b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__channel.silt
index a98b45b54..5b61085ea 100644
--- a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__channel.silt
+++ b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__channel.silt
@@ -4,7 +4,7 @@
 -- stderr-contains: 'Channel'
 -- stderr-not-contains: required for string interpolation
 import channel
-fn show(x: a) -> String where a: Display { x.display() }
+fn show(x: a) -> String where a: Display { "{x}" }
 fn main() {
   let c = channel.new(1)
   println(show(c))
diff --git a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__display_values_still_work.silt b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__display_values_still_work.silt
index 93330ae43..616b9888f 100644
--- a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__display_values_still_work.silt
+++ b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__display_values_still_work.silt
@@ -5,7 +5,7 @@
 -- stdout-contains: P {
 import int
 type P { name: String, age: Int }
-fn show(x: a) -> String where a: Display { x.display() }
+fn show(x: a) -> String where a: Display { "{x}" }
 fn main() {
   println(show(42))
   println(show("hi"))
diff --git a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__lambda.silt b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__lambda.silt
index 8a31c9387..2b43216c0 100644
--- a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__lambda.silt
+++ b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__lambda.silt
@@ -3,5 +3,5 @@
 -- stderr-contains: does not implement trait 'Display'
 -- stderr-contains: 'Fn'
 -- stderr-not-contains: required for string interpolation
-fn show(x: a) -> String where a: Display { x.display() }
+fn show(x: a) -> String where a: Display { "{x}" }
 fn main() { println(show({ y -> y })) }
diff --git a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__list_of_fn_rejected.silt b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__list_of_fn_rejected.silt
index 0fe935d55..f0ec6e5de 100644
--- a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__list_of_fn_rejected.silt
+++ b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__list_of_fn_rejected.silt
@@ -5,5 +5,5 @@
 -- a list of functions has none, as for `println`.
 fn main() {
   let f = { y -> y }
-  println([f].display())
+  println("{[f]}")
 }
diff --git a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__task_handle.silt b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__task_handle.silt
index 90e6707d5..c29725e2a 100644
--- a/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__task_handle.silt
+++ b/tests/golden/typecheck/display/round101_polymorphic_display_method_gate__task_handle.silt
@@ -4,7 +4,7 @@
 -- stderr-contains: 'task.Handle'
 -- stderr-not-contains: required for string interpolation
 import task
-fn show(x: a) -> String where a: Display { x.display() }
+fn show(x: a) -> String where a: Display { "{x}" }
 fn main() {
   let h = task.spawn({ -> 42 })
   println(show(h))
diff --git a/tests/golden/typecheck/display/round74_display_eq_message_runtime__io_error_three_forms_agree.silt b/tests/golden/typecheck/display/round74_display_eq_message_runtime__io_error_three_forms_agree.silt
index 9050b609e..b989c3c94 100644
--- a/tests/golden/typecheck/display/round74_display_eq_message_runtime__io_error_three_forms_agree.silt
+++ b/tests/golden/typecheck/display/round74_display_eq_message_runtime__io_error_three_forms_agree.silt
@@ -5,8 +5,8 @@ fn main() {
         Ok(_) -> ()
         Err(e) -> {
             let display_form = "{e}"
-            let message_form = e.message()
-            let display_method_form = e.display()
+            let message_form = Error.message(e)
+            let display_method_form = "{e}"
             match display_form == message_form {
                 true -> ()
                 false -> {
diff --git a/tests/golden/typecheck/display/round74_display_eq_message_runtime__json_error_display_eq_message.silt b/tests/golden/typecheck/display/round74_display_eq_message_runtime__json_error_display_eq_message.silt
index 637940794..2d6b0ac42 100644
--- a/tests/golden/typecheck/display/round74_display_eq_message_runtime__json_error_display_eq_message.silt
+++ b/tests/golden/typecheck/display/round74_display_eq_message_runtime__json_error_display_eq_message.silt
@@ -4,8 +4,8 @@ fn main() {
     match json.parse("not valid json at all", String) {
         Ok(_) -> ()
         Err(e) -> {
-            let display_method_form = e.display()
-            let message_form = e.message()
+            let display_method_form = "{e}"
+            let message_form = Error.message(e)
             match display_method_form == message_form {
                 true -> println("EQUIV")
                 false -> {
diff --git a/tests/golden/typecheck/display/round74_display_eq_message_runtime__user_enum_keeps_constructor_form.silt b/tests/golden/typecheck/display/round74_display_eq_message_runtime__user_enum_keeps_constructor_form.silt
index d3abbd5ba..c51c35871 100644
--- a/tests/golden/typecheck/display/round74_display_eq_message_runtime__user_enum_keeps_constructor_form.silt
+++ b/tests/golden/typecheck/display/round74_display_eq_message_runtime__user_enum_keeps_constructor_form.silt
@@ -2,5 +2,5 @@
 type Color { Red, Green(Int), Blue }
 fn main() {
   let c = Green(42)
-  println(c.display())
+  println("{c}")
 }
diff --git a/tests/golden/typecheck/display/texts__an_anonymous_record_is_written_without_a_tag.silt b/tests/golden/typecheck/display/texts__an_anonymous_record_is_written_without_a_tag.silt
index 66abd9681..c9d36238a 100644
--- a/tests/golden/typecheck/display/texts__an_anonymous_record_is_written_without_a_tag.silt
+++ b/tests/golden/typecheck/display/texts__an_anonymous_record_is_written_without_a_tag.silt
@@ -18,10 +18,10 @@ fn main() {
   println([r])
   println(io.inspect(r))
   println(string.from(r))
-  println(r.display())
-  println(r.equal(r))
-  println(r.equal({ b: 2, a: P { z: 1, a: 2 } }))
-  println(r.hash() == r.hash())
+  println("{r}")
+  println(r == r)
+  println(r == { b: 2, a: P { z: 1, a: 2 } })
+  println(Hash.hash(r) == Hash.hash(r))
   println(io.inspect(P { z: 1, a: 2 }))
   println(io.inspect([P { z: 1, a: 2 }]))
   println(#{ r: 1 })
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__compare_method_int_lists.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__compare_method_int_lists.silt
index 26e2725ef..b82a88a12 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__compare_method_int_lists.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__compare_method_int_lists.silt
@@ -1,3 +1,3 @@
 -- Positive control: `.compare()` on Int lists gives -1.
-fn cmpm(a: t, b: t) -> Int where t: Compare { a.compare(b) }
+fn cmpm(a: t, b: t) -> Int where t: Compare { Compare.compare(a, b) }
 fn main() { println(cmpm([1, 2], [3, 4])) }
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_fn_list.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_fn_list.silt
index 69589fd6b..9e60ba9f1 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_fn_list.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_fn_list.silt
@@ -3,5 +3,5 @@
 -- stderr-contains: error[type]: type 'List(Fn(_) -> _)' does not implement trait 'Hash': element is of type 'Fn(_) -> _', which does not
 fn main() {
   let xs = [{ y -> y }]
-  println(xs.hash())
+  println(Hash.hash(xs))
 }
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_tuple_and_string.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_tuple_and_string.silt
index 8a9fc3dc3..cd3ae4a11 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_tuple_and_string.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__concrete_hash_tuple_and_string.silt
@@ -1,2 +1,2 @@
 -- Positive control: equal tuples and strings hash equal.
-fn main() { println((1, "a").hash() == (1, "a").hash() && "abc".hash() == "abc".hash()) }
+fn main() { println(Hash.hash((1, "a")) == Hash.hash((1, "a")) && Hash.hash("abc") == Hash.hash("abc")) }
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_compare_method_fn_lists.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_compare_method_fn_lists.silt
index ed133218e..d635cbb14 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_compare_method_fn_lists.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_compare_method_fn_lists.silt
@@ -1,7 +1,7 @@
 -- `.compare()` through a polymorphic wrapper on lists of functions fails.
 -- exit: 1
 -- stderr-contains: error[type]: type 'List(Fn(_) -> _)' does not implement trait 'Compare': element is of type 'Fn(_) -> _', which does not
-fn cmpm(a: t, b: t) -> Int where t: Compare { a.compare(b) }
+fn cmpm(a: t, b: t) -> Int where t: Compare { Compare.compare(a, b) }
 fn main() {
   println(cmpm([{ y -> y }], [{ y -> y }]))
 }
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_equal_method_fn_lists.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_equal_method_fn_lists.silt
index fb672dd62..492fdacc3 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_equal_method_fn_lists.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_equal_method_fn_lists.silt
@@ -1,7 +1,7 @@
 -- `.equal()` through a polymorphic wrapper on lists of functions fails.
 -- exit: 1
 -- stderr-contains: error[type]: type 'List(Fn(_) -> _)' does not implement trait 'Equal': element is of type 'Fn(_) -> _', which does not
-fn eqm(a: t, b: t) -> Bool where t: Equal { a.equal(b) }
+fn eqm(a: t, b: t) -> Bool where t: Equal { a == b }
 fn main() {
   println(eqm([{ y -> y }], [{ y -> y }]))
 }
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_lists.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_lists.silt
index 757bf190f..f93acd78d 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_lists.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_lists.silt
@@ -1,7 +1,7 @@
 -- `.hash()` through a polymorphic wrapper on lists of functions fails.
 -- exit: 1
 -- stderr-contains: error[type]: type 'List(Fn(_) -> _)' does not implement trait 'Hash': element is of type 'Fn(_) -> _', which does not
-fn h(a: x) -> Int where x: Hash { a.hash() }
+fn h(a: x) -> Int where x: Hash { Hash.hash(a) }
 fn main() {
   println(h([{ y -> y }]) == h([{ z -> z * 99 }]))
 }
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_tuples.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_tuples.silt
index 7c1903b16..3be032b2b 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_tuples.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_fn_tuples.silt
@@ -1,7 +1,7 @@
 -- `.hash()` through a polymorphic wrapper on tuples holding functions fails.
 -- exit: 1
 -- stderr-contains: error[type]: type '(Fn(_) -> _, Int)' does not implement trait 'Hash': part #1 is of type 'Fn(_) -> _', which does not
-fn h(a: x) -> Int where x: Hash { a.hash() }
+fn h(a: x) -> Int where x: Hash { Hash.hash(a) }
 fn main() {
   println(h(({ y -> y }, 1)) == h(({ z -> z + 5 }, 1)))
 }
diff --git a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_int_lists.silt b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_int_lists.silt
index 0ca7e8ef8..2279e1b85 100644
--- a/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_int_lists.silt
+++ b/tests/golden/typecheck/fn_compare/container_fn_compare_runtime_gate__polymorphic_hash_int_lists.silt
@@ -1,3 +1,3 @@
 -- Positive control: equal Int lists hash equal.
-fn h(a: x) -> Int where x: Hash { a.hash() }
+fn h(a: x) -> Int where x: Hash { Hash.hash(a) }
 fn main() { println(h([1, 2, 3]) == h([1, 2, 3])) }
diff --git a/tests/golden/typecheck/hashing/round74_hash_eq_ord_contract__list_range_hash_eq.silt b/tests/golden/typecheck/hashing/round74_hash_eq_ord_contract__list_range_hash_eq.silt
index 15a166877..80d674379 100644
--- a/tests/golden/typecheck/hashing/round74_hash_eq_ord_contract__list_range_hash_eq.silt
+++ b/tests/golden/typecheck/hashing/round74_hash_eq_ord_contract__list_range_hash_eq.silt
@@ -4,5 +4,5 @@ fn main() {
   let a: List(Int) = [1, 2, 3]
   let b: List(Int) = 1..3
   println(a == b)
-  println(a.hash() == b.hash())
+  println(Hash.hash(a) == Hash.hash(b))
 }
diff --git a/tests/golden/typecheck/inference/closure_params_from_expected__builtin_callee.silt b/tests/golden/typecheck/inference/closure_params_from_expected__builtin_callee.silt
index 8b19a729f..36b811412 100644
--- a/tests/golden/typecheck/inference/closure_params_from_expected__builtin_callee.silt
+++ b/tests/golden/typecheck/inference/closure_params_from_expected__builtin_callee.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: unknown method 'missing' on type Int
+-- stderr-contains: error[type]: type 'Int' has no field 'missing'
 -- The closure's parameter is the list's element type, known from the
 -- argument before it.
 import list
diff --git a/tests/golden/typecheck/inference/closure_params_from_expected__method_result.silt b/tests/golden/typecheck/inference/closure_params_from_expected__method_result.silt
index 02d1cda97..278e9dcc0 100644
--- a/tests/golden/typecheck/inference/closure_params_from_expected__method_result.silt
+++ b/tests/golden/typecheck/inference/closure_params_from_expected__method_result.silt
@@ -6,4 +6,4 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 fn apply(f: Fn(Int) -> Int, x: Int) -> Int { f(x) }
-fn main() { println(apply({ n -> n.greet() }, 3)) }
+fn main() { println(apply({ n -> Greet.greet(n) }, 3)) }
diff --git a/tests/golden/typecheck/inference/closure_params_from_expected__unknown_field.silt b/tests/golden/typecheck/inference/closure_params_from_expected__unknown_field.silt
index 62a5dc3ed..e5d9b6a12 100644
--- a/tests/golden/typecheck/inference/closure_params_from_expected__unknown_field.silt
+++ b/tests/golden/typecheck/inference/closure_params_from_expected__unknown_field.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: unknown field or method 'nam' on type P
+-- stderr-contains: error[type]: type 'P' has no field 'nam'
 -- A closure literal passed to a function has the parameter types the
 -- function expects before its body is checked: `p` is a `P` at `p.nam`.
 type P { name: String }
diff --git a/tests/golden/typecheck/inference/deferred__bound_on_outer_let_checked_when_decided.silt b/tests/golden/typecheck/inference/deferred__bound_on_outer_let_checked_when_decided.silt
index b4e80730d..6c965d4a9 100644
--- a/tests/golden/typecheck/inference/deferred__bound_on_outer_let_checked_when_decided.silt
+++ b/tests/golden/typecheck/inference/deferred__bound_on_outer_let_checked_when_decided.silt
@@ -7,7 +7,7 @@
 import channel
 trait Loud { fn loud(self) -> String }
 trait Loud for Int { fn loud(self) -> String { "int!" } }
-fn shout(x: a) -> String where a: Loud { x.loud() }
+fn shout(x: a) -> String where a: Loud { Loud.loud(x) }
 let ch = channel.new(4)
 fn drain() {
   match channel.receive(ch) {
diff --git a/tests/golden/typecheck/inference/deferred__operator_method_and_question_on_outer_let_checked_when_decided.silt b/tests/golden/typecheck/inference/deferred__operator_method_and_question_on_outer_let_checked_when_decided.silt
index 58b493f7b..dee3fec6b 100644
--- a/tests/golden/typecheck/inference/deferred__operator_method_and_question_on_outer_let_checked_when_decided.silt
+++ b/tests/golden/typecheck/inference/deferred__operator_method_and_question_on_outer_let_checked_when_decided.silt
@@ -1,10 +1,10 @@
 -- cmd: check
 -- exit: 1
--- An operator, a method call and `?` on a value whose type a top-level
+-- An operator, a field call and `?` on a value whose type a top-level
 -- `let` leaves unknown are checked when a later function decides it.
 -- stderr-contains: operator '*' requires Int or Float, got 'String'
 -- stderr-contains: requires Int or Float, got 'String'
--- stderr-contains: unknown field or method 'loud' on type String
+-- stderr-contains: type 'String' has no field 'loud'
 -- stderr-contains: '?' operator requires Result or Option type, got 'String'
 import channel
 trait Loud { fn loud(self) -> String }
diff --git a/tests/golden/typecheck/inference/infer_order__bound_inferred_through_wrappers.silt b/tests/golden/typecheck/inference/infer_order__bound_inferred_through_wrappers.silt
index bc42ad2ae..8a274fb52 100644
--- a/tests/golden/typecheck/inference/infer_order__bound_inferred_through_wrappers.silt
+++ b/tests/golden/typecheck/inference/infer_order__bound_inferred_through_wrappers.silt
@@ -7,7 +7,7 @@
 -- stderr-not-contains: enclosing function
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn wrap(x) { hello(x) }
 fn wrap2(x) { wrap(x) }
 fn main() {
diff --git a/tests/golden/typecheck/inference/infer_order__group_functions_share_annotation_variables.silt b/tests/golden/typecheck/inference/infer_order__group_functions_share_annotation_variables.silt
index af85b0dc9..95e416b82 100644
--- a/tests/golden/typecheck/inference/infer_order__group_functions_share_annotation_variables.silt
+++ b/tests/golden/typecheck/inference/infer_order__group_functions_share_annotation_variables.silt
@@ -30,7 +30,7 @@ fn size_all(ts: List(Tree(b))) {
 }
 fn say(x: a, n: Int) where a: Loud {
   match n {
-    0 -> x.loud()
+    0 -> Loud.loud(x)
     _ -> echo(x, n - 1)
   }
 }
diff --git a/tests/golden/typecheck/inference/infer_order__group_keeps_one_functions_variables_apart.silt b/tests/golden/typecheck/inference/infer_order__group_keeps_one_functions_variables_apart.silt
index b276b4f81..4305c959c 100644
--- a/tests/golden/typecheck/inference/infer_order__group_keeps_one_functions_variables_apart.silt
+++ b/tests/golden/typecheck/inference/infer_order__group_keeps_one_functions_variables_apart.silt
@@ -16,7 +16,7 @@ fn pair(x: a, y: b, n: Int) {
 fn flip(u: c, v: c, n: Int) { pair(u, v, n) }
 fn say(x: a, n: Int) where a: Loud {
   match n {
-    0 -> x.loud()
+    0 -> Loud.loud(x)
     _ -> echo(x, n - 1)
   }
 }
diff --git a/tests/golden/typecheck/inference/infer_order__group_member_owes_neighbours_bound.silt b/tests/golden/typecheck/inference/infer_order__group_member_owes_neighbours_bound.silt
index 56fac5646..08bdd544f 100644
--- a/tests/golden/typecheck/inference/infer_order__group_member_owes_neighbours_bound.silt
+++ b/tests/golden/typecheck/inference/infer_order__group_member_owes_neighbours_bound.silt
@@ -8,7 +8,7 @@ trait Loud { fn loud(self) -> String }
 trait Loud for Int { fn loud(self) -> String { "int!" } }
 fn shout(x: a, n) where a: Loud {
   match n {
-    0 -> x.loud()
+    0 -> Loud.loud(x)
     _ -> relay(x, n - 1)
   }
 }
diff --git a/tests/golden/typecheck/inference/infer_order__wrappers_of_bounded_fn_run.silt b/tests/golden/typecheck/inference/infer_order__wrappers_of_bounded_fn_run.silt
index fd8585d01..962446eb8 100644
--- a/tests/golden/typecheck/inference/infer_order__wrappers_of_bounded_fn_run.silt
+++ b/tests/golden/typecheck/inference/infer_order__wrappers_of_bounded_fn_run.silt
@@ -2,7 +2,7 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Bool { fn greet(self) -> String { "bool" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn wrap(x) { hello(x) }
 fn wrap2(x) { wrap(x) }
 fn main() {
diff --git a/tests/golden/typecheck/inference/rigid__annotated_variable_needs_declared_bound.silt b/tests/golden/typecheck/inference/rigid__annotated_variable_needs_declared_bound.silt
index 0e097dcda..c003a7b84 100644
--- a/tests/golden/typecheck/inference/rigid__annotated_variable_needs_declared_bound.silt
+++ b/tests/golden/typecheck/inference/rigid__annotated_variable_needs_declared_bound.silt
@@ -3,11 +3,10 @@
 -- A parameter annotated with a type variable has the bounds its `where`
 -- clauses declare and no other, also when the return type is left out.
 -- stderr-contains: error[type]: type variable `b` is not known to implement trait 'Greet', which 'hello' needs
--- stderr-contains: no field or method 'greet' on a value of type `c`: the type variable has no trait bound
--- stderr-contains: add `where c: SomeTrait`
+-- stderr-contains: error[type]: type 'c' has no field 'greet'
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn partly(x: b) { hello(x) }
 fn method(x: c) -> String { x.greet() }
 fn main() { println(partly(1)) }
diff --git a/tests/golden/typecheck/inference/select__a_method_is_not_a_value.silt b/tests/golden/typecheck/inference/select__a_method_is_not_a_value.silt
index 04d854165..cbf22c1e5 100644
--- a/tests/golden/typecheck/inference/select__a_method_is_not_a_value.silt
+++ b/tests/golden/typecheck/inference/select__a_method_is_not_a_value.silt
@@ -1,7 +1,9 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: method 'add' is not a value: a method is called
--- stderr-contains: help: call it, `x.add(..)`, or pass a closure that does, `{ x -> x.add(..) }`
+-- stderr-contains: error[type]: type 'Int' has no field 'add'
+-- stderr-contains: help: `add` is a method of trait `Adder`: call it as `Adder.add(x, ..)`
+-- A dot after a value is a field, called or not: a trait's method is
+-- taken through its trait (`Adder.add`).
 trait Adder { fn add(self, x: Int) -> Int }
 trait Adder for Int { fn add(self, x: Int) -> Int { self + x } }
 fn main() {
diff --git a/tests/golden/typecheck/inference/select__method_result_is_the_methods.silt b/tests/golden/typecheck/inference/select__method_result_is_the_methods.silt
index 81d895bca..e3f977f39 100644
--- a/tests/golden/typecheck/inference/select__method_result_is_the_methods.silt
+++ b/tests/golden/typecheck/inference/select__method_result_is_the_methods.silt
@@ -5,7 +5,7 @@
 -- does, the receiver's type.
 trait Same { fn same(self) -> Self }
 trait Same for String { fn same(self) -> Self { self } }
-fn coerce(x) { x.same() }
+fn coerce(x) { Same.same(x) }
 fn main() {
   let n: Int = coerce("not an int")
   println(n)
diff --git a/tests/golden/typecheck/inference/select__one_trait_bound_is_owed.silt b/tests/golden/typecheck/inference/select__one_trait_bound_is_owed.silt
index 96a7e8b35..25ef33ba5 100644
--- a/tests/golden/typecheck/inference/select__one_trait_bound_is_owed.silt
+++ b/tests/golden/typecheck/inference/select__one_trait_bound_is_owed.silt
@@ -3,7 +3,7 @@
 -- stderr-contains: error[type]: type 'String' does not implement trait 'Greet'
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn g(x) { x.greet() }
+fn g(x) { Greet.greet(x) }
 fn main() {
   println(g(1))
   println(g("s"))
diff --git a/tests/golden/typecheck/inference/select__one_trait_bounds_the_receiver.silt b/tests/golden/typecheck/inference/select__one_trait_bounds_the_receiver.silt
index 41ef72d06..3aeae1e3f 100644
--- a/tests/golden/typecheck/inference/select__one_trait_bounds_the_receiver.silt
+++ b/tests/golden/typecheck/inference/select__one_trait_bounds_the_receiver.silt
@@ -3,10 +3,10 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Bool { fn greet(self) -> String { "bool" } }
-fn g(x) { x.greet() }
+fn g(x) { Greet.greet(x) }
 fn main() {
   println(g(1))
   println(g(true))
-  let h = { y -> "{y.greet()}!" }
+  let h = { y -> "{Greet.greet(y)}!" }
   println(h(2))
 }
diff --git a/tests/golden/typecheck/inference/select__receiver_decided_later.silt b/tests/golden/typecheck/inference/select__receiver_decided_later.silt
index d825ffb67..8e3c3eb18 100644
--- a/tests/golden/typecheck/inference/select__receiver_decided_later.silt
+++ b/tests/golden/typecheck/inference/select__receiver_decided_later.silt
@@ -7,7 +7,7 @@ fn main() {
   let ch = channel.new(1)
   let f = { ->
     match channel.try_receive(ch) {
-      channel.Message(m) -> m.greet()
+      channel.Message(m) -> Greet.greet(m)
       _ -> "none"
     }
   }
diff --git a/tests/golden/typecheck/init_order/init_order__a_call_into_another_module/other.silt b/tests/golden/typecheck/init_order/init_order__a_call_into_another_module/other.silt
index 72adc9b53..bf5aebe89 100644
--- a/tests/golden/typecheck/init_order/init_order__a_call_into_another_module/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__a_call_into_another_module/other.silt
@@ -1,3 +1,3 @@
 pub trait Greet { fn greet(self) -> String }
-pub fn run(x: a) -> String where a: Greet { x.greet() }
+pub fn run(x: a) -> String where a: Greet { Greet.greet(x) }
 pub fn load() -> Int { 1 }
diff --git a/tests/golden/typecheck/init_order/init_order__a_display_impl_that_reads_the_let_it_shows_for.silt b/tests/golden/typecheck/init_order/init_order__a_display_impl_that_reads_the_let_it_shows_for.silt
index 8a30a6b3b..6c6142d6d 100644
--- a/tests/golden/typecheck/init_order/init_order__a_display_impl_that_reads_the_let_it_shows_for.silt
+++ b/tests/golden/typecheck/init_order/init_order__a_display_impl_that_reads_the_let_it_shows_for.silt
@@ -32,7 +32,7 @@ type Holder {
   w: Wrap,
 }
 
-let label = Some(Holder { w: Wrap { t: 1 } }).display()
+let label = string.from(Some(Holder { w: Wrap { t: 1 } }))
 
 fn main() {
   println(total)
diff --git a/tests/golden/typecheck/init_order/init_order__a_function_shows_what_it_is_named_at__an_own_type.silt b/tests/golden/typecheck/init_order/init_order__a_function_shows_what_it_is_named_at__an_own_type.silt
index 6f9718c2e..f15f41200 100644
--- a/tests/golden/typecheck/init_order/init_order__a_function_shows_what_it_is_named_at__an_own_type.silt
+++ b/tests/golden/typecheck/init_order/init_order__a_function_shows_what_it_is_named_at__an_own_type.silt
@@ -16,7 +16,7 @@ fn label(x: a) -> String where a: Display {
 }
 
 fn dlabel(x: a) -> String where a: Display {
-  x.display()
+  "{x}"
 }
 
 fn slabel(x: a) -> String where a: Display {
diff --git a/tests/golden/typecheck/init_order/init_order__a_let_that_reaches_itself.silt b/tests/golden/typecheck/init_order/init_order__a_let_that_reaches_itself.silt
index 29576abd7..ee0cd9b4c 100644
--- a/tests/golden/typecheck/init_order/init_order__a_let_that_reaches_itself.silt
+++ b/tests/golden/typecheck/init_order/init_order__a_let_that_reaches_itself.silt
@@ -15,7 +15,7 @@ let a = f()
 fn f() -> Int { g() + 1 }
 fn g() -> Int { b }
 let b = a + 1
-let table = P { n: 1 }.size()
+let table = Size.size(P { n: 1 })
 let own = own + 1
 let fine = 3
 fn main() { println(a + table + own + fine) }
diff --git a/tests/golden/typecheck/init_order/init_order__lets_run_after_what_they_reach.silt b/tests/golden/typecheck/init_order/init_order__lets_run_after_what_they_reach.silt
index 79497ed2c..8e7a577b2 100644
--- a/tests/golden/typecheck/init_order/init_order__lets_run_after_what_they_reach.silt
+++ b/tests/golden/typecheck/init_order/init_order__lets_run_after_what_they_reach.silt
@@ -7,7 +7,7 @@ import list
 type P { n: Int }
 trait Get {
   fn get(self) -> Int
-  fn twice(self) -> Int { self.get() * 2 }
+  fn twice(self) -> Int { Get.get(self) * 2 }
 }
 trait Get for P { fn get(self) -> Int { self.n + base } }
 let a = b + 1
@@ -18,7 +18,7 @@ let b = {
 }
 let e = {
   println("e")
-  P { n: 1 }.twice()
+  Get.twice(P { n: 1 })
 }
 let base = {
   println("base")
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__a_builtin_default_method.silt b/tests/golden/typecheck/init_order/init_order__outside_code__a_builtin_default_method.silt
index b3817e549..3bde8be28 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__a_builtin_default_method.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__a_builtin_default_method.silt
@@ -7,7 +7,7 @@
 type MyErr { code: Int }
 trait Display for MyErr { fn display(self) -> String { "E{self.code}/{late}" } }
 trait Error for MyErr { }
-let m = MyErr { code: 1 }.message()
+let m = Error.message(MyErr { code: 1 })
 let late = {
   println("late")
   5
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__b_generic_wrapper/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__b_generic_wrapper/other.silt
index b3dfa812d..3f79fecc5 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__b_generic_wrapper/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__b_generic_wrapper/other.silt
@@ -1,3 +1,3 @@
 pub trait Greet { fn greet(self) -> String }
-pub fn run(x: a) -> String where a: Greet { x.greet() }
+pub fn run(x: a) -> String where a: Greet { Greet.greet(x) }
 pub fn each(xs: List(a)) -> List(String) where a: Greet { [] }
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/main.silt b/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/main.silt
index d5ada7c84..787b2cfc5 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/main.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/main.silt
@@ -6,7 +6,7 @@
 import other
 type P { n: Int }
 trait other.Tag for P { fn tag(self) -> String { "main.P.tag {late}" } }
-fn tg(x: a) -> String where a: other.Tag { x.tagged() }
+fn tg(x: a) -> String where a: other.Tag { other.Tag.tagged(x) }
 let v = tg(P { n: 1 })
 let late = {
   println("late")
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/other.silt
index 153cf0b33..b30cf6dbc 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__c_default_method_of_another_module/other.silt
@@ -3,10 +3,10 @@ pub type E { X, Y(Int) }
 pub trait Name { fn name(self) -> String }
 trait Name for P { fn name(self) -> String { "other.P" } }
 trait Name for E { fn name(self) -> String { "other.E" } }
-pub fn dyn_name(x: a) -> String where a: Name { x.name() }
+pub fn dyn_name(x: a) -> String where a: Name { Name.name(x) }
 pub trait Tag {
   fn tag(self) -> String
-  fn tagged(self) -> String { "<{self.tag()}>" }
+  fn tagged(self) -> String { "<{Tag.tag(self)}>" }
 }
 trait Tag for P { fn tag(self) -> String { "other.P.tag" } }
 pub fn mk() -> P { P { n: 1 } }
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__d_argument_inside_a_generic_type/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__d_argument_inside_a_generic_type/other.silt
index e005dba0d..44b15f926 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__d_argument_inside_a_generic_type/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__d_argument_inside_a_generic_type/other.silt
@@ -2,5 +2,5 @@ pub fn call(f: Fn() -> a) -> a { f() }
 pub fn apply(f: Fn(a) -> b, x: a) -> b { f(x) }
 pub type Box(a) { item: a }
 pub trait Greet { fn greet(self) -> String }
-pub fn greet_box(b: Box(a)) -> String where a: Greet { b.item.greet() }
-pub fn greet2(x: a) -> String where a: Greet { x.greet() }
+pub fn greet_box(b: Box(a)) -> String where a: Greet { Greet.greet(b.item) }
+pub fn greet2(x: a) -> String where a: Greet { Greet.greet(x) }
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__e_function_of_another_module_in_a_let/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__e_function_of_another_module_in_a_let/other.silt
index e005dba0d..44b15f926 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__e_function_of_another_module_in_a_let/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__e_function_of_another_module_in_a_let/other.silt
@@ -2,5 +2,5 @@ pub fn call(f: Fn() -> a) -> a { f() }
 pub fn apply(f: Fn(a) -> b, x: a) -> b { f(x) }
 pub type Box(a) { item: a }
 pub trait Greet { fn greet(self) -> String }
-pub fn greet_box(b: Box(a)) -> String where a: Greet { b.item.greet() }
-pub fn greet2(x: a) -> String where a: Greet { x.greet() }
+pub fn greet_box(b: Box(a)) -> String where a: Greet { Greet.greet(b.item) }
+pub fn greet2(x: a) -> String where a: Greet { Greet.greet(x) }
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__f_handed_to_a_builtin_function/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__f_handed_to_a_builtin_function/other.silt
index e005dba0d..44b15f926 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__f_handed_to_a_builtin_function/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__f_handed_to_a_builtin_function/other.silt
@@ -2,5 +2,5 @@ pub fn call(f: Fn() -> a) -> a { f() }
 pub fn apply(f: Fn(a) -> b, x: a) -> b { f(x) }
 pub type Box(a) { item: a }
 pub trait Greet { fn greet(self) -> String }
-pub fn greet_box(b: Box(a)) -> String where a: Greet { b.item.greet() }
-pub fn greet2(x: a) -> String where a: Greet { x.greet() }
+pub fn greet_box(b: Box(a)) -> String where a: Greet { Greet.greet(b.item) }
+pub fn greet2(x: a) -> String where a: Greet { Greet.greet(x) }
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__g_handed_to_a_function_of_the_module/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__g_handed_to_a_function_of_the_module/other.silt
index e005dba0d..44b15f926 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__g_handed_to_a_function_of_the_module/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__g_handed_to_a_function_of_the_module/other.silt
@@ -2,5 +2,5 @@ pub fn call(f: Fn() -> a) -> a { f() }
 pub fn apply(f: Fn(a) -> b, x: a) -> b { f(x) }
 pub type Box(a) { item: a }
 pub trait Greet { fn greet(self) -> String }
-pub fn greet_box(b: Box(a)) -> String where a: Greet { b.item.greet() }
-pub fn greet2(x: a) -> String where a: Greet { x.greet() }
+pub fn greet_box(b: Box(a)) -> String where a: Greet { Greet.greet(b.item) }
+pub fn greet2(x: a) -> String where a: Greet { Greet.greet(x) }
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__h_bound_in_a_block_or_closure/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__h_bound_in_a_block_or_closure/other.silt
index e005dba0d..44b15f926 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__h_bound_in_a_block_or_closure/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__h_bound_in_a_block_or_closure/other.silt
@@ -2,5 +2,5 @@ pub fn call(f: Fn() -> a) -> a { f() }
 pub fn apply(f: Fn(a) -> b, x: a) -> b { f(x) }
 pub type Box(a) { item: a }
 pub trait Greet { fn greet(self) -> String }
-pub fn greet_box(b: Box(a)) -> String where a: Greet { b.item.greet() }
-pub fn greet2(x: a) -> String where a: Greet { x.greet() }
+pub fn greet_box(b: Box(a)) -> String where a: Greet { Greet.greet(b.item) }
+pub fn greet2(x: a) -> String where a: Greet { Greet.greet(x) }
diff --git a/tests/golden/typecheck/init_order/init_order__outside_code__i_held_in_a_record_field/other.silt b/tests/golden/typecheck/init_order/init_order__outside_code__i_held_in_a_record_field/other.silt
index e005dba0d..44b15f926 100644
--- a/tests/golden/typecheck/init_order/init_order__outside_code__i_held_in_a_record_field/other.silt
+++ b/tests/golden/typecheck/init_order/init_order__outside_code__i_held_in_a_record_field/other.silt
@@ -2,5 +2,5 @@ pub fn call(f: Fn() -> a) -> a { f() }
 pub fn apply(f: Fn(a) -> b, x: a) -> b { f(x) }
 pub type Box(a) { item: a }
 pub trait Greet { fn greet(self) -> String }
-pub fn greet_box(b: Box(a)) -> String where a: Greet { b.item.greet() }
-pub fn greet2(x: a) -> String where a: Greet { x.greet() }
+pub fn greet_box(b: Box(a)) -> String where a: Greet { Greet.greet(b.item) }
+pub fn greet2(x: a) -> String where a: Greet { Greet.greet(x) }
diff --git a/tests/golden/typecheck/init_order/init_order__showing_a_value_reaches_its_display_impls.silt b/tests/golden/typecheck/init_order/init_order__showing_a_value_reaches_its_display_impls.silt
index bf64596d4..8ea2dad82 100644
--- a/tests/golden/typecheck/init_order/init_order__showing_a_value_reaches_its_display_impls.silt
+++ b/tests/golden/typecheck/init_order/init_order__showing_a_value_reaches_its_display_impls.silt
@@ -30,7 +30,7 @@ let a = "{Temp { degrees: 1 }}"
 
 let b = string.from(Wrap { inner: [Temp { degrees: 2 }] })
 
