Unbound TypeVar variable in overloaded class

huangapple
go评论129阅读模式
英文:

Unbound TypeVar variable in overloaded class

问题

我有以下的代码，这是一个简化版本的Python实体组件系统：

  1. from __future__ import annotations
  3. from typing import TYPE_CHECKING, TypeVar, overload
  5. if TYPE_CHECKING:
  6.     from collections.abc import Generator
  8. T = TypeVar("T")
  9. T1 = TypeVar("T1")
  10. T2 = TypeVar("T2")
  12. class Registry:
  13.     def __init__(self) -> None:
  14.         self._next_game_object_id = 0
  15.         self._components: dict[type[T], set[int]] = {}
  16.         self._game_objects: dict[int, dict[type[T], T]] = {}
  18.     @overload
  19.     def get_components(
  20.         self,
  21.         component: type[T],
  22.     ) -> Generator[tuple[int, T], None, None]:
  23.         ...
  25.     @overload
  26.     def get_components(
  27.         self,
  28.         component: type[T],
  29.         component_two: type[T1],
  30.     ) -> Generator[tuple[int, T, T1], None, None]:
  31.         ...
  33.     @overload
  34.     def get_components(
  35.         self,
  36.         component: type[T],
  37.         component_two: type[T1],
  38.         component_three: type[T2],
  39.     ) -> Generator[tuple[int, T, T1, T2], None, None]:
  40.         ...
  42.     def get_components(self, *components: type[T]) -> Generator[tuple[int, tuple[T, ...]], None, None]:
  43.         game_object_ids = set.intersection(
  44.             *(self._components[component] for component in components),
  45.         )
  47.         for game_object_id in game_object_ids:
  48.             yield game_object_id, tuple(
  49.                 self._game_objects[game_object_id][component]
  50.                 for component in components
  51.             )

然而，我遇到了一些mypy错误，我无法弄清楚如何解决。其中一个错误说TypeVar T 未绑定，另一个说get_components 不接受所有可能的签名 1、2 和 3 的参数。我该如何修复这些错误？

英文:

I have this following code which is a simplified version of an entity component system in python:

  1. from __future__ import annotations
  3. from typing import TYPE_CHECKING, TypeVar, overload
  5. if TYPE_CHECKING:
  6.     from collections.abc import Generator
  9. T = TypeVar("T")
  10. T1 = TypeVar("T1")
  11. T2 = TypeVar("T2")
  14. class Registry:
  15.     def __init__(self) -> None:
  16.         self._next_game_object_id = 0
  17.         self._components: dict[type[T], set[int]] = {}
  18.         self._game_objects: dict[int, dict[type[T], T]] = {}
  20.     @overload
  21.     def get_components(
  22.         self,
  23.         component: type[T],
  24.     ) -> Generator[tuple[int, T], None, None]:
  25.         ...
  27.     @overload
  28.     def get_components(
  29.         self,
  30.         component: type[T],
  31.         component_two: type[T1],
  32.     ) -> Generator[tuple[int, T, T1], None, None]:
  33.         ...
  35.     @overload
  36.     def get_components(
  37.         self,
  38.         component: type[T],
  39.         component_two: type[T1],
  40.         component_three: type[T2],
  41.     ) -> Generator[tuple[int, T, T1, T2], None, None]:
  42.         ...
  44.     def get_components(self, *components: type[T]) -> Generator[tuple[int, tuple[T, ...]], None, None]:
  45.         game_object_ids = set.intersection(
  46.             *(self._components[component] for component in components),
  47.         )
  49.         for game_object_id in game_object_ids:
  50.             yield game_object_id, tuple(
  51.                 self._game_objects[game_object_id][component]
  52.                 for component in components
  53.             )

However, I'm getting some mypy errors which I cannot figure out. One of which says that the TypeVar T is unbound and another says that get_components does not accept all possible arguments of signature 1, 2, and 3. How can I fix these errors?

