[ty] Narrow tuple expression match subjects

[charliermarsh]

Summary

This is stacked on #25637, which provides the complete-pattern element inference reused here.

Prior to this change, we narrowed a tuple value used as a match subject, but not the names used to construct a tuple expression:

class A: ...
class A1(A): ...
class B: ...
class B1(B): ...

def f(a: A, b: B) -> None:
    match a, b:
        case [A1(), B1()]:
            reveal_type(a)  # revealed: A1
            reveal_type(b)  # revealed: B1

This projects a successful exact sequence match back onto each simple-name tuple element. We retain whole-pattern filtering from #25637 and intersect constraints for repeated names. We do not project failed matches because they do not identify which element failed, and we exclude more complex subject expressions because they can rebind or mutate an earlier place before the case body.

We also preserve unconstrained or alternatives when combining pattern constraints, so one constrained alternative cannot narrow the overall match.

Closes astral-sh/ty#3743.

[astral-sh-bot]

Typing conformance results

No changes detected ✅

Current numbers

The percentage of diagnostics emitted that were expected errors held steady at 94.36%. The percentage of expected errors that received a diagnostic held steady at 88.82%. The number of fully passing files held steady at 93/134.

[astral-sh-bot]

Memory usage report

Memory usage unchanged ✅

[astral-sh-bot]

ecosystem-analyzer results

Lint rule	Added	Removed	Changed
unresolved-attribute	0	12	0
invalid-argument-type	3	6	0
unsupported-operator	0	2	0
invalid-assignment	0	0	1
no-matching-overload	0	1	0
Total	3	21	1

Raw diff (25 changes)

jax (https://github.com/google/jax)
- jax/experimental/mosaic/gpu/constraints.py:544:13 error[invalid-argument-type] Argument to function `splat_is_compatible_with_tiled` is incorrect: Expected `WGSplatFragLayout`, found `WGSplatFragLayout | WGStridedFragLayout | TiledLayout`
- jax/experimental/mosaic/gpu/constraints.py:544:28 error[invalid-argument-type] Argument to function `splat_is_compatible_with_tiled` is incorrect: Expected `TiledLayout`, found `WGSplatFragLayout | WGStridedFragLayout | TiledLayout`
- jax/experimental/mosaic/gpu/constraints.py:548:13 error[invalid-argument-type] Argument to function `_is_supported_tiled_relayout` is incorrect: Expected `TiledLayout`, found `WGSplatFragLayout | WGStridedFragLayout | TiledLayout`
- jax/experimental/mosaic/gpu/constraints.py:548:28 error[invalid-argument-type] Argument to function `_is_supported_tiled_relayout` is incorrect: Expected `TiledLayout`, found `WGSplatFragLayout | WGStridedFragLayout | TiledLayout`

kopf (https://github.com/nolar/kopf)
- kopf/_cogs/structs/references.py:305:45 error[no-matching-overload] No overload of bound method `Pattern.fullmatch` matches arguments
- kopf/_cogs/structs/references.py:306:24 error[unresolved-attribute] Attribute `split` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:307:55 error[unresolved-attribute] Attribute `split` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:308:53 error[unresolved-attribute] Attribute `split` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:309:54 error[unresolved-attribute] Attribute `split` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:310:45 error[unsupported-operator] Operator `in` is not supported between objects of type `Literal["."]` and `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:311:51 error[unresolved-attribute] Attribute `split` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:312:54 error[unresolved-attribute] Attribute `split` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:315:42 error[unsupported-operator] Operator `in` is not supported between objects of type `Literal["/"]` and `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:316:51 error[unresolved-attribute] Attribute `rsplit` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
- kopf/_cogs/structs/references.py:317:53 error[unresolved-attribute] Attribute `rsplit` is not defined on `Marker`, `(Resource, /) -> bool`, `None` in union `str | Marker | ((Resource, /) -> bool) | None`
+ kopf/_cogs/structs/diffs.py:180:52 error[invalid-argument-type] Argument to function `diff_iter` is incorrect: Expected `tuple[str, ...]`, found `tuple[object, ...]`
+ kopf/_cogs/structs/diffs.py:182:52 error[invalid-argument-type] Argument to function `diff_iter` is incorrect: Expected `tuple[str, ...]`, found `tuple[object, ...]`
+ kopf/_cogs/structs/diffs.py:184:54 error[invalid-argument-type] Argument to function `diff_iter` is incorrect: Expected `tuple[str, ...]`, found `tuple[object, ...]`

pylint (https://github.com/pycqa/pylint)
- pylint/checkers/utils.py:2123:20 error[unresolved-attribute] Attribute `name` is not defined on `AssignAttr` in union `AssignName | AssignAttr`
- pylint/checkers/utils.py:2123:35 error[unresolved-attribute] Object of type `NodeNG | None` has no attribute `name`
- pylint/checkers/utils.py:2125:42 error[unresolved-attribute] Attribute `as_string` is not defined on `None` in union `NodeNG | None`
- pylint/checkers/utils.py:2127:45 error[invalid-argument-type] Argument to function `subscript_chain_is_equal` is incorrect: Expected `Subscript`, found `AssignName | AssignAttr`
- pylint/checkers/utils.py:2127:53 error[invalid-argument-type] Argument to function `subscript_chain_is_equal` is incorrect: Expected `Subscript`, found `NodeNG | None`

pytest (https://github.com/pytest-dev/pytest)
- src/_pytest/assertion/rewrite.py:1127:21 error[unresolved-attribute] Object of type `expr` has no attribute `target`
- src/_pytest/assertion/rewrite.py:1128:21 error[invalid-assignment] Invalid subscript assignment with key of type `@Todo` and value of type `expr` on object of type `dict[str, str]`
+ src/_pytest/assertion/rewrite.py:1128:21 error[invalid-assignment] Invalid subscript assignment with key of type `@Todo` and value of type `NamedExpr` on object of type `dict[str, str]`

Full report with detailed diff (timing results)

[charliermarsh]

Superseded by #25874, which implements tuple-subject narrowing directly on main by targeting the bindings captured when the match subject is evaluated.