(🐞) `type`s/`Instance`s don't join properly with `Callable`s
Open
Nobody has claimed this yet.
bug
- Dominant language
- Python
- Stars
- 20.6k
- Forks
- 3.3k
- PR merge metrics
- PR metrics pending
Description
from typing import Callable
c: Callable[[], object]
t: type[object]
reveal_type(c if bool() else t) # object
class I:
def __call__(self) -> None: ...
i: I
reveal_type(i if bool() else t) # object
type[object]/I is a subtype of Callable[[], object], so this should join to Callable[[], object], not object.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by running the provided Python examples and checking the reveal_type results for the conditional expressions involving Callable, type[object], and I. Trace the type-joining behavior for these cases; done means the expressions reveal Callable[[], object] rather than object.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 42/100