-let c = Node(Leaf(Temp { degrees: 3 }), Leaf(Temp { degrees: 4 })).display()
+let c = string.from(Node(Leaf(Temp { degrees: 3 }), Leaf(Temp { degrees: 4 })))
 
 let d = [Some(Temp { degrees: 5 })] |> list.map(string.from)
 
@@ -47,7 +47,7 @@ let f = show((Temp { degrees: 7 }, 1))
 
 let plain = {
   println("plain")
-  "{[1, 2]} {3.display()}"
+  "{[1, 2]} {3}"
 }
 
 let unit = {
diff --git a/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__a_default_method.silt b/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__a_default_method.silt
index bc0784d7b..ce610813f 100644
--- a/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__a_default_method.silt
+++ b/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__a_default_method.silt
@@ -17,7 +17,7 @@ trait Container {
   type Item: Display
   fn first(self) -> Self::Item
   fn shown(self) -> String {
-    "first is {self.first()}"
+    "first is {Container.first(self)}"
   }
 }
 
@@ -32,7 +32,7 @@ trait Container for Holder {
   }
 }
 
-let a = Holder { t: T { n: 1 } }.shown()
+let a = Container.shown(Holder { t: T { n: 1 } })
 
 let unit = {
   println("unit")
diff --git a/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__b_bounded_function.silt b/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__b_bounded_function.silt
index a55528317..2d9c44558 100644
--- a/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__b_bounded_function.silt
+++ b/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__b_bounded_function.silt
@@ -30,7 +30,7 @@ trait Container for Holder {
 }
 
 fn shown(c: c) -> String where c: Container {
-  "first is {c.first()}"
+  "first is {Container.first(c)}"
 }
 
 let a = shown(Holder { t: T { n: 1 } })
diff --git a/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__c_inside_a_list.silt b/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__c_inside_a_list.silt
index 1893c2e52..d81ca7cea 100644
--- a/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__c_inside_a_list.silt
+++ b/tests/golden/typecheck/init_order/init_order__showing_an_associated_type__c_inside_a_list.silt
@@ -18,10 +18,10 @@ trait Container {
   type Item: Display
   fn all(self) -> List(Self::Item)
   fn shown(self) -> String {
-    string.from(self.all())
+    string.from(Container.all(self))
   }
   fn shown2(self) -> String {
-    self.all().display()
+    "{Container.all(self)}"
   }
 }
 
@@ -36,9 +36,9 @@ trait Container for Holder {
   }
 }
 
-let a = Holder { t: T { n: 1 } }.shown()
+let a = Container.shown(Holder { t: T { n: 1 } })
 
-let a2 = Holder { t: T { n: 2 } }.shown2()
+let a2 = Container.shown2(Holder { t: T { n: 2 } })
 
 let unit = {
   println("unit")
diff --git a/tests/golden/typecheck/init_order/init_order__what_is_not_a_plain_value.silt b/tests/golden/typecheck/init_order/init_order__what_is_not_a_plain_value.silt
index 0c807bf47..744eacf63 100644
--- a/tests/golden/typecheck/init_order/init_order__what_is_not_a_plain_value.silt
+++ b/tests/golden/typecheck/init_order/init_order__what_is_not_a_plain_value.silt
@@ -37,7 +37,7 @@ trait Label for Other {
 }
 
 fn lbl(x: a) -> String where a: Label {
-  x.label()
+  Label.label(x)
 }
 
 let version = lbl(Other { k: 1 })
@@ -67,7 +67,7 @@ type P {
 trait S {
   fn s(self) -> Int
   fn t(self) -> Int {
-    self.s() + 1
+    S.s(self) + 1
   }
 }
 
@@ -77,7 +77,7 @@ trait S for P {
   }
 }
 
-let (p, q) = (r, P { n: 1 }.t())
+let (p, q) = (r, S.t(P { n: 1 }))
 
 let r = 1
 
diff --git a/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_satisfied/a.silt b/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_satisfied/a.silt
index a391d1379..3f436353e 100644
--- a/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_satisfied/a.silt
+++ b/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_satisfied/a.silt
@@ -1 +1 @@
-pub fn show(x: a) -> String where a: Display { x.display() }
+pub fn show(x: a) -> String where a: Display { "{x}" }
diff --git a/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_unsatisfied/a.silt b/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_unsatisfied/a.silt
index e01479e45..4c7ce6cb1 100644
--- a/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_unsatisfied/a.silt
+++ b/tests/golden/typecheck/modules/cross_module_inference__constrained_fn_unsatisfied/a.silt
@@ -2,4 +2,4 @@ pub trait Greet {
     fn greet(self) -> String
 }
 
-pub fn announce(x: a) -> String where a: Greet { x.greet() }
+pub fn announce(x: a) -> String where a: Greet { Greet.greet(x) }
diff --git a/tests/golden/typecheck/modules/cross_module_inference__pub_trait_local_impl/main.silt b/tests/golden/typecheck/modules/cross_module_inference__pub_trait_local_impl/main.silt
index 85c9955ae..0e04e451f 100644
--- a/tests/golden/typecheck/modules/cross_module_inference__pub_trait_local_impl/main.silt
+++ b/tests/golden/typecheck/modules/cross_module_inference__pub_trait_local_impl/main.silt
@@ -14,5 +14,5 @@ trait a.Describe for Box(t) where t: Display {
 }
 
 fn main() {
-  Wrap(42).describe()
+  a.Describe.describe(Wrap(42))
 }
diff --git a/tests/golden/typecheck/modules/cross_module_inference__pub_trait_pub_impl_consumer/main.silt b/tests/golden/typecheck/modules/cross_module_inference__pub_trait_pub_impl_consumer/main.silt
index f3f92ab27..03d0a6a8d 100644
--- a/tests/golden/typecheck/modules/cross_module_inference__pub_trait_pub_impl_consumer/main.silt
+++ b/tests/golden/typecheck/modules/cross_module_inference__pub_trait_pub_impl_consumer/main.silt
@@ -3,7 +3,7 @@
 -- stderr-not-contains: error
 import a
 
-fn announce(x: a) -> String where a: a.Greet { x.greet() }
+fn announce(x: a) -> String where a: a.Greet { a.Greet.greet(x) }
 
 fn main() {
   announce(7)
diff --git a/tests/golden/typecheck/modules/impl_place__a_bounded_function_of_a_module_that_does_not_import_the_impl/x.silt b/tests/golden/typecheck/modules/impl_place__a_bounded_function_of_a_module_that_does_not_import_the_impl/x.silt
index 83cd46a9d..c83420b0c 100644
--- a/tests/golden/typecheck/modules/impl_place__a_bounded_function_of_a_module_that_does_not_import_the_impl/x.silt
+++ b/tests/golden/typecheck/modules/impl_place__a_bounded_function_of_a_module_that_does_not_import_the_impl/x.silt
@@ -1,7 +1,7 @@
 import t
 
 pub fn f(v: a) -> String where a: t.T {
-  "f: {v.m()}"
+  "f: {t.T.m(v)}"
 }
 
 pub fn shown(v: a) -> String where a: Display {
diff --git a/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_for_a_builtin_type.silt b/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_for_a_builtin_type.silt
index 875f9aec3..0ef9307af 100644
--- a/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_for_a_builtin_type.silt
+++ b/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_for_a_builtin_type.silt
@@ -6,7 +6,7 @@ trait Display for Int {
 }
 fn need_d(x: a) -> Int where a: Display { 1 }
 fn main() {
-  let _ = 1.display()
+  let _ = "{1}"
   let _ = "{1}"
   let _ = need_d(1)
   let _ = need_d([1])
diff --git a/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_is_no_impl/main.silt b/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_is_no_impl/main.silt
index 1db7be60a..04d476f59 100644
--- a/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_is_no_impl/main.silt
+++ b/tests/golden/typecheck/modules/impl_place__a_refused_display_impl_is_no_impl/main.silt
@@ -17,7 +17,7 @@ fn need_d(x: a) -> Int where a: Display { 1 }
 
 fn main() {
   let t = Tag { name: "m" }
-  let _ = t.display()
+  let _ = "{t}"
   let _ = "{t}"
   println(t)
   let _ = need_d(t)
diff --git a/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/early.silt b/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/early.silt
index 4acbbed99..f3f5a78df 100644
--- a/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/early.silt
+++ b/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/early.silt
@@ -3,6 +3,6 @@ import traits
 
 pub let first = traits.measure(shapes.unit_square())
 
-pub let second = shapes.Square { side: 2 }.told()
+pub let second = traits.Area.told(shapes.Square { side: 2 })
 
-pub let third = 3.area()
+pub let third = traits.Area.area(3)
diff --git a/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/traits.silt b/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/traits.silt
index 532c0b0a3..f6e84fe99 100644
--- a/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/traits.silt
+++ b/tests/golden/typecheck/modules/impl_place__an_impl_in_the_traits_module_for_a_type_of_a_third/traits.silt
@@ -3,7 +3,7 @@ import shapes
 pub trait Area {
   fn area(self) -> Int
   fn told(self) -> String {
-    "{label}{self.area()}"
+    "{label}{Area.area(self)}"
   }
 }
 
@@ -27,5 +27,5 @@ let scale = {
 let label = "area "
 
 pub fn measure(x: a) -> Int where a: Area {
-  x.area()
+  Area.area(x)
 }
diff --git a/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/case.stderr b/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/case.stderr
index b2106067c..b6a7741e9 100644
--- a/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/case.stderr
+++ b/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/case.stderr
@@ -1,5 +1,5 @@
 error[type]: the impl of trait 'Display' for type 'types.Tag' is written in module 'main', which declares neither the trait nor the type; it may be written in module 'types', which declares the type
- --> main.silt:10:1
+ --> main.silt:11:1
     |
- 10 | trait Display for Tag {
+ 11 | trait Display for Tag {
     | ^^^^^^^^^^^^^^^^^^^^^^^ the impl of trait 'Display' for type 'types.Tag' is written in module 'main', which declares neither the trait nor the type; it may be written in module 'types', which declares the type
diff --git a/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/early.silt b/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/early.silt
index 7bd373fdd..e194bddb0 100644
--- a/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/early.silt
+++ b/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/early.silt
@@ -1,7 +1,8 @@
 import types.{ Tag }
+import string
 pub fn show(x: a) -> String where a: Display {
-  x.display()
+  "{x}"
 }
-pub let text = Tag { name: "e" }.display()
+pub let text = string.from(Tag { name: "e" })
 pub let text2 = show(Tag { name: "e2" })
-pub let text3 = Tag.display(Tag { name: "e3" })
+pub let text3 = string.from(Tag { name: "e3" })
diff --git a/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/main.silt b/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/main.silt
index 830b6c6d7..603e3b2e6 100644
--- a/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/main.silt
+++ b/tests/golden/typecheck/modules/impl_place__m09_display_called_before_its_module_is_initialised/main.silt
@@ -6,6 +6,7 @@
 -- impl is the one error: the type keeps its structural Display.
 import early
 import types.{ Tag }
+import string
 
 trait Display for Tag {
   fn display(self) -> String {
@@ -19,6 +20,6 @@ fn main() {
   println(early.text)
   println(early.text2)
   println(early.text3)
-  println(Tag { name: "m" }.display())
+  println(string.from(Tag { name: "m" }))
   println(early.show(Tag { name: "m2" }))
 }
diff --git a/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/early.silt b/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/early.silt
index 37fdd07f2..25b7c956d 100644
--- a/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/early.silt
+++ b/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/early.silt
@@ -1,11 +1,12 @@
 import types.{ Tag }
+import string
 
 pub fn show(x: a) -> String where a: Display {
-  x.display()
+  "{x}"
 }
 
-pub let text = Tag { name: "e" }.display()
+pub let text = string.from(Tag { name: "e" })
 
 pub let text2 = show(Tag { name: "e2" })
 
-pub let text3 = Tag.display(Tag { name: "e3" })
+pub let text3 = string.from(Tag { name: "e3" })
diff --git a/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/main.silt b/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/main.silt
index a761f58e7..adf1cd3cd 100644
--- a/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/main.silt
+++ b/tests/golden/typecheck/modules/impl_place__m10_an_impl_that_reads_a_let_of_its_module/main.silt
@@ -4,11 +4,12 @@
 -- it is initialised first.
 import early
 import types.{ Tag }
+import string
 
 fn main() {
   println(early.text)
   println(early.text2)
   println(early.text3)
-  println(Tag { name: "m" }.display())
+  println(string.from(Tag { name: "m" }))
   println(early.show(Tag { name: "m2" }))
 }
diff --git a/tests/golden/typecheck/modules/impl_place__m11_called_through_a_function_of_another_module/early.silt b/tests/golden/typecheck/modules/impl_place__m11_called_through_a_function_of_another_module/early.silt
index 30aa72e60..29ecc9380 100644
--- a/tests/golden/typecheck/modules/impl_place__m11_called_through_a_function_of_another_module/early.silt
+++ b/tests/golden/typecheck/modules/impl_place__m11_called_through_a_function_of_another_module/early.silt
@@ -1,5 +1,6 @@
 import types.{ Tag }
+import string
 
 pub fn show3() -> String {
-  Tag.display(Tag { name: "e3" })
+  string.from(Tag { name: "e3" })
 }
diff --git a/tests/golden/typecheck/modules/impl_place__the_error_names_both_modules/main.silt b/tests/golden/typecheck/modules/impl_place__the_error_names_both_modules/main.silt
index 29aad99b4..362040e3c 100644
--- a/tests/golden/typecheck/modules/impl_place__the_error_names_both_modules/main.silt
+++ b/tests/golden/typecheck/modules/impl_place__the_error_names_both_modules/main.silt
@@ -1,7 +1,7 @@
 -- cmd: check
 -- exit: 1
 -- stderr-contains: the impl of trait 'traits.Area' for type 'shapes.Square' is written in module 'main', which declares neither the trait nor the type; it may be written in module 'traits', which declares the trait, or in module 'shapes', which declares the type
--- stderr-contains: unknown field or method 'area' on type shapes.Square
+-- stderr-contains: type 'shapes.Square' does not implement trait 'traits.Area'
 -- An impl written elsewhere is no impl: nothing is called through it.
 import shapes.{ Square }
 import traits.{ Area }
@@ -13,5 +13,5 @@ trait Area for Square {
 }
 
