| """ |
| Tests the handling of recursive protocols. |
| """ |
|
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| |
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|
| from typing import Generic, Iterable, Never, Protocol, Self, TypeVar, assert_type |
|
|
| T = TypeVar("T") |
| T_co = TypeVar("T_co", covariant=True) |
| T_contra = TypeVar("T_contra", contravariant=True) |
|
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|
|
| class Traversable(Protocol): |
| def leaves(self) -> Iterable["Traversable"]: |
| ... |
|
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|
|
| class SimpleTree: |
| def leaves(self) -> list["SimpleTree"]: |
| return [] |
|
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|
|
| root: Traversable = SimpleTree() |
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|
|
| class Tree(Generic[T]): |
| def leaves(self) -> list["Tree[T]"]: |
| return [] |
|
|
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|
| def walk(graph: Traversable) -> None: |
| pass |
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|
|
| tree: Tree[float] = Tree() |
| walk(tree) |
|
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|
|
| class ProtoA(Protocol[T_co, T_contra]): |
| def method1(self) -> "ProtoA[T_co, T_contra]": |
| ... |
|
|
| @classmethod |
| def method2(cls, value: T_contra) -> None: |
| ... |
|
|
|
|
| class ProtoB(Protocol[T_co, T_contra]): |
| def method3(self) -> ProtoA[T_co, T_contra]: |
| ... |
|
|
|
|
| class ImplA: |
| def method1(self) -> Self: |
| return self |
|
|
| @classmethod |
| def method2(cls, value: int) -> None: |
| pass |
|
|
|
|
| class ImplB: |
| def method3(self) -> ImplA: |
| return ImplA() |
|
|
| def method1(self) -> Self: |
| return self |
|
|
| @classmethod |
| def method2(cls: type[ProtoB[object, T]], value: list[T]) -> None: |
| pass |
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|
|
| def func1(x: ProtoA[Never, T]) -> T: |
| raise NotImplementedError |
|
|
|
|
| v1 = func1(ImplB()) |
| assert_type(v1, list[int]) |
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|
