## Summary
This PR introduces a new rule to sort `__slots__` and `__match_args__`
according to a [natural sort](https://en.wikipedia.org/wiki/Natural_sort_order), as was
requested in https://github.com/astral-sh/ruff/issues/1198#issuecomment-1881418365.
The implementation here generalises some of the machinery introduced in
3aae16f1bd
so that different kinds of sorts can be applied to lists of string
literals. (We use an "isort-style" sort for `__all__`, but that isn't
really appropriate for `__slots__` and `__match_args__`, where nearly
all items will be snake_case.) Several sections of code have been moved
from `sort_dunder_all.rs` to a new module, `sorting_helpers.rs`, which
`sort_dunder_all.rs` and `sort_dunder_slots.rs` both make use of.
`__match_args__` is very similar to `__all__`, in that it can only be a
tuple or a list. `__slots__` differs from the other two, however, in
that it can be any iterable of strings. If slots is a dictionary, the
values are used by the builtin `help()` function as per-attribute
docstrings that show up in the output of `help()`. (There's no
particular use-case for making `__slots__` a set, but it's perfectly
legal at runtime, so there's no reason for us not to handle it in this
rule.)
Note that we don't do an autofix for multiline `__slots__` if `__slots__` is a dictionary: that's out of scope. Everything else, we can nearly always fix, however.
## Test Plan
`cargo test` / `cargo insta review`.
I also ran this rule on CPython, and the diff looked pretty good
---
Co-authored-by: Micha Reiser <micha@reiser.io>
f5061dbb8e