Fix number type variable collision in arithmetic operators#131
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mdgriffith merged 1 commit intomdgriffith:mainfrom Mar 31, 2026
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When multiple arithmetic operators appeared as siblings (e.g. in a tuple or record), their internal "number" type variables could collide because toExpressionDetails reuses index values across siblings. The fix eagerly resolves fully-determined type variables in applyType after unification, so concrete types (Float, Int, etc.) are stored directly in the result instead of leaving GenericType references in the inference cache where they could be overwritten by siblings. This is a general fix in Compiler.applyType that protects all callers, not just arithmetic operators. Before: `Elm.tuple (Elm.Op.plus (Elm.float 1.5) (Elm.float 2.5)) (Elm.Op.plus (Elm.int 1) (Elm.int 2))` generated `( Int, Int )` instead of `( Float, Int )`. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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amazing. Tests, clear explanation, 😻 |
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When multiple arithmetic operators appeared within the same tuple or record, their internal
numbertype variables could collide becausetoExpressionDetailsreuses index values across siblings.This eagerly resolves type variables in
applyTypeafter unification, so concrete types (Float, Int, etc.) are stored directly in the result instead of leavingGenericTypereferences in the inference cache where they could be overwritten by siblings.Before:
generated
( Int, Int )Now it correctly generates the type annotation
( Float, Int ).