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90db033955
This commit makes type folding more like the way chalk does it. Currently, `TypeFoldable` has `fold_with` and `super_fold_with` methods. - `fold_with` is the standard entry point, and defaults to calling `super_fold_with`. - `super_fold_with` does the actual work of traversing a type. - For a few types of interest (`Ty`, `Region`, etc.) `fold_with` instead calls into a `TypeFolder`, which can then call back into `super_fold_with`. With the new approach, `TypeFoldable` has `fold_with` and `TypeSuperFoldable` has `super_fold_with`. - `fold_with` is still the standard entry point, *and* it does the actual work of traversing a type, for all types except types of interest. - `super_fold_with` is only implemented for the types of interest. Benefits of the new model. - I find it easier to understand. The distinction between types of interest and other types is clearer, and `super_fold_with` doesn't exist for most types. - With the current model is easy to get confused and implement a `super_fold_with` method that should be left defaulted. (Some of the precursor commits fixed such cases.) - With the current model it's easy to call `super_fold_with` within `TypeFolder` impls where `fold_with` should be called. The new approach makes this mistake impossible, and this commit fixes a number of such cases. - It's potentially faster, because it avoids the `fold_with` -> `super_fold_with` call in all cases except types of interest. A lot of the time the compile would inline those away, but not necessarily always. |
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| .. | ||
| nonstandard_style | ||
| array_into_iter.rs | ||
| builtin.rs | ||
| context.rs | ||
| early.rs | ||
| enum_intrinsics_non_enums.rs | ||
| expect.rs | ||
| hidden_unicode_codepoints.rs | ||
| internal.rs | ||
| late.rs | ||
| levels.rs | ||
| lib.rs | ||
| methods.rs | ||
| non_ascii_idents.rs | ||
| non_fmt_panic.rs | ||
| nonstandard_style.rs | ||
| noop_method_call.rs | ||
| pass_by_value.rs | ||
| passes.rs | ||
| redundant_semicolon.rs | ||
| tests.rs | ||
| traits.rs | ||
| types.rs | ||
| unused.rs | ||