Alex Waygood 71b52b83e4 [red-knot] Allow type[] to be subscripted (#13667) ...

Fixed a TODO by adding another TODO. It's the red-knot way!

## Summary

`builtins.type` can be subscripted at runtime on Python 3.9+, even
though it has no `__class_getitem__` method and its metaclass (which
is... itself) has no `__getitem__` method. The special case is
[hardcoded directly into `PyObject_GetItem` in
CPython](744caa8ef4/Objects/abstract.c (L181-L184)).
We just have to replicate the special case in our semantic model.

This will fail at runtime on Python <3.9. However, there's a bunch of
outstanding questions (detailed in the TODO comment I added) regarding
how we deal with subscriptions of other generic types on lower Python
versions. Since we want to avoid too many false positives for now, I
haven't tried to address this; I've just made `type` subscriptable on
all Python versions.

## Test Plan

`cargo test -p red_knot_python_semantic --lib`

2024-10-07 19:43:47 +01:00

..

src

[red-knot] Allow type[] to be subscripted (#13667)

2024-10-07 19:43:47 +01:00

Cargo.toml

[red-knot] feat: implement integer comparison (#13571)

2024-10-04 10:40:59 -07:00