ruff/crates/ty_python_semantic
Alex Waygood ec3d5ebda2
[ty] Upcast heterogeneous and mixed tuples to homogeneous tuples where it's necessary to solve a TypeVar (#19635)
## Summary

This PR improves our generics solver such that we are able to solve the
`TypeVar` in this snippet to `int | str` (the union of the elements in
the heterogeneous tuple) by upcasting the heterogeneous tuple to its
pure-homogeneous-tuple supertype:

```py
def f[T](x: tuple[T, ...]) -> T:
    return x[0]

def g(x: tuple[int, str]):
    reveal_type(f(x))
```

## Test Plan

Mdtests. Some TODOs remain in the mdtest regarding solving `TypeVar`s
for mixed tuples, but I think this PR on its own is a significant step
forward for our generics solver when it comes to tuple types.

---------

Co-authored-by: Douglas Creager <dcreager@dcreager.net>
2025-07-30 17:12:21 +01:00
..
resources [ty] Upcast heterogeneous and mixed tuples to homogeneous tuples where it's necessary to solve a TypeVar (#19635) 2025-07-30 17:12:21 +01:00
src [ty] Upcast heterogeneous and mixed tuples to homogeneous tuples where it's necessary to solve a TypeVar (#19635) 2025-07-30 17:12:21 +01:00
tests [ty] Track open files in the server (#19264) 2025-07-18 19:33:35 +05:30
build.rs Rename Red Knot (#17820) 2025-05-03 19:49:15 +02:00
Cargo.toml [ty] Split ScopedPlaceId into ScopedSymbolId and ScopedMemberId (#19497) 2025-07-25 13:54:33 +02:00
mdtest.py Rename Red Knot (#17820) 2025-05-03 19:49:15 +02:00
mdtest.py.lock Rename Red Knot (#17820) 2025-05-03 19:49:15 +02:00