 fn main() {
-  println(Square { side: 2 }.area())
+  println(Area.area(Square { side: 2 }))
 }
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/a.silt b/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/a.silt
similarity index 100%
rename from tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/a.silt
rename to tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/a.silt
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/case.stdout b/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/case.stdout
similarity index 100%
rename from tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/case.stdout
rename to tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/case.stdout
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/m.silt b/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/m.silt
new file mode 100644
index 000000000..7d63cf283
--- /dev/null
+++ b/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/m.silt
@@ -0,0 +1,5 @@
+import a
+
+pub fn both(x: t) -> String where t: a.Tag {
+  "{a.Tag.tag(x)} {a.Tag.tag(x)}"
+}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/main.silt b/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/main.silt
new file mode 100644
index 000000000..dcc1e9750
--- /dev/null
+++ b/tests/golden/typecheck/modules/method_reach__a_trait_is_called_where_it_is_named/main.silt
@@ -0,0 +1,10 @@
+-- A trait's method is called where the trait is named: `m` names it
+-- through its module, `a.Tag`; `main` imports it by name, though `m`
+-- already imports its module.
+import a.{ Tag }
+import m
+
+fn main() {
+  println(Tag.tag(3))
+  println(m.both(4))
+}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/m.silt b/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/m.silt
deleted file mode 100644
index 90cdf003b..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/m.silt
+++ /dev/null
@@ -1,5 +0,0 @@
-import a
-
-pub fn both(x: a) -> String where a: a.Tag {
-  "{x.tag()} {x.tag()}"
-}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/main.silt b/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/main.silt
deleted file mode 100644
index a9baccbca..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_of_a_module_imported_by_an_import/main.silt
+++ /dev/null
@@ -1,8 +0,0 @@
--- `main` imports `m`, which imports the trait's module: the trait's
--- methods are called here without an import of its own.
-import m
-
-fn main() {
-  println(3.tag())
-  println(m.both(4))
-}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/a.silt b/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/a.silt
deleted file mode 100644
index fb4f94943..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/a.silt
+++ /dev/null
@@ -1,16 +0,0 @@
-pub trait Tag {
-  fn tag(self) -> String
-  fn tagged(self) -> String {
-    "<{self.tag()}>"
-  }
-}
-
-trait Tag for Int {
-  fn tag(self) -> String {
-    "int {self}"
-  }
-}
-
-pub fn touch() -> Int {
-  0
-}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/c.silt b/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/c.silt
deleted file mode 100644
index 71fbc1b5f..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/c.silt
+++ /dev/null
@@ -1,3 +0,0 @@
-pub fn v() -> String {
-  3.tagged()
-}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/main.silt b/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/main.silt
deleted file mode 100644
index a8c144782..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_after/main.silt
+++ /dev/null
@@ -1,17 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'tagged' on type Int
--- stderr-contains: trait 'Tag' of module 'a' has a method 'tagged' for this type; import 'a' to call it
--- A module calls the methods of the traits whose modules it imports
--- (or they import, and so on). `c` does not import `a`: whether `a`
--- was checked before `c` or after it, `c` has no method `tagged`.
--- (It once had it when an earlier import had brought the impl in.) The
--- help that names the module is made once all modules are checked: it
--- is there in both orders.
-import c
-import a
-
-fn main() {
-  println(c.v())
-  println(a.touch())
-}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/a.silt b/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/a.silt
deleted file mode 100644
index fb4f94943..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/a.silt
+++ /dev/null
@@ -1,16 +0,0 @@
-pub trait Tag {
-  fn tag(self) -> String
-  fn tagged(self) -> String {
-    "<{self.tag()}>"
-  }
-}
-
-trait Tag for Int {
-  fn tag(self) -> String {
-    "int {self}"
-  }
-}
-
-pub fn touch() -> Int {
-  0
-}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/c.silt b/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/c.silt
deleted file mode 100644
index 71fbc1b5f..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/c.silt
+++ /dev/null
@@ -1,3 +0,0 @@
-pub fn v() -> String {
-  3.tagged()
-}
diff --git a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/main.silt b/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/main.silt
deleted file mode 100644
index 37b761782..000000000
--- a/tests/golden/typecheck/modules/method_reach__a_trait_out_of_reach__imported_before/main.silt
+++ /dev/null
@@ -1,15 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown method 'tagged' on type Int
--- stderr-contains: trait 'Tag' of module 'a' has a method 'tagged' for this type; import 'a' to call it
--- A module calls the methods of the traits whose modules it imports
--- (or they import, and so on). `c` does not import `a`: whether `a`
--- was checked before `c` or after it, `c` has no method `tagged`.
--- (It once had it when an earlier import had brought the impl in.)
-import a
-import c
-
-fn main() {
-  println(c.v())
-  println(a.touch())
-}
diff --git a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/c.silt b/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/c.silt
deleted file mode 100644
index 9315c57a7..000000000
--- a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/c.silt
+++ /dev/null
@@ -1,9 +0,0 @@
-import shapes
-
-pub fn on_a_value() -> Int {
-  shapes.Square { side: 2 }.area()
-}
-
-pub fn through_the_type() -> Int {
-  shapes.Square.area(shapes.Square { side: 3 })
-}
diff --git a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/main.silt b/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/main.silt
deleted file mode 100644
index 98436383a..000000000
--- a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/main.silt
+++ /dev/null
@@ -1,14 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: unknown field or method 'area' on type shapes.Square
--- stderr-contains: type 'shapes.Square' has no method 'area'
--- stderr-contains: trait 'Area' of module 'traits' has a method 'area' for this type; import 'traits' to call it
--- The help names the module to import for a method called on a value
--- of a declared type and through the type, with the trait's module
--- checked after the caller.
-import c
-import traits
-
-fn main() {
-  println(c.on_a_value() + c.through_the_type() + traits.touch())
-}
diff --git a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/shapes.silt b/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/shapes.silt
deleted file mode 100644
index 736894780..000000000
--- a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/shapes.silt
+++ /dev/null
@@ -1,3 +0,0 @@
-pub type Square {
-  side: Int,
-}
diff --git a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/traits.silt b/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/traits.silt
deleted file mode 100644
index 438d78276..000000000
--- a/tests/golden/typecheck/modules/method_reach__the_help_for_a_type_of_a_module/traits.silt
+++ /dev/null
@@ -1,15 +0,0 @@
-import shapes
-
-pub trait Area {
-  fn area(self) -> Int
-}
-
-trait Area for shapes.Square {
-  fn area(self) -> Int {
-    self.side * self.side
-  }
-}
-
-pub fn touch() -> Int {
-  0
-}
diff --git a/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/c.silt b/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/c.silt
deleted file mode 100644
index 032730bc9..000000000
--- a/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/c.silt
+++ /dev/null
@@ -1,5 +0,0 @@
-import shapes
-
-pub fn on_a_value() -> Int {
-  shapes.Square { side: 2 }.area()
-}
diff --git a/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/main.silt b/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/main.silt
deleted file mode 100644
index 1e10a6027..000000000
--- a/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/main.silt
+++ /dev/null
@@ -1,26 +0,0 @@
--- cmd: check
--- exit: 1
--- verdict: same
--- stderr-contains: c.silt:4:3
--- stderr-contains: unknown field or method 'area' on type shapes.Square
--- stderr-contains: trait 'Area' of module 'main' has a method 'area' for this type, but 'main' imports this module and cannot be imported by it
--- stderr-not-contains: import 'main' to call it
--- The trait that has the method is declared in a module that imports
--- the one that calls it: importing it there would be a cycle, so the
--- help does not say to. It says where the trait would have to be.
-import c
-import shapes
-
-pub trait Area {
-  fn area(self) -> Int
-}
-
-trait Area for shapes.Square {
-  fn area(self) -> Int {
-    self.side * self.side
-  }
-}
-
-fn main() {
-  println(c.on_a_value())
-}
diff --git a/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/shapes.silt b/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/shapes.silt
deleted file mode 100644
index 736894780..000000000
--- a/tests/golden/typecheck/modules/method_reach__the_trait_is_in_a_module_that_imports_this_one/shapes.silt
+++ /dev/null
@@ -1,3 +0,0 @@
-pub type Square {
-  side: Int,
-}
diff --git a/tests/golden/typecheck/operators/compare__tuple_holding_a_function.silt b/tests/golden/typecheck/operators/compare__tuple_holding_a_function.silt
index 14b16f39e..31488fbe6 100644
--- a/tests/golden/typecheck/operators/compare__tuple_holding_a_function.silt
+++ b/tests/golden/typecheck/operators/compare__tuple_holding_a_function.silt
@@ -10,5 +10,5 @@ fn main() {
   println((1, f) < (1, f))
   println(lt((1, f), (2, f)))
   println(list.sort([(1, #{ "a": 1 })]))
-  println((1, #[1]).compare((1, #[2])))
+  println(Compare.compare((1, #[1]), (1, #[2])))
 }
diff --git a/tests/golden/typecheck/operators/compare__tuples_bool_and_unit_are_ordered.silt b/tests/golden/typecheck/operators/compare__tuples_bool_and_unit_are_ordered.silt
index 750d0702b..a9e92c33d 100644
--- a/tests/golden/typecheck/operators/compare__tuples_bool_and_unit_are_ordered.silt
+++ b/tests/golden/typecheck/operators/compare__tuples_bool_and_unit_are_ordered.silt
@@ -4,16 +4,16 @@
 import list
 type Pair { t: (Int, Int) }
 fn lt(x: a, y: a) -> Bool where a: Compare { x < y }
-fn cmp(x: a, y: a) -> Int where a: Compare { x.compare(y) }
+fn cmp(x: a, y: a) -> Int where a: Compare { Compare.compare(x, y) }
 fn less(x, y) { x <= y }
 fn main() {
   println((1, "a") < (1, "b"))
   println((2, 1) >= (1, 9))
-  println((1, 2).compare((1, 3)))
+  println(Compare.compare((1, 2), (1, 3)))
   println(false < true)
-  println(true.compare(false))
+  println(Compare.compare(true, false))
   println(() <= ())
-  println(().compare(()))
+  println(Compare.compare((), ()))
   println(lt((1, true), (1, false)))
   println(cmp((1, (2, "x")), (1, (2, "x"))))
   println(lt(false, true))
diff --git a/tests/golden/typecheck/operators/type_domain__field_access_on_int.silt b/tests/golden/typecheck/operators/type_domain__field_access_on_int.silt
index 07c71c88e..25a9a4881 100644
--- a/tests/golden/typecheck/operators/type_domain__field_access_on_int.silt
+++ b/tests/golden/typecheck/operators/type_domain__field_access_on_int.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: unknown method 'foo'
+-- stderr-contains: type 'Int' has no field 'foo'
 fn main() {
   let x = 42
   let _ = x.foo
diff --git a/tests/golden/typecheck/operators/type_domain__record_wrong_field.silt b/tests/golden/typecheck/operators/type_domain__record_wrong_field.silt
index 905e67747..f14db7fdb 100644
--- a/tests/golden/typecheck/operators/type_domain__record_wrong_field.silt
+++ b/tests/golden/typecheck/operators/type_domain__record_wrong_field.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: unknown field or method 'z' on type Point
+-- stderr-contains: error[type]: type 'Point' has no field 'z'
 type Point { x: Int, y: Int }
 fn main() {
   let p = Point { x: 1, y: 2 }
diff --git a/tests/golden/typecheck/ranges/round92_range_hash__equal_over_cap_ranges_hash_equal.silt b/tests/golden/typecheck/ranges/round92_range_hash__equal_over_cap_ranges_hash_equal.silt
index f9285c970..9a0023994 100644
--- a/tests/golden/typecheck/ranges/round92_range_hash__equal_over_cap_ranges_hash_equal.silt
+++ b/tests/golden/typecheck/ranges/round92_range_hash__equal_over_cap_ranges_hash_equal.silt
@@ -3,5 +3,5 @@ fn main() {
   let a = 0..4000000000
   let b = 0..4000000000
   println(a == b)
-  println(a.hash() == b.hash())
+  println(Hash.hash(a) == Hash.hash(b))
 }
diff --git a/tests/golden/typecheck/ranges/round92_range_hash__huge_range_hash_completes.silt b/tests/golden/typecheck/ranges/round92_range_hash__huge_range_hash_completes.silt
index 90a2bc93c..1baa2600b 100644
--- a/tests/golden/typecheck/ranges/round92_range_hash__huge_range_hash_completes.silt
+++ b/tests/golden/typecheck/ranges/round92_range_hash__huge_range_hash_completes.silt
@@ -1,10 +1,10 @@
 -- Hashing a ~4e9-element range (and one near i64::MAX) is closed-form and finishes promptly.
 fn main() {
   let r = 0..4000000000
-  let h = r.hash()
+  let h = Hash.hash(r)
   println("hashed ok")
   let big = 0..9223372036854775806
-  let h2 = big.hash()
+  let h2 = Hash.hash(big)
   println("hashed max ok")
   println(h == h)
   println(h2 == h2)
diff --git a/tests/golden/typecheck/ranges/round92_range_hash__nested_huge_range_hash_completes.silt b/tests/golden/typecheck/ranges/round92_range_hash__nested_huge_range_hash_completes.silt
index fadb87dbb..17dcf3362 100644
--- a/tests/golden/typecheck/ranges/round92_range_hash__nested_huge_range_hash_completes.silt
+++ b/tests/golden/typecheck/ranges/round92_range_hash__nested_huge_range_hash_completes.silt
@@ -2,10 +2,10 @@
 type R { xs: List(Int) }
 fn main() {
   let t = (1, 0..4000000000)
-  let th = t.hash()
+  let th = Hash.hash(t)
   println("tuple hashed ok")
   let r = R { xs: 0..4000000000 }
-  let rh = r.hash()
+  let rh = Hash.hash(r)
   println("record hashed ok")
   println(th == th)
   println(rh == rh)
diff --git a/tests/golden/typecheck/ranges/round92_range_hash__small_range_list_hash_contract.silt b/tests/golden/typecheck/ranges/round92_range_hash__small_range_list_hash_contract.silt
index b19a9edf0..14d4204ed 100644
--- a/tests/golden/typecheck/ranges/round92_range_hash__small_range_list_hash_contract.silt
+++ b/tests/golden/typecheck/ranges/round92_range_hash__small_range_list_hash_contract.silt
@@ -1,4 +1,4 @@
 -- Within the cap, a range hashes equal to the equal list.
 fn main() {
-  println((1..5).hash() == [1, 2, 3, 4, 5].hash())
+  println(Hash.hash(1..5) == Hash.hash([1, 2, 3, 4, 5]))
 }
diff --git a/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_const_on_range.silt b/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_const_on_range.silt
index afc98a39f..a72406141 100644
--- a/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_const_on_range.silt
+++ b/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_const_on_range.silt
@@ -2,5 +2,5 @@ trait Foo { fn bar(self) -> Int }
 trait Foo for List(a) { fn bar(self) -> Int { 42 } }
 fn main() {
     let r = 1..5
-    println(r.bar())
+    println(Foo.bar(r))
 }
diff --git a/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_on_range_literal.silt b/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_on_range_literal.silt
index ffa7c721d..0f7f732eb 100644
--- a/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_on_range_literal.silt
+++ b/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_on_range_literal.silt
@@ -3,5 +3,5 @@ trait Sum { fn sum_of(self) -> Int }
 type Ints = List(Int)
 trait Sum for Ints { fn sum_of(self) -> Int { list.sum(self) } }
 fn main() {
-    println((2..4).sum_of())
+    println(Sum.sum_of(2..4))
 }
diff --git a/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_uses_self_on_range.silt b/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_uses_self_on_range.silt
index 09173be13..cbb2a66f5 100644
--- a/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_uses_self_on_range.silt
+++ b/tests/golden/typecheck/ranges/vm_range_receiver_trait_method__list_impl_uses_self_on_range.silt
@@ -4,5 +4,5 @@ type Ints = List(Int)
 trait Sum for Ints { fn sum_of(self) -> Int { list.sum(self) } }
 fn main() {
     let r = 1..5
-    println(r.sum_of())
+    println(Sum.sum_of(r))
 }
diff --git a/tests/golden/typecheck/records/inference_round26__field_access_no_near_match.silt b/tests/golden/typecheck/records/inference_round26__field_access_no_near_match.silt
index a026a74a7..1103500cb 100644
--- a/tests/golden/typecheck/records/inference_round26__field_access_no_near_match.silt
+++ b/tests/golden/typecheck/records/inference_round26__field_access_no_near_match.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: unknown field or method 'completelydifferent' on type User
+-- stderr-contains: error[type]: type 'User' has no field 'completelydifferent'
 -- stderr-not-contains: did you mean
 type User { name: String, age: Int }
 fn main() {
diff --git a/tests/golden/typecheck/records/inference_round26__field_access_typo_suggests.silt b/tests/golden/typecheck/records/inference_round26__field_access_typo_suggests.silt
index 2a4f94f63..a0f9a4451 100644
--- a/tests/golden/typecheck/records/inference_round26__field_access_typo_suggests.silt
+++ b/tests/golden/typecheck/records/inference_round26__field_access_typo_suggests.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: unknown field or method 'nam' on type User
+-- stderr-contains: error[type]: type 'User' has no field 'nam'
 -- stderr-contains: did you mean `name`?
 type User { name: String, age: Int }
 fn main() {
diff --git a/tests/golden/typecheck/records/nominal__open_row_needs_its_listed_fields.silt b/tests/golden/typecheck/records/nominal__open_row_needs_its_listed_fields.silt
index 3ec0816b2..9ae462118 100644
--- a/tests/golden/typecheck/records/nominal__open_row_needs_its_listed_fields.silt
+++ b/tests/golden/typecheck/records/nominal__open_row_needs_its_listed_fields.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: record Person has no field 'email'
+-- stderr-contains: error[type]: type 'Person' has no field 'email'
 -- stderr-contains: error[type]: type mismatch: expected String, got Int
 type Person { name: String, age: Int }
 fn email_of(p: {email: String, ...r}) -> String { p.email }
diff --git a/tests/golden/typecheck/records/nominal__through_an_open_row_stays_itself.silt b/tests/golden/typecheck/records/nominal__through_an_open_row_stays_itself.silt
index be9003a0a..113e37061 100644
--- a/tests/golden/typecheck/records/nominal__through_an_open_row_stays_itself.silt
+++ b/tests/golden/typecheck/records/nominal__through_an_open_row_stays_itself.silt
@@ -10,7 +10,7 @@ fn older(p: Person) -> Person { p.{ age: p.age + 1 } }
 fn main() {
   let q = id_name(Person { name: "Bob", age: 42 })
   println(q.age)
-  println(q.greet())
+  println(Greet.greet(q))
   println(older(q).age)
   println(name_of(q))
   match q { Person { name, age } -> println("{name} {age}") }
diff --git a/tests/golden/typecheck/records/round73_typechecker_fixes__anon_record_no_user_trait_bypass.silt b/tests/golden/typecheck/records/round73_typechecker_fixes__anon_record_no_user_trait_bypass.silt
index e33e8a8ba..060d8aa31 100644
--- a/tests/golden/typecheck/records/round73_typechecker_fixes__anon_record_no_user_trait_bypass.silt
+++ b/tests/golden/typecheck/records/round73_typechecker_fixes__anon_record_no_user_trait_bypass.silt
@@ -7,7 +7,7 @@ trait MyTrait {
 trait MyTrait for Int {
   fn my_ident(self) -> Int { self }
 }
-fn use_it(x: a) -> Int where a: MyTrait { x.my_ident() }
+fn use_it(x: a) -> Int where a: MyTrait { MyTrait.my_ident(x) }
 fn main() {
     let r = {x: 1, y: 2}
     let _ = use_it(r)
diff --git a/tests/golden/typecheck/records/round81_anon_record_typeck_fixes__field_access_typo_hint.silt b/tests/golden/typecheck/records/round81_anon_record_typeck_fixes__field_access_typo_hint.silt
index 47d4f3a5e..7466c6ab7 100644
--- a/tests/golden/typecheck/records/round81_anon_record_typeck_fixes__field_access_typo_hint.silt
+++ b/tests/golden/typecheck/records/round81_anon_record_typeck_fixes__field_access_typo_hint.silt
@@ -1,7 +1,7 @@
 -- cmd: check
 -- exit: 1
--- A typo'd field on an anonymous record keeps its wording and gains a did-you-mean hint.
--- stderr-contains: anon record has no field 'nam'
+-- A typo'd field on an anonymous record is named by its type and gains a did-you-mean hint.
+-- stderr-contains: type '{name: String}' has no field 'nam'
 -- stderr-contains: did you mean `name`?
 fn main() {
   let r = {name: "x"}
diff --git a/tests/golden/typecheck/records/rows__a_method_is_not_a_field_of_the_row.silt b/tests/golden/typecheck/records/rows__a_method_is_not_a_field_of_the_row.silt
index da1b708b1..9a0ddd1bb 100644
--- a/tests/golden/typecheck/records/rows__a_method_is_not_a_field_of_the_row.silt
+++ b/tests/golden/typecheck/records/rows__a_method_is_not_a_field_of_the_row.silt
@@ -1,12 +1,11 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: record Person has no field 'greet'
--- stderr-contains: help: 'greet' is a method of `Person`, and what is asked for here is a record with a field 'greet'
--- stderr-contains: annotate it, `p: Person`
--- stderr-contains: 18:17
+-- stderr-contains: error[type]: type 'Person' has no field 'greet'
+-- stderr-contains: help: `greet` is a method of trait `Greet`: call it as `Greet.greet(x)`
+-- stderr-contains: 17:17
 -- A value whose field is read is a record, and `p.greet()` on it calls
--- a function its field `greet` holds: a `Person` has a method of that
--- name, not a field, and the error says so.
+-- a function its field `greet` holds: a `Person` has no such field, and
+-- the help names the trait whose method `greet` is.
 type Person { name: String, age: Int }
 trait Greet { fn greet(self) -> String }
 trait Greet for Person { fn greet(self) -> String { "I am {self.name}" } }
diff --git a/tests/golden/typecheck/records/rows__an_anonymous_record_has_no_written_impl.silt b/tests/golden/typecheck/records/rows__an_anonymous_record_has_no_written_impl.silt
index 41fd1f5a2..8be9ee4b5 100644
--- a/tests/golden/typecheck/records/rows__an_anonymous_record_has_no_written_impl.silt
+++ b/tests/golden/typecheck/records/rows__an_anonymous_record_has_no_written_impl.silt
@@ -7,8 +7,8 @@
 -- A message writes an anonymous record's type, not a name for it.
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "i" } }
-fn f(x) { x.greet() }
-fn g(x: a) -> String where a: Greet { x.greet() }
+fn f(x) { Greet.greet(x) }
+fn g(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   println(f({name: "a"}))
   println(g({name: "a"}))
diff --git a/tests/golden/typecheck/records/rows__annotation_row_is_rigid.silt b/tests/golden/typecheck/records/rows__annotation_row_is_rigid.silt
index 227eaeece..65717b6c6 100644
--- a/tests/golden/typecheck/records/rows__annotation_row_is_rigid.silt
+++ b/tests/golden/typecheck/records/rows__annotation_row_is_rigid.silt
@@ -1,6 +1,6 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: anon record has no field 'age'
+-- stderr-contains: error[type]: type '{name: String, ...r}' has no field 'age'
 -- stderr-contains: error[type]: type mismatch: expected {name: String, ...r}, got {name: String}
 -- The row variable of an annotation is whatever the caller's record
 -- has: the function may not read a field behind it, nor return a
diff --git a/tests/golden/typecheck/records/rows__spread_over_a_row_no_signature_owns.silt b/tests/golden/typecheck/records/rows__spread_over_a_row_no_signature_owns.silt
index 0cb50fd75..dd10e4544 100644
--- a/tests/golden/typecheck/records/rows__spread_over_a_row_no_signature_owns.silt
+++ b/tests/golden/typecheck/records/rows__spread_over_a_row_no_signature_owns.silt
@@ -12,5 +12,5 @@ trait Tag { fn tag(self, p: {name: String, ...r}) -> {name: String, ...r} }
 trait Tag for Int { fn tag(self, p: {name: String, ...r}) -> {name: String, ...r} { {...p} } }
 fn main() {
   let f: Fn({name: String, ...r}) -> {name: String, ...r} = { p -> {...p} }
-  println(1.tag(Person { name: "a", age: 1 }))
+  println(Tag.tag(1, Person { name: "a", age: 1 }))
 }
diff --git a/tests/golden/typecheck/records/rows__trait_method_row_accepts.silt b/tests/golden/typecheck/records/rows__trait_method_row_accepts.silt
index 784ac67ca..b13fd1fb9 100644
--- a/tests/golden/typecheck/records/rows__trait_method_row_accepts.silt
+++ b/tests/golden/typecheck/records/rows__trait_method_row_accepts.silt
@@ -6,7 +6,7 @@ trait Keep { fn keep(self, p: {name: String, ...r}) -> {name: String, ...r} { p
 trait Keep for Int {}
 type Person { name: String, age: Int }
 fn main() {
-  println(1.name_of({name: "a", age: 1}))
-  println(1.keep(Person { name: "b", age: 2 }).age)
-  println(1.keep({name: "c", z: true}).z)
+  println(Namer.name_of(1, {name: "a", age: 1}))
+  println(Keep.keep(1, Person { name: "b", age: 2 }).age)
+  println(Keep.keep(1, {name: "c", z: true}).z)
 }
diff --git a/tests/golden/typecheck/records/rows__trait_method_row_is_rigid.silt b/tests/golden/typecheck/records/rows__trait_method_row_is_rigid.silt
index 19a2fffba..5969692a1 100644
--- a/tests/golden/typecheck/records/rows__trait_method_row_is_rigid.silt
+++ b/tests/golden/typecheck/records/rows__trait_method_row_is_rigid.silt
@@ -1,10 +1,10 @@
 -- cmd: check
 -- exit: 1
--- stderr-contains: error[type]: anon record has no field 'age'
+-- stderr-contains: error[type]: type '{name: String, ...r}' has no field 'age'
 -- stderr-contains: error[type]: type mismatch: expected {name: String, ...r}, got {name: String}
 -- The row variable of a trait method's or an impl method's annotation
 -- is fixed inside the body, as in a function's signature.
 trait Namer { fn name_of(self, p: {name: String, ...r}) -> String }
 trait Namer for Bool { fn name_of(self, p: {name: String, ...r}) -> String { "{p.name} {p.age}" } }
 trait Bad { fn bad(self, p: {name: String, ...r}) -> {name: String, ...r} { {name: "x"} } }
-fn main() { println(true.name_of({name: "a", age: 1})) }
+fn main() { println(Namer.name_of(true, {name: "a", age: 1})) }
diff --git a/tests/golden/typecheck/traits/default_method__body_checked_without_impl_using_it.silt b/tests/golden/typecheck/traits/default_method__body_checked_without_impl_using_it.silt
index b2b51ce08..0e3f71956 100644
--- a/tests/golden/typecheck/traits/default_method__body_checked_without_impl_using_it.silt
+++ b/tests/golden/typecheck/traits/default_method__body_checked_without_impl_using_it.silt
@@ -9,4 +9,4 @@ trait Area {
 }
 type Sq { side: Float }
 trait Area for Sq { fn area(self) -> Float { self.side * self.side } }
-fn main() { println(Sq { side: 2.0 }.area()) }
+fn main() { println(Area.area(Sq { side: 2.0 })) }
diff --git a/tests/golden/typecheck/traits/default_method__calls_trait_and_supertrait_methods.silt b/tests/golden/typecheck/traits/default_method__calls_trait_and_supertrait_methods.silt
index 0dda968ed..d53c3a3ba 100644
--- a/tests/golden/typecheck/traits/default_method__calls_trait_and_supertrait_methods.silt
+++ b/tests/golden/typecheck/traits/default_method__calls_trait_and_supertrait_methods.silt
@@ -3,9 +3,9 @@
 trait Named { fn name(self) -> String }
 trait Loud: Named {
   fn volume(self) -> Int
-  fn shout(self) -> String { "{self.name()}{self.bangs()}" }
+  fn shout(self) -> String { "{Named.name(self)}{Loud.bangs(self)}" }
   fn bangs(self) -> String {
-    match self.volume() > 1 {
+    match Loud.volume(self) > 1 {
       true -> "!!"
       false -> "!"
     }
@@ -21,6 +21,6 @@ trait Loud for Cat {
   fn bangs(self) -> String { "?" }
 }
 fn main() {
-  println(Dog { n: "rex" }.shout())
-  println(Cat { n: "tom" }.shout())
+  println(Loud.shout(Dog { n: "rex" }))
+  println(Loud.shout(Cat { n: "tom" }))
 }
diff --git a/tests/golden/typecheck/traits/default_method__uses_unpromised_field.silt b/tests/golden/typecheck/traits/default_method__uses_unpromised_field.silt
index 3eae69edd..f2a2b03ba 100644
--- a/tests/golden/typecheck/traits/default_method__uses_unpromised_field.silt
+++ b/tests/golden/typecheck/traits/default_method__uses_unpromised_field.silt
@@ -3,7 +3,7 @@
 -- A default method is checked once, in its trait: `Self` has what the
 -- trait and its supertraits promise, not the fields of the types that
 -- happen to implement it.
--- stderr-contains: no method 'label' found in trait constraints (Loud)
+-- stderr-contains: type 'Self' has no field 'label'
 -- stderr-contains: default_method__uses_unpromised_field.silt:10:32
 trait Loud {
   fn volume(self) -> Int
@@ -11,4 +11,4 @@ trait Loud {
 }
 type Dog { label: String }
 trait Loud for Dog { fn volume(self) -> Int { 2 } }
-fn main() { println(Dog { label: "rex" }.shout()) }
+fn main() { println(Loud.shout(Dog { label: "rex" })) }
diff --git a/tests/golden/typecheck/traits/field_method__default_method.silt b/tests/golden/typecheck/traits/field_method__default_method.silt
index 4aa71a3f6..de8bae59e 100644
--- a/tests/golden/typecheck/traits/field_method__default_method.silt
+++ b/tests/golden/typecheck/traits/field_method__default_method.silt
@@ -17,5 +17,5 @@ trait Run for H {
 fn main() {
   let h = H { run: 1, name: "n" }
   println(h.run)
-  println(h.stop())
+  println(Run.stop(h))
 }
diff --git a/tests/golden/typecheck/traits/field_method__impl_in_the_traits_module/runner.silt b/tests/golden/typecheck/traits/field_method__impl_in_the_traits_module/runner.silt
index 8cd921dfb..d5203391a 100644
--- a/tests/golden/typecheck/traits/field_method__impl_in_the_traits_module/runner.silt
+++ b/tests/golden/typecheck/traits/field_method__impl_in_the_traits_module/runner.silt
@@ -2,4 +2,4 @@ import shapes
 pub trait Run { fn run(self, x: Int) -> Int }
 trait Run for shapes.H { fn run(self, x: Int) -> Int { x + self.n } }
 trait Run for Int { fn run(self, x: Int) -> Int { self + x } }
-pub fn go(x: Int) -> Int { x.run(1) }
+pub fn go(x: Int) -> Int { Run.run(x, 1) }
diff --git a/tests/golden/typecheck/traits/field_method__supertrait_default_method.silt b/tests/golden/typecheck/traits/field_method__supertrait_default_method.silt
index 1a7f5c84a..986fe672b 100644
--- a/tests/golden/typecheck/traits/field_method__supertrait_default_method.silt
+++ b/tests/golden/typecheck/traits/field_method__supertrait_default_method.silt
@@ -9,5 +9,5 @@ type H { size: Int }
 trait Base for H {}
 trait Top for H { fn top(self) -> Int { self.size } }
 fn main() {
-  println(H { size: 2 }.top())
+  println(Top.top(H { size: 2 }))
 }
diff --git a/tests/golden/typecheck/traits/field_method__what_is_no_clash.silt b/tests/golden/typecheck/traits/field_method__what_is_no_clash.silt
index aed0738ba..8635c5c17 100644
--- a/tests/golden/typecheck/traits/field_method__what_is_no_clash.silt
+++ b/tests/golden/typecheck/traits/field_method__what_is_no_clash.silt
@@ -23,18 +23,18 @@ type H { run: Fn(Int) -> Int, area: Int }
 type Other { n: Int }
 trait Run for Other { fn run(self, x: Int) -> Int { self.n * x } }
 fn run(x: Int) -> Int { x * 2 }
-fn bounded(r: a, x: Int) -> Int where a: Run { r.run(x) }
-fn inferred(r, x) { r.run(x) }
+fn bounded(r: a, x: Int) -> Int where a: Run { Run.run(r, x) }
+fn inferred(r, x) { Run.run(r, x) }
 fn main() {
   let h = H { run: { x -> x + 1 }, area: 9 }
   println(h.run(1))
   println(1 |> h.run)
   println(h.area)
-  println(3.run(4))
-  println(Other { n: 5 }.run(2))
+  println(Run.run(3, 4))
+  println(Run.run(Other { n: 5 }, 2))
   println(bounded(Other { n: 5 }, 3))
   println(run(5))
-  println(Circle(2).area())
+  println(Area.area(Circle(2)))
   let anon = {run: { x -> x - 1 }}
   println(anon.run(0))
   let hs = [h, H { run: { x -> x * 10 }, area: 0 }]
diff --git a/tests/golden/typecheck/traits/field_method__written_method.silt b/tests/golden/typecheck/traits/field_method__written_method.silt
index d3e6e911a..c7f559574 100644
--- a/tests/golden/typecheck/traits/field_method__written_method.silt
+++ b/tests/golden/typecheck/traits/field_method__written_method.silt
@@ -8,13 +8,13 @@
 type H { run: Fn(Int) -> Int, n: Int }
 trait Run { fn run(self, x: Int) -> Int }
 trait Run for H { fn run(self, x: Int) -> Int { -1 } }
-fn bounded(r: a, x: Int) -> Int where a: Run { r.run(x) }
-fn inferred(r, x) { r.run(x) }
+fn bounded(r: a, x: Int) -> Int where a: Run { Run.run(r, x) }
+fn inferred(r, x) { Run.run(r, x) }
 fn main() {
   let h = H { run: { x -> x + 1 }, n: 0 }
   println(h.run(1))
   println(bounded(h, 1))
   println(inferred(h, 1))
-  let k = { r -> r.run(2) }
+  let k = { r -> Run.run(r, 2) }
   println(k(h))
 }
diff --git a/tests/golden/typecheck/traits/impl_method_bound__restates_a_supertrait.silt b/tests/golden/typecheck/traits/impl_method_bound__restates_a_supertrait.silt
index 295a16515..c3eda160f 100644
--- a/tests/golden/typecheck/traits/impl_method_bound__restates_a_supertrait.silt
+++ b/tests/golden/typecheck/traits/impl_method_bound__restates_a_supertrait.silt
@@ -5,9 +5,9 @@ trait Two: Greet { fn two(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Two for Int { fn two(self) -> String { "2" } }
 trait Sh { fn sh(self, x: a) -> String where a: Two }
-trait Sh for Bool { fn sh(self, x: a) -> String where a: Greet { x.greet() } }
-trait Sh for Int { fn sh(self, x: a) -> String { "{x.greet()}{x.two()}" } }
+trait Sh for Bool { fn sh(self, x: a) -> String where a: Greet { Greet.greet(x) } }
+trait Sh for Int { fn sh(self, x: a) -> String { "{Greet.greet(x)}{Two.two(x)}" } }
 fn main() {
-  println(true.sh(1))
-  println(1.sh(1))
+  println(Sh.sh(true, 1))
+  println(Sh.sh(1, 1))
 }
diff --git a/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.silt b/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.silt
index 2d877d65d..64f8e49f1 100644
--- a/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.silt
+++ b/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.silt
@@ -8,5 +8,5 @@ trait Conv(to) { fn conv(self) -> to }
 trait Conv(String) for Int { fn conv(self) -> String { "i" } }
 trait Conv(Int) for Bool { fn conv(self) -> Int { 1 } }
 trait Sh { fn sh(self, x: a) -> String where a: Conv(String) }
-trait Sh for Int { fn sh(self, x: a) -> String where a: Conv(Int) { "{x.conv()}" } }
-fn main() { println(1.sh(1)) }
+trait Sh for Int { fn sh(self, x: a) -> String where a: Conv(Int) { "{Conv.conv(x)}" } }
+fn main() { println(Sh.sh(1, 1)) }
diff --git a/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.stderr b/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.stderr
index 136e362bf..90cead629 100644
--- a/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.stderr
+++ b/tests/golden/typecheck/traits/impl_method_bound__trait_argument_differs.stderr
@@ -1,6 +1,6 @@
 error[type]: method 'sh' of the impl of 'Sh' for 'Int' adds the bound `a: Conv(Int)`, which the trait does not declare for it
  --> impl_method_bound__trait_argument_differs.silt:11:20
     |
- 11 | trait Sh for Int { fn sh(self, x: a) -> String where a: Conv(Int) { "{x.conv()}" } }
-    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ method 'sh' of the impl of 'Sh' for 'Int' adds the bound `a: Conv(Int)`, which the trait does not declare for it
+ 11 | trait Sh for Int { fn sh(self, x: a) -> String where a: Conv(Int) { "{Conv.conv(x)}" } }
+    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ method 'sh' of the impl of 'Sh' for 'Int' adds the bound `a: Conv(Int)`, which the trait does not declare for it
   = help: a call through the trait would not owe it: declare the bound on the method in trait 'Sh', or on the impl's header
diff --git a/tests/golden/typecheck/traits/multi_trait_bound__comma_form_accepts_both.silt b/tests/golden/typecheck/traits/multi_trait_bound__comma_form_accepts_both.silt
index b744de3a8..e4c88f996 100644
--- a/tests/golden/typecheck/traits/multi_trait_bound__comma_form_accepts_both.silt
+++ b/tests/golden/typecheck/traits/multi_trait_bound__comma_form_accepts_both.silt
@@ -13,9 +13,9 @@ trait MyOrd for Int {
   }
 }
 fn use_both(x: a, y: a) -> Int where a: MyEq, a: MyOrd {
-  match x.my_eq(y) {
+  match MyEq.my_eq(x, y) {
     true -> 0
-    false -> x.my_cmp(y)
+    false -> MyOrd.my_cmp(x, y)
   }
 }
 fn main() { println(use_both(5, 5)) }
diff --git a/tests/golden/typecheck/traits/multi_trait_bound__comma_form_rejects_only_one.silt b/tests/golden/typecheck/traits/multi_trait_bound__comma_form_rejects_only_one.silt
index e6cc215e0..752db1fa0 100644
--- a/tests/golden/typecheck/traits/multi_trait_bound__comma_form_rejects_only_one.silt
+++ b/tests/golden/typecheck/traits/multi_trait_bound__comma_form_rejects_only_one.silt
@@ -5,9 +5,9 @@ trait MyEq { fn my_eq(self, other: Self) -> Bool }
 trait MyOrd { fn my_cmp(self, other: Self) -> Int }
 trait MyEq for String { fn my_eq(self, other: String) -> Bool { self == other } }
 fn use_both(x: a, y: a) -> Int where a: MyEq, a: MyOrd {
-  match x.my_eq(y) {
+  match MyEq.my_eq(x, y) {
     true -> 0
-    false -> x.my_cmp(y)
+    false -> MyOrd.my_cmp(x, y)
   }
 }
 fn main() { println(use_both("a", "b")) }
diff --git a/tests/golden/typecheck/traits/multi_trait_bound__plus_form_accepts_both.silt b/tests/golden/typecheck/traits/multi_trait_bound__plus_form_accepts_both.silt
index 4ba2feea5..f76d17781 100644
--- a/tests/golden/typecheck/traits/multi_trait_bound__plus_form_accepts_both.silt
+++ b/tests/golden/typecheck/traits/multi_trait_bound__plus_form_accepts_both.silt
@@ -13,9 +13,9 @@ trait MyOrd for Int {
   }
 }
 fn use_both(x: a, y: a) -> Int where a: MyEq + MyOrd {
-  match x.my_eq(y) {
+  match MyEq.my_eq(x, y) {
     true -> 0
-    false -> x.my_cmp(y)
+    false -> MyOrd.my_cmp(x, y)
   }
 }
 fn main() { println(use_both(3, 7)) }
diff --git a/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_first_missing.silt b/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_first_missing.silt
index 3b3bb6b7c..0664a2938 100644
--- a/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_first_missing.silt
+++ b/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_first_missing.silt
@@ -15,9 +15,9 @@ trait MyOrd for Float {
   }
 }
 fn use_both(x: a, y: a) -> Int where a: MyEq + MyOrd {
-  match x.my_eq(y) {
+  match MyEq.my_eq(x, y) {
     true -> 0
-    false -> x.my_cmp(y)
+    false -> MyOrd.my_cmp(x, y)
   }
 }
 fn main() { println(use_both(1.0, 2.0)) }
diff --git a/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_only_one.silt b/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_only_one.silt
index 52ae2a997..b6fc16bce 100644
--- a/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_only_one.silt
+++ b/tests/golden/typecheck/traits/multi_trait_bound__plus_form_rejects_only_one.silt
@@ -5,9 +5,9 @@ trait MyEq { fn my_eq(self, other: Self) -> Bool }
 trait MyOrd { fn my_cmp(self, other: Self) -> Int }
 trait MyEq for String { fn my_eq(self, other: String) -> Bool { self == other } }
 fn use_both(x: a, y: a) -> Int where a: MyEq + MyOrd {
-  match x.my_eq(y) {
+  match MyEq.my_eq(x, y) {
     true -> 0
-    false -> x.my_cmp(y)
+    false -> MyOrd.my_cmp(x, y)
   }
 }
 fn main() { println(use_both("a", "b")) }
diff --git a/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_accepts.silt b/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_accepts.silt
index b3af66834..3f06b9da8 100644
--- a/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_accepts.silt
+++ b/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_accepts.silt
@@ -16,8 +16,8 @@ trait MyOrd for Int {
 trait MyShow for Int { fn my_show(self) -> String { "int" } }
 
 fn use_three(x: a, y: a) -> String where a: MyEq + MyOrd + MyShow {
-  match x.my_eq(y) {
-    true -> x.my_show()
+  match MyEq.my_eq(x, y) {
+    true -> MyShow.my_show(x)
     false -> "diff"
   }
 }
diff --git a/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_rejects_last_missing.silt b/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_rejects_last_missing.silt
index d8198a23f..ec49d9724 100644
--- a/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_rejects_last_missing.silt
+++ b/tests/golden/typecheck/traits/multi_trait_bound__three_bounds_rejects_last_missing.silt
@@ -8,8 +8,8 @@ trait MyShow { fn my_show(self) -> String }
 trait MyEq for Int { fn my_eq(self, other: Int) -> Bool { self == other } }
 trait MyOrd for Int { fn my_cmp(self, other: Int) -> Int { 0 } }
 fn use_three(x: a, y: a) -> String where a: MyEq + MyOrd + MyShow {
-  match x.my_eq(y) {
-    true -> x.my_show()
+  match MyEq.my_eq(x, y) {
+    true -> MyShow.my_show(x)
     false -> "diff"
   }
 }
diff --git a/tests/golden/typecheck/traits/no_self__a_call_on_a_type_has_every_method.stderr b/tests/golden/typecheck/traits/no_self__a_call_on_a_type_has_every_method.stderr
deleted file mode 100644
index 67b5d8cc3..000000000
--- a/tests/golden/typecheck/traits/no_self__a_call_on_a_type_has_every_method.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[type]: ambiguous method 'decode' on type 'String': provided by traits Mk, Rd
- --> no_self__a_call_on_a_type_has_every_method.silt:49:19
-    |
- 49 |   let t: String = String.decode(4)
-    |                   ^^^^^^^^^^^^^ ambiguous method 'decode' on type 'String': provided by traits Mk, Rd
-  = help: say which is meant: call it through a function bounded by the trait you mean, `where a: Mk`
-
-error[type]: method `make` takes no `self` — call it on the type instead: `Int.make(..)`
- --> no_self__a_call_on_a_type_has_every_method.silt:51:11
-    |
- 51 |   println(7.make(1))
-    |           ^^^^^^ method `make` takes no `self` — call it on the type instead: `Int.make(..)`
diff --git a/tests/golden/typecheck/traits/no_self__a_method_without_self_is_no_candidate_on_a_value.silt b/tests/golden/typecheck/traits/no_self__a_method_without_self_is_no_candidate_on_a_value.silt
index 36c5be257..a131a3d4e 100644
--- a/tests/golden/typecheck/traits/no_self__a_method_without_self_is_no_candidate_on_a_value.silt
+++ b/tests/golden/typecheck/traits/no_self__a_method_without_self_is_no_candidate_on_a_value.silt
@@ -42,11 +42,11 @@ trait Rd for P {
 }
 
 fn bounded(x: a) -> Int where a: Mk, a: Rd {
-  x.decode(10)
+  Rd.decode(x, 10)
 }
 
 fn unknown(x) {
-  x.decode(20)
+  Rd.decode(x, 20)
 }
 
 fn first(x: a) -> a {
@@ -54,15 +54,15 @@ fn first(x: a) -> a {
 }
 
 fn later(x: a) -> Int where a: Mk + Rd {
-  let f = { y -> first(y).decode(30) }
+  let f = { y -> Rd.decode(first(y), 30) }
   f(x)
 }
 
 fn main() {
   let s = "a"
-  println(s.decode(3))
+  println(Rd.decode(s, 3))
   println(bounded(s))
   println(unknown(s))
   println(later(s))
-  println(P { n: 5 }.decode(40))
+  println(Rd.decode(P { n: 5 }, 40))
 }
diff --git a/tests/golden/typecheck/traits/parameterized_traits__concrete_method_call.silt b/tests/golden/typecheck/traits/parameterized_traits__concrete_method_call.silt
index 935837a3d..7554c340f 100644
--- a/tests/golden/typecheck/traits/parameterized_traits__concrete_method_call.silt
+++ b/tests/golden/typecheck/traits/parameterized_traits__concrete_method_call.silt
@@ -14,6 +14,6 @@ trait Convertible(Int) for String {
 }
 
 fn main() {
-    let n: Int = "42".convert()
+    let n: Int = Convertible.convert("42")
     println(n)
 }
diff --git a/tests/golden/typecheck/traits/parameterized_traits__generic_fn_constraint.silt b/tests/golden/typecheck/traits/parameterized_traits__generic_fn_constraint.silt
index a4b33f85d..a27e30c85 100644
--- a/tests/golden/typecheck/traits/parameterized_traits__generic_fn_constraint.silt
+++ b/tests/golden/typecheck/traits/parameterized_traits__generic_fn_constraint.silt
@@ -14,7 +14,7 @@ trait Convertible(Int) for String {
 }
 
 fn unpack(x: a, type b) -> b where a: Convertible(b) {
-    x.convert()
+    Convertible.convert(x)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/traits/parameterized_traits__multiple_impls.silt b/tests/golden/typecheck/traits/parameterized_traits__multiple_impls.silt
index 6b7a1dfed..c34e17774 100644
--- a/tests/golden/typecheck/traits/parameterized_traits__multiple_impls.silt
+++ b/tests/golden/typecheck/traits/parameterized_traits__multiple_impls.silt
@@ -11,8 +11,8 @@ trait Wrap(String) for String {
 }
 
 fn main() {
-    let a: Int = 1.wrap()
-    let b: String = "x".wrap()
+    let a: Int = Wrap.wrap(1)
+    let b: String = Wrap.wrap("x")
     println(a)
     println(b)
 }
diff --git a/tests/golden/typecheck/traits/recursive_trait_dispatch__chained_cross_trait.silt b/tests/golden/typecheck/traits/recursive_trait_dispatch__chained_cross_trait.silt
index e62b94747..9c30807ce 100644
--- a/tests/golden/typecheck/traits/recursive_trait_dispatch__chained_cross_trait.silt
+++ b/tests/golden/typecheck/traits/recursive_trait_dispatch__chained_cross_trait.silt
@@ -4,6 +4,6 @@ trait Quadruple { fn quad(self) -> Int }
 
 trait Halve for Int { fn halve(self) -> Int { self / 2 } }
 trait Double for Int { fn double(self) -> Int { self * 2 } }
-trait Quadruple for Int { fn quad(self) -> Int { self.double().double() } }
+trait Quadruple for Int { fn quad(self) -> Int { Double.double(Double.double(self)) } }
 
