Mirror of OCaml Step 5 to the JavaScript host. Native ADT representation
for define-type instances, with the same dict-shaped shim approach so
spec-level match-pattern code in evaluator.sx works without changes.
- platform.py typeOf: recognize ._adtv tag, return ._type (so
(type-of (Just 42)) returns "Maybe" not "dict").
- platform.py adds makeAdtValue/isAdtValue helpers and registers
PRIMITIVES["adt?"], "make-adt-value", "adt-value?".
- platform.py inspect: format AdtValue as "(Ctor f1 f2 ...)" and
register as a primitive (was missing entirely on JS).
- fixups_js: hand-written define-type override that constructs
AdtValue via makeAdtValue, with arity check, type/ctor predicates,
and field accessors. Re-registered via registerSpecialForm so the
CEK dispatch routes through it.
- dict? unchanged: AdtValue still passes (no _adtv exclusion) so
the existing (and (dict? v) (get v :_adt) ...) checks in spec
predicates keep working.
Tests: 2578 pass (was 2575), zero regressions. All 43 ADT tests
pass on the JS host (was 40, the 3 new Step 5 tests for type-of /
adt? / inspect are now green).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>