This commit refactors the type checking logic for functions and
operators to improve type safety and expressiveness.
Key changes include:
- Introduced `StaticType::FunctionOverloads` to represent functions with
multiple possible signatures, enabling better handling of operator
overloading.
- Updated the `TypeChecker` to correctly infer function types and
resolve calls with overloaded functions.
- Modified the `Environment` to register standard library functions with
specific `FunctionOverloads` signatures, replacing the previous
`StaticType::Any` approach.
- Enhanced the `StaticType::resolve_call` method to intelligently match
argument types against expected parameters, including handling of
overloaded functions.
- Added new tests to verify the correctness of type inference for lambda
returns and operator overloading.
Introduces a `Symbol` struct to represent identifiers, incorporating
macro hygiene context. Updates various parts of the AST compiler and
environment to use `Symbol` instead of raw `Rc<str>` for identifiers,
improving robustness for macro expansions.
Also includes:
- Adds a new example `macro_hygiene.myc`.
- Updates `.gitignore`.
- Refactors `MacroExpander` to use `ExpansionState` for cleaner template
expansion.
- Adjusts `VM::eval_observed` to ensure `after_eval` is called
correctly.
- Resets `Environment` for each test run and compilation/dumping in
`main.rs`.
Michael Schimmel