Crash on a project using lots of generics #14783
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Thanks for the crash report! Here's a minimal repro: from typing import Generic, ParamSpec
P = ParamSpec("P")
class Foo(Generic[P]): ...
def checker(foo1: Foo[[int]], foo2: Foo[[str]]) -> None:
foo1 == foo2Note that, interestingly, this only crashes if you run mypy with |
AlexWaygood
added
topic-paramspec
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The crash is reproducible as far back as 0.950, which is the first mypy version that properly supported |
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Here's a snippet illustrating mypy's current semantics for some similar cases involving from typing import Callable, Generic, ParamSpec, TypeVar
T = TypeVar("T")
T1 = TypeVar("T1")
P = ParamSpec("P")
P1 = ParamSpec("P1")
class Foo(Generic[T]):
x: T
class Bar(Generic[P]):
x: Callable[P, str]
def checker(foo1: Foo[int], foo2: Foo[str]) -> bool:
return foo1 == foo2 # error: Non-overlapping equality check (left operand type: "Foo[int]", right operand type: "Foo[str]") [comparison-overlap]
def checker1(foo1: Foo[int], foo2: Foo[bool]) -> bool:
return foo1 == foo2
def checker2(foo1: Foo[T], foo2: Foo[T1]) -> tuple[T, T1] | None:
if foo1 == foo2:
return foo1.x, foo2.x
return None
def checker3(bar1: Bar[P], bar2: Bar[P1]) -> tuple[Callable[P, str], Callable[P1, str]] | None:
if bar1 == bar2:
return bar1.x, bar2.x
return None |
JukkaL
pushed a commit
that referenced
this issue
Feb 27, 2023
… `ParamSpec` (#14792) Fixes #14783. Running mypy on this snippet of code currently causes a crash if you have the `--strict-equality` option enabled: ```python from typing import Generic, ParamSpec P = ParamSpec("P") class Foo(Generic[P]): ... def checker(foo1: Foo[[int]], foo2: Foo[[str]]) -> None: foo1 == foo2 ``` This is because the overlapping-equality logic in `meet.py` currently does not account for the fact that `left` and `right` might both be instances of `mypy.types.Parameters`, leading to this assertion being tripped: https://github.com/python/mypy/blob/800e8ffdf17de9fc641fefff46389a940f147eef/mypy/meet.py#L519 This PR attempts to add the necessary logic to `meet.py` to handle instances of `mypy.types.Parameters`.
koogoro
pushed a commit
that referenced
this issue
Mar 2, 2023
… `ParamSpec` (#14792) Fixes #14783. Running mypy on this snippet of code currently causes a crash if you have the `--strict-equality` option enabled: ```python from typing import Generic, ParamSpec P = ParamSpec("P") class Foo(Generic[P]): ... def checker(foo1: Foo[[int]], foo2: Foo[[str]]) -> None: foo1 == foo2 ``` This is because the overlapping-equality logic in `meet.py` currently does not account for the fact that `left` and `right` might both be instances of `mypy.types.Parameters`, leading to this assertion being tripped: https://github.com/python/mypy/blob/800e8ffdf17de9fc641fefff46389a940f147eef/mypy/meet.py#L519 This PR attempts to add the necessary logic to `meet.py` to handle instances of `mypy.types.Parameters`.
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Crash Report
source code of the project is at commit 2f2947e4401a3f8d69fa6c77e0108ad110f8af0f of
https://github.com/kode-konveyor/cdd-python
BTW, have you ever thought about adopting the principles of the type system of TypeScript?
They got it quite right. Typing generics in python is still quite a challenge even with 3.11.
See type: ignore comments in the project.
Traceback
To Reproduce
(Write what you did to reproduce the crash. Full source code is
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Your Environment
mypy.ini(and other config files):The text was updated successfully, but these errors were encountered: