v6 Semantics

Type checker stack

• infer first, then validate consistency
• unknown lets the checker continue without spurious cascades
• nil can flow into typed locations

Core invariants

• variable declarations are either annotated or inferable
• function signatures are mandatory
• return checks against declared return type
• assignments/indexing respect assignability
• expression operators enforce operand families

Collections

• arrays are homogeneous
• maps keep stable key/value typing
• empty array/map literals need expected type context

Module + types

• exported declarations carry types
• member access checks still require alias and export
• function member calls are type-checked by exported signature

Error model

• undefined name, return/break/continue context errors still apply
• cannot infer type for ambiguous declarations
• type mismatch and specialized operand errors
• arity mismatch and call of non-function

Focus for this module

• static phase catches as much as possible
• VM should receive better-typed bytecode shape