Skip overload resolution when positional arguments have no type information#393
Merged
mame merged 1 commit intoruby:masterfrom Feb 25, 2026
Merged
Skip overload resolution when positional arguments have no type information#393mame merged 1 commit intoruby:masterfrom
mame merged 1 commit intoruby:masterfrom
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…mation When a multi-overload method is called with an empty (untyped) positional argument, we cannot determine which overload to select. Previously, empty vertices matched all overloads via the found_any mechanism in typecheck, which caused infinite oscillation in cyclic patterns like: @x = Foo.transform(@x) # transform has disjoint overloads The cycle was: empty -> all match -> types flow in -> mismatch -> types removed -> empty -> repeat forever. Fix: in resolve_overloads, if any positional argument vertex is empty, skip overload resolution entirely and return untyped. Dependency edges are still added so the box re-runs when arguments later receive types. This is stateless (no flags on boxes or vertices), naturally convergent, and semantically correct: we cannot dispatch on what we do not know. Trade-off: passing untyped to an overloaded method now returns untyped instead of the union of all return types. This affects 4 existing tests. Single-signature methods (force=true) are unaffected.
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When a multi-overload method is called with an empty (untyped) positional argument, we cannot determine which overload to select. Previously, empty vertices matched all overloads via the found_any mechanism in typecheck, which caused infinite oscillation in cyclic patterns like:
The cycle was: empty -> all match -> types flow in -> mismatch -> types removed -> empty -> repeat forever.
Fix: in resolve_overloads, if any positional argument vertex is empty, skip overload resolution entirely and return untyped. Dependency edges are still added so the box re-runs when arguments later receive types.
This is stateless (no flags on boxes or vertices), naturally convergent, and semantically correct: we cannot dispatch on what we do not know.
Trade-off: passing untyped to an overloaded method now returns untyped instead of the union of all return types. This affects 4 existing tests. Single-signature methods (force=true) are unaffected.