Make GenericAlias generic

stdlib/_typeshed/__init__.pyi

@@ -177,10 +177,7 @@ WriteableBuffer = Union[bytearray, memoryview, array.array[Any], mmap.mmap, ctyp
 ReadableBuffer = Union[ReadOnlyBuffer, WriteableBuffer]  # stable
 
 # stable
-if sys.version_info >= (3, 10):
-    from types import NoneType as NoneType
-else:
-    # Used by type checkers for checks involving None (does not exist at runtime)
-    @final
-    class NoneType:
-        def __bool__(self) -> Literal[False]: ...
+# Used by type checkers for checks involving None (does not exist at runtime)
+@final
+class NoneType:
+    def __bool__(self) -> Literal[False]: ...

stdlib/asyncio/coroutines.pyi

@@ -1,4 +1,3 @@
-import sys
 import types
 from collections.abc import Callable, Coroutine
 from typing import Any, TypeVar
@@ -9,8 +8,4 @@ _F = TypeVar("_F", bound=Callable[..., Any])
 def coroutine(func: _F) -> _F: ...
 def iscoroutinefunction(func: object) -> bool: ...
 
-if sys.version_info < (3, 8):
-    def iscoroutine(obj: object) -> TypeGuard[types.GeneratorType[Any, Any, Any] | Coroutine[Any, Any, Any]]: ...
-
-else:
-    def iscoroutine(obj: object) -> TypeGuard[Coroutine[Any, Any, Any]]: ...
+def iscoroutine(obj: object) -> TypeGuard[types.GeneratorType | Coroutine[Any, Any, Any]]: ...

stdlib/types.pyi

@@ -40,7 +40,7 @@ class _Cell:
     cell_contents: Any
 
 @final
-class FunctionType:
+class FunctionType(Callable):
     __closure__: Tuple[_Cell, ...] | None
     __code__: CodeType
     __defaults__: Tuple[Any, ...] | None
@@ -248,7 +248,7 @@ class _StaticFunctionType:
     def __get__(self, obj: object | None, type: type | None) -> FunctionType: ...
 
 @final
-class MethodType:
+class MethodType(Callable):
     __closure__: Tuple[_Cell, ...] | None  # inherited from the added function
     __defaults__: Tuple[Any, ...] | None  # inherited from the added function
     __func__: _StaticFunctionType
@@ -259,7 +259,7 @@ class MethodType:
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
 
 @final
-class BuiltinFunctionType:
+class BuiltinFunctionType(Callable):
     __self__: object | ModuleType
     __name__: str
     __qualname__: str
@@ -269,14 +269,14 @@ BuiltinMethodType = BuiltinFunctionType
 
 if sys.version_info >= (3, 7):
     @final
-    class WrapperDescriptorType:
+    class WrapperDescriptorType(Callable):
         __name__: str
         __qualname__: str
         __objclass__: type
         def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
         def __get__(self, obj: Any, type: type = ...) -> Any: ...
     @final
-    class MethodWrapperType:
+    class MethodWrapperType(Callable):
         __self__: object
         __name__: str
         __qualname__: str
@@ -285,14 +285,14 @@ if sys.version_info >= (3, 7):
         def __eq__(self, other: Any) -> bool: ...
         def __ne__(self, other: Any) -> bool: ...
     @final
-    class MethodDescriptorType:
+    class MethodDescriptorType(Callable):
         __name__: str
         __qualname__: str
         __objclass__: type
         def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
         def __get__(self, obj: Any, type: type = ...) -> Any: ...
     @final
-    class ClassMethodDescriptorType:
+    class ClassMethodDescriptorType(Callable):
         __name__: str
         __qualname__: str
         __objclass__: type
@@ -375,18 +375,19 @@ def coroutine(func: Callable[..., Any]) -> CoroutineType[Any, Any, Any]: ...
 if sys.version_info >= (3, 8):
     CellType = _Cell
 
+_Origin = TypeVar("_Origin", bound=type)
+_Args = TypeVar("_Args", bound=tuple[object, ...])
+
 if sys.version_info >= (3, 9):
-    class GenericAlias:
-        __origin__: type
-        __args__: Tuple[Any, ...]
+    class GenericAlias(Generic[_Origin, _Args]):
+        __origin__: _Origin
+        __args__: _Args
         __parameters__: Tuple[Any, ...]
-        def __init__(self, origin: type, args: Any) -> None: ...
+        def __init__(self, origin: _Origin, args: _Args) -> None: ...
         def __getattr__(self, name: str) -> Any: ...  # incomplete
 
 if sys.version_info >= (3, 10):
-    @final
-    class NoneType:
-        def __bool__(self) -> Literal[False]: ...
+    NoneType = type(None)
     EllipsisType = ellipsis  # noqa F811 from builtins
     from builtins import _NotImplementedType
 

stdlib/typing.pyi

@@ -32,15 +32,25 @@ class TypeVar:
 
 _promote = object()
 
-class _SpecialForm:
-    def __getitem__(self, typeargs: Any) -> object: ...
+_Origin = TypeVar("_Origin", bound=type)
+_Args = TypeVar("_Args", bound=tuple[object, ...])
+
+class _SpecialForm(Generic[_Origin]):
+    @overload
+    def __getitem__(self, typeargs: _Args) -> _GenericAlias[_Origin, _Args]: ...
+    @overload
+    def __getitem__(self, typeargs: _T) -> _GenericAlias[_Origin, tuple[_T]]: ...
 
 _F = TypeVar("_F", bound=Callable[..., Any])
 _P = _ParamSpec("_P")
 _T = TypeVar("_T")
 
 def overload(func: _F) -> _F: ...
 
+class _GenericAlias(Generic[_Origin, _Args]):
+    __origin__: _Origin
+    __args__: _Args
+
 Union: _SpecialForm = ...
 Optional: _SpecialForm = ...
 Tuple: _SpecialForm = ...
@@ -53,7 +63,7 @@ ClassVar: _SpecialForm = ...
 if sys.version_info >= (3, 8):
     Final: _SpecialForm = ...
     def final(f: _T) -> _T: ...
-    Literal: _SpecialForm = ...
+    Literal: _SpecialForm[object] = ...
     # TypedDict is a (non-subscriptable) special form.
     TypedDict: object
 
@@ -647,7 +657,13 @@ else:
     ) -> dict[str, Any]: ...
 
 if sys.version_info >= (3, 8):
+    @overload
+    def get_origin(tp: _GenericAlias[_Origin, _Args]) -> _Origin: ...
+    @overload
     def get_origin(tp: Any) -> Any | None: ...
+    @overload
+    def get_args(tp: _GenericAlias[_Origin, _Args]) -> _Args: ...
+    @overload
     def get_args(tp: Any) -> Tuple[Any, ...]: ...
 
 @overload