mirror of https://github.com/astral-sh/ruff
ea812d0813
We already had support for homogeneous tuples (`tuple[int, ...]`). This PR extends this to also support mixed tuples (`tuple[str, str, *tuple[int, ...], str str]`). A mixed tuple consists of a fixed-length (possibly empty) prefix and suffix, and a variable-length portion in the middle. Every element of the variable-length portion must be of the same type. A homogeneous tuple is then just a mixed tuple with an empty prefix and suffix. The new data representation uses different Rust types for a fixed-length (aka heterogeneous) tuple. Another option would have been to use the `VariableLengthTuple` representation for all tuples, and to wrap the "variable + suffix" portion in an `Option`. I don't think that would simplify the method implementations much, though, since we would still have a 2×2 case analysis for most of them. One wrinkle is that the definition of the `tuple` class in the typeshed has a single typevar, and canonically represents a homogeneous tuple. When getting the class of a tuple instance, that means that we have to summarize our detailed mixed tuple type information into its "homogeneous supertype". (We were already doing this for heterogeneous types.) A similar thing happens when concatenating two mixed tuples: the variable-length portion and suffix of the LHS, and the prefix and variable-length portion of the RHS, all get unioned into the variable-length portion of the result. The LHS prefix and RHS suffix carry through unchanged. --------- Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com> |
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| bytes.md | ||
| class.md | ||
| instance.md | ||
| lists.md | ||
| stepsize_zero.md | ||
| string.md | ||
| tuple.md | ||