The type inference for collections (tuples, vectors, matrices, and
records) has been significantly refactored.
This includes:
- Introducing distinct `StaticType` variants for `Tuple`, `Vector`, and
`Matrix`.
- Implementing more robust type checking for these collections, allowing
for homogeneous and heterogeneous structures.
- Enhancing the `is_assignable_from` method to handle type compatibility
between these collection types.
- Updating `Value::static_type()` to correctly infer the types of
literal collections.
- Improving the type inference for map literals to create `Record`
types.
- Adding comprehensive unit tests for tuple, vector, matrix, and record
type inference.
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`.