-fn main() { println((5).quad()) }
+fn main() { println(Quadruple.quad(5)) }
diff --git a/tests/golden/typecheck/traits/recursive_trait_dispatch__cross_trait_on_self.silt b/tests/golden/typecheck/traits/recursive_trait_dispatch__cross_trait_on_self.silt
index ef916e5f2..8dae3edc3 100644
--- a/tests/golden/typecheck/traits/recursive_trait_dispatch__cross_trait_on_self.silt
+++ b/tests/golden/typecheck/traits/recursive_trait_dispatch__cross_trait_on_self.silt
@@ -5,7 +5,7 @@ trait Loud for Int { fn loud(self) -> String { "INT" } }
 
 trait Combined { fn combined(self) -> String }
 trait Combined for Int {
-  fn combined(self) -> String { "{self.greet()}-{self.loud()}" }
+  fn combined(self) -> String { "{Greet.greet(self)}-{Loud.loud(self)}" }
 }
 
-fn main() { println((1).combined()) }
+fn main() { println(Combined.combined(1)) }
diff --git a/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box.silt b/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box.silt
index 5b89eeca5..da1789e26 100644
--- a/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box.silt
+++ b/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box.silt
@@ -3,8 +3,8 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "leaf" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> "[{inner.greet()}]" }
+    match self { Box(inner) -> "[{Greet.greet(inner)}]" }
   }
 }
 
-fn main() { println(Box(Box(99)).greet()) }
+fn main() { println(Greet.greet(Box(Box(99)))) }
diff --git a/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box_rejects_innermost.silt b/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box_rejects_innermost.silt
index a7c6ba663..aaa693d20 100644
--- a/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box_rejects_innermost.silt
+++ b/tests/golden/typecheck/traits/recursive_trait_dispatch__nested_box_rejects_innermost.silt
@@ -6,11 +6,11 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "leaf" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> "[{inner.greet()}]" }
+    match self { Box(inner) -> "[{Greet.greet(inner)}]" }
   }
 }
 
 fn main() {
   let b = Box(Box("x"))
-  println(b.greet())
+  println(Greet.greet(b))
 }
diff --git a/tests/golden/typecheck/traits/recursive_trait_dispatch__same_trait_through_other_impl.silt b/tests/golden/typecheck/traits/recursive_trait_dispatch__same_trait_through_other_impl.silt
index 2a612bf88..211996754 100644
--- a/tests/golden/typecheck/traits/recursive_trait_dispatch__same_trait_through_other_impl.silt
+++ b/tests/golden/typecheck/traits/recursive_trait_dispatch__same_trait_through_other_impl.silt
@@ -3,8 +3,8 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int-leaf" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> "box({inner.greet()})" }
+    match self { Box(inner) -> "box({Greet.greet(inner)})" }
   }
 }
 
-fn main() { println(Box(7).greet()) }
+fn main() { println(Greet.greet(Box(7))) }
diff --git a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__list_arg.silt b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__list_arg.silt
index bb89da4f6..6147040ba 100644
--- a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__list_arg.silt
+++ b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__list_arg.silt
@@ -4,9 +4,9 @@ trait Carry(c) { fn carry(self) -> c }
 trait Holds(b): Carry(List(b)) { fn hold(self) -> b }
 trait Carry(List(Int)) for Bag { fn carry(self) -> List(Int) { [1, 2] } }
 trait Holds(Int) for Bag { fn hold(self) -> Int { 1 } }
-fn first_carried(x: t) -> List(Int) where t: Holds(Int) { x.carry() }
+fn first_carried(x: t) -> List(Int) where t: Holds(Int) { Carry.carry(x) }
 fn main() {
   let b = Bag { n: 1 }
-  println("{b.hold()}")
+  println("{Holds.hold(b)}")
   println("{first_carried(b)}")
 }
diff --git a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__map_arg.silt b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__map_arg.silt
index 0d9bc1364..2924071fe 100644
--- a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__map_arg.silt
+++ b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__map_arg.silt
@@ -6,6 +6,6 @@ trait Carry(Map(String, Int)) for Bag { fn carry(self) -> Map(String, Int) { #{"
 trait Holds(Int) for Bag { fn hold(self) -> Int { 1 } }
 fn main() {
   let b = Bag { n: 1 }
-  println("{b.hold()}")
-  println("{b.carry()}")
+  println("{Holds.hold(b)}")
+  println("{Carry.carry(b)}")
 }
diff --git a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__mismatched_list_arg_rejected.silt b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__mismatched_list_arg_rejected.silt
index 52965db2c..0a121514f 100644
--- a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__mismatched_list_arg_rejected.silt
+++ b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__mismatched_list_arg_rejected.silt
@@ -8,4 +8,4 @@ trait Carry(c) { fn carry(self) -> c }
 trait Holds(b): Carry(List(b)) { fn hold(self) -> b }
 trait Carry(List(String)) for Bag { fn carry(self) -> List(String) { ["x"] } }
 trait Holds(Int) for Bag { fn hold(self) -> Int { 1 } }
-fn main() { println("{(Bag { n: 1 }).hold()}") }
+fn main() { println("{Holds.hold(Bag { n: 1 })}") }
diff --git a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__unit_arg.silt b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__unit_arg.silt
index 2f5adb1ff..363a28a67 100644
--- a/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__unit_arg.silt
+++ b/tests/golden/typecheck/traits/round101_supertrait_container_arg_canon__unit_arg.silt
@@ -4,4 +4,4 @@ trait Carry(c) { fn carry(self) -> c }
 trait Holds(b): Carry(Unit) { fn hold(self) -> b }
 trait Carry(Unit) for Bag { fn carry(self) -> Unit { () } }
 trait Holds(Int) for Bag { fn hold(self) -> Int { 1 } }
-fn main() { println("{(Bag { n: 1 }).hold()}") }
+fn main() { println("{Holds.hold(Bag { n: 1 })}") }
diff --git a/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__anon_record_rejected.silt b/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__anon_record_rejected.silt
index c34b6bdaa..541271141 100644
--- a/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__anon_record_rejected.silt
+++ b/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__anon_record_rejected.silt
@@ -6,7 +6,7 @@
 -- stderr-contains: type '{x: Int, y: Int}' does not implement trait 'MyTrait'
 trait MyTrait { fn ident(self) -> Int }
 trait MyTrait for Int { fn ident(self) { self } }
-fn use_it(x: a) -> Int where a: MyTrait { x.ident() }
+fn use_it(x: a) -> Int where a: MyTrait { MyTrait.ident(x) }
 fn main() {
   let r = {x: 1, y: 2}
   println(use_it(r))
diff --git a/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__nominal_record_rejected.silt b/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__nominal_record_rejected.silt
index 211af83d9..866c9c135 100644
--- a/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__nominal_record_rejected.silt
+++ b/tests/golden/typecheck/traits/round73_anon_record_trait_bypass__nominal_record_rejected.silt
@@ -6,7 +6,7 @@
 trait MyTrait { fn ident(self) -> Int }
 trait MyTrait for Int { fn ident(self) { self } }
 type Foo { x: Int }
-fn use_it(x: a) -> Int where a: MyTrait { x.ident() }
+fn use_it(x: a) -> Int where a: MyTrait { MyTrait.ident(x) }
 fn main() {
   let r = Foo { x: 1 }
   println(use_it(r))
diff --git a/tests/golden/typecheck/traits/round74_unit_trait_dispatch__user_trait_for_unit.silt b/tests/golden/typecheck/traits/round74_unit_trait_dispatch__user_trait_for_unit.silt
index 469224bda..0bb2b24c9 100644
--- a/tests/golden/typecheck/traits/round74_unit_trait_dispatch__user_trait_for_unit.silt
+++ b/tests/golden/typecheck/traits/round74_unit_trait_dispatch__user_trait_for_unit.silt
@@ -3,5 +3,5 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Unit { fn greet(self) -> String { "hi" } }
 fn main() {
   let u = ()
-  println(u.greet())
+  println(Greet.greet(u))
 }
diff --git a/tests/golden/typecheck/traits/round76_trait_impl_subst__broken_program_prints_nothing.silt b/tests/golden/typecheck/traits/round76_trait_impl_subst__broken_program_prints_nothing.silt
index f08593559..1ba1ab185 100644
--- a/tests/golden/typecheck/traits/round76_trait_impl_subst__broken_program_prints_nothing.silt
+++ b/tests/golden/typecheck/traits/round76_trait_impl_subst__broken_program_prints_nothing.silt
@@ -5,7 +5,7 @@
 trait Foo(a) { fn produce(self) -> a }
 trait Foo(Int) for String { fn produce(self) -> String { "haha" } }
 fn use_foo(s: a) -> Int where a: Foo(Int) {
-  s.produce()
+  Foo.produce(s)
 }
 fn main() {
   let s: String = "hi"
diff --git a/tests/golden/typecheck/traits/round76_trait_impl_subst__matching_signature_ok.silt b/tests/golden/typecheck/traits/round76_trait_impl_subst__matching_signature_ok.silt
index 1276f892f..d96cd797c 100644
--- a/tests/golden/typecheck/traits/round76_trait_impl_subst__matching_signature_ok.silt
+++ b/tests/golden/typecheck/traits/round76_trait_impl_subst__matching_signature_ok.silt
@@ -1,7 +1,7 @@
 trait Foo(a) { fn produce(self) -> a }
 trait Foo(Int) for String { fn produce(self) -> Int { 42 } }
 fn use_foo(s: a) -> Int where a: Foo(Int) {
-  s.produce()
+  Foo.produce(s)
 }
 fn main() {
   let s: String = "hi"
diff --git a/tests/golden/typecheck/traits/round76_trait_impl_subst__signature_mismatch_rejected.silt b/tests/golden/typecheck/traits/round76_trait_impl_subst__signature_mismatch_rejected.silt
index 7d5a08f4b..78c66dac2 100644
--- a/tests/golden/typecheck/traits/round76_trait_impl_subst__signature_mismatch_rejected.silt
+++ b/tests/golden/typecheck/traits/round76_trait_impl_subst__signature_mismatch_rejected.silt
@@ -4,7 +4,7 @@
 trait Foo(a) { fn produce(self) -> a }
 trait Foo(Int) for String { fn produce(self) -> String { "haha" } }
 fn use_foo(s: a) -> Int where a: Foo(Int) {
-  s.produce()
+  Foo.produce(s)
 }
 fn main() {
   let s: String = "hi"
diff --git a/tests/golden/typecheck/traits/round79_typechecker_fixes__anon_record_trait_arg.silt b/tests/golden/typecheck/traits/round79_typechecker_fixes__anon_record_trait_arg.silt
index eab2eb2ba..6e48917a4 100644
--- a/tests/golden/typecheck/traits/round79_typechecker_fixes__anon_record_trait_arg.silt
+++ b/tests/golden/typecheck/traits/round79_typechecker_fixes__anon_record_trait_arg.silt
@@ -5,7 +5,7 @@ trait Convert({a: Int, b: String}) for Int {
   fn convert(self) -> {a: Int, b: String} { {a: self, b: "x"} }
 }
 fn use_it(x: a) -> Int where a: Convert({a: Int, b: String}) {
-  let r = x.convert()
+  let r = Convert.convert(x)
   r.a
 }
 fn main() { println(use_it(7)) }
diff --git a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_enum_in_supertrait.silt b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_enum_in_supertrait.silt
index b69a33a51..e8593fcf1 100644
--- a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_enum_in_supertrait.silt
+++ b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_enum_in_supertrait.silt
@@ -6,7 +6,7 @@ trait Carry(t) { fn carry(self, x: t) -> t }
 trait Holds: Carry(Box) { fn hold(self) -> Int }
 
 fn use_holds(x: t) -> Int where t: Holds {
-  x.hold()
+  Holds.hold(x)
 }
 
 fn main() { }
diff --git a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_name_inside_generic_arg.silt b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_name_inside_generic_arg.silt
index b31e4bce6..abc6308f7 100644
--- a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_name_inside_generic_arg.silt
+++ b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_name_inside_generic_arg.silt
@@ -7,7 +7,7 @@ trait Carry(t) { fn carry(self, x: t) -> t }
 trait Holds: Carry(List(Box)) { fn hold(self) -> Int }
 
 fn use_holds(x: t) -> Int where t: Holds {
-  x.hold()
+  Holds.hold(x)
 }
 
 fn main() { }
diff --git a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_record_in_supertrait.silt b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_record_in_supertrait.silt
index 3c1bc7348..9d7b18d45 100644
--- a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_record_in_supertrait.silt
+++ b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__bare_record_in_supertrait.silt
@@ -6,7 +6,7 @@ trait Carry(t) { fn carry(self, x: t) -> t }
 trait Holds: Carry(Wrapper) { fn hold(self) -> Int }
 
 fn use_holds(x: t) -> Int where t: Holds {
-  x.hold()
+  Holds.hold(x)
 }
 
 fn main() { }
diff --git a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__enum_with_args_ok.silt b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__enum_with_args_ok.silt
index 86a4ff0c7..0b7bee6fb 100644
--- a/tests/golden/typecheck/traits/round88_supertrait_arg_arity__enum_with_args_ok.silt
+++ b/tests/golden/typecheck/traits/round88_supertrait_arg_arity__enum_with_args_ok.silt
@@ -6,7 +6,7 @@ trait Carry(t) { fn carry(self, x: t) -> t }
 trait Holds: Carry(Box(Int)) { fn hold(self) -> Int }
 
 fn use_holds(x: t) -> Int where t: Holds {
-  x.hold()
+  Holds.hold(x)
 }
 
 fn main() { }
diff --git a/tests/golden/typecheck/traits/sealed_traits__derived_compare_equal_hash_and_hand_written_display.silt b/tests/golden/typecheck/traits/sealed_traits__derived_compare_equal_hash_and_hand_written_display.silt
index 2b3ac1600..8eb4e4cdc 100644
--- a/tests/golden/typecheck/traits/sealed_traits__derived_compare_equal_hash_and_hand_written_display.silt
+++ b/tests/golden/typecheck/traits/sealed_traits__derived_compare_equal_hash_and_hand_written_display.silt
@@ -12,7 +12,7 @@ fn main() {
   let b = Version { major: 1, minor: 10 }
   println(a < b)
   println(a == Version { major: 1, minor: 2 })
-  println(a.compare(b))
+  println(Compare.compare(a, b))
   println(map.get(#{ a: "old", b: "new" }, b))
-  println(a.display())
+  println("{a}")
 }
diff --git a/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.silt b/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.silt
index e4aa29f7d..3f10a99dc 100644
--- a/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.silt
+++ b/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.silt
@@ -1,20 +1,20 @@
 -- cmd: check
 -- exit: 1
 -- verdict: same
--- `equal` and `compare` take a value of the receiver's type: comparing
--- an Int with a String, or a record with a number, is a type mismatch
--- and not a `false` (or an error when the program runs).
+-- `Compare.compare` and `==` take two values of one type: comparing an
+-- Int with a String, or a record with a number, is a type mismatch and
+-- not a `false` (or an error when the program runs).
 type P {
   n: Int,
 }
 
 fn main() {
   let p = P { n: 1 }
-  println(1.equal("a"))
-  println(p.equal(2))
-  println(p.compare("x"))
-  println([1].equal(["a"]))
-  println(Some(1).equal(Some("a")))
-  println(1.equal(1))
-  println(p.compare(P { n: 2 }))
+  println(Compare.compare(1, "a"))
+  println(p == 2)
+  println(Compare.compare(p, "x"))
+  println([1] == ["a"])
+  println(Some(1) == Some("a"))
+  println(Compare.compare(1, 1))
+  println(Compare.compare(p, P { n: 2 }))
 }
diff --git a/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.stderr b/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.stderr
index a8832b47e..2c35c07df 100644
--- a/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.stderr
+++ b/tests/golden/typecheck/traits/structural_method__the_other_operand_is_of_the_receivers_type.stderr
@@ -1,29 +1,29 @@
 error[type]: type mismatch: expected Int, got String
- --> structural_method__the_other_operand_is_of_the_receivers_type.silt:13:19
+ --> structural_method__the_other_operand_is_of_the_receivers_type.silt:13:30
     |
- 13 |   println(1.equal("a"))
-    |                   ^^^ type mismatch: expected Int, got String
+ 13 |   println(Compare.compare(1, "a"))
+    |                              ^^^ type mismatch: expected Int, got String
 
 error[type]: type mismatch: expected P, got Int
- --> structural_method__the_other_operand_is_of_the_receivers_type.silt:14:19
+ --> structural_method__the_other_operand_is_of_the_receivers_type.silt:14:16
     |
- 14 |   println(p.equal(2))
-    |                   ^ type mismatch: expected P, got Int
+ 14 |   println(p == 2)
+    |                ^ type mismatch: expected P, got Int
 
 error[type]: type mismatch: expected P, got String
- --> structural_method__the_other_operand_is_of_the_receivers_type.silt:15:21
+ --> structural_method__the_other_operand_is_of_the_receivers_type.silt:15:30
     |
- 15 |   println(p.compare("x"))
-    |                     ^^^ type mismatch: expected P, got String
+ 15 |   println(Compare.compare(p, "x"))
+    |                              ^^^ type mismatch: expected P, got String
 
 error[type]: type mismatch: expected Int, got String
- --> structural_method__the_other_operand_is_of_the_receivers_type.silt:16:21
+ --> structural_method__the_other_operand_is_of_the_receivers_type.silt:16:18
     |
- 16 |   println([1].equal(["a"]))
-    |                     ^^^^^ type mismatch: expected Int, got String
+ 16 |   println([1] == ["a"])
+    |                  ^^^^^ type mismatch: expected Int, got String
 
 error[type]: type mismatch: expected Int, got String
- --> structural_method__the_other_operand_is_of_the_receivers_type.silt:17:25
+ --> structural_method__the_other_operand_is_of_the_receivers_type.silt:17:22
     |
- 17 |   println(Some(1).equal(Some("a")))
-    |                         ^^^^^^^^^ type mismatch: expected Int, got String
+ 17 |   println(Some(1) == Some("a"))
+    |                      ^^^^^^^^^ type mismatch: expected Int, got String
diff --git a/tests/golden/typecheck/traits/structural_method__through_a_type_is_typed.silt b/tests/golden/typecheck/traits/structural_method__through_a_type_is_typed.silt
deleted file mode 100644
index e53d278c5..000000000
--- a/tests/golden/typecheck/traits/structural_method__through_a_type_is_typed.silt
+++ /dev/null
@@ -1,23 +0,0 @@
--- cmd: check
--- exit: 1
--- A method of a structural trait written through a type (`Int.display`,
--- `P.compare`) or through a type held in a value has the type it has on
--- a value of that type, with the receiver as its first argument: the
--- arguments, their number and the result are checked.
-import list
-
-type P {
-  x: Int,
-}
-
-fn main() {
-  println(Int.equal(1, 2.0))
-  println(P.display(5))
-  let n: Int = String.display("s")
-  let names: List(Int) = list.map(["a", "b"], String.display)
-  let q = P
-  println(q.compare(P { x: 1 }, 3))
-  println(Int.display())
-  println(Tuple.display((1, 2)))
-  println("{n} {names}")
-}
diff --git a/tests/golden/typecheck/traits/structural_method__through_a_type_is_typed.stderr b/tests/golden/typecheck/traits/structural_method__through_a_type_is_typed.stderr
deleted file mode 100644
index b8fe532b1..000000000
--- a/tests/golden/typecheck/traits/structural_method__through_a_type_is_typed.stderr
+++ /dev/null
@@ -1,41 +0,0 @@
-error[type]: type mismatch: expected Int, got Float
- --> structural_method__through_a_type_is_typed.silt:14:24
-    |
- 14 |   println(Int.equal(1, 2.0))
-    |                        ^^^ type mismatch: expected Int, got Float
-
-error[type]: type mismatch: expected P, got Int
- --> structural_method__through_a_type_is_typed.silt:15:21
-    |
- 15 |   println(P.display(5))
-    |                     ^ type mismatch: expected P, got Int
-
-error[type]: type mismatch: expected Int, got String
- --> structural_method__through_a_type_is_typed.silt:16:16
-    |
- 16 |   let n: Int = String.display("s")
-    |                ^^^^^^^^^^^^^^^^^^^ type mismatch: expected Int, got String
-
-error[type]: type mismatch: expected Int, got String
- --> structural_method__through_a_type_is_typed.silt:17:26
-    |
- 17 |   let names: List(Int) = list.map(["a", "b"], String.display)
-    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type mismatch: expected Int, got String
-
-error[type]: type mismatch: expected P, got Int
- --> structural_method__through_a_type_is_typed.silt:19:33
-    |
- 19 |   println(q.compare(P { x: 1 }, 3))
-    |                                 ^ type mismatch: expected P, got Int
-
-error[type]: function expects 1 argument, got 0
- --> structural_method__through_a_type_is_typed.silt:20:11
-    |
- 20 |   println(Int.display())
-    |           ^^^^^^^^^^^^^ function expects 1 argument, got 0
-
-error[type]: method `display` of the impl for every `Tuple` is called on a value: write `x.display(..)`, not `Tuple.display`
- --> structural_method__through_a_type_is_typed.silt:21:11
-    |
- 21 |   println(Tuple.display((1, 2)))
-    |           ^^^^^^^^^^^^^ method `display` of the impl for every `Tuple` is called on a value: write `x.display(..)`, not `Tuple.display`
diff --git a/tests/golden/typecheck/traits/structural_method__through_a_type_runs.silt b/tests/golden/typecheck/traits/structural_method__through_a_type_runs.silt
index 971691c6e..6c953cad5 100644
--- a/tests/golden/typecheck/traits/structural_method__through_a_type_runs.silt
+++ b/tests/golden/typecheck/traits/structural_method__through_a_type_runs.silt
@@ -2,6 +2,7 @@
 -- type held in a value, is the method of the type's values.
 import json
 import list
+import string
 
 type P {
   x: Int,
@@ -17,25 +18,25 @@ type Color {
 }
 
 fn shown(x: a, type a) -> String where a: Display {
-  a.display(x)
+  "{x}"
 }
 
 fn order(x: a, y: a, type a) -> Int where a: Compare {
-  a.compare(x, y)
+  Compare.compare(x, y)
 }
 
 fn main() {
-  println(Int.display(3))
-  println(Option.display(Some(1)))
-  println(Box.display(Box { v: "b" }))
-  println(Color.compare(Red, Green))
-  println(Float.equal(1.0, 1.0))
-  println(json.Value.display(json.Null))
-  println(list.map([1, 2], Int.display))
-  println(list.fold([P { x: 2 }, P { x: 1 }], 0, { acc, p -> acc + P.compare(p, P { x: 1 }) }))
+  println("{3}")
+  println("{Some(1)}")
+  println(string.from(Box { v: "b" }))
+  println(Compare.compare(Red, Green))
+  println(1.0 == 1.0)
+  println("{json.Null}")
+  println(list.map([1, 2], string.from))
+  println(list.fold([P { x: 2 }, P { x: 1 }], 0, { acc, p -> acc + Compare.compare(p, P { x: 1 }) }))
   let q = P
-  println(q.display(P { x: 4 }))
-  println(Int.hash(3) == 3.hash())
+  println(string.from(P { x: 4 }))
+  println(Hash.hash(3) == Hash.hash(3))
   println(shown(P { x: 5 }, P))
   println(order(2, 1, Int))
 }
diff --git a/tests/golden/typecheck/traits/structural_method__through_its_trait_is_typed.silt b/tests/golden/typecheck/traits/structural_method__through_its_trait_is_typed.silt
new file mode 100644
index 000000000..3a7ed8897
--- /dev/null
+++ b/tests/golden/typecheck/traits/structural_method__through_its_trait_is_typed.silt
@@ -0,0 +1,21 @@
+-- cmd: check
+-- exit: 1
+-- A method of a structural trait called through its trait
+-- (`Compare.compare`, `Hash.hash`), or taken as a value, has the type it
+-- has for a value of the argument's type: the arguments, their number
+-- and the result are checked.
+import list
+
+type P {
+  x: Int,
+}
+
+fn main() {
+  println(Compare.compare(1, 2.0))
+  let n: String = Hash.hash("s")
+  let hashes: List(String) = list.map(["a", "b"], Hash.hash)
+  println(Compare.compare(P { x: 1 }, 3))
+  println(Compare.compare())
+  println(Hash.hash((1, 2)))
+  println("{n} {hashes}")
+}
diff --git a/tests/golden/typecheck/traits/structural_method__through_its_trait_is_typed.stderr b/tests/golden/typecheck/traits/structural_method__through_its_trait_is_typed.stderr
new file mode 100644
index 000000000..986e3129c
--- /dev/null
+++ b/tests/golden/typecheck/traits/structural_method__through_its_trait_is_typed.stderr
@@ -0,0 +1,29 @@
+error[type]: type mismatch: expected Int, got Float
+ --> structural_method__through_its_trait_is_typed.silt:14:30
+    |
+ 14 |   println(Compare.compare(1, 2.0))
+    |                              ^^^ type mismatch: expected Int, got Float
+
+error[type]: type mismatch: expected String, got Int
+ --> structural_method__through_its_trait_is_typed.silt:15:19
+    |
+ 15 |   let n: String = Hash.hash("s")
+    |                   ^^^^^^^^^^^^^^ type mismatch: expected String, got Int
+
+error[type]: type mismatch: expected String, got Int
+ --> structural_method__through_its_trait_is_typed.silt:16:30
+    |
+ 16 |   let hashes: List(String) = list.map(["a", "b"], Hash.hash)
+    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ type mismatch: expected String, got Int
+
+error[type]: type mismatch: expected P, got Int
+ --> structural_method__through_its_trait_is_typed.silt:17:39
+    |
+ 17 |   println(Compare.compare(P { x: 1 }, 3))
+    |                                       ^ type mismatch: expected P, got Int
+
+error[type]: `Compare.compare` expects 2 arguments, got 0
+ --> structural_method__through_its_trait_is_typed.silt:18:11
+    |
+ 18 |   println(Compare.compare())
+    |           ^^^^^^^^^^^^^^^^^ `Compare.compare` expects 2 arguments, got 0
diff --git a/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.silt b/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.silt
index b3f508146..67d3f9820 100644
--- a/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.silt
+++ b/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.silt
@@ -35,12 +35,12 @@ fn same(a: a, b: a) -> Bool where a: Equal {
 
 fn main() {
   let p = Plain { n: 1 }
-  println(p.equal(p))
+  println(p == p)
   println(same(p, p))
   println(p == p)
-  println(p.rank())
+  println(Ranked.rank(p))
   let h = Held { f: { x -> x } }
-  println(h.equal(h))
+  println(h == h)
   println(same(h, h))
   println(h == h)
 }
diff --git a/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.stderr b/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.stderr
index 25f5deaaf..e435ce527 100644
--- a/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.stderr
+++ b/tests/golden/typecheck/traits/structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.stderr
@@ -7,8 +7,8 @@ error[type]: type 'Held' implements 'Ranked' but does not implement supertrait '
 error[type]: type 'Held' does not implement trait 'Equal': field 'f' is of type 'Fn(Int) -> Int', which does not
  --> structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.silt:43:11
     |
- 43 |   println(h.equal(h))
-    |           ^^^^^^^ type 'Held' does not implement trait 'Equal': field 'f' is of type 'Fn(Int) -> Int', which does not
+ 43 |   println(h == h)
+    |           ^^^^^^ type 'Held' does not implement trait 'Equal': field 'f' is of type 'Fn(Int) -> Int', which does not
 
 error[type]: type 'Held' does not implement trait 'Equal': field 'f' is of type 'Fn(Int) -> Int', which does not
  --> structural_trait__one_answer_for_a_method_a_supertrait_a_bound_and_an_operator.silt:44:16
diff --git a/tests/golden/typecheck/traits/structure__compare_method_on_structured_types.silt b/tests/golden/typecheck/traits/structure__compare_method_on_structured_types.silt
index 66001f490..267c6d500 100644
--- a/tests/golden/typecheck/traits/structure__compare_method_on_structured_types.silt
+++ b/tests/golden/typecheck/traits/structure__compare_method_on_structured_types.silt
@@ -2,9 +2,9 @@
 -- has the trait by its structure.
 type Pt { x: Int, y: Int }
 fn main() {
-  println(Some(1).compare(Some(2)))
-  println(Ok(2).compare(Ok(1)))
-  println(None.equal(Some(1)))
-  println(Pt { x: 1, y: 2 }.compare(Pt { x: 1, y: 3 }))
-  println(Some((1, "a")).hash() == Some((1, "a")).hash())
+  println(Compare.compare(Some(1), Some(2)))
+  println(Compare.compare(Ok(2), Ok(1)))
+  println(None == Some(1))
+  println(Compare.compare(Pt { x: 1, y: 2 }, Pt { x: 1, y: 3 }))
+  println(Hash.hash(Some((1, "a"))) == Hash.hash(Some((1, "a"))))
 }
diff --git a/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.silt b/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.silt
index 0bb5627ed..bcedc5e8d 100644
--- a/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.silt
+++ b/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.silt
@@ -9,5 +9,5 @@ fn main() {
   let h = H { f: { n -> n } }
   println(Y(Box(h)))
   println(Z == Z)
-  println([Box(h)].display())
+  println("{[Box(h)]}")
 }
diff --git a/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.stderr b/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.stderr
index 47313b214..1d524519d 100644
--- a/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.stderr
+++ b/tests/golden/typecheck/traits/structure__error_is_at_the_use_once.stderr
@@ -11,7 +11,7 @@ error[type]: type 'E' does not implement trait 'Equal': variant 'X' payload #1 >
     |           ^^^^^^ type 'E' does not implement trait 'Equal': variant 'X' payload #1 > variant 'Some' payload #1 is of type 'Fn(Int) -> Int', which does not
 
 error[type]: type 'List(Box(H))' does not implement trait 'Display': element > variant 'Box' payload #1 > field 'f' is of type 'Fn(Int) -> Int', which does not
- --> structure__error_is_at_the_use_once.silt:12:11
+ --> structure__error_is_at_the_use_once.silt:12:13
     |
- 12 |   println([Box(h)].display())
-    |           ^^^^^^^^^^^^^^^^ type 'List(Box(H))' does not implement trait 'Display': element > variant 'Box' payload #1 > field 'f' is of type 'Fn(Int) -> Int', which does not
+ 12 |   println("{[Box(h)]}")
+    |             ^^^^^^^^ type 'List(Box(H))' does not implement trait 'Display': element > variant 'Box' payload #1 > field 'f' is of type 'Fn(Int) -> Int', which does not
diff --git a/tests/golden/typecheck/traits/structure__written_display_impl_answers.silt b/tests/golden/typecheck/traits/structure__written_display_impl_answers.silt
index e293b39af..23d318cc0 100644
--- a/tests/golden/typecheck/traits/structure__written_display_impl_answers.silt
+++ b/tests/golden/typecheck/traits/structure__written_display_impl_answers.silt
@@ -4,7 +4,7 @@ type Job { name: String, run: Fn(Int) -> Int }
 trait Display for Job { fn display(self) -> String { "job {self.name}" } }
 type Box(a) { Box(a) }
 trait Display for Box(a) where a: Display { fn display(self) -> String { match self { Box(v) -> "box of {v}" } } }
-fn show(x: a) -> String where a: Display { x.display() }
+fn show(x: a) -> String where a: Display { "{x}" }
 fn main() {
   let j = Job { name: "j", run: { n -> n } }
   println(show(j))
diff --git a/tests/golden/typecheck/traits/structure__written_display_impl_header_owed.silt b/tests/golden/typecheck/traits/structure__written_display_impl_header_owed.silt
index e5e0f9459..305914cb2 100644
--- a/tests/golden/typecheck/traits/structure__written_display_impl_header_owed.silt
+++ b/tests/golden/typecheck/traits/structure__written_display_impl_header_owed.silt
@@ -3,7 +3,7 @@
 -- stderr-contains: error[type]: type 'Fn' does not implement trait 'Display'
 type Box(a) { Box(a) }
 trait Display for Box(a) where a: Display { fn display(self) -> String { match self { Box(v) -> "box of {v}" } } }
-fn show(x: a) -> String where a: Display { x.display() }
+fn show(x: a) -> String where a: Display { "{x}" }
 fn main() {
   println(show([Box({ n -> n })]))
 }
diff --git a/tests/golden/typecheck/traits/supertrait__multiple_all_satisfied.silt b/tests/golden/typecheck/traits/supertrait__multiple_all_satisfied.silt
index 796530e32..068c41295 100644
--- a/tests/golden/typecheck/traits/supertrait__multiple_all_satisfied.silt
+++ b/tests/golden/typecheck/traits/supertrait__multiple_all_satisfied.silt
@@ -20,10 +20,10 @@ trait Tr2 for Baz {
   fn t2(self) -> Int { self.v + 1 }
 }
 trait Both for Baz {
-  fn both(self) -> Int { self.t1() + self.t2() }
+  fn both(self) -> Int { Tr1.t1(self) + Tr2.t2(self) }
 }
 
 fn main() {
   let b = Baz { v: 5 }
-  println(b.both())
+  println(Both.both(b))
 }
diff --git a/tests/golden/typecheck/traits/supertrait__runtime_dispatch_through_constraint.silt b/tests/golden/typecheck/traits/supertrait__runtime_dispatch_through_constraint.silt
index cbaf680d0..71c56ed39 100644
--- a/tests/golden/typecheck/traits/supertrait__runtime_dispatch_through_constraint.silt
+++ b/tests/golden/typecheck/traits/supertrait__runtime_dispatch_through_constraint.silt
@@ -18,9 +18,9 @@ trait Ord2 for Foo {
 }
 
 fn label(a: t, b: t) -> String where t: Ord2 {
-  match a.eq2(b) {
+  match Eq2.eq2(a, b) {
     true -> "equal"
-    false -> match a.lt2(b) {
+    false -> match Ord2.lt2(a, b) {
       true -> "less"
       false -> "greater"
     }
diff --git a/tests/golden/typecheck/traits/supertrait__transitive_methods_through_where.silt b/tests/golden/typecheck/traits/supertrait__transitive_methods_through_where.silt
index 8e0cbc768..a6bdc7e5b 100644
--- a/tests/golden/typecheck/traits/supertrait__transitive_methods_through_where.silt
+++ b/tests/golden/typecheck/traits/supertrait__transitive_methods_through_where.silt
@@ -29,7 +29,7 @@ trait C1 for Bar {
 
