Module semantic 

Semantic Types

Defines the types that users see and work with in Shape code. These are separate from storage types (how data is physically represented).

Key design:

• Option<f64> is a semantic type - user sees it as nullable
• Storage may use NaN sentinel instead of tagged union
• Result<T> defaults to universal Error (no explicit E required)

Structs

EnumVariant

Enum variant

FunctionParam

Function parameter

FunctionSignature

Function signature

TypeVarId

Semantic type identifier for type variables during inference

Enums

SemanticType

Semantic types - what the user sees in type annotations