[DamianReeves]

Summary

Completes morphir.sdk against the Morphir.SDK package specification in morphir-elm. #24 added the twelve core modules; this adds the other ten: local_date, local_time, instant, uuid, regex, aggregate, rule, key, stateful_app and result_list.

test_spec_coverage.py now lists all 372 values of the 22 Morphir.IR.SDK.* module specifications and checks that each exists under its Python name. The Json modules are not part of the SDK package specification and are not included. The design mirrors finos/morphir-typescript#28.

Design

Same conventions as the core modules: snake_case Elm names, Elm argument order with the data last, immutable data, standard library only.

• local_date.LocalDate is datetime.date, with no time zone. Month and DayOfWeek are Enums with the Elm constructor names. Month-end clamping matches justinmimbs/date, which the Elm runtime uses.
• local_time.LocalTime is a frozen dataclass holding milliseconds from the epoch. In Elm it is an alias of Time.Posix, so it is a point in time and does not go around midnight; the Elm tests require from_iso("12:56:30") to be Nothing.
• instant.Instant is a datetime.datetime with a time zone. The specification gives it a type and no functions; two conversion helpers are marked as additions.
• uuid.UUID is the standard library uuid.UUID. parse follows the elm-uuid rules and error order; for_name is version 5.
• regex.Regex wraps the re module.
• result_list.ResultList[E, A] is tuple[Result[E, A], ...] and StatefulApp holds logic: (state, command) -> (state, event), both exactly as the Elm types are.
• key.Key2 to Key16 are flat tuples, so they work as Dict keys. Elm nests them only because its tuples stop at three elements; the ordering is the same.

Name mapping additions: is becomes is_, and the initialisms toISOString and fromISO become to_iso_string and from_iso.

Deliberate departures from the Elm runtime

Each is documented in the module docstring.

• regex patterns use Python re syntax, which differs from JavaScript in places: named groups are (?P<name>...), and \d, \w and \b follow Unicode. Match.index counts code points. split terminates on a pattern that matches the empty string, where Elm does not stop.
• aggregate omits constructAggregationCall and its types. They inspect Morphir IR values, belong to tooling, and have no entry in the specification. aggregate yields rows in ascending key order, because it uses the SDK Dict where Elm uses an insertion-ordered AssocList. count is a function, count(), so the type checker can infer the row type.
• local_date.diff_in_months and diff_in_years use integer arithmetic. Elm's float formula loses a month when the month count crosses a power of two. datetime.date holds the years 1 to 9999 only.
• local_time.from_iso rejects out-of-range fields that the Elm library accepts, and subtracts the minutes of a negative offset, which Elm adds.
• uuid.parse accepts versions 1 to 8, as elm-uuid 4.3.1 does.

Test plan

• uv run pytest tests/: 1579 passed. Every Elm test case for these modules is ported.
• uv run behave features/: 19 scenarios passed.
• uv run ruff check . and uv run ruff format --check .
• uv run mypy packages/morphir/src packages/morphir-tools/src
• uv run pyright packages/morphir/src packages/morphir-tools/src
• Docstring examples of all 22 modules run through test_doctests.py.

[chatgpt-codex-connector]

Codex Review Summary

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-18T07:20:25.836251Z	bff4c3f	PR opened

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: bff4c3f8b3

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[chatgpt-codex-connector]

Prevent constructing naive Instant values

Because Instant is only an alias for datetime.datetime, callers can construct Instant(2026, 9, 18) and it passes every annotation despite not identifying a point on the timeline. Such a value raises TypeError when compared with an aware instant and ValueError when passed to to_milliseconds_since_epoch; represent Instant with a validated constructor or wrapper that requires a non-None UTC offset.

AGENTS.md reference: AGENTS.md:L96-L99

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[DamianReeves]

Confirmed and fixed in ca82532. Instant is no longer an alias of datetime.datetime. It is a frozen, ordered dataclass that holds milliseconds since the epoch, the form of Elm's Time.Posix and of local_time.LocalTime. The constructor rejects anything that is not an int, so Instant(datetime.datetime(2026, 9, 18)) raises TypeError, and a naive value cannot exist. from_datetime raises ValueError for a naive datetime; to_datetime yields UTC. Tests: tests/unit/sdk/test_instant.py.