 -- All three method calls must resolve via the C1 -> B1 -> A1 chain.
 fn use_all(x: t) -> Int where t: C1 {
-  x.a1() + x.b1() + x.c1()
+  A1.a1(x) + B1.b1(x) + C1.c1(x)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/traits/supertrait__where_subtrait_enables_supertrait_methods.silt b/tests/golden/typecheck/traits/supertrait__where_subtrait_enables_supertrait_methods.silt
index 899ee674b..751accff7 100644
--- a/tests/golden/typecheck/traits/supertrait__where_subtrait_enables_supertrait_methods.silt
+++ b/tests/golden/typecheck/traits/supertrait__where_subtrait_enables_supertrait_methods.silt
@@ -21,9 +21,9 @@ trait Ord2 for Foo {
 
 -- This should typecheck because Eq2 is a supertrait of Ord2.
 fn cmp(a: t, b: t) -> Bool where t: Ord2 {
-  match a.eq2(b) {
+  match Eq2.eq2(a, b) {
     true -> false
-    false -> a.lt2(b)
+    false -> Ord2.lt2(a, b)
   }
 }
 
diff --git a/tests/golden/typecheck/traits/no_self__a_call_on_a_type_has_every_method.silt b/tests/golden/typecheck/traits/through_the_type__a_method_that_makes_a_value.silt
similarity index 56%
rename from tests/golden/typecheck/traits/no_self__a_call_on_a_type_has_every_method.silt
rename to tests/golden/typecheck/traits/through_the_type__a_method_that_makes_a_value.silt
index 4ad15457a..3258c46c4 100644
--- a/tests/golden/typecheck/traits/no_self__a_call_on_a_type_has_every_method.silt
+++ b/tests/golden/typecheck/traits/through_the_type__a_method_that_makes_a_value.silt
@@ -1,10 +1,11 @@
 -- cmd: check
 -- exit: 1
--- The rule that a method without `self` is no candidate is for a call
--- on a value: a call on the type (`String.decode(4)`) has both traits'
--- methods, and is ambiguous. A call on a value of methods that all take
--- no `self` has no candidate: it is refused as taking no `self`, with
--- the call on the type to write.
+-- Through the type a call means a method that makes a value: of a
+-- method `decode` that makes a String and one that takes a String,
+-- `String.decode(4)` is the first, with no ambiguity (the other is
+-- called through its trait). Two traits that each give the type a
+-- method `make` that makes a value are ambiguous, with the help to call
+-- it through a bounded function.
 trait Mk {
   fn decode(v: Int) -> Self
 }
@@ -48,5 +49,5 @@ trait Build for Int {
 fn main() {
   let t: String = String.decode(4)
   println(t)
-  println(7.make(1))
+  println(Int.make(1))
 }
diff --git a/tests/golden/typecheck/traits/through_the_type__a_method_that_makes_a_value.stderr b/tests/golden/typecheck/traits/through_the_type__a_method_that_makes_a_value.stderr
new file mode 100644
index 000000000..33e7f8edb
--- /dev/null
+++ b/tests/golden/typecheck/traits/through_the_type__a_method_that_makes_a_value.stderr
@@ -0,0 +1,6 @@
+error[type]: ambiguous method 'make' on type 'Int': provided by traits Build, Make
+ --> through_the_type__a_method_that_makes_a_value.silt:52:11
+    |
+ 52 |   println(Int.make(1))
+    |           ^^^^^^^^ ambiguous method 'make' on type 'Int': provided by traits Build, Make
+  = help: say which is meant: call it through a function bounded by the trait you mean, `where a: Build`
diff --git a/tests/golden/typecheck/traits/trait_ambiguity__distinct_methods_same_type.silt b/tests/golden/typecheck/traits/trait_ambiguity__distinct_methods_same_type.silt
index 31df93574..e820fd101 100644
--- a/tests/golden/typecheck/traits/trait_ambiguity__distinct_methods_same_type.silt
+++ b/tests/golden/typecheck/traits/trait_ambiguity__distinct_methods_same_type.silt
@@ -6,6 +6,6 @@ trait B { fn beta(self) -> Int }
 trait A for Int { fn alpha(self) -> Int { 1 } }
 trait B for Int { fn beta(self) -> Int { 2 } }
 fn main() {
-  println((5).alpha())
-  println((5).beta())
+  println(A.alpha(5))
+  println(B.beta(5))
 }
diff --git a/tests/golden/typecheck/traits/trait_ambiguity__names_both_traits.silt b/tests/golden/typecheck/traits/trait_ambiguity__names_both_traits.silt
deleted file mode 100644
index f1f6e22c5..000000000
--- a/tests/golden/typecheck/traits/trait_ambiguity__names_both_traits.silt
+++ /dev/null
@@ -1,13 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: ambiguous method 'render'
--- stderr-contains: 'String'
--- stderr-contains: Display1
--- stderr-contains: Display2
--- The ambiguity diagnostic, at a call that sees both traits, names the
--- method, the type and both traits.
-trait Display1 { fn render(self) -> String }
-trait Display2 { fn render(self) -> String }
-trait Display1 for String { fn render(self) -> String { "1" } }
-trait Display2 for String { fn render(self) -> String { "2" } }
-fn main() { println("s".render()) }
diff --git a/tests/golden/typecheck/traits/trait_ambiguity__same_method_different_types.silt b/tests/golden/typecheck/traits/trait_ambiguity__same_method_different_types.silt
index 8ff4e0c66..6473404e3 100644
--- a/tests/golden/typecheck/traits/trait_ambiguity__same_method_different_types.silt
+++ b/tests/golden/typecheck/traits/trait_ambiguity__same_method_different_types.silt
@@ -6,6 +6,6 @@ trait B { fn show(self) -> String }
 trait A for Int { fn show(self) -> String { "int" } }
 trait B for String { fn show(self) -> String { self } }
 fn main() {
-  println((5).show())
-  println(("hi").show())
+  println(A.show(5))
+  println(B.show("hi"))
 }
diff --git a/tests/golden/typecheck/traits/trait_ambiguity__same_method_same_type.silt b/tests/golden/typecheck/traits/trait_ambiguity__same_method_same_type.silt
deleted file mode 100644
index b85eadec9..000000000
--- a/tests/golden/typecheck/traits/trait_ambiguity__same_method_same_type.silt
+++ /dev/null
@@ -1,10 +0,0 @@
--- cmd: check
--- exit: 1
--- stderr-contains: ambiguous method 'show' on type 'Int': provided by traits A, B
--- Two traits providing `show` both implemented for Int: a call that
--- sees both is ambiguous.
-trait A { fn show(self) -> String }
-trait B { fn show(self) -> String }
-trait A for Int { fn show(self) -> String { "from-A" } }
-trait B for Int { fn show(self) -> String { "from-B" } }
-fn main() { println(5.show()) }
diff --git a/tests/golden/typecheck/traits/trait_ambiguity__same_trait_multiple_types.silt b/tests/golden/typecheck/traits/trait_ambiguity__same_trait_multiple_types.silt
index c686950cd..11a3e110d 100644
--- a/tests/golden/typecheck/traits/trait_ambiguity__same_trait_multiple_types.silt
+++ b/tests/golden/typecheck/traits/trait_ambiguity__same_trait_multiple_types.silt
@@ -11,7 +11,7 @@ trait Show for Bool {
   } }
 }
 fn main() {
-  println((1).show())
-  println(("x").show())
-  println(true.show())
+  println(Show.show(1))
+  println(Show.show("x"))
+  println(Show.show(true))
 }
diff --git a/tests/golden/typecheck/traits/trait_fn_name_collision__impl_method_still_works.silt b/tests/golden/typecheck/traits/trait_fn_name_collision__impl_method_still_works.silt
index d8d0ee1fb..c3d4441ea 100644
--- a/tests/golden/typecheck/traits/trait_fn_name_collision__impl_method_still_works.silt
+++ b/tests/golden/typecheck/traits/trait_fn_name_collision__impl_method_still_works.silt
@@ -1,4 +1,4 @@
 trait Showable { fn show(self) -> String }
 trait Showable for Int { fn show(self) -> String { "int" } }
 fn show(x) { x + 1 }
-fn main() { println((5).show()) }
+fn main() { println(Showable.show(5)) }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__bare_target.silt b/tests/golden/typecheck/traits/trait_impl_params__bare_target.silt
index 79fb99f3b..4af4792cc 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__bare_target.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__bare_target.silt
@@ -1,3 +1,3 @@
 trait Double { fn double(self) -> Int }
 trait Double for Int { fn double(self) -> Int { self * 2 } }
-fn main() { println((5).double()) }
+fn main() { println(Double.double(5)) }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__bare_target_parameterized_record.silt b/tests/golden/typecheck/traits/trait_impl_params__bare_target_parameterized_record.silt
index bedb02f0b..b8c0fb5a5 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__bare_target_parameterized_record.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__bare_target_parameterized_record.silt
@@ -3,5 +3,5 @@ trait Tag { fn tag(self) -> String }
 trait Tag for Box { fn tag(self) -> String { "box" } }
 fn main() {
   let b = Box { value: 42 }
-  println(b.tag())
+  println(Tag.tag(b))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__distinct_element_types.silt b/tests/golden/typecheck/traits/trait_impl_params__distinct_element_types.silt
index 20d4f325e..ef8ad6abe 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__distinct_element_types.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__distinct_element_types.silt
@@ -6,5 +6,5 @@ trait Unwrap for Box(a) {
 fn main() {
   let b = Box(99)
   let c = Box("hello")
-  println(b.get() + c.get())
+  println(Unwrap.get(b) + Unwrap.get(c))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__enum_pattern_matches_self.silt b/tests/golden/typecheck/traits/trait_impl_params__enum_pattern_matches_self.silt
index 7355073bd..c21014caf 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__enum_pattern_matches_self.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__enum_pattern_matches_self.silt
@@ -7,5 +7,5 @@ trait Wrap for Box(a) {
 }
 fn main() {
   let b = Box(99)
-  println(b.unwrap())
+  println(Wrap.unwrap(b))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__impl_where_accepts_conforming.silt b/tests/golden/typecheck/traits/trait_impl_params__impl_where_accepts_conforming.silt
index b64d29382..aaf3f402d 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__impl_where_accepts_conforming.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__impl_where_accepts_conforming.silt
@@ -3,9 +3,9 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
-  println(Box(5).greet())
+  println(Greet.greet(Box(5)))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__impl_where_comma_clauses.silt b/tests/golden/typecheck/traits/trait_impl_params__impl_where_comma_clauses.silt
index aecda26fb..ea92fbd50 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__impl_where_comma_clauses.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__impl_where_comma_clauses.silt
@@ -6,10 +6,10 @@ trait Loud for Int { fn loud(self) -> String { "INT" } }
 trait Greet for Box(a) where a: Greet, a: Loud {
   fn greet(self) -> String {
     match self {
-      Box(inner) -> "{inner.greet()}/{inner.loud()}"
+      Box(inner) -> "{Greet.greet(inner)}/{Loud.loud(inner)}"
     }
   }
 }
 fn main() {
-  println(Box(7).greet())
+  println(Greet.greet(Box(7)))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__impl_where_partial_impl_rejected.silt b/tests/golden/typecheck/traits/trait_impl_params__impl_where_partial_impl_rejected.silt
index 7fac70793..6dec5e80c 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__impl_where_partial_impl_rejected.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__impl_where_partial_impl_rejected.silt
@@ -7,10 +7,10 @@ trait Loud { fn loud(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet + Loud {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
   let b = Box(5)
-  println(b.greet())
+  println(Greet.greet(b))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__impl_where_plus_constraints.silt b/tests/golden/typecheck/traits/trait_impl_params__impl_where_plus_constraints.silt
index 1326c7a98..50767e84f 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__impl_where_plus_constraints.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__impl_where_plus_constraints.silt
@@ -6,10 +6,10 @@ trait Loud for Int { fn loud(self) -> String { "INT" } }
 trait Greet for Box(a) where a: Greet + Loud {
   fn greet(self) -> String {
     match self {
-      Box(inner) -> "{inner.greet()}-{inner.loud()}"
+      Box(inner) -> "{Greet.greet(inner)}-{Loud.loud(inner)}"
     }
   }
 }
 fn main() {
-  println(Box(42).greet())
+  println(Greet.greet(Box(42)))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__impl_where_propagates_to_body.silt b/tests/golden/typecheck/traits/trait_impl_params__impl_where_propagates_to_body.silt
index 128b18e3d..83d0daed9 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__impl_where_propagates_to_body.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__impl_where_propagates_to_body.silt
@@ -3,9 +3,9 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int-greet" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
-  println(Box(5).greet())
+  println(Greet.greet(Box(5)))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__impl_where_rejects_violator.silt b/tests/golden/typecheck/traits/trait_impl_params__impl_where_rejects_violator.silt
index 7d0b8447d..e096a1a26 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__impl_where_rejects_violator.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__impl_where_rejects_violator.silt
@@ -6,10 +6,10 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
   let b = Box("hello")
-  println(b.greet())
+  println(Greet.greet(b))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__method_level_where_on_binder.silt b/tests/golden/typecheck/traits/trait_impl_params__method_level_where_on_binder.silt
index 9ae6969be..f7b3a13c2 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__method_level_where_on_binder.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__method_level_where_on_binder.silt
@@ -7,10 +7,10 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int-greet" } }
 trait Greet for Box(a) {
   fn greet(self) -> String where a: Greet {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
   let b = Box(5)
-  println(b.greet())
+  println(Greet.greet(b))
 }
diff --git a/tests/golden/typecheck/traits/trait_impl_params__record_field_on_type_var.silt b/tests/golden/typecheck/traits/trait_impl_params__record_field_on_type_var.silt
index 73e04a169..13f34ffc4 100644
--- a/tests/golden/typecheck/traits/trait_impl_params__record_field_on_type_var.silt
+++ b/tests/golden/typecheck/traits/trait_impl_params__record_field_on_type_var.silt
@@ -2,9 +2,9 @@ type Cell(a) { value: a }
 trait Peek { fn peek(self) -> Int }
 trait Peek for Int { fn peek(self) -> Int { self } }
 trait Peek for Cell(a) where a: Peek {
-  fn peek(self) -> Int { self.value.peek() }
+  fn peek(self) -> Int { Peek.peek(self.value) }
 }
 fn main() {
   let c = Cell { value: 42 }
-  println(c.peek())
+  println(Peek.peek(c))
 }
diff --git a/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__monomorphic_return_two_sites.silt b/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__monomorphic_return_two_sites.silt
index 323bf0053..9ba817925 100644
--- a/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__monomorphic_return_two_sites.silt
+++ b/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__monomorphic_return_two_sites.silt
@@ -10,8 +10,8 @@ trait Summarizable for Int {
 trait Summarizable for String {
   fn summarize(self) -> String { self }
 }
-fn show_a(x: a) -> String where a: Summarizable { x.summarize() }
-fn show_b(y: b) -> String where b: Summarizable { y.summarize() }
+fn show_a(x: a) -> String where a: Summarizable { Summarizable.summarize(x) }
+fn show_b(y: b) -> String where b: Summarizable { Summarizable.summarize(y) }
 fn main() {
   println(show_a(42))
   println(show_b("hello"))
diff --git a/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__polymorphic_return_two_sites.silt b/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__polymorphic_return_two_sites.silt
index cb2c31c48..27571556f 100644
--- a/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__polymorphic_return_two_sites.silt
+++ b/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__polymorphic_return_two_sites.silt
@@ -13,8 +13,8 @@ trait Container(String) for StrBox {
   fn get_val(self) -> String { self.v }
 }
 
-fn use_int(c: x) -> Int where x: Container(Int) { c.get_val() }
-fn use_str(c: y) -> String where y: Container(String) { c.get_val() }
+fn use_int(c: x) -> Int where x: Container(Int) { Container.get_val(c) }
+fn use_str(c: y) -> String where y: Container(String) { Container.get_val(c) }
 
 fn main() {
   let a = IntBox { v: 42 }
diff --git a/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__rejects_non_implementor.silt b/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__rejects_non_implementor.silt
index 367229dd4..82e1eb531 100644
--- a/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__rejects_non_implementor.silt
+++ b/tests/golden/typecheck/traits/trait_method_tyvar_instantiation__rejects_non_implementor.silt
@@ -8,5 +8,5 @@ trait Measurable {
 trait Measurable for String {
   fn measure(self) -> Int { 0 }
 }
-fn measure_it(x: a) -> Int where a: Measurable { x.measure() }
+fn measure_it(x: a) -> Int where a: Measurable { Measurable.measure(x) }
 fn main() { println(measure_it(42)) }
diff --git a/tests/golden/typecheck/traits/trait_param_polish__supertrait_arg_flows_to_super_method.silt b/tests/golden/typecheck/traits/trait_param_polish__supertrait_arg_flows_to_super_method.silt
index 138379feb..aef91497c 100644
--- a/tests/golden/typecheck/traits/trait_param_polish__supertrait_arg_flows_to_super_method.silt
+++ b/tests/golden/typecheck/traits/trait_param_polish__supertrait_arg_flows_to_super_method.silt
@@ -17,7 +17,7 @@ trait Child(Int) for Holder {
 }
 
 fn call_parent(x: b, type a) -> a where b: Child(a) {
-    x.parent_fn()
+    Parent.parent_fn(x)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/traits/trait_sig__impl_for_bare_target_is_for_every_argument.silt b/tests/golden/typecheck/traits/trait_sig__impl_for_bare_target_is_for_every_argument.silt
index 102778483..d44b884d0 100644
--- a/tests/golden/typecheck/traits/trait_sig__impl_for_bare_target_is_for_every_argument.silt
+++ b/tests/golden/typecheck/traits/trait_sig__impl_for_bare_target_is_for_every_argument.silt
@@ -8,6 +8,6 @@ type Box(a) { Box(a) }
 trait Get { fn get(self) -> Int }
 trait Get for Box { fn get(self) -> Int { match self { Box(v) -> v } } }
 fn main() {
-  println(Box(1).get())
-  println(Box("s").get() + 1)
+  println(Get.get(Box(1)))
+  println(Get.get(Box("s")) + 1)
 }
diff --git a/tests/golden/typecheck/traits/trait_sig__impl_less_general_than_trait.silt b/tests/golden/typecheck/traits/trait_sig__impl_less_general_than_trait.silt
index ac9fdcaf0..ca6f44c19 100644
--- a/tests/golden/typecheck/traits/trait_sig__impl_less_general_than_trait.silt
+++ b/tests/golden/typecheck/traits/trait_sig__impl_less_general_than_trait.silt
@@ -9,4 +9,4 @@
 trait Wrap { fn wrap(self, x: a) -> List(a) }
 trait Wrap for Int { fn wrap(self, x: b) -> List(b) { [x] } }
 trait Wrap for Bool { fn wrap(self, x: Int) -> List(Int) { [x] } }
-fn main() { println(1.wrap("s")) }
+fn main() { println(Wrap.wrap(1, "s")) }
diff --git a/tests/golden/typecheck/traits/trait_sig__method_where_clause_is_part_of_signature.silt b/tests/golden/typecheck/traits/trait_sig__method_where_clause_is_part_of_signature.silt
index b71d49a63..08eed550b 100644
--- a/tests/golden/typecheck/traits/trait_sig__method_where_clause_is_part_of_signature.silt
+++ b/tests/golden/typecheck/traits/trait_sig__method_where_clause_is_part_of_signature.silt
@@ -4,21 +4,21 @@ trait Loud { fn loud(self) -> String }
 trait Loud for Int { fn loud(self) -> String { "INT" } }
 trait Shw {
   fn shw(self, x: a) -> String where a: Loud
-  fn twice(self, x: a) -> String where a: Loud { "{x.loud()}{x.loud()}" }
+  fn twice(self, x: a) -> String where a: Loud { "{Loud.loud(x)}{Loud.loud(x)}" }
   fn text(self, x: a) -> String where a: Display
 }
 trait Shw for Int {
-  fn shw(self, x) { x.loud() }
-  fn text(self, x) { x.display() }
+  fn shw(self, x) { Loud.loud(x) }
+  fn text(self, x) { "{x}" }
 }
 trait Shw for Bool {
-  fn shw(self, x: b) -> String where b: Loud { x.loud() }
-  fn text(self, x: b) -> String { "bool {x.display()}" }
+  fn shw(self, x: b) -> String where b: Loud { Loud.loud(x) }
+  fn text(self, x: b) -> String { "bool {x}" }
 }
 fn main() {
-  println(1.shw(2))
-  println(true.shw(3))
-  println(1.twice(4))
-  println(1.text("s"))
-  println(true.text(5))
+  println(Shw.shw(1, 2))
+  println(Shw.shw(true, 3))
+  println(Shw.twice(1, 4))
+  println(Shw.text(1, "s"))
+  println(Shw.text(true, 5))
 }
diff --git a/tests/golden/typecheck/traits/trait_sig__method_where_clause_owed_by_callers.silt b/tests/golden/typecheck/traits/trait_sig__method_where_clause_owed_by_callers.silt
index e4ebdc8ec..9a6a7a207 100644
--- a/tests/golden/typecheck/traits/trait_sig__method_where_clause_owed_by_callers.silt
+++ b/tests/golden/typecheck/traits/trait_sig__method_where_clause_owed_by_callers.silt
@@ -9,7 +9,7 @@
 trait Loud { fn loud(self) -> String }
 trait Loud for Int { fn loud(self) -> String { "INT" } }
 trait Shw { fn shw(self, x: a) -> String where a: Loud }
-trait Shw for Bool { fn shw(self, x) { x.loud() } }
-fn call(s: t, v: String) -> String where t: Shw { s.shw(v) }
-fn call_ok(s: t, v: Int) -> String where t: Shw { s.shw(v) }
-fn main() { println(true.shw("s")) }
+trait Shw for Bool { fn shw(self, x) { Loud.loud(x) } }
+fn call(s: t, v: String) -> String where t: Shw { Shw.shw(s, v) }
+fn call_ok(s: t, v: Int) -> String where t: Shw { Shw.shw(s, v) }
+fn main() { println(Shw.shw(true, "s")) }
diff --git a/tests/golden/typecheck/traits/trait_sig__no_return_type_is_unit.silt b/tests/golden/typecheck/traits/trait_sig__no_return_type_is_unit.silt
index ad80c47f9..3fee2623b 100644
--- a/tests/golden/typecheck/traits/trait_sig__no_return_type_is_unit.silt
+++ b/tests/golden/typecheck/traits/trait_sig__no_return_type_is_unit.silt
@@ -6,4 +6,4 @@
 -- stderr-contains: trait_sig__no_return_type_is_unit.silt:8:34
 trait Sz { fn sz(self) }
 trait Sz for Int { fn sz(self) { "str" } }
-fn main() { println(1.sz()) }
+fn main() { println(Sz.sz(1)) }
diff --git a/tests/golden/typecheck/traits/trait_sig__parameter_needs_annotation.silt b/tests/golden/typecheck/traits/trait_sig__parameter_needs_annotation.silt
index 12bda860e..1fa11f407 100644
--- a/tests/golden/typecheck/traits/trait_sig__parameter_needs_annotation.silt
+++ b/tests/golden/typecheck/traits/trait_sig__parameter_needs_annotation.silt
@@ -7,4 +7,4 @@
 -- stderr-contains: a trait declares complete signatures
 trait Mk { fn mk(self, other) -> Self }
 trait Mk for Int { fn mk(self, other) { other } }
-fn main() { println(1.mk(2)) }
+fn main() { println(Mk.mk(1, 2)) }
diff --git a/tests/golden/typecheck/traits/trait_sig__unannotated_impl_method_has_trait_types.silt b/tests/golden/typecheck/traits/trait_sig__unannotated_impl_method_has_trait_types.silt
index 91f3c59e5..c583eca40 100644
--- a/tests/golden/typecheck/traits/trait_sig__unannotated_impl_method_has_trait_types.silt
+++ b/tests/golden/typecheck/traits/trait_sig__unannotated_impl_method_has_trait_types.silt
@@ -8,5 +8,5 @@
 trait Scale { fn scale(self, by: Int) -> Int }
 trait Scale for Int { fn scale(self, by) { self * by } }
 trait Scale for Bool { fn scale(self, by) { "unannotated string" } }
-fn total(x: a, y: a) -> Int where a: Scale { x.scale(2) + y.scale(3) }
+fn total(x: a, y: a) -> Int where a: Scale { Scale.scale(x, 2) + Scale.scale(y, 3) }
 fn main() { println(total(1, 2)) }
diff --git a/tests/golden/typecheck/traits/two_traits_one_method_name__each_called_through_its_trait.silt b/tests/golden/typecheck/traits/two_traits_one_method_name__each_called_through_its_trait.silt
new file mode 100644
index 000000000..4e576810e
--- /dev/null
+++ b/tests/golden/typecheck/traits/two_traits_one_method_name__each_called_through_its_trait.silt
@@ -0,0 +1,10 @@
+-- Two traits providing `show`, both implemented for Int: each call names
+-- its trait, so neither is ambiguous.
+trait A { fn show(self) -> String }
+trait B { fn show(self) -> String }
+trait A for Int { fn show(self) -> String { "from-A" } }
+trait B for Int { fn show(self) -> String { "from-B" } }
+fn main() {
+  println(A.show(5))
+  println(B.show(5))
+}
diff --git a/tests/golden/typecheck/traits/two_traits_one_method_name__each_called_through_its_trait.stdout b/tests/golden/typecheck/traits/two_traits_one_method_name__each_called_through_its_trait.stdout
new file mode 100644
index 000000000..0606a3e6d
--- /dev/null
+++ b/tests/golden/typecheck/traits/two_traits_one_method_name__each_called_through_its_trait.stdout
@@ -0,0 +1,2 @@
+from-A
+from-B
diff --git a/tests/golden/typecheck/traits/type_descriptor_dispatch__generic_fn_body_with_constraint.silt b/tests/golden/typecheck/traits/type_descriptor_dispatch__generic_fn_body_with_constraint.silt
index 4885b5c84..f5c045cea 100644
--- a/tests/golden/typecheck/traits/type_descriptor_dispatch__generic_fn_body_with_constraint.silt
+++ b/tests/golden/typecheck/traits/type_descriptor_dispatch__generic_fn_body_with_constraint.silt
@@ -14,7 +14,7 @@ trait Monoid for Int {
 }
 
 fn reduce(xs: List(a), type a) -> a where a: Monoid {
-    list.fold(xs, a.empty()) { acc, x -> a.combine(acc, x) }
+    list.fold(xs, a.empty()) { acc, x -> Monoid.combine(acc, x) }
 }
 
 fn use_it() {
diff --git a/tests/golden/typecheck/traits/type_descriptor_dispatch__monoid_multi_arg.silt b/tests/golden/typecheck/traits/type_descriptor_dispatch__monoid_multi_arg.silt
index 6a23296ea..604270536 100644
--- a/tests/golden/typecheck/traits/type_descriptor_dispatch__monoid_multi_arg.silt
+++ b/tests/golden/typecheck/traits/type_descriptor_dispatch__monoid_multi_arg.silt
@@ -13,7 +13,7 @@ trait Monoid for Int {
 
 fn use_it() {
     let e = Int.empty()
-    let c = Int.combine(1, 2)
+    let c = Monoid.combine(1, 2)
 }
 
 fn main() {}
diff --git a/tests/golden/typecheck/traits/type_param_trait_impl__bad_descriptor_rejected.silt b/tests/golden/typecheck/traits/type_param_trait_impl__bad_descriptor_rejected.silt
index b7194c8e0..1bddca18e 100644
--- a/tests/golden/typecheck/traits/type_param_trait_impl__bad_descriptor_rejected.silt
+++ b/tests/golden/typecheck/traits/type_param_trait_impl__bad_descriptor_rejected.silt
@@ -11,7 +11,7 @@ trait Tag for Int {
 }
 
 fn use_it() {
-    let _ = 42.tag("not a type")
+    let _ = Tag.tag(42, "not a type")
 }
 
 fn main() {}
diff --git a/tests/golden/typecheck/traits/type_param_trait_impl__impl_type_param_dispatches.silt b/tests/golden/typecheck/traits/type_param_trait_impl__impl_type_param_dispatches.silt
index cddcd4be9..7654840ee 100644
--- a/tests/golden/typecheck/traits/type_param_trait_impl__impl_type_param_dispatches.silt
+++ b/tests/golden/typecheck/traits/type_param_trait_impl__impl_type_param_dispatches.silt
@@ -16,7 +16,7 @@ trait Decodable for String {
 }
 
 fn use_it(body: String) {
-    let _ = body.decode(Todo)
+    let _ = Decodable.decode(body, Todo)
 }
 
 fn main() {}
diff --git a/tests/golden/typecheck/traits/type_param_trait_impl__method_arg_offset.silt b/tests/golden/typecheck/traits/type_param_trait_impl__method_arg_offset.silt
index 4b792fea2..4ee5e4dfb 100644
--- a/tests/golden/typecheck/traits/type_param_trait_impl__method_arg_offset.silt
+++ b/tests/golden/typecheck/traits/type_param_trait_impl__method_arg_offset.silt
@@ -18,7 +18,7 @@ fn use_it() {
     -- Passing a record type here exercises: receiver=Int flows
     -- into the self slot via dispatch_method_entry; the explicit
     -- arg Box unifies against the `type a` slot (params[1]).
-    let _ = 42.cast(Box)
+    let _ = Cast.cast(42, Box)
 }
 
 fn main() {}
diff --git a/tests/golden/typecheck/traits/unified_trait_registration__error_default_message_synthesis.silt b/tests/golden/typecheck/traits/unified_trait_registration__error_default_message_synthesis.silt
index 0d413ea1d..b58d3be4b 100644
--- a/tests/golden/typecheck/traits/unified_trait_registration__error_default_message_synthesis.silt
+++ b/tests/golden/typecheck/traits/unified_trait_registration__error_default_message_synthesis.silt
@@ -8,5 +8,5 @@ trait Error for MyErr {}
 
 fn main() {
     let e = Boom
-    println(e.message())
+    println(Error.message(e))
 }
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_list.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_list.silt
index afd1cb8d5..00faf273b 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_list.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_list.silt
@@ -1,5 +1,5 @@
 -- `.compare()` on List(Int) through a Compare bound orders element-wise.
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() {
   let x: List(Int) = [1, 2, 3]
   let y: List(Int) = [1, 2, 4]
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_unit.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_unit.silt
index 03ca0cea6..ae44be97c 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_unit.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__compare_on_unit.silt
@@ -1,3 +1,3 @@
 -- `.compare()` on Unit through a Compare bound is 0.
-fn cmp_gen(a: a, b: a) -> Int where a: Compare { a.compare(b) }
+fn cmp_gen(a: a, b: a) -> Int where a: Compare { Compare.compare(a, b) }
 fn main() { println(cmp_gen((), ())) }
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_deterministic.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_deterministic.silt
index b16affff6..b5535e335 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_deterministic.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_deterministic.silt
@@ -1,5 +1,5 @@
 -- Hashing the same Int twice gives the same result.
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
   let a = h(42)
   let b = h(42)
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_err_string.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_err_string.silt
index 50411d2f8..0c5b6a777 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_err_string.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_err_string.silt
@@ -1,3 +1,3 @@
 -- `.hash()` through a Hash bound runs on a Result variant.
-fn h(v: a) -> Int where a: Hash { v.hash() }
+fn h(v: a) -> Int where a: Hash { Hash.hash(v) }
 fn main() { println(h(Err("boom")) == h(Err("boom"))) }
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_float_string_bool_list.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_float_string_bool_list.silt
index 589641667..6e4da06db 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_float_string_bool_list.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_float_string_bool_list.silt
@@ -1,5 +1,5 @@
 -- `.hash()` through a Hash bound runs on Float, String, Bool and List.
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
   println(h(3.14) == h(3.14))
   println(h("abc") == h("abc"))
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_int.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_int.silt
index cff8791d8..028408d1f 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_int.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_int.silt
@@ -1,5 +1,5 @@
 -- `.hash()` on Int through a Hash bound runs (the value itself is not pinned).
-fn h(a: a) -> Int where a: Hash { a.hash() }
+fn h(a: a) -> Int where a: Hash { Hash.hash(a) }
 fn main() {
   let v = h(42)
   println(v == v)
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_range.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_range.silt
index c102200f9..99e34016a 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_range.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_range.silt
@@ -1,5 +1,5 @@
 -- `.hash()` through a Hash bound runs on a range.
-fn h(v: a) -> Int where a: Hash { v.hash() }
+fn h(v: a) -> Int where a: Hash { Hash.hash(v) }
 fn main() {
   let r = 1..5
   println(h(r) == h(r))
diff --git a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_some_int.silt b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_some_int.silt
index 52d4700dd..32231beca 100644
--- a/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_some_int.silt
+++ b/tests/golden/typecheck/traits/vm_trait_dispatch_runtime__hash_on_some_int.silt
@@ -1,3 +1,3 @@
 -- `.hash()` through a Hash bound runs on an Option variant.
-fn h(v: a) -> Int where a: Hash { v.hash() }
+fn h(v: a) -> Int where a: Hash { Hash.hash(v) }
 fn main() { println(h(Some(1)) == h(Some(1))) }
diff --git a/tests/golden/typecheck/types/type_value__no_trait_and_no_message_names_its_internal_type.silt b/tests/golden/typecheck/types/type_value__no_trait_and_no_message_names_its_internal_type.silt
index e71aa8957..222affa66 100644
--- a/tests/golden/typecheck/types/type_value__no_trait_and_no_message_names_its_internal_type.silt
+++ b/tests/golden/typecheck/types/type_value__no_trait_and_no_message_names_its_internal_type.silt
@@ -25,11 +25,11 @@ fn less(x: a) -> Bool where a: Compare {
 }
 
 fn hashed(x: a) -> Int where a: Hash {
-  x.hash()
+  Hash.hash(x)
 }
 
 fn told(x: a) -> String where a: Show {
-  x.show()
+  Show.show(x)
 }
 
 fn named(type a) -> String {
diff --git a/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.silt b/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.silt
index 166bfc49f..361a24552 100644
--- a/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.silt
+++ b/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.silt
@@ -14,7 +14,7 @@ trait Greet for Int {
 }
 
 fn hello(x) {
-  x.greet()
+  Greet.greet(x)
   2
 }
 
diff --git a/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.stderr b/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.stderr
index ce2242980..8a1b879ab 100644
--- a/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.stderr
+++ b/tests/golden/typecheck/unused/unused_value__a_method_of_a_bounded_receiver.stderr
@@ -1,5 +1,5 @@
 error[type]: this `String` value is unused; write `let _ = ...` to discard it
  --> unused_value__a_method_of_a_bounded_receiver.silt:17:3
     |
- 17 |   x.greet()
-    |   ^^^^^^^^^ this `String` value is unused; write `let _ = ...` to discard it
+ 17 |   Greet.greet(x)
+    |   ^^^^^^^^^^^^^^ this `String` value is unused; write `let _ = ...` to discard it
diff --git a/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.silt b/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.silt
index a07309c4b..3afb126ed 100644
--- a/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.silt
+++ b/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.silt
@@ -9,18 +9,18 @@ trait Source {
   type Item
   fn next(self) -> Self::Item
   fn skip(self) -> String {
-    self.next()
+    Source.next(self)
     "skipped"
   }
 }
 
 fn drain(s: a) -> String where a: Source {
-  s.next()
+  Source.next(s)
   "drained"
 }
 
 fn drain_inferred(s) {
-  s.next()
+  Source.next(s)
   "drained"
 }
 
@@ -32,7 +32,7 @@ trait Source for Int {
 }
 
 fn main() {
-  println(1.skip())
+  println(Source.skip(1))
   println(drain(1))
   println(drain_inferred(1))
 }
diff --git a/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.stderr b/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.stderr
index ca12bab6b..b348caede 100644
--- a/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.stderr
+++ b/tests/golden/typecheck/unused/unused_value__an_associated_type_of_an_unknown_type.stderr
@@ -1,17 +1,17 @@
 error[type]: this `<Self as Source>::Item` value is unused; write `let _ = ...` to discard it
  --> unused_value__an_associated_type_of_an_unknown_type.silt:12:5
     |
- 12 |     self.next()
-    |     ^^^^^^^^^^^ this `<Self as Source>::Item` value is unused; write `let _ = ...` to discard it
+ 12 |     Source.next(self)
+    |     ^^^^^^^^^^^^^^^^^ this `<Self as Source>::Item` value is unused; write `let _ = ...` to discard it
 
 error[type]: this `<a as Source>::Item` value is unused; write `let _ = ...` to discard it
  --> unused_value__an_associated_type_of_an_unknown_type.silt:18:3
     |
- 18 |   s.next()
-    |   ^^^^^^^^ this `<a as Source>::Item` value is unused; write `let _ = ...` to discard it
+ 18 |   Source.next(s)
+    |   ^^^^^^^^^^^^^^ this `<a as Source>::Item` value is unused; write `let _ = ...` to discard it
 
 error[type]: this value is unused; write `let _ = ...` to discard it
  --> unused_value__an_associated_type_of_an_unknown_type.silt:23:3
     |
- 23 |   s.next()
-    |   ^^^^^^^^ this value is unused; write `let _ = ...` to discard it
+ 23 |   Source.next(s)
+    |   ^^^^^^^^^^^^^^ this value is unused; write `let _ = ...` to discard it
diff --git a/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.silt b/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.silt
index 05678e0d7..3c4f410d8 100644
--- a/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.silt
+++ b/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.silt
@@ -31,7 +31,7 @@ trait Source for Counter {
 }
 
 fn main() {
-  Disk { name: "a" }.next()
-  Counter { n: 1 }.next()
+  Source.next(Disk { name: "a" })
+  Source.next(Counter { n: 1 })
   println("done")
 }
diff --git a/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.stderr b/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.stderr
index b02922f0c..8b378ad65 100644
--- a/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.stderr
+++ b/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_a_value.stderr
@@ -1,11 +1,11 @@
 error[type]: this `Result` is unused: an error in it would go unseen; handle it, return it with `?`, or write `let _ = ...`
  --> unused_value__an_associated_type_that_is_a_value.silt:34:3
     |
- 34 |   Disk { name: "a" }.next()
-    |   ^^^^^^^^^^^^^^^^^^^^^^^^^ this `Result` is unused: an error in it would go unseen; handle it, return it with `?`, or write `let _ = ...`
+ 34 |   Source.next(Disk { name: "a" })
+    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this `Result` is unused: an error in it would go unseen; handle it, return it with `?`, or write `let _ = ...`
 
 error[type]: this `Int` value is unused; write `let _ = ...` to discard it
  --> unused_value__an_associated_type_that_is_a_value.silt:35:3
     |
- 35 |   Counter { n: 1 }.next()
-    |   ^^^^^^^^^^^^^^^^^^^^^^^ this `Int` value is unused; write `let _ = ...` to discard it
+ 35 |   Source.next(Counter { n: 1 })
+    |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this `Int` value is unused; write `let _ = ...` to discard it
diff --git a/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_unit.silt b/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_unit.silt
index 974b6a581..759dc82b4 100644
--- a/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_unit.silt
+++ b/tests/golden/typecheck/unused/unused_value__an_associated_type_that_is_unit.silt
@@ -19,7 +19,7 @@ trait Sink for Printer {
 
 fn main() {
   let p = Printer { name: "p" }
-  p.emit()
-  let u: () = p.emit()
+  Sink.emit(p)
+  let u: () = Sink.emit(p)
   println("done {u}")
 }
diff --git a/tests/golden/typecheck/unused/unused_value__in_trait_methods.silt b/tests/golden/typecheck/unused/unused_value__in_trait_methods.silt
index ea19a54b5..4fb3b45ac 100644
--- a/tests/golden/typecheck/unused/unused_value__in_trait_methods.silt
+++ b/tests/golden/typecheck/unused/unused_value__in_trait_methods.silt
@@ -5,8 +5,8 @@
 trait Describe {
   fn name(self) -> String
   fn twice(self) -> String {
-    self.name()
-    "{self.name()} {self.name()}"
+    Describe.name(self)
+    "{Describe.name(self)} {Describe.name(self)}"
   }
 }
 
@@ -18,5 +18,5 @@ trait Describe for Int {
 }
 
 fn main() {
-  println(3.twice())
+  println(Describe.twice(3))
 }
diff --git a/tests/golden/typecheck/unused/unused_value__in_trait_methods.stderr b/tests/golden/typecheck/unused/unused_value__in_trait_methods.stderr
index 2a11faa85..aa9854921 100644
--- a/tests/golden/typecheck/unused/unused_value__in_trait_methods.stderr
+++ b/tests/golden/typecheck/unused/unused_value__in_trait_methods.stderr
@@ -1,8 +1,8 @@
 error[type]: this `String` value is unused; write `let _ = ...` to discard it
  --> unused_value__in_trait_methods.silt:8:5
    |
- 8 |     self.name()
-   |     ^^^^^^^^^^^ this `String` value is unused; write `let _ = ...` to discard it
+ 8 |     Describe.name(self)
+   |     ^^^^^^^^^^^^^^^^^^^ this `String` value is unused; write `let _ = ...` to discard it
 
 error[type]: this `Int` value is unused; write `let _ = ...` to discard it
  --> unused_value__in_trait_methods.silt:15:5
diff --git a/tests/golden/typecheck/wave1/wave1_typechecker__guard_correct_impls_alias_and_range.silt b/tests/golden/typecheck/wave1/wave1_typechecker__guard_correct_impls_alias_and_range.silt
index 2b8a17b97..c7077e8cb 100644
--- a/tests/golden/typecheck/wave1/wave1_typechecker__guard_correct_impls_alias_and_range.silt
+++ b/tests/golden/typecheck/wave1/wave1_typechecker__guard_correct_impls_alias_and_range.silt
@@ -10,8 +10,8 @@ trait Bar for List(a) {
   fn bar(self) -> Int { 8 }
 }
 fn main() {
-  println([1, 2].foo())
-  println((1..3).foo())
-  println((1..3).bar())
-  println([4, 5].bar())
+  println(Foo.foo([1, 2]))
+  println(Foo.foo(1..3))
+  println(Bar.bar(1..3))
+  println(Bar.bar([4, 5]))
 }
diff --git a/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_alias_no_narrowing.silt b/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_alias_no_narrowing.silt
index fa239157b..fbd3992da 100644
--- a/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_alias_no_narrowing.silt
+++ b/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_alias_no_narrowing.silt
@@ -8,4 +8,4 @@ type Ints = List(Int)
 trait Foo for Ints {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() -> () { println([1, 2].foo()) }
+fn main() -> () { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_list_body_error.silt b/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_list_body_error.silt
index 14c39020e..50adb0269 100644
--- a/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_list_body_error.silt
+++ b/tests/golden/typecheck/wave1/wave1_typechecker__guard_impl_for_list_body_error.silt
@@ -7,4 +7,4 @@ trait Foo { fn foo(self) -> Int }
 trait Foo for List(a) {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() { println([1, 2].foo()) }
+fn main() { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/typecheck/wave1/wave1_typechecker__impl_error_with_other_errors.silt b/tests/golden/typecheck/wave1/wave1_typechecker__impl_error_with_other_errors.silt
index d3c88f06d..ed81f5a4a 100644
--- a/tests/golden/typecheck/wave1/wave1_typechecker__impl_error_with_other_errors.silt
+++ b/tests/golden/typecheck/wave1/wave1_typechecker__impl_error_with_other_errors.silt
@@ -12,5 +12,5 @@ trait Foo for Ints {
 fn helper(x) { x + 1 }
 fn main() {
   let n: String = helper(1)
-  println([1, 2].foo())
+  println(Foo.foo([1, 2]))
 }
diff --git a/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error.silt b/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error.silt
index 42ea26da7..ec0bc976b 100644
--- a/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error.silt
+++ b/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error.silt
@@ -8,4 +8,4 @@ type Ints = List(Int)
 trait Foo for Ints {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() { println([1, 2].foo()) }
+fn main() { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error_run.silt b/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error_run.silt
index e30342af0..4a831358d 100644
--- a/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error_run.silt
+++ b/tests/golden/typecheck/wave1/wave1_typechecker__impl_for_alias_body_error_run.silt
@@ -7,4 +7,4 @@ type Ints = List(Int)
 trait Foo for Ints {
   fn foo(self) -> Int { "not an int" }
 }
-fn main() { println([1, 2].foo()) }
+fn main() { println(Foo.foo([1, 2])) }
diff --git a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_fn_value_rejected.silt b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_fn_value_rejected.silt
index f44815758..6d4e98313 100644
--- a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_fn_value_rejected.silt
+++ b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_fn_value_rejected.silt
@@ -13,7 +13,7 @@ trait Keys for Named(a) where a: Display {
   fn k(self) -> Int { map.length(self) }
 }
 
-fn go(x: b) -> Int where b: Keys { x.k() }
+fn go(x: b) -> Int where b: Keys { Keys.k(x) }
 
 fn main() {
   println(go(#{ "a": { x -> x + 1 } }))
diff --git a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_value_slot_accepts.silt b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_value_slot_accepts.silt
index 29f7a9bdf..66c62fdbe 100644
--- a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_value_slot_accepts.silt
+++ b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__alias_value_slot_accepts.silt
@@ -12,7 +12,7 @@ trait Keys for Named(a) where a: Marked {
   fn k(self) -> Int { map.length(self) }
 }
 
-fn go(x: b) -> Int where b: Keys { x.k() }
+fn go(x: b) -> Int where b: Keys { Keys.k(x) }
 
 fn main() {
   println(go(#{ "a": 1 }))
diff --git a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_key_bound_rejected.silt b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_key_bound_rejected.silt
index 4de120120..75cf70380 100644
--- a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_key_bound_rejected.silt
+++ b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_key_bound_rejected.silt
@@ -11,7 +11,7 @@ trait Keyed for Map(k, v) where k: Marked {
   fn total(self) -> Int { map.length(self) }
 }
 
-fn go(x: b) -> Int where b: Keyed { x.total() }
+fn go(x: b) -> Int where b: Keyed { Keyed.total(x) }
 
 fn main() {
   println(go(#{ "a": 7 }))
diff --git a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_value_bound.silt b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_value_bound.silt
index 9b09cff8b..8cb4a8bce 100644
--- a/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_value_bound.silt
+++ b/tests/golden/typecheck/where_clauses/alias_impl_where_clause_slot__direct_map_value_bound.silt
@@ -9,7 +9,7 @@ trait Vals for Map(k, v) where v: Marked {
   fn total(self) -> Int { map.length(self) }
 }
 
-fn go(x: b) -> Int where b: Vals { x.total() }
+fn go(x: b) -> Int where b: Vals { Vals.total(x) }
 
 fn main() {
   println(go(#{ "a": 7 }))
diff --git a/tests/golden/typecheck/where_clauses/impl_header__bound_on_a_nested_part.silt b/tests/golden/typecheck/where_clauses/impl_header__bound_on_a_nested_part.silt
index 03c1c0f7e..5bccc0772 100644
--- a/tests/golden/typecheck/where_clauses/impl_header__bound_on_a_nested_part.silt
+++ b/tests/golden/typecheck/where_clauses/impl_header__bound_on_a_nested_part.silt
@@ -7,7 +7,7 @@ trait Marked { fn mark(self) -> String }
 trait Marked for Int { fn mark(self) -> String { "int" } }
 type Named(a) = Map(String, List(a))
 trait Marked for Named(a) where a: Marked { fn mark(self) -> String { "named" } }
-fn need(x: t) -> String where t: Marked { x.mark() }
+fn need(x: t) -> String where t: Marked { Marked.mark(x) }
 fn main() {
   println(need(#{ "a": [1] }))
   println(need(#{ "a": ["s"] }))
diff --git a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__closure_let.silt b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__closure_let.silt
index 1ac25447c..6eeaf9999 100644
--- a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__closure_let.silt
+++ b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__closure_let.silt
@@ -6,8 +6,8 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 type Box(a) { Box(a) }
-trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> i.greet() } } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> Greet.greet(i) } } }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   let g = { x -> hello(Box(x)) }
   println(g(3))
diff --git a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__decided_later.silt b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__decided_later.silt
index 7bec9d451..e77b8cb84 100644
--- a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__decided_later.silt
+++ b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__decided_later.silt
@@ -6,16 +6,16 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 type Box(a) { Box(a) }
-trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> i.greet() } } }
+trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> Greet.greet(i) } } }
 trait Greet for List(a) where a: Greet {
   fn greet(self) -> String {
     match self {
-      [x, ..r] -> x.greet()
+      [x, ..r] -> Greet.greet(x)
       _ -> "e"
     }
   }
 }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 import channel
 fn main() {
   let ch = channel.new(2)
diff --git a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__nothing_decides_the_type.silt b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__nothing_decides_the_type.silt
index 594171b07..3703957d3 100644
--- a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__nothing_decides_the_type.silt
+++ b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__nothing_decides_the_type.silt
@@ -6,7 +6,7 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 type Box(a) { Box(a) }
-trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> i.greet() } } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> Greet.greet(i) } } }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 import list
 fn main() { println(list.length(list.map([], hello))) }
diff --git a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__unannotated_fn.silt b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__unannotated_fn.silt
index ac7ad4314..6ece53acb 100644
--- a/tests/golden/typecheck/where_clauses/impl_header_sub_goal__unannotated_fn.silt
+++ b/tests/golden/typecheck/where_clauses/impl_header_sub_goal__unannotated_fn.silt
@@ -7,7 +7,7 @@
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 type Box(a) { Box(a) }
-trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> i.greet() } } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+trait Greet for Box(a) where a: Greet { fn greet(self) -> String { match self { Box(i) -> Greet.greet(i) } } }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn w(x) { hello(Box(x)) }
 fn main() { println(w("s")) }
diff --git a/tests/golden/typecheck/where_clauses/let_annotation_variable__cannot_have_a_bound.silt b/tests/golden/typecheck/where_clauses/let_annotation_variable__cannot_have_a_bound.silt
index 55ba87c6e..44906c1aa 100644
--- a/tests/golden/typecheck/where_clauses/let_annotation_variable__cannot_have_a_bound.silt
+++ b/tests/golden/typecheck/where_clauses/let_annotation_variable__cannot_have_a_bound.silt
@@ -5,7 +5,7 @@
 -- stderr-not-contains: enclosing function
 trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
-fn hello(x: a) -> String where a: Greet { x.greet() }
+fn hello(x: a) -> String where a: Greet { Greet.greet(x) }
 fn main() {
   let f: Fn(a) -> String = hello
   println(f(3))
diff --git a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__generic_impl_any_elements.silt b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__generic_impl_any_elements.silt
index f5ff06189..05608484b 100644
--- a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__generic_impl_any_elements.silt
+++ b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__generic_impl_any_elements.silt
@@ -1,5 +1,5 @@
 import list
 trait Total { fn total(self) -> Int }
 trait Total for List(a) { fn total(self) -> Int { list.length(self) } }
-fn sum_it(x: a) -> Int where a: Total { x.total() }
+fn sum_it(x: a) -> Int where a: Total { Total.total(x) }
 fn main() { println(sum_it(["a", "b", "c"])) }
diff --git a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_rejects_key_type.silt b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_rejects_key_type.silt
index 0e2aa6664..dff385b38 100644
--- a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_rejects_key_type.silt
+++ b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_rejects_key_type.silt
@@ -5,5 +5,5 @@ import map
 type Named(a) = Map(String, a)
 trait Keys { fn keys_count(self) -> Int }
 trait Keys for Named(a) { fn keys_count(self) -> Int { map.length(self) } }
-fn count_it(x: b) -> Int where b: Keys { x.keys_count() }
+fn count_it(x: b) -> Int where b: Keys { Keys.keys_count(x) }
 fn main() { println(count_it(#{ 1: true, 2: false })) }
diff --git a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_runs_matching_key.silt b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_runs_matching_key.silt
index 8fb417724..6a171ed38 100644
--- a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_runs_matching_key.silt
+++ b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__named_runs_matching_key.silt
@@ -2,5 +2,5 @@ import map
 type Named(a) = Map(String, a)
 trait Keys { fn keys_count(self) -> Int }
 trait Keys for Named(a) { fn keys_count(self) -> Int { map.length(self) } }
-fn count_it(x: b) -> Int where b: Keys { x.keys_count() }
+fn count_it(x: b) -> Int where b: Keys { Keys.keys_count(x) }
 fn main() { println(count_it(#{ "a": 1, "b": 2 })) }
diff --git a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__rejects_mismatched_elements.silt b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__rejects_mismatched_elements.silt
index 7a9f9a568..ae07f0138 100644
--- a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__rejects_mismatched_elements.silt
+++ b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__rejects_mismatched_elements.silt
@@ -9,5 +9,5 @@ import list
 type Bytes2 = List(Int)
 trait Total { fn total(self) -> Int }
 trait Total for Bytes2 { fn total(self) -> Int { list.fold(self, 0, { acc, x -> acc + x }) } }
-fn sum_it(x: a) -> Int where a: Total { x.total() }
+fn sum_it(x: a) -> Int where a: Total { Total.total(x) }
 fn main() { println(sum_it(["a", "b"])) }
diff --git a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__runs_matching_elements.silt b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__runs_matching_elements.silt
index da8b4e574..b8e64e634 100644
--- a/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__runs_matching_elements.silt
+++ b/tests/golden/typecheck/where_clauses/round102_alias_impl_self_type_args_where_bound__runs_matching_elements.silt
@@ -2,7 +2,7 @@ import list
 type Bytes2 = List(Int)
 trait Total { fn total(self) -> Int }
 trait Total for Bytes2 { fn total(self) -> Int { list.fold(self, 0, { acc, x -> acc + x }) } }
-fn sum_it(x: a) -> Int where a: Total { x.total() }
+fn sum_it(x: a) -> Int where a: Total { Total.total(x) }
 fn main() {
     let s = [1, 2] |> sum_it
     println(s)
diff --git a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__bare_tuple_impl_any_tuple.silt b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__bare_tuple_impl_any_tuple.silt
index beb0ab8d1..ce9ca5ba5 100644
--- a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__bare_tuple_impl_any_tuple.silt
+++ b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__bare_tuple_impl_any_tuple.silt
@@ -1,4 +1,4 @@
 trait Tag { fn tag(self) -> String }
 trait Tag for Tuple { fn tag(self) -> String { "tuple" } }
-fn tag_it(x: a) -> String where a: Tag { x.tag() }
+fn tag_it(x: a) -> String where a: Tag { Tag.tag(x) }
 fn main() { println(tag_it((1, "x", true))) }
diff --git a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_rejects_mismatched.silt b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_rejects_mismatched.silt
index 0a0af1d13..3551fed22 100644
--- a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_rejects_mismatched.silt
+++ b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_rejects_mismatched.silt
@@ -6,5 +6,5 @@
 type IntOp = Fn(Int) -> Int
 trait Apply1 { fn app(self) -> Int }
 trait Apply1 for IntOp { fn app(self) -> Int { self(41) + 1 } }
-fn go(x: a) -> Int where a: Apply1 { x.app() }
+fn go(x: a) -> Int where a: Apply1 { Apply1.app(x) }
 fn main() { println(go({ s: String -> "{s}!" })) }
diff --git a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_runs_matching.silt b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_runs_matching.silt
index d69fca873..9f6684b66 100644
--- a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_runs_matching.silt
+++ b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__fn_runs_matching.silt
@@ -1,5 +1,5 @@
 type IntOp = Fn(Int) -> Int
 trait Apply1 { fn app(self) -> Int }
 trait Apply1 for IntOp { fn app(self) -> Int { self(41) + 1 } }
-fn go(x: a) -> Int where a: Apply1 { x.app() }
+fn go(x: a) -> Int where a: Apply1 { Apply1.app(x) }
 fn main() { println(go({ x -> x + 1 })) }
diff --git a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_rejects_mismatched.silt b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_rejects_mismatched.silt
index cc36084e0..a77113932 100644
--- a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_rejects_mismatched.silt
+++ b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_rejects_mismatched.silt
@@ -11,5 +11,5 @@ trait Total for P2 {
     x + y
   }
 }
-fn sum_it(x: a) -> Int where a: Total { x.total() }
+fn sum_it(x: a) -> Int where a: Total { Total.total(x) }
 fn main() { println(sum_it(("a", "b"))) }
diff --git a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_runs_matching.silt b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_runs_matching.silt
index 250dc9fe3..c92517c88 100644
--- a/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_runs_matching.silt
+++ b/tests/golden/typecheck/where_clauses/round103_tuple_fn_alias_where_bound__tuple_runs_matching.silt
@@ -6,5 +6,5 @@ trait Total for P2 {
     x + y
   }
 }
-fn sum_it(x: a) -> Int where a: Total { x.total() }
+fn sum_it(x: a) -> Int where a: Total { Total.total(x) }
 fn main() { println(sum_it((1, 2))) }
diff --git a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__linear_two_param_mixed_slots.silt b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__linear_two_param_mixed_slots.silt
index e0f76af95..14c3cb30b 100644
--- a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__linear_two_param_mixed_slots.silt
+++ b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__linear_two_param_mixed_slots.silt
@@ -6,5 +6,5 @@ trait First for Two(a, b) where a: Display {
     "{x}"
   }
 }
-fn head_of(x: p) -> String where p: First { x.first_str() }
+fn head_of(x: p) -> String where p: First { First.first_str(x) }
 fn main() { println(head_of((7, "seven"))) }
diff --git a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_fn.silt b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_fn.silt
index 0a39315bb..a1ef74874 100644
--- a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_fn.silt
+++ b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_fn.silt
@@ -10,7 +10,7 @@ trait Show2 for Pair(a) where a: Display {
     "{x} and {y}"
   }
 }
-fn describe(x: p) -> String where p: Show2 { x.show2() }
+fn describe(x: p) -> String where p: Show2 { Show2.show2(x) }
 fn main() {
   let f = { n -> n + 1 }
   println(describe((1, f)))
diff --git a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_string.silt b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_string.silt
index 6920ac53e..913c45cf3 100644
--- a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_string.silt
+++ b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_rejects_int_string.silt
@@ -10,5 +10,5 @@ trait Show2 for Pair(a) where a: Display {
     "{x} and {y}"
   }
 }
-fn describe(x: p) -> String where p: Show2 { x.show2() }
+fn describe(x: p) -> String where p: Show2 { Show2.show2(x) }
 fn main() { println(describe((1, "z"))) }
diff --git a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_runs_matching.silt b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_runs_matching.silt
index 9c70d73a7..d19b95af7 100644
--- a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_runs_matching.silt
+++ b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__pair_runs_matching.silt
@@ -6,5 +6,5 @@ trait Show2 for Pair(a) where a: Display {
     "{x} and {y}"
   }
 }
-fn describe(x: p) -> String where p: Show2 { x.show2() }
+fn describe(x: p) -> String where p: Show2 { Show2.show2(x) }
 fn main() { println(describe((1, 2))) }
diff --git a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_rejects_mismatch.silt b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_rejects_mismatch.silt
index ae69d642d..a931da365 100644
--- a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_rejects_mismatch.silt
+++ b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_rejects_mismatch.silt
@@ -4,5 +4,5 @@
 type Square(a) = Map(a, a)
 trait Tag { fn tag(self) -> String }
 trait Tag for Square(a) { fn tag(self) -> String { "square" } }
-fn tag_it(x: t) -> String where t: Tag { x.tag() }
+fn tag_it(x: t) -> String where t: Tag { Tag.tag(x) }
 fn main() { println(tag_it(#{ "k": 1 })) }
diff --git a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_runs_matching.silt b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_runs_matching.silt
index 023e5bae9..21e5c3637 100644
--- a/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_runs_matching.silt
+++ b/tests/golden/typecheck/where_clauses/round104_nonlinear_impl_self_type_linkage__square_map_runs_matching.silt
@@ -1,5 +1,5 @@
 type Square(a) = Map(a, a)
 trait Tag { fn tag(self) -> String }
 trait Tag for Square(a) { fn tag(self) -> String { "square" } }
-fn tag_it(x: t) -> String where t: Tag { x.tag() }
+fn tag_it(x: t) -> String where t: Tag { Tag.tag(x) }
 fn main() { println(tag_it(#{ 1: 2 })) }
diff --git a/tests/golden/typecheck/where_clauses/trait_args_verification__matching_args_ok.silt b/tests/golden/typecheck/where_clauses/trait_args_verification__matching_args_ok.silt
index 045fd8cff..498c754c3 100644
--- a/tests/golden/typecheck/where_clauses/trait_args_verification__matching_args_ok.silt
+++ b/tests/golden/typecheck/where_clauses/trait_args_verification__matching_args_ok.silt
@@ -1,4 +1,4 @@
 trait TryInto(b) { fn try_into(self) -> Result(b, String) }
 trait TryInto(Float) for String { fn try_into(self) { Ok(1.5) } }
-fn convert(s: a) -> Result(Float, String) where a: TryInto(Float) { s.try_into() }
+fn convert(s: a) -> Result(Float, String) where a: TryInto(Float) { TryInto.try_into(s) }
 fn main() { println(convert("hi")) }
diff --git a/tests/golden/typecheck/where_clauses/trait_args_verification__mismatched_args_rejected.silt b/tests/golden/typecheck/where_clauses/trait_args_verification__mismatched_args_rejected.silt
index 043d3b2c6..64b70376d 100644
--- a/tests/golden/typecheck/where_clauses/trait_args_verification__mismatched_args_rejected.silt
+++ b/tests/golden/typecheck/where_clauses/trait_args_verification__mismatched_args_rejected.silt
@@ -4,5 +4,5 @@
 -- stderr-contains: TryInto(Int)
 trait TryInto(b) { fn try_into(self) -> Result(b, String) }
 trait TryInto(Float) for String { fn try_into(self) { Ok(1.5) } }
-fn convert(s: a) -> Result(Int, String) where a: TryInto(Int) { s.try_into() }
+fn convert(s: a) -> Result(Int, String) where a: TryInto(Int) { TryInto.try_into(s) }
 fn main() { println(convert("hi")) }
diff --git a/tests/golden/typecheck/where_clauses/trait_args_verification__parameterless_where_ok.silt b/tests/golden/typecheck/where_clauses/trait_args_verification__parameterless_where_ok.silt
index c00594c89..0f6f20f0d 100644
--- a/tests/golden/typecheck/where_clauses/trait_args_verification__parameterless_where_ok.silt
+++ b/tests/golden/typecheck/where_clauses/trait_args_verification__parameterless_where_ok.silt
@@ -1,4 +1,4 @@
 trait MyDisplay { fn my_display(self) -> String }
 trait MyDisplay for Int { fn my_display(self) -> String { "int" } }
-fn show(x: a) -> String where a: MyDisplay { x.my_display() }
+fn show(x: a) -> String where a: MyDisplay { MyDisplay.my_display(x) }
 fn main() { println(show(42)) }
diff --git a/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__impl_level_where_args.silt b/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__impl_level_where_args.silt
index e9147876b..d777fc391 100644
--- a/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__impl_level_where_args.silt
+++ b/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__impl_level_where_args.silt
@@ -11,14 +11,14 @@ trait UseIt for List(a) where a: Conv(Int) {
       match self {
           [] -> 0
           [x, ..rest] -> {
-            let n: Int = x.conv()
-            n + rest.use_it()
+            let n: Int = Conv.conv(x)
+            n + UseIt.use_it(rest)
           }
       }
     }
 }
 fn main() {
     let xs: List(Int) = [1, 2, 3]
-    let r: Int = xs.use_it()
+    let r: Int = UseIt.use_it(xs)
     println(r)
 }
diff --git a/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__method_signature_mismatch_span.silt b/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__method_signature_mismatch_span.silt
index b698f8c5d..a89ea3877 100644
--- a/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__method_signature_mismatch_span.silt
+++ b/tests/golden/typecheck/where_clauses/trait_args_where_clause_runtime__method_signature_mismatch_span.silt
@@ -9,4 +9,4 @@ trait Foo(a) { fn bar(self: a) -> Int }
 trait Foo(String) for String {
   fn bar(self) -> String { "hello" }
 }
-fn main() { println("x".bar()) }
+fn main() { println(Foo.bar("x")) }
diff --git a/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl.silt b/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl.silt
index 42eae352a..80e775004 100644
--- a/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl.silt
+++ b/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl.silt
@@ -6,6 +6,6 @@
 -- a function of a String.
 trait Conv(to) { fn conv(self) -> to }
 trait Conv(String) for Int { fn conv(self) -> String { "an int" } }
-fn s(x: a, y: b) -> b where a: Conv(b) { x.conv() }
+fn s(x: a, y: b) -> b where a: Conv(b) { Conv.conv(x) }
 fn w(y) { s(3, y) }
 fn main() { println(w(1) + 1) }
diff --git a/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl_accepts.silt b/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl_accepts.silt
index 756a8f545..013a56fe5 100644
--- a/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl_accepts.silt
+++ b/tests/golden/typecheck/where_clauses/trait_argument__decided_by_the_impl_accepts.silt
@@ -1,7 +1,7 @@
 -- The same, used at the type the impl says.
 trait Conv(to) { fn conv(self) -> to }
 trait Conv(String) for Int { fn conv(self) -> String { "an int" } }
-fn s(x: a, y: b) -> b where a: Conv(b) { x.conv() }
+fn s(x: a, y: b) -> b where a: Conv(b) { Conv.conv(x) }
 fn w(y) { s(3, y) }
 fn main() {
   let g = { y -> s(3, y) }
diff --git a/tests/golden/typecheck/where_clauses/trait_argument__rigid_bound_argument_differs.silt b/tests/golden/typecheck/where_clauses/trait_argument__rigid_bound_argument_differs.silt
index 0ea976709..5c7c08fc6 100644
--- a/tests/golden/typecheck/where_clauses/trait_argument__rigid_bound_argument_differs.silt
+++ b/tests/golden/typecheck/where_clauses/trait_argument__rigid_bound_argument_differs.silt
@@ -4,6 +4,6 @@
 -- A declared bound has its trait arguments: `a: Conv(String)` does not
 -- give `a: Conv(Int)`.
 trait Conv(to) { fn conv(self) -> to }
-fn need_int(x: a) -> Int where a: Conv(Int) { x.conv() }
+fn need_int(x: a) -> Int where a: Conv(Int) { Conv.conv(x) }
 fn f(x: a) -> Int where a: Conv(String) { need_int(x) }
 fn main() { println(1) }
diff --git a/tests/golden/typecheck/where_clauses/trait_argument__sub_goal_with_argument.silt b/tests/golden/typecheck/where_clauses/trait_argument__sub_goal_with_argument.silt
index 43eb4a935..de05a3056 100644
--- a/tests/golden/typecheck/where_clauses/trait_argument__sub_goal_with_argument.silt
+++ b/tests/golden/typecheck/where_clauses/trait_argument__sub_goal_with_argument.silt
@@ -5,8 +5,8 @@
 -- is owed with its argument.
 trait Conv(to) { fn conv(self) -> to }
 trait Conv(String) for Int { fn conv(self) -> String { "an int" } }
-fn s(x: a, y: b) -> b where a: Conv(b) { x.conv() }
+fn s(x: a, y: b) -> b where a: Conv(b) { Conv.conv(x) }
 type Box(a) { Box(a) }
-trait Conv(String) for Box(a) where a: Conv(String) { fn conv(self) -> String { match self { Box(i) -> i.conv() } } }
+trait Conv(String) for Box(a) where a: Conv(String) { fn conv(self) -> String { match self { Box(i) -> Conv.conv(i) } } }
 fn w(y) { s(Box(y), "q") }
 fn main() { println(w(true)) }
diff --git a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt
index c22f4655a..8d0d3c134 100644
--- a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt
+++ b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt
@@ -1,10 +1,12 @@
 -- cmd: check
 -- exit: 1
--- Two bounds of one trait at different arguments are two bounds: a
--- method both give is ambiguous (on a value and on a `type a`), whether
--- its type names the trait's argument or not, with the bounds help; a
--- function that needs one of the two is given it, and one that needs a
--- third is told the two that are declared.
+-- Two bounds of one trait at different arguments are two bounds: a call
+-- through the trait whose type does not decide the argument is
+-- ambiguous (`Conv.show`), one whose result type does is not
+-- (`Conv.conv` returning String); a constructor on a `type a` both give
+-- is ambiguous, with the bounds help; a function that needs one of the
+-- two is given it, and one that needs a third is told the two that are
+-- declared.
 trait Conv(b) {
   fn show(self) -> String
   fn conv(self) -> b
@@ -15,11 +17,11 @@ trait Make(b) {
 }
 
