Module arg_shape 

Coarse classification of argument shapes at call sites and clause heads.

A clause-head pattern is encoded as Vec<ArgShape>: one entry per formal parameter. A call site’s arguments are encoded the same way: one entry per actual. Matching is per-position: each call argument must satisfies the clause’s pattern at the same position.

Unknown is the safe fallback: when the extractor cannot classify an actual or pattern with confidence, it emits Unknown, and matching always accepts Unknown on either side so no false positives result.

Enums

ArgShape

Functions

satisfies_any

True when args (the call site’s actuals) satisfies any of the supplied clause-head patterns. Empty clauses returns true: with no pattern data recorded, we can’t penalize the call.