feat: ElementId — recognize blake3: content-hash scheme (+ HASH_SCHEMES / content_hash_scheme helpers)

CHANGELOG.md

@@ -6,6 +6,26 @@ for reference without a full itemized history.
 
 ## [Unreleased]
 
+## [0.14.0] - pending tag
+
+Additive, non-breaking release. No public API was removed or changed
+incompatibly since `v0.13.0`.
+
+Added:
+- `sysml_model`: `ElementId` now documents and recognizes `blake3:` as a
+  sanctioned content-hash scheme alongside `sha256:` and `git:`. The
+  newtype itself is unchanged — still `pub struct ElementId(pub String)`,
+  opaque; this is purely additive.
+  - `ElementId::HASH_SCHEMES` — the `&'static [&'static str]` of
+    recognized content-hash / VCS scheme prefixes (`"sha256:"`,
+    `"blake3:"`, `"git:"`).
+  - `ElementId::content_hash_scheme()` — the scheme prefix this id
+    carries if it is content-addressed, else `None`.
+  - `ElementId::is_content_addressed()` — whether this id is a content /
+    VCS hash rather than a human-meaningful name.
+  - The `ElementId` doc comment now lists `blake3:…` among the sanctioned
+    content / VCS hash forms; the **never numeric** rule is unchanged.
+
 ## [0.13.0] - pending tag
 
 Additive, non-breaking release. No public API was removed or changed

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ufo-types"
-version = "0.13.0"
+version = "0.14.0"
 edition = "2024"
 rust-version = "1.85"
 authors = ["Brian Horakh <brian@promptexecution.com>"]

src/sysml_model.rs

@@ -38,7 +38,7 @@ use serde::{Deserialize, Serialize};
 ///
 /// MAY be a human-meaningful name (`"bus-3"`, `"agent.foo"`), a KerML
 /// qualified name (`Pkg::Sub::Item`), or a content / VCS hash
-/// (`sha256:…`, `git:<blob-sha>`) where an element needs a stable derived
+/// (`sha256:…`, `blake3:…`, `git:<blob-sha>`) where an element needs a stable derived
 /// identity. It is **never** a numeric id — a random integer breaks the
 /// byte-identical, git-diffable artifact model; a derived one is just a less
 /// legible string (kr0ki `DESIGN-NOTE-typed-model-layer.md` §2.4).
@@ -55,6 +55,23 @@ impl ElementId {
     pub fn as_str(&self) -> &str {
         &self.0
     }
+
+    /// The recognized content-hash / VCS scheme prefixes an `ElementId` may carry.
+    pub const HASH_SCHEMES: &'static [&'static str] = &["sha256:", "blake3:", "git:"];
+
+    /// If this id is content-addressed, the scheme prefix it uses
+    /// (`"sha256:"`, `"blake3:"`, `"git:"`), else `None`.
+    pub fn content_hash_scheme(&self) -> Option<&'static str> {
+        Self::HASH_SCHEMES
+            .iter()
+            .copied()
+            .find(|p| self.0.starts_with(p))
+    }
+
+    /// Whether this id is a content / VCS hash rather than a name.
+    pub fn is_content_addressed(&self) -> bool {
+        self.content_hash_scheme().is_some()
+    }
 }
 
 impl std::fmt::Display for ElementId {
@@ -521,6 +538,26 @@ mod tests {
         assert_eq!(serde_json::from_str::<ElementId>(&json).unwrap(), id);
     }
 
+    #[test]
+    fn element_id_content_hash_scheme_detection() {
+        assert_eq!(eid("blake3:abc123").content_hash_scheme(), Some("blake3:"));
+        assert!(eid("blake3:abc123").is_content_addressed());
+
+        assert_eq!(
+            eid("sha256:deadbeef").content_hash_scheme(),
+            Some("sha256:")
+        );
+        assert!(eid("sha256:deadbeef").is_content_addressed());
+
+        assert_eq!(eid("git:deadbeef").content_hash_scheme(), Some("git:"));
+        assert!(eid("git:deadbeef").is_content_addressed());
+
+        assert_eq!(eid("bus-3").content_hash_scheme(), None);
+        assert!(!eid("bus-3").is_content_addressed());
+
+        assert_eq!(ElementId::HASH_SCHEMES.len(), 3);
+    }
+
     #[test]
     fn element_kind_all_is_complete_and_ordered() {
         // Exhaustive match: a new variant fails to compile until it is also