 fn shown(x: a) -> String where a: Conv(Int), a: Conv(String) {
-  x.show()
+  Conv.show(x)
 }
 
 fn converted(x: a) -> String where a: Conv(Int) + Conv(String) {
-  x.conv()
+  Conv.conv(x)
 }
 
 fn made(type a) -> a where a: Make(Int), a: Make(String) {
@@ -27,7 +29,7 @@ fn made(type a) -> a where a: Make(Int), a: Make(String) {
 }
 
 fn one(x: a) -> String where a: Conv(String) {
-  x.show()
+  Conv.show(x)
 }
 
 fn passes(x: a) -> String where a: Conv(Int), a: Conv(String) {
@@ -35,7 +37,7 @@ fn passes(x: a) -> String where a: Conv(Int), a: Conv(String) {
 }
 
 fn other(x: a) -> String where a: Conv(Bool) {
-  x.show()
+  Conv.show(x)
 }
 
 fn wrong(x: a) -> String where a: Conv(Int), a: Conv(String) {
diff --git a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.stderr b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.stderr
index 0303288e1..09c66fcc6 100644
--- a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.stderr
+++ b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_method_both_give_is_ambiguous.stderr
@@ -1,26 +1,18 @@
-error[type]: ambiguous method 'show' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
- --> two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt:18:3
+error[type]: type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', and which of them this use needs is not known
+ --> two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt:20:13
     |
- 18 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
-  = help: the bounds `Conv(Int)` and `Conv(String)` both give `show`: call it from a function bounded by only one of them
-
-error[type]: ambiguous method 'conv' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
- --> two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt:22:3
-    |
- 22 |   x.conv()
-    |   ^^^^^^ ambiguous method 'conv' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
-  = help: the bounds `Conv(Int)` and `Conv(String)` both give `conv`: call it from a function bounded by only one of them
+ 20 |   Conv.show(x)
+    |             ^ type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', and which of them this use needs is not known
 
 error[type]: ambiguous method 'make' on `type a`: provided by bounds Make(Int), Make(String)
- --> two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt:26:3
+ --> two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt:28:3
     |
- 26 |   a.make()
+ 28 |   a.make()
     |   ^^^^^^ ambiguous method 'make' on `type a`: provided by bounds Make(Int), Make(String)
   = help: the bounds `Make(Int)` and `Make(String)` both give `make`: call it from a function bounded by only one of them
 
 error[type]: type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', not 'Conv(Bool)'
- --> two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt:42:9
+ --> two_bounds_of_one_trait__a_method_both_give_is_ambiguous.silt:44:9
     |
- 42 |   other(x)
+ 44 |   other(x)
     |         ^ type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', not 'Conv(Bool)'
diff --git a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_use_waits_for_its_arguments.silt b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_use_waits_for_its_arguments.silt
index b5a71e5fb..a363050ca 100644
--- a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_use_waits_for_its_arguments.silt
+++ b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__a_use_waits_for_its_arguments.silt
@@ -12,7 +12,7 @@ type T { n: Int }
 trait Conv(b) for T {
   fn show(self) -> String { "T {self.n}" }
 }
-fn gen2(x: a, y: List(c)) -> String where a: Conv(c) { x.show() }
+fn gen2(x: a, y: List(c)) -> String where a: Conv(c) { Conv.show(x) }
 fn both(x: a, ys) -> String where a: Conv(Int), a: Conv(String) {
   let r = gen2(x, ys)
   let _ = [1] == ys
diff --git a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt
index aec2369c3..311dd534a 100644
--- a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt
+++ b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt
@@ -1,8 +1,9 @@
 -- cmd: check
 -- exit: 1
--- The help of a method two bounds give names the bounds as the `where`
--- clause writes them: `Sub(Int)`, whose supertrait `Conv(Int)` gives the
--- method, and `Conv(String)`; two bounds of a subtrait are named so too.
+-- A call through a trait whose argument two bounds give differently is
+-- ambiguous: `Sub(Int)` gives `Conv(Int)` through its supertrait, beside
+-- `Conv(String)`, and two bounds of a subtrait give two too; a bound and
+-- a subtrait's bound at one argument are one.
 trait Conv(b) {
   fn show(self) -> String
 }
@@ -12,15 +13,15 @@ trait Sub(b): Conv(b) {
 }
 
 fn mixed(x: a) -> String where a: Sub(Int), a: Conv(String) {
-  x.show()
+  Conv.show(x)
 }
 
 fn subs(x: a) -> String where a: Sub(Int), a: Sub(String) {
-  x.show()
+  Conv.show(x)
 }
 
 fn same(x: a) -> String where a: Sub(Int), a: Conv(Int) {
-  x.show()
+  Conv.show(x)
 }
 
 fn main() {
diff --git a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.stderr b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.stderr
index 3592b6b28..4cf6df55e 100644
--- a/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.stderr
+++ b/tests/golden/typecheck/where_clauses/two_bounds_of_one_trait__the_help_names_the_bounds_as_written.stderr
@@ -1,13 +1,11 @@
-error[type]: ambiguous method 'show' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
- --> two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt:15:3
+error[type]: type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', and which of them this use needs is not known
+ --> two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt:16:13
     |
- 15 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
-  = help: the bounds `Conv(String)` and `Sub(Int)` both give `show`: call it from a function bounded by only one of them
+ 16 |   Conv.show(x)
+    |             ^ type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', and which of them this use needs is not known
 
-error[type]: ambiguous method 'show' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
- --> two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt:19:3
+error[type]: type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', and which of them this use needs is not known
+ --> two_bounds_of_one_trait__the_help_names_the_bounds_as_written.silt:20:13
     |
- 19 |   x.show()
-    |   ^^^^^^ ambiguous method 'show' on a value of type `a`: provided by bounds Conv(Int), Conv(String)
-  = help: the bounds `Sub(Int)` and `Sub(String)` both give `show`: call it from a function bounded by only one of them
+ 20 |   Conv.show(x)
+    |             ^ type variable `a` is declared to implement 'Conv(Int)' and 'Conv(String)', and which of them this use needs is not known
diff --git a/tests/golden/typecheck/where_clauses/unknown_trait_in_where__no_cascade_on_method_calls.silt b/tests/golden/typecheck/where_clauses/unknown_trait_in_where__no_cascade_on_method_calls.silt
index 30e45d72a..e02520c5e 100644
--- a/tests/golden/typecheck/where_clauses/unknown_trait_in_where__no_cascade_on_method_calls.silt
+++ b/tests/golden/typecheck/where_clauses/unknown_trait_in_where__no_cascade_on_method_calls.silt
@@ -9,7 +9,7 @@
 -- stderr-not-contains: does not declare constraint
 type Box(a) { Box(a) }
 trait Loud { fn loud(self) -> String }
-fn shout(x: a) -> String where a: Loud { x.loud() }
+fn shout(x: a) -> String where a: Loud { Loud.loud(x) }
 fn f(x: a) -> String where a: Lowd { "{x.loud()}{shout(x)}" }
 trait Loud for Box(a) where a: Lowd {
   fn loud(self) -> String { match self { Box(v) -> v.loud() } }
diff --git a/tests/golden/typecheck/where_clauses/where_clause_bound_arity__matching_arity_ok.silt b/tests/golden/typecheck/where_clauses/where_clause_bound_arity__matching_arity_ok.silt
index 9addd53f4..ba130197c 100644
--- a/tests/golden/typecheck/where_clauses/where_clause_bound_arity__matching_arity_ok.silt
+++ b/tests/golden/typecheck/where_clauses/where_clause_bound_arity__matching_arity_ok.silt
@@ -4,7 +4,7 @@ trait Cast(to) {
 trait Cast(Float) for Int {
   fn cast(self) -> Float { 1.0 }
 }
-fn g(x: a) -> Float where a: Cast(Float) { x.cast() }
+fn g(x: a) -> Float where a: Cast(Float) { Cast.cast(x) }
 fn main() {
   println(g(42))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_clause_bound_arity__parameterless_trait_ok.silt b/tests/golden/typecheck/where_clauses/where_clause_bound_arity__parameterless_trait_ok.silt
index ab1756928..6b1db0ddc 100644
--- a/tests/golden/typecheck/where_clauses/where_clause_bound_arity__parameterless_trait_ok.silt
+++ b/tests/golden/typecheck/where_clauses/where_clause_bound_arity__parameterless_trait_ok.silt
@@ -4,5 +4,5 @@
 trait Display2 {
   fn display2(self) -> String
 }
-fn g(x: a) -> String where a: Display2 { x.display2() }
+fn g(x: a) -> String where a: Display2 { Display2.display2(x) }
 fn main() { }
diff --git a/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_matching_arity_runs.silt b/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_matching_arity_runs.silt
index 611c16f09..6118e2500 100644
--- a/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_matching_arity_runs.silt
+++ b/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_matching_arity_runs.silt
@@ -6,11 +6,11 @@ trait Use for List(a) where a: Conv(Int) {
     fn use_it(self) -> Int {
       match self {
           [] -> 0
-          [x, ..rest] -> x.conv() + rest.use_it()
+          [x, ..rest] -> Conv.conv(x) + Use.use_it(rest)
       }
     }
 }
 fn main() {
     let xs: List(Int) = [1, 2, 3]
-    println(xs.use_it())
+    println(Use.use_it(xs))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity.silt b/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity.silt
index 0365a3d9c..5833a300f 100644
--- a/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity.silt
+++ b/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity.silt
@@ -9,11 +9,11 @@ trait Use for List(a) where a: Cast(Int, String) {
     fn use_it(self) -> Float {
       match self {
           [] -> 0.0
-          [x, ..rest] -> x.cast() + rest.use_it()
+          [x, ..rest] -> x.cast() + Use.use_it(rest)
       }
     }
 }
 fn main() {
     let xs: List(Int) = [1]
-    println(xs.use_it())
+    println(Use.use_it(xs))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity_run.silt b/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity_run.silt
index 8961d2dea..f6b262a68 100644
--- a/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity_run.silt
+++ b/tests/golden/typecheck/where_clauses/where_clause_bound_arity_mismatch__impl_level_over_arity_run.silt
@@ -8,11 +8,11 @@ trait Use for List(a) where a: Cast(Int, String) {
     fn use_it(self) -> Float {
       match self {
           [] -> 0.0
-          [x, ..rest] -> x.cast() + rest.use_it()
+          [x, ..rest] -> x.cast() + Use.use_it(rest)
       }
     }
 }
 fn main() {
     let xs: List(Int) = [1]
-    println(xs.use_it())
+    println(Use.use_it(xs))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_rejects_int.silt b/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_rejects_int.silt
index 664bd39be..e2ef959b0 100644
--- a/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_rejects_int.silt
+++ b/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_rejects_int.silt
@@ -4,6 +4,6 @@
 -- A where-constraint survives a lambda wrapper: calling f(42) is rejected.
 trait Greetable { fn greet(self) -> String }
 trait Greetable for String { fn greet(self) -> String { self } }
-fn use_g(x: a) -> String where a: Greetable { x.greet() }
+fn use_g(x: a) -> String where a: Greetable { Greetable.greet(x) }
 let f = { x -> use_g(x) }
 fn main() { f(42) }
diff --git a/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_valid_call.silt b/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_valid_call.silt
index 07b48c0fa..b6ffcc8a4 100644
--- a/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_valid_call.silt
+++ b/tests/golden/typecheck/where_clauses/where_constraint_alias__lambda_wrapper_valid_call.silt
@@ -2,6 +2,6 @@
 -- A valid call through the lambda wrapper still runs.
 trait Greetable { fn greet(self) -> String }
 trait Greetable for String { fn greet(self) -> String { self } }
-fn use_g(x: a) -> String where a: Greetable { x.greet() }
+fn use_g(x: a) -> String where a: Greetable { Greetable.greet(x) }
 let f = { x -> use_g(x) }
 fn main() { println(f("hello")) }
diff --git a/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_rejects_int.silt b/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_rejects_int.silt
index b18b783c8..ee5a04580 100644
--- a/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_rejects_int.silt
+++ b/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_rejects_int.silt
@@ -4,6 +4,6 @@
 -- A where-constraint survives `let f = use_g`: calling f(42) is rejected.
 trait Greetable { fn greet(self) -> String }
 trait Greetable for String { fn greet(self) -> String { self } }
-fn use_g(x: a) -> String where a: Greetable { x.greet() }
+fn use_g(x: a) -> String where a: Greetable { Greetable.greet(x) }
 let f = use_g
 fn main() { f(42) }
diff --git a/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_valid_call.silt b/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_valid_call.silt
index 5aa637d71..f06428189 100644
--- a/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_valid_call.silt
+++ b/tests/golden/typecheck/where_clauses/where_constraint_alias__let_alias_valid_call.silt
@@ -2,6 +2,6 @@
 -- A valid call through the `let` alias still runs.
 trait Greetable { fn greet(self) -> String }
 trait Greetable for String { fn greet(self) -> String { self } }
-fn use_g(x: a) -> String where a: Greetable { x.greet() }
+fn use_g(x: a) -> String where a: Greetable { Greetable.greet(x) }
 let f = use_g
 fn main() { println(f("hello")) }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_header__bound_accepts_and_runs.silt b/tests/golden/typecheck/where_clauses/where_impl_header__bound_accepts_and_runs.silt
index c450b623b..8a0279931 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_header__bound_accepts_and_runs.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_header__bound_accepts_and_runs.silt
@@ -6,11 +6,11 @@ trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Wrap { fn unwrap(self) -> String }
 trait Wrap for Box(a) where a: Greet {
   fn unwrap(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
-fn through(x: t) -> String where t: Wrap { x.unwrap() }
+fn through(x: t) -> String where t: Wrap { Wrap.unwrap(x) }
 fn main() {
-  println(Box(42).unwrap())
+  println(Wrap.unwrap(Box(42)))
   println(through(Box(7)))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_header__bound_with_trait_argument_runs.silt b/tests/golden/typecheck/where_clauses/where_impl_header__bound_with_trait_argument_runs.silt
index 5984e69ab..bec7d05c2 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_header__bound_with_trait_argument_runs.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_header__bound_with_trait_argument_runs.silt
@@ -8,7 +8,7 @@ trait Foo for Box(a) where a: Conv(Int) {
     fn do_it(self) -> Int {
       match self {
           Wrap(x) -> {
-            let n: Int = x.conv()
+            let n: Int = Conv.conv(x)
             n + 100
           }
       }
@@ -16,5 +16,5 @@ trait Foo for Box(a) where a: Conv(Int) {
 }
 fn main() {
     let b: Box(String) = Wrap("five")
-    println(b.do_it())
+    println(Foo.do_it(b))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_positive.silt b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_positive.silt
index 6a4a3fc30..52a50b533 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_positive.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_positive.silt
@@ -3,8 +3,8 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
-fn use_box(b: Box(a)) -> String where a: Greet { b.greet() }
+fn use_box(b: Box(a)) -> String where a: Greet { Greet.greet(b) }
 fn main() { println(use_box(Box(99))) }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_rejection.silt b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_rejection.silt
index 3cd777214..1098ee426 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_rejection.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__generic_fn_propagates_rejection.silt
@@ -6,10 +6,10 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
-fn use_box(b: Box(a)) -> String where a: Greet { b.greet() }
+fn use_box(b: Box(a)) -> String where a: Greet { Greet.greet(b) }
 fn main() {
   let bad = Box("hello")
   println(use_box(bad))
diff --git a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_accepts_int.silt b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_accepts_int.silt
index ab290efc1..287392e92 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_accepts_int.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_accepts_int.silt
@@ -3,9 +3,9 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
-  println(Box(42).greet())
+  println(Greet.greet(Box(42)))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_rejects_string.silt b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_rejects_string.silt
index 7d0b8447d..e096a1a26 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_rejects_string.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__impl_where_rejects_string.silt
@@ -6,10 +6,10 @@ trait Greet { fn greet(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
   let b = Box("hello")
-  println(b.greet())
+  println(Greet.greet(b))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__method_where_rejects_at_call_site.silt b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__method_where_rejects_at_call_site.silt
index 6f81628ba..ee14e222c 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__method_where_rejects_at_call_site.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__method_where_rejects_at_call_site.silt
@@ -1,7 +1,6 @@
 -- cmd: check
 -- exit: 1
 -- stderr-contains: adds the bound `a: Greet`, which the trait does not declare for it
--- stderr-contains: type 'String' does not implement trait 'Greet'
 -- A bound on the impl's type variable belongs on the impl's header: a
 -- call through the trait does not know a method's own.
 type Box(a) { Box(a) }
@@ -10,10 +9,10 @@ trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Wrap { fn unwrap(self) -> String }
 trait Wrap for Box(a) {
   fn unwrap(self) -> String where a: Greet {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
   let b = Box("hello")
-  println(b.unwrap())
+  println(Wrap.unwrap(b))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_greet.silt b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_greet.silt
index 1ef30c5c3..ff5360cf8 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_greet.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_greet.silt
@@ -7,10 +7,10 @@ trait Loud { fn loud(self) -> String }
 trait Loud for Int { fn loud(self) -> String { "INT" } }
 trait Greet for Box(a) where a: Greet + Loud {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.loud() }
+    match self { Box(inner) -> Loud.loud(inner) }
   }
 }
 fn main() {
   let b = Box(5)
-  println(b.greet())
+  println(Greet.greet(b))
 }
diff --git a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_loud.silt b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_loud.silt
index 7fac70793..6dec5e80c 100644
--- a/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_loud.silt
+++ b/tests/golden/typecheck/where_clauses/where_impl_level_enforcement__multi_constraint_missing_loud.silt
@@ -7,10 +7,10 @@ trait Loud { fn loud(self) -> String }
 trait Greet for Int { fn greet(self) -> String { "int" } }
 trait Greet for Box(a) where a: Greet + Loud {
   fn greet(self) -> String {
-    match self { Box(inner) -> inner.greet() }
+    match self { Box(inner) -> Greet.greet(inner) }
   }
 }
 fn main() {
   let b = Box(5)
-  println(b.greet())
+  println(Greet.greet(b))
 }
diff --git a/tests/heavy/integration.rs b/tests/heavy/integration.rs
index 4ac5d5bf2..2a5803d8d 100644
--- a/tests/heavy/integration.rs
+++ b/tests/heavy/integration.rs
@@ -815,9 +815,9 @@ fn main() {
     let body = match http.get("http://127.0.0.1:{port}/test") {
       Ok(resp) -> match bytes.to_string(resp.body) {
         Ok(text) -> text
-        Err(e) -> "the body is no text: {e.message()}"
+        Err(e) -> "the body is no text: {Error.message(e)}"
       }
-      Err(e) -> "the request failed: {e.message()}"
+      Err(e) -> "the request failed: {Error.message(e)}"
     }
     channel.send(result_ch, body)
   })
diff --git a/tests/heavy/repl_session.rs b/tests/heavy/repl_session.rs
index e8c1bf169..7c248b8d6 100644
--- a/tests/heavy/repl_session.rs
+++ b/tests/heavy/repl_session.rs
@@ -35,7 +35,7 @@ fn session(rounds: usize, waiting: bool) -> (Vec<String>, Vec<usize>) {
             "trait Named for T{i} {{ fn name(self) -> String {{ \"t{i}\" }} }}"
         ));
         entries.push(format!(
-            "println(\"M {{f{i}(1)}} {{T{i} {{ a: 1 }}.name()}}\")"
+            "println(\"M {{f{i}(1)}} {{Named.name(T{i} {{ a: 1 }})}}\")"
         ));
         markers.push(entries.len());
         entries.push(format!("let bad{i}: Int = \"s\""));
diff --git a/tests/heavy/runtime_scaling.rs b/tests/heavy/runtime_scaling.rs
index 5a333df98..931deed8e 100644
--- a/tests/heavy/runtime_scaling.rs
+++ b/tests/heavy/runtime_scaling.rs
@@ -418,7 +418,7 @@ trait Size for Other{i} {{
             )
         })
         .collect();
-    let call = format!("x.{method}()");
+    let call = format!("Size.{method}(x)");
     let calls = [call.as_str(); 8].join(" + ");
     format!(
         "trait Size {{
diff --git a/tests/lang/builtin_structural_traits_tests.rs b/tests/lang/builtin_structural_traits_tests.rs
index bbe5cdd56..c2e8c67b1 100644
--- a/tests/lang/builtin_structural_traits_tests.rs
+++ b/tests/lang/builtin_structural_traits_tests.rs
@@ -7,7 +7,7 @@
 #[test]
 fn every_builtin_enum_has_stamps_for_policy_permitted_traits() {
     use silt::typechecker::__trait_init_fingerprint_check_program;
-    let (impls, _) = __trait_init_fingerprint_check_program();
+    let impls = __trait_init_fingerprint_check_program();
     // Built-in enums that should have all four built-in trait stamps
     // (every variant arg type is Compare/Equal/Hash/Display-able).
     for type_name in [
@@ -58,7 +58,7 @@ fn every_builtin_enum_has_stamps_for_policy_permitted_traits() {
 #[test]
 fn every_builtin_record_has_stamps_for_policy_permitted_traits() {
     use silt::typechecker::__trait_init_fingerprint_check_program;
-    let (impls, _) = __trait_init_fingerprint_check_program();
+    let impls = __trait_init_fingerprint_check_program();
     // time records — all four built-in trait stamps via
     // `register_structural_traits_for(time, &[...], all_auto_traits)`.
     for type_name in ["Instant", "Date", "Time", "DateTime", "Duration"] {
diff --git a/tests/lang/deep_value_stack_tests.rs b/tests/lang/deep_value_stack_tests.rs
index dbf1bab8b..2b0a3dfcf 100644
--- a/tests/lang/deep_value_stack_tests.rs
+++ b/tests/lang/deep_value_stack_tests.rs
@@ -91,7 +91,7 @@ fn deep_values_compare_order_and_hash() {
             &[
                 "a == b",
                 "a < b",
-                "a.hash() == b.hash()",
+                "Hash.hash(a) == Hash.hash(b)",
                 "set.length(set.from_list([a, b]))",
             ]
         ),
diff --git a/tests/lang/fs_walk_stat_tests.rs b/tests/lang/fs_walk_stat_tests.rs
index 04ed1c2b2..db34e8135 100644
--- a/tests/lang/fs_walk_stat_tests.rs
+++ b/tests/lang/fs_walk_stat_tests.rs
@@ -285,7 +285,7 @@ import string
 fn main() {{
     match {call} {{
         Ok(paths) -> string.join(list.sort(paths), "\n")
-        Err(e) -> "Err: {{e.message()}}"
+        Err(e) -> "Err: {{Error.message(e)}}"
     }}
 }}
 "#
diff --git a/tests/lang/round76_assoc_cycle_tests.rs b/tests/lang/round76_assoc_cycle_tests.rs
index 59dec8f98..70a9ab16c 100644
--- a/tests/lang/round76_assoc_cycle_tests.rs
+++ b/tests/lang/round76_assoc_cycle_tests.rs
@@ -39,7 +39,7 @@ trait Container for Int {
 
 fn main() {
   let x: Int = 7
-  println(x.unwrap())
+  println(Container.unwrap(x))
 }
 "#;
 
diff --git a/tests/lang/stage7_io_pool_tests.rs b/tests/lang/stage7_io_pool_tests.rs
index af14a8d25..7a62287b2 100644
--- a/tests/lang/stage7_io_pool_tests.rs
+++ b/tests/lang/stage7_io_pool_tests.rs
@@ -455,8 +455,8 @@ fn main() {{
   match task.deadline(time.ms(300), {{ -> fill(conn, chunk, 256) }}) {{
     Err(task.Timeout) -> println("timed out")
     Ok(Ok(_)) -> println("the peer took everything")
-    Ok(Err(e)) -> println("a write failed: {{e.message()}}")
-    Err(e) -> println("a write failed: {{e.message()}}")
+    Ok(Err(e)) -> println("a write failed: {{Error.message(e)}}")
+    Err(e) -> println("a write failed: {{Error.message(e)}}")
   }}
   match tcp.write(conn, chunk) {{
     Err(tcp.Closed) -> println("closed")
@@ -563,7 +563,7 @@ fn main() {{
   tries(100)
   match io.read_file("{file}") {{
     Ok(_) -> println("read the file")
-    Err(e) -> println(e.message())
+    Err(e) -> println(Error.message(e))
   }}
 }}
 "#
diff --git a/tests/lang/stale_method_row_test.rs b/tests/lang/stale_method_row_test.rs
index 1a01c5af6..b54fe2cf5 100644
--- a/tests/lang/stale_method_row_test.rs
+++ b/tests/lang/stale_method_row_test.rs
@@ -7,11 +7,11 @@ use silt::session::testing::{session_with, test_path};
 
 const A: &str = "pub type T { T(Int) }\npub trait Ta { fn m(self) -> String }\n\
                  trait Ta for T { fn m(self) -> String { \"a\" } }\n\
-                 pub fn via_a(t: T) -> String { t.m() }\n";
+                 pub fn via_a(t: T) -> String { Ta.m(t) }\n";
 const B: &str = "import a\nimport a.{ T }\npub trait Tb { fn m(self) -> String }\n\
                  trait Tb for T { fn m(self) -> String { \"b\" } }\n\
-                 pub fn via_b(t: T) -> String { t.m() }\n";
-const C: &str = "import a\nimport a.{ T, Ta }\nfn main() {\n  println(T(1).m())\n  \
+                 pub fn via_b(t: T) -> String { Tb.m(t) }\n";
+const C: &str = "import a\nimport a.{ T, Ta }\nfn main() {\n  println(Ta.m(T(1)))\n  \
                  println(a.via_a(T(2)))\n}\n";
 
 /// `b` gives `T` a second method `m`, by its own trait; then `b` drops
@@ -44,7 +44,7 @@ fn a_dropped_trait_checked_first_leaves_no_row() {
 }
 