答案1

得分: 1

以下是翻译好的部分：

  1. from __future__ import annotations
  3. from typing import TYPE_CHECKING, TypeVar, overload, Generic
  5. if TYPE_CHECKING:
  6.     from collections.abc import Generator
  8. T = TypeVar("T")
  9. T1 = TypeVar("T1")
  10. T2 = TypeVar("T2")
  12. class Registry(Generic[T, T1, T2]):
  13.     def __init__(self) -> None:
  14.         self._next_game_object_id = 0
  15.         self._components: dict[type[T | T1 | T2], set[int]] = {}
  16.         self._game_objects: dict[int, dict[type[T | T1 | T2], T | T1 | T2]] = {}
  18.     @overload
  19.     def get_components(
  20.         self,
  21.         __component: type[T],
  22.     ) -> Generator[tuple[int, tuple[T]], None, None]:
  23.         ...
  25.     @overload
  26.     def get_components(
  27.         self,
  28.         __component: type[T],
  29.         __component_two: type[T1],
  30.     ) -> Generator[tuple[int, tuple[T, T1]], None, None]:
  31.         ...
  33.     @overload
  34.     def get_components(
  35.         self,
  36.         __component: type[T],
  37.         __component_two: type[T1],
  38.         __component_three: type[T2],
  39.     ) -> Generator[tuple[int, tuple[T, T1, T2]], None, None]:
  40.         ...
  42.     def get_components(
  43.         self,
  44.         *components: type[T | T1 |T2]
  45.     ) -> Generator[tuple[int, tuple[T | T1 | T2, ...]], None, None]:
  46.         game_object_ids = set.intersection(
  47.             *(self._components[component] for component in components),
  48.         )
  50.         for game_object_id in game_object_ids:
  51.             yield game_object_id, tuple(
  52.                 self._game_objects[game_object_id][component]
  53.                 for component in components
  54.             )

注意：在代码中我替换了HTML实体 " 为普通的双引号 " 以保持代码的正确性。

英文:

Possible solution:

  1. from __future__ import annotations
  3. from typing import TYPE_CHECKING, TypeVar, overload, Generic
  5. if TYPE_CHECKING:
  6.     from collections.abc import Generator
  9. T = TypeVar("T")
  10. T1 = TypeVar("T1")
  11. T2 = TypeVar("T2")
  14. class Registry(Generic[T, T1, T2]):
  15.     def __init__(self) -> None:
  16.         self._next_game_object_id = 0
  17.         self._components: dict[type[T | T1 | T2], set[int]] = {}
  18.         self._game_objects: dict[int, dict[type[T | T1 | T2], T | T1 | T2]] = {}
  20.     @overload
  21.     def get_components(
  22.         self,
  23.         __component: type[T],
  24.     ) -> Generator[tuple[int, tuple[T]], None, None]:
  25.         ...
  27.     @overload
  28.     def get_components(
  29.         self,
  30.         __component: type[T],
  31.         __component_two: type[T1],
  32.     ) -> Generator[tuple[int, tuple[T, T1]], None, None]:
  33.         ...
  35.     @overload
  36.     def get_components(
  37.         self,
  38.         __component: type[T],
  39.         __component_two: type[T1],
  40.         __component_three: type[T2],
  41.     ) -> Generator[tuple[int, tuple[T, T1, T2]], None, None]:
  42.         ...
  44.     def get_components(
  45.         self,
  46.         *components: type[T | T1 |T2]
  47.     ) -> Generator[tuple[int, tuple[T | T1 | T2, ...]], None, None]:
  48.         game_object_ids = set.intersection(
  49.             *(self._components[component] for component in components),
  50.         )
  52.         for game_object_id in game_object_ids:
  53.             yield game_object_id, tuple(
  54.                 self._game_objects[game_object_id][component]
  55.                 for component in components
  56.             )

Explanations:

  1. Inheriting from typing.Generic binds the TypeVars to the class through making it a generic class which depends on those TypeVars (More on Generics)
  2. Generalizing the method definition of get_components is crucial to accept all the different types that can occur through the overloads
  3. wrapping all the T, T, T1 and T, T1, T2 inside a tuple[...] as this ensures consistency with the return annotation of the now generalized method definition
  4. Making the components in the @overloaded methods positional only. This behaviour of *args and @overload seems not very well documented, only through a resolved issue on GitHub

huangapple
  • 本文由 发表于 2023年7月31日 19:36:29
  • 转载请务必保留本文链接：https://go.coder-hub.com/76803230.html
  • mypy
  • python
  • python-3.x
  • type-hinting
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定