Module checker 

Static type checker for rl - runs after parsing, before evaluation.

The checker walks the AST and verifies:

• Variable and constant declarations match their declared types
• Binary/unary operators receive compatible operand types
• Function calls receive the correct number and types of arguments
• return types match the enclosing function’s declared return type
• break and continue only appear inside loops
• Array elements are all the same type

It also populates TypeChecker::hovers - a side-table of (Span, markdown) pairs used by the LSP hover provider.

Two-pass function checking

TypeChecker::check does two passes over the statement list: first it pre-declares all top-level FunctionDeclarations so they are visible to each other regardless of order, then it checks every statement body. This allows mutual recursion at the top level.

Re-exports

pub use structs::TypeChecker;

Modules

operators

Operator type-checking - binary, unary, and index-assign.

scope

Scope management and name lookup for the type checker.

statements

Statement-level helpers shared between expression and statement checking.

structs

Core data structures for the type checker.

types

Helper methods on CheckType and ScopeItem, plus private type-matching utilities.

Functions

collect_fn_names 🔒

Collects all function names from a stdlib [Module] tree into out.