 /// `c` is checked before `b` is: the row still names `Tb`, which `c`
-/// does not reach, and `a`'s `m` is lost. (On main b22fba2d: "unknown
+/// does not name, and `a`'s `m` is lost. (On main b22fba2d: "unknown
 /// field or method 'm' on type T".)
 #[test]
 fn a_dropped_trait_not_yet_checked_leaves_no_row() {
diff --git a/tests/lang/tcp_module_tests.rs b/tests/lang/tcp_module_tests.rs
index 4472a466d..9e7f39ce3 100644
--- a/tests/lang/tcp_module_tests.rs
+++ b/tests/lang/tcp_module_tests.rs
@@ -44,7 +44,7 @@ import tcp
 fn main() {
   match tcp.listen("127.0.0.1:0") {
     Ok(_) -> "ok"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 "#);
@@ -85,18 +85,18 @@ fn main() {
           let result = match tcp.read(conn, 1024) {
             Ok(buf) -> match bytes.to_string(buf) {
               Ok(s) -> s
-              Err(e) -> e.message()
+              Err(e) -> Error.message(e)
             }
-            Err(e) -> e.message()
+            Err(e) -> Error.message(e)
           }
           tcp.close(conn)
           task.join(server)
           result
         }
-        Err(e) -> e.message()
+        Err(e) -> Error.message(e)
       }
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 "#
@@ -134,18 +134,18 @@ fn main() {
           let result = match tcp.read_exact(conn, 8) {
             Ok(buf) -> match bytes.to_string(buf) {
               Ok(s) -> s
-              Err(e) -> e.message()
+              Err(e) -> Error.message(e)
             }
-            Err(e) -> e.message()
+            Err(e) -> Error.message(e)
           }
           tcp.close(conn)
           task.join(server)
           result
         }
-        Err(e) -> e.message()
+        Err(e) -> Error.message(e)
       }
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 "#
@@ -182,10 +182,10 @@ fn main() {
           task.join(server)
           result
         }
-        Err(e) -> e.message()
+        Err(e) -> Error.message(e)
       }
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 "#
@@ -227,10 +227,10 @@ fn main() {
           task.join(server)
           result
         }
-        Err(e) -> e.message()
+        Err(e) -> Error.message(e)
       }
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 "#
diff --git a/tests/lang/tcp_mtls_tests.rs b/tests/lang/tcp_mtls_tests.rs
index fcd7de307..561b436e7 100644
--- a/tests/lang/tcp_mtls_tests.rs
+++ b/tests/lang/tcp_mtls_tests.rs
@@ -184,17 +184,17 @@ fn main() -> String {{
           Ok(ca) -> match tcp.accept(listener) {{
             Ok(conn) -> match tcp.tls_server_mtls(conn, cert, key, ca) {{
               Ok(_) -> "ok"
-              Err(e) -> "err:{{e.message()}}"
+              Err(e) -> "err:{{Error.message(e)}}"
             }}
-            Err(e) -> "accept:{{e.message()}}"
+            Err(e) -> "accept:{{Error.message(e)}}"
           }}
-          Err(e) -> "ca-parse:{{e.message()}}"
+          Err(e) -> "ca-parse:{{Error.message(e)}}"
         }}
-        Err(e) -> "key-parse:{{e.message()}}"
+        Err(e) -> "key-parse:{{Error.message(e)}}"
       }}
-      Err(e) -> "cert-parse:{{e.message()}}"
+      Err(e) -> "cert-parse:{{Error.message(e)}}"
     }}
-    Err(e) -> "listen:{{e.message()}}"
+    Err(e) -> "listen:{{Error.message(e)}}"
   }}
 }}
 "#,
@@ -357,13 +357,13 @@ fn serve(conn, cert, key, done) {{
       -- A TLS connection is not handed to tls_server again.
       let again = match tcp.tls_server(tls, cert, key) {{
         Ok(_) -> "a second handshake"
-        Err(e) -> e.message()
+        Err(e) -> Error.message(e)
       }}
       let _ = tcp.write(tls, bytes.from_string("hello over TLS"))
       tcp.close(tls)
       channel.send(done, "served; {{again}}")
     }}
-    Err(e) -> channel.send(done, "err:{{e.message()}}")
+    Err(e) -> channel.send(done, "err:{{Error.message(e)}}")
   }}
 }}
 
diff --git a/tests/lang/tcp_tls_tests.rs b/tests/lang/tcp_tls_tests.rs
index 512981d6e..b863d7604 100644
--- a/tests/lang/tcp_tls_tests.rs
+++ b/tests/lang/tcp_tls_tests.rs
@@ -47,7 +47,7 @@ fn main() {
             Ok(_) -> "wrong: should error"
             Err(_) -> "errored"
           }
-          Err(e) -> "accept-err:{e.message()}"
+          Err(e) -> "accept-err:{Error.message(e)}"
         }
       })
       time.sleep(time.ms(50))
@@ -55,7 +55,7 @@ fn main() {
       let _ = tcp.connect("127.0.0.1:{tcp.local_port(listener)}")
       task.join(server)
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 "#
@@ -98,13 +98,13 @@ fn main() {{
             Ok(key) -> match tcp.accept(listener) {{
               Ok(conn) -> match tcp.tls_server(conn, cert, key) {{
                 Ok(_) -> "ok"
-                Err(e) -> "handshake-failed:{{e.message()}}"
+                Err(e) -> "handshake-failed:{{Error.message(e)}}"
               }}
-              Err(e) -> "accept:{{e.message()}}"
+              Err(e) -> "accept:{{Error.message(e)}}"
             }}
-            Err(e) -> "key-parse:{{e.message()}}"
+            Err(e) -> "key-parse:{{Error.message(e)}}"
           }}
-          Err(e) -> "cert-parse:{{e.message()}}"
+          Err(e) -> "cert-parse:{{Error.message(e)}}"
         }}
       }})
       time.sleep(time.ms(50))
@@ -118,7 +118,7 @@ fn main() {{
       }}
       task.join(server)
     }}
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }}
 }}
 "#,
@@ -225,13 +225,13 @@ fn main() {{
   match task.deadline(time.ms(100), {{ -> tcp.tls_server(conn, cert, key) }}) {{
     Ok(Ok(_)) -> println("a handshake with a silent client")
     Err(task.Timeout) -> println("given up")
-    Ok(Err(e)) -> println("another error: {{e.message()}}")
-    Err(e) -> println("another error: {{e.message()}}")
+    Ok(Err(e)) -> println("another error: {{Error.message(e)}}")
+    Err(e) -> println("another error: {{Error.message(e)}}")
   }}
   -- The connection of the handshake was closed from the server's side.
   match tcp.read(silent, 1) {{
     Ok(data) -> println("the client reads {{bytes.length(data)}} bytes")
-    Err(e) -> println("the client's read fails: {{e.message()}}")
+    Err(e) -> println("the client's read fails: {{Error.message(e)}}")
   }}
 }}
 "#,
diff --git a/tests/lang/wave1_frontend_tests.rs b/tests/lang/wave1_frontend_tests.rs
index 0c7931b22..38d2fd27c 100644
--- a/tests/lang/wave1_frontend_tests.rs
+++ b/tests/lang/wave1_frontend_tests.rs
@@ -644,7 +644,7 @@ fn main() {
     _ -> "other"
   } })
   let words = "a b c" |> string.split(" ") |> list.map { w -> string.to_upper(w) }
-  println(u.greet())
+  println(Greet.greet(u))
   println("{classify(first)} {sum_to(4)} {words} {older.age} {nested}")
 }
 "#,
diff --git a/tests/lsp/lsp_semantic_tokens_tests.rs b/tests/lsp/lsp_semantic_tokens_tests.rs
index f4886de7d..2d67d0693 100644
--- a/tests/lsp/lsp_semantic_tokens_tests.rs
+++ b/tests/lsp/lsp_semantic_tokens_tests.rs
@@ -86,3 +86,49 @@ fn semantic_tokens_full_returns_classified_tokens() {
 
     client.shutdown();
 }
+
+/// A call through a trait (`Show.show(5)`): the trait's name is an
+/// INTERFACE token, the method's a FUNCTION token, each where it is
+/// written.
+#[test]
+fn semantic_tokens_of_a_call_through_a_trait() {
+    let mut client = LspClient::spawn();
+    let uri = "file:///tmp/silt_sem_tokens_trait_call.silt";
+    let src = "trait Show { fn show(self) -> String }\n\
+               trait Show for Int { fn show(self) -> String { \"i\" } }\n\
+               fn main() { println(Show.show(5)) }\n";
+    client.did_open_and_wait(uri, src);
+    let resp = client.request(
+        "textDocument/semanticTokens/full",
+        json!({ "textDocument": { "uri": uri } }),
+    );
+    let data = resp
+        .pointer("/result/data")
+        .and_then(|v| v.as_array())
+        .unwrap_or_else(|| panic!("expected /result/data array; got: {resp}"));
+    let (mut line, mut start) = (0u64, 0u64);
+    let mut tokens: Vec<(u64, u64, u64, u64)> = Vec::new();
+    for chunk in data.as_chunks::<5>().0 {
+        let dl = chunk[0].as_u64().expect("deltaLine");
+        let ds = chunk[1].as_u64().expect("deltaStart");
+        match dl {
+            0 => start += ds,
+            _ => {
+                line += dl;
+                start = ds;
+            }
+        }
+        let len = chunk[2].as_u64().expect("length");
+        tokens.push((line, start, len, chunk[3].as_u64().expect("tokenType")));
+    }
+    // `fn main() { println(Show.show(5)) }`: `Show` at 20, `show` at 25.
+    assert!(
+        tokens.contains(&(2, 20, 4, TT_INTERFACE)),
+        "the trait's name: {tokens:?}"
+    );
+    assert!(
+        tokens.contains(&(2, 25, 4, TT_FUNCTION)),
+        "the method's name: {tokens:?}"
+    );
+    client.shutdown();
+}
diff --git a/tests/lsp/main.rs b/tests/lsp/main.rs
index dc7f707d2..203495e6b 100644
--- a/tests/lsp/main.rs
+++ b/tests/lsp/main.rs
@@ -48,7 +48,6 @@ mod round76_lsp_folding_no_dups_tests;
 mod round76_lsp_hover_stdlib_method_tests;
 mod round77_lsp_inlay_trait_default_tests;
 mod round80_lsp_round80_tests;
-mod round81_lsp_dot_type_narrow_tests;
 mod round81_lsp_rename_user_shadow_tests;
 mod round83_lsp_selection_range_decl_bounds_tests;
 mod round84_lsp_selection_range_fn_body_tests;
diff --git a/tests/lsp/rename_sweep/g1/main.silt b/tests/lsp/rename_sweep/g1/main.silt
index c6b87d756..5a16bb404 100644
--- a/tests/lsp/rename_sweep/g1/main.silt
+++ b/tests/lsp/rename_sweep/g1/main.silt
@@ -30,7 +30,7 @@ fn pair((a, b): (Int, Int), P { x, y }) {
 
 trait Scale {
   fn scale(self, by: Int) -> Int {
-    self.size() * by
+    Scale.size(self) * by
   }
   fn size(self) -> Int
 }
diff --git a/tests/lsp/rename_sweep/t1/main.silt b/tests/lsp/rename_sweep/t1/main.silt
index f3e14fb66..7abdefc7c 100644
--- a/tests/lsp/rename_sweep/t1/main.silt
+++ b/tests/lsp/rename_sweep/t1/main.silt
@@ -1,6 +1,6 @@
 trait Scale {
   fn scale(self, by: Int) -> Int {
-    self.size() * by
+    Scale.size(self) * by
   }
   fn size(self) -> Int
 }
@@ -16,10 +16,10 @@ trait Scale for Box {
 }
 
 fn twice(x: a) -> Int where a: Scale {
-  x.scale(2) + x.size()
+  Scale.scale(x, 2) + Scale.size(x)
 }
 
 fn main() {
   let b = Box { w: 3 }
-  println(b.scale(2) + twice(b) + b.size())
+  println(Scale.scale(b, 2) + twice(b) + Scale.size(b))
 }
diff --git a/tests/lsp/rename_sweep/t11/main.silt b/tests/lsp/rename_sweep/t11/main.silt
index f13e53546..dbd61ce5e 100644
--- a/tests/lsp/rename_sweep/t11/main.silt
+++ b/tests/lsp/rename_sweep/t11/main.silt
@@ -16,7 +16,7 @@ trait Sized {
 trait Named: Sized {
   fn name(self) -> String
   fn both(self, other: Self) -> Int {
-    self.size() + other.size()
+    Sized.size(self) + Sized.size(other)
   }
 }
 
@@ -44,7 +44,7 @@ fn depth(t: Tree(a)) -> Int {
 
 fn describe(x: t) -> String where t: Named + Sized {
   let n = 1
-  let s = "äö€😀 {x.name()} 😀 {x.size() + n} 😀 {n}"
+  let s = "äö€😀 {Named.name(x)} 😀 {Sized.size(x) + n} 😀 {n}"
   "{s} {n}"
 }
 
@@ -60,7 +60,7 @@ fn locals() -> Int {
 fn main() {
   let b = Box { w: 3 }
   println(describe(b))
-  println(b.both(Box { w: 4 }) + locals() + second)
+  println(Named.both(b, Box { w: 4 }) + locals() + second)
   let Box { w } = b
   println(w)
   let Box { w: width } = b
diff --git a/tests/lsp/rename_sweep/t18/impls.silt b/tests/lsp/rename_sweep/t18/impls.silt
index 91f142fa0..c74f6fbc9 100644
--- a/tests/lsp/rename_sweep/t18/impls.silt
+++ b/tests/lsp/rename_sweep/t18/impls.silt
@@ -16,6 +16,6 @@ trait Area for shapes.Shape {
 pub fn total(xs: List(shapes.Shape)) -> Int {
   match xs {
     [] -> 0
-    [x, ..rest] -> x.area() + total(rest)
+    [x, ..rest] -> Area.area(x) + total(rest)
   }
 }
diff --git a/tests/lsp/rename_sweep/t18/main.silt b/tests/lsp/rename_sweep/t18/main.silt
index 470aa6a77..69c791dad 100644
--- a/tests/lsp/rename_sweep/t18/main.silt
+++ b/tests/lsp/rename_sweep/t18/main.silt
@@ -3,7 +3,7 @@ import impls.{ Area }
 import shapes.{ Shape, Box, Dot }
 
 fn twice(x: a) -> Int where a: Area {
-  x.area() * 2
+  Area.area(x) * 2
 }
 
 fn main() {
diff --git a/tests/lsp/rename_sweep/t19/main.silt b/tests/lsp/rename_sweep/t19/main.silt
index 8bdfb8597..79e3e20a8 100644
--- a/tests/lsp/rename_sweep/t19/main.silt
+++ b/tests/lsp/rename_sweep/t19/main.silt
@@ -35,13 +35,13 @@ fn apply(f: Fn(Meters) -> Meters, pair: (Meters, Int)) -> {m: Meters, n: Int} {
 }
 
 fn get(c: t) -> <t as Container>::Item where t: Container {
-  c.unwrap()
+  Container.unwrap(c)
 }
 
 fn main() {
   let w: Wide = Box { item: Meters(2) }
   let g = { x: Meters -> x }
-  let r = apply(g, (w.unwrap(), 3))
+  let r = apply(g, (Container.unwrap(w), 3))
   let v: List(Meters) = [r.m]
   let k = (Meters(4) as Meters)
   println(get(k) + get(Box { item: 1 }) + r.n)
diff --git a/tests/lsp/rename_sweep/t3/other.silt b/tests/lsp/rename_sweep/t3/other.silt
index c404f92cf..313775dc0 100644
--- a/tests/lsp/rename_sweep/t3/other.silt
+++ b/tests/lsp/rename_sweep/t3/other.silt
@@ -6,7 +6,7 @@ pub fn mk(w: Int) -> Int {
 }
 
 pub fn label(s: a) -> String where a: Named {
-  s.name()
+  Named.name(s)
 }
 
 pub fn pt() -> g.Point {
diff --git a/tests/lsp/round75_lsp_trait_tests.rs b/tests/lsp/round75_lsp_trait_tests.rs
index ea706005c..eea4b18ac 100644
--- a/tests/lsp/round75_lsp_trait_tests.rs
+++ b/tests/lsp/round75_lsp_trait_tests.rs
@@ -166,7 +166,7 @@ fn rename_trait_updates_impl_header_and_where_clause() {
     // references stale.
     let source = "trait Greet {\n  fn hello(self) -> String\n}\n\
                   trait Greet for Int {\n  fn hello(self) -> String { \"hi\" }\n}\n\
-                  fn x(n: a) -> String where a: Greet {\n  n.hello()\n}\n";
+                  fn x(n: a) -> String where a: Greet {\n  Greet.hello(n)\n}\n";
     let mut client = LspClient::spawn();
     let uri = unique_uri("rename_trait_xref");
     client.did_open_and_wait(&uri, source);
diff --git a/tests/lsp/round76_lsp_folding_no_dups_tests.rs b/tests/lsp/round76_lsp_folding_no_dups_tests.rs
index 24f81b00c..520babcf8 100644
--- a/tests/lsp/round76_lsp_folding_no_dups_tests.rs
+++ b/tests/lsp/round76_lsp_folding_no_dups_tests.rs
@@ -91,7 +91,7 @@ trait T for W {
 }
 fn main() {
   let w = W { v: 1 }
-  w.a()
+  T.a(w)
 }
 ";
     client.did_open_and_wait(file, src);
diff --git a/tests/lsp/round77_lsp_inlay_trait_default_tests.rs b/tests/lsp/round77_lsp_inlay_trait_default_tests.rs
index 0a687ac39..daccb733a 100644
--- a/tests/lsp/round77_lsp_inlay_trait_default_tests.rs
+++ b/tests/lsp/round77_lsp_inlay_trait_default_tests.rs
@@ -271,12 +271,12 @@ trait Loud {
   fn loud(self) -> String
   fn twice(self) -> String {
     let me = self
-    \"{me.loud()}{me.loud()}\"
+    \"{Loud.loud(me)}{Loud.loud(me)}\"
   }
 }
 ";
     let with_impl = format!(
-        "{body}trait Loud for Int {{ fn loud(self) -> String {{ \"i\" }} }}\nfn main() {{ println(1.twice()) }}\n"
+        "{body}trait Loud for Int {{ fn loud(self) -> String {{ \"i\" }} }}\nfn main() {{ println(Loud.twice(1)) }}\n"
     );
     let without_impl = format!("{body}fn main() {{ println(1) }}\n");
     for (name, src) in [("with_impl", with_impl), ("without_impl", without_impl)] {
@@ -284,7 +284,7 @@ trait Loud {
         let uri = format!("file:///tmp/silt_hover_trait_default_{name}.silt");
         client.did_open_and_wait(&uri, &src);
         // `me` in the interpolation, and `self` in the `let`.
-        for (line, character) in [(4, 6), (3, 13)] {
+        for (line, character) in [(4, 16), (3, 13)] {
             let hover = client.hover(&uri, line, character);
             let shown = hover.to_string();
             assert!(
diff --git a/tests/lsp/round81_lsp_dot_type_narrow_tests.rs b/tests/lsp/round81_lsp_dot_type_narrow_tests.rs
deleted file mode 100644
index 4a50c3313..000000000
--- a/tests/lsp/round81_lsp_dot_type_narrow_tests.rs
+++ /dev/null
@@ -1,273 +0,0 @@
-//! Round 81 (DX-G4): `textDocument/completion`'s dot-completion path
-//! must narrow the surfaced method set to those valid for the
-//! receiver's inferred type.
-//!
-//! Pre-round-81 behaviour: the dot-completion path emitted record
-//! fields when applicable but never surfaced trait methods. As a
-//! result, `xs.|` on a `let xs: List(Int)` produced an empty
-//! completion list — silt was a "second source of truth" relative to
-//! the typechecker because the LSP couldn't tell the user which
-//! methods were dispatchable on a List.
-//!
-//! Round 81 ships a minimum-viable type-aware narrowing pass:
-//!
-//!   - When the receiver is a let-bound local with a recoverable type
-//!     (annotation or initializer-inferred), the LSP filters the
-//!     emitted method set to methods declared for that type's
-//!     canonical head name.
-//!   - When the receiver type cannot be inferred narrowly (no
-//!     annotation, complex expression, generic stuck on type
-//!     variables), the LSP falls back to the union of every method
-//!     name declared in the program — discoverable but unfiltered.
-//!
-//! The minimum-viable contract: filtering NEVER hides completions on a
-//! receiver whose type the LSP can't pin down. Out of scope for this
-//! round: chained calls past the first dot, generic instantiation,
-//! trait constraints. See `src/lsp/completion.rs::dot_completions`
-//! and the `methods_for_receiver` helper for the narrowing logic.
-//!
-//! All tests drive a real `silt lsp` subprocess end-to-end over the
-//! LSP JSON-RPC transport so the full pipeline (lex → parse →
-//! typecheck → publish → completion) is exercised.
-
-use std::sync::atomic::{AtomicU64, Ordering};
-
-use serde_json::{Value, json};
-
-use crate::support::LspClient;
-
-static URI_COUNTER: AtomicU64 = AtomicU64::new(1);
-
-fn unique_uri(tag: &str) -> String {
-    let n = URI_COUNTER.fetch_add(1, Ordering::SeqCst);
-    format!("file:///tmp/silt_lsp_round81_{tag}_{n}.silt")
-}
-
-/// Pull `(label, kind)` pairs out of either the bare-array or
-/// `CompletionList` response shapes. Mirrors the helper in
-/// `tests/lsp/lsp_anon_record_field_completion_tests.rs`.
-fn extract_completion_labels(result: &Value) -> Vec<String> {
-    let arr = if let Some(arr) = result.as_array() {
-        arr.clone()
-    } else if let Some(arr) = result.pointer("/items").and_then(|v| v.as_array()) {
-        arr.clone()
-    } else {
-        return Vec::new();
-    };
-    arr.iter()
-        .filter_map(|it| {
-            it.get("label")
-                .and_then(|l| l.as_str())
-                .map(|s| s.to_string())
-        })
-        .collect()
-}
-
-// ── (a) Typed List local — narrow to List methods ─────────────────────
-//
-// Receiver is `let xs: List(Int) = [1, 2, 3]`. The LSP must surface
-// methods that exist on a `List(Int)` receiver — at minimum the
-// auto-derived built-in trait methods (`display`, `equal`, `compare`,
-// `hash`) — and must NOT surface methods that only exist on `String`
-// receivers (e.g. user-declared trait methods on String, or — should
-// the LSP ever start surfacing module-style helpers — `to_upper`,
-// `chars`, `split`).
-//
-// We assert positive presence of `display` (List auto-derives Display
-// per `register_builtin_trait_impls` policy) and absence of
-// String-specific user trait method names defined in the source. Names
-// like `to_upper` / `chars` / `split` are stdlib module functions
-// (`string.to_upper(s)`), not methods on a String value, so a silt
-// program never reaches the LSP with them in the AST — to make the
-// "must NOT include obviously-wrong methods" assertion meaningful we
-// declare a `trait UpperCaser for String { fn to_upper(self) ... }`
-// in the source and assert that `to_upper` does NOT appear in the
-// completion for the `List` receiver. Without narrowing, both
-// `display` (from List's auto-derive) AND `to_upper` (from the user
-// String impl) would appear in `xs.|`. With narrowing, only List
-// methods survive.
-
-#[test]
-fn dot_completion_on_typed_list_local_filters_to_list_methods() {
-    let mut client = LspClient::spawn();
-    let uri = unique_uri("typed_list_narrow");
-    // Declare a String-only trait impl in the source so the program
-    // has at least one method name that is incontestably wrong for a
-    // List receiver. Without narrowing, `to_upper` would be in the
-    // unfiltered union; the narrowed set must drop it.
-    let text = "trait UpperCaser { fn to_upper(self) -> String }\n\
-                trait UpperCaser for String { fn to_upper(self) -> String { \"X\" } }\n\
-                fn main() {\n\
-                \x20\x20let xs: List(Int) = [1, 2, 3]\n\
-                \x20\x20let _ = xs.\n\
-                }\n";
-    client.did_open_and_wait(&uri, text);
-
-    // Cursor placement: line 4 (0-indexed), column 13 — right after
-    // the `.` in `xs.`. Counting:
-    //   "  let _ = xs."
-    //    0         1
-    //    01234567890123
-    //                 ^ char=13 sits one past the dot.
-    let resp = client.request(
-        "textDocument/completion",
-        json!({
-            "textDocument": { "uri": uri },
-            "position": { "line": 4, "character": 13 },
-            "context": { "triggerKind": 2, "triggerCharacter": "." }
-        }),
-    );
-    let result = resp.get("result").expect("completion has result");
-    let labels = extract_completion_labels(result);
-
-    // Positive: List auto-derives Display, so `display` MUST appear in
-    // the narrowed completion set.
-    assert!(
-        labels.contains(&"display".to_string()),
-        "List receiver completion must include `display` (auto-derived); \
-         got labels: {labels:?}"
-    );
-    // Negative: a String-only user trait method must NOT appear.
-    // Pre-round-81 (no narrowing), it would.
-    assert!(
-        !labels.contains(&"to_upper".to_string()),
-        "List receiver completion must NOT include String-only method \
-         `to_upper`; got labels: {labels:?}"
-    );
-
-    client.shutdown();
-}
-
-// ── (b) Typed String local — narrow to String methods ────────────────
-//
-// Mirror of (a). Receiver is `let s: String = "hello"`. The LSP must
-// surface `display` (String auto-derives Display) AND the
-// String-specific user trait method `to_upper` (declared in the
-// source); it must NOT surface a List-only user trait method like
-// `head_int` from the same source.
-
-#[test]
-fn dot_completion_on_typed_string_local_filters_to_string_methods() {
-    let mut client = LspClient::spawn();
-    let uri = unique_uri("typed_string_narrow");
-    let text = "trait UpperCaser { fn to_upper(self) -> String }\n\
-                trait UpperCaser for String { fn to_upper(self) -> String { \"X\" } }\n\
-                trait IntListHead { fn head_int(self) -> Int }\n\
-                trait IntListHead for List { fn head_int(self) -> Int { 0 } }\n\
-                fn main() {\n\
-                \x20\x20let s: String = \"hello\"\n\
-                \x20\x20let _ = s.\n\
-                }\n";
-    client.did_open_and_wait(&uri, text);
-
-    // Cursor: line 6, char=12 — after `let _ = s.` (10 chars before
-    // the `.` plus the `.` itself plus the leading two spaces gives 12).
-    //   "  let _ = s."
-    //    0         1
-    //    012345678901
-    //                ^ char=12
-    let resp = client.request(
-        "textDocument/completion",
-        json!({
-            "textDocument": { "uri": uri },
-            "position": { "line": 6, "character": 12 },
-            "context": { "triggerKind": 2, "triggerCharacter": "." }
-        }),
-    );
-    let result = resp.get("result").expect("completion has result");
-    let labels = extract_completion_labels(result);
-
-    // Positive: `display` (auto-derived for String) AND `to_upper`
-    // (user trait impl on String) must both appear.
-    assert!(
-        labels.contains(&"display".to_string()),
-        "String receiver completion must include `display` (auto-derived); \
-         got labels: {labels:?}"
-    );
-    assert!(
-        labels.contains(&"to_upper".to_string()),
-        "String receiver completion must include `to_upper` (user trait impl \
-         on String); got labels: {labels:?}"
-    );
-    // Negative: a List-only user trait method must NOT appear.
-    assert!(
-        !labels.contains(&"head_int".to_string()),
-        "String receiver completion must NOT include List-only method \
-         `head_int`; got labels: {labels:?}"
-    );
-
-    client.shutdown();
-}
-
-// ── (c) Untyped local with unknowable type — full set fallback ───────
-//
-// Receiver is bound to a complex expression whose inferred type is a
-// stuck type variable (no annotation, no concrete initializer). The
-// minimum-viable contract: when narrowing isn't safe, the LSP must
-// fall back to the union of every method name declared in the program
-// — `to_upper` AND `head_int` from the example source must both
-// appear, because the LSP cannot prove either one wrong.
-//
-// Test name documents the limit: `untyped_local` here means a binding
-// whose recoverable type is `None` from the LSP's vantage point.
-// (Round 81 minimum-viable: any receiver expression that is not a
-// straight identifier resolving to an inferred non-`_` type lands in
-// the fallback set. Future rounds can tighten this for literals and
-// chained calls.)
-
-#[test]
-fn dot_completion_on_untyped_local_returns_full_set() {
-    let mut client = LspClient::spawn();
-    let uri = unique_uri("untyped_fallback");
-    // The receiver `x` is bound to a recursive call that the LSP
-    // cannot resolve to a concrete type — its `expr.ty` either stays
-    // an unresolved variable or is missing entirely after typecheck,
-    // depending on inference order. Either way the dot-completion
-    // path's `find_ident_type_by_name` returns `None` (it explicitly
-    // filters out types containing unresolved vars; see
-    // `src/lsp/ast_walk.rs::has_unresolved_vars`), so the receiver
-    // type stays `None` and the fallback union must surface both the
-    // String-only `to_upper` and the List-only `head_int`.
-    let text = "trait UpperCaser { fn to_upper(self) -> String }\n\
-                trait UpperCaser for String { fn to_upper(self) -> String { \"X\" } }\n\
-                trait IntListHead { fn head_int(self) -> Int }\n\
-                trait IntListHead for List { fn head_int(self) -> Int { 0 } }\n\
-                fn unknown(a) { unknown(a) }\n\
-                fn main() {\n\
-                \x20\x20let x = unknown(0)\n\
-                \x20\x20let _ = x.\n\
-                }\n";
-    client.did_open_and_wait(&uri, text);
-
-    // Cursor: line 7, char=12.
-    //   "  let _ = x."
-    //    0         1
-    //    012345678901
-    //                ^ char=12
-    let resp = client.request(
-        "textDocument/completion",
-        json!({
-            "textDocument": { "uri": uri },
-            "position": { "line": 7, "character": 12 },
-            "context": { "triggerKind": 2, "triggerCharacter": "." }
-        }),
-    );
-    let result = resp.get("result").expect("completion has result");
-    let labels = extract_completion_labels(result);
-
-    // Both user-declared trait methods must appear in the fallback set
-    // — narrowing only ever reduces noise; on an unknown receiver it
-    // must NOT silently drop completions.
-    assert!(
-        labels.contains(&"to_upper".to_string()),
-        "untyped receiver completion must include `to_upper` from the \
-         fallback union (no narrowing took effect); got labels: {labels:?}"
-    );
-    assert!(
-        labels.contains(&"head_int".to_string()),
-        "untyped receiver completion must include `head_int` from the \
-         fallback union (no narrowing took effect); got labels: {labels:?}"
-    );
-
-    client.shutdown();
-}
diff --git a/tests/lsp/stage5_session_tests.rs b/tests/lsp/stage5_session_tests.rs
index d581281e6..63ae53ea7 100644
--- a/tests/lsp/stage5_session_tests.rs
+++ b/tests/lsp/stage5_session_tests.rs
@@ -129,11 +129,11 @@ fn editing_an_imported_file_republishes_its_importer() {
 fn closing_a_module_leaves_the_method_rows_of_the_others() {
     const A: &str = "pub type T { T(Int) }\npub trait Ta { fn m(self) -> String }\n\
         trait Ta for T { fn m(self) -> String { \"a\" } }\n\
-        pub fn via_a(t: T) -> String { t.m() }\n";
+        pub fn via_a(t: T) -> String { Ta.m(t) }\n";
     const B: &str = "import a\nimport a.{ T }\npub trait Tb { fn m(self) -> String }\n\
         trait Tb for T { fn m(self) -> String { \"b\" } }\n\
-        pub fn via_b(t: T) -> String { t.m() }\n";
-    const C: &str = "import a\nimport a.{ T, Ta }\nfn main() {\n  println(T(1).m())\n  \
+        pub fn via_b(t: T) -> String { Tb.m(t) }\n";
+    const C: &str = "import a\nimport a.{ T, Ta }\nfn main() {\n  println(Ta.m(T(1)))\n  \
         println(a.via_a(T(2)))\n}\n";
     let dir = project("rows", &[("a.silt", A), ("b.silt", B), ("c.silt", C)]);
     let [a_uri, b_uri, c_uri] = ["a.silt", "b.silt", "c.silt"].map(|name| uri(&dir.join(name)));
diff --git a/tests/meta/round80_dead_code_tests.rs b/tests/meta/round80_dead_code_tests.rs
index d34287138..8b446b990 100644
--- a/tests/meta/round80_dead_code_tests.rs
+++ b/tests/meta/round80_dead_code_tests.rs
@@ -38,7 +38,7 @@ import tcp
 fn main() -> String {{
   match tcp.connect_tls("{unused_port}", "localhost") {{
     Ok(_) -> "unexpected ok"
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }}
 }}
 "#
@@ -71,16 +71,16 @@ fn main() -> String {
         match tcp.accept(listener) {
           Ok(conn) -> match tcp.tls_server(conn, bad_cert, bad_key) {
             Ok(_) -> "wrong: server expected to fail"
-            Err(e) -> e.message()
+            Err(e) -> Error.message(e)
           }
-          Err(e) -> e.message()
+          Err(e) -> Error.message(e)
         }
       })
       time.sleep(time.ms(50))
       let _ = tcp.connect("127.0.0.1:{tcp.local_port(listener)}")
       task.join(server)
     }
-    Err(e) -> e.message()
+    Err(e) -> Error.message(e)
   }
 }
 "#
diff --git a/tests/typecheck/error_enum_message_rows_tests.rs b/tests/typecheck/error_enum_message_rows_tests.rs
index 6b60b504f..81bbc32db 100644
--- a/tests/typecheck/error_enum_message_rows_tests.rs
+++ b/tests/typecheck/error_enum_message_rows_tests.rs
@@ -83,7 +83,7 @@ fn every_builtin_error_enum_has_a_message_row() {
             "import {module}\n\
              fn main() {{\n\
                  let e = {module}.{call}\n\
-                 println(e.message())\n\
+                 println(Error.message(e))\n\
              }}\n"
         );
         let path = temp_silt_file(&format!("trait_{enum_name}"), &src);