Module unify 

Unification engine for the bidirectional type checker.

Provides Robinson unification for InferType, which extends LogosType with type variables for the inference pass. After inference, UnificationTable::zonk converts InferType → LogosType. Unsolved variables become LogosType::Unknown, preserving the existing codegen safety net.

Architecture

InferType  ←  inference pass (this module + check.rs)
    │
    │  zonk (after inference)
    ▼
LogosType  →  codegen (unchanged)

Structs

TyVar

A type variable used during inference.

TypeScheme

A quantified polymorphic type.

UnificationTable

Union-Find table implementing Robinson unification with occurs check.

Enums

InferType

Inference-time type representation.

TypeError

A type error detected during unification or checking.

Functions

infer_to_logos

Convert a zonked InferType to LogosType.

unify_numeric

Numeric promotion: Float wins; Int + Int = Int; Nat + Nat = Nat; Byte + Byte = Byte; otherwise error.