Brummel
916460ab03
The `IndexElementFn` trait and its associated `series_element_type` function have been removed. The `TypeChecker` now directly inspects the `StaticType::Series` variant to extract the element type when propagating index constraints. This simplifies the type-checking logic by removing an unnecessary layer of indirection and adhering to the project rule of keeping the AST simple and pushing complexity into the system.