Replace Literal and Protocol with runtime-referable symbols. (#651)

* Remove `Literal` from `hints`
and add the typing symbol to `shelllink`.

* Move `_MethodTypeDesc`
from `hints` to `tools.codegenerator.typeannotator`.

comtypes/hints.pyi

@@ -3,17 +3,11 @@
 # - utilities for type hints.
 import ctypes
 import sys
-from typing import Any as Any, ClassVar, Generic, NoReturn, TypeVar, overload
+from typing import Any as Any, ClassVar, Generic, NoReturn, Protocol, TypeVar, overload
 from typing import Optional, Union as _UnionT
-from typing import List, Tuple as Tuple, Type
+from typing import Tuple as Tuple, Type
 from typing import Callable, Iterator, Sequence
 
-if sys.version_info >= (3, 8):
-    from typing import Protocol
-    from typing import Literal as Literal
-else:
-    from typing_extensions import Protocol
-    from typing_extensions import Literal as Literal
 if sys.version_info >= (3, 9):
     from typing import Annotated as Annotated
 else:
@@ -85,11 +79,6 @@ class FirstComItfOf(Generic[_T_coclass]):
     as an argument.
     """
 
-class _MethodTypeDesc(Protocol):
-    arguments: List[Tuple[Any, str, List[str], Optional[Any]]]
-    idlflags: List[str]
-    name: str
-
 _P_Put = ParamSpec("_P_Put")
 _R_Put = TypeVar("_R_Put")
 _P_PutRef = ParamSpec("_P_PutRef")

comtypes/shelllink.py

@@ -2,7 +2,7 @@
 from ctypes import POINTER
 from ctypes import byref, create_string_buffer, create_unicode_buffer
 from ctypes.wintypes import DWORD, WIN32_FIND_DATAA, WIN32_FIND_DATAW, MAX_PATH
-from typing import Tuple, TYPE_CHECKING
+from typing import Tuple, TYPE_CHECKING, Literal
 
 from comtypes import IUnknown, GUID, COMMETHOD, HRESULT, CoClass
 
@@ -143,7 +143,7 @@ def ShowCmd(self) -> int: ...
         def ShowCmd(self, piShowCmd: int) -> None: ...
         def SetIconLocation(self, pszIconPath: bytes, iIcon: int) -> hints.Hresult: ...
         def SetRelativePath(
-            self, pszPathRel: bytes, dwReserved: hints.Literal[0]
+            self, pszPathRel: bytes, dwReserved: Literal[0]
         ) -> hints.Hresult: ...
         def Resolve(self, hwnd: int, fFlags: int) -> hints.Hresult: ...
         def SetPath(self, pszFile: bytes) -> hints.Hresult: ...
@@ -278,7 +278,7 @@ def ShowCmd(self) -> int: ...
         def ShowCmd(self, piShowCmd: int) -> None: ...
         def SetIconLocation(self, pszIconPath: str, iIcon: int) -> hints.Hresult: ...
         def SetRelativePath(
-            self, pszPathRel: str, dwReserved: hints.Literal[0]
+            self, pszPathRel: str, dwReserved: Literal[0]
         ) -> hints.Hresult: ...
         def Resolve(self, hwnd: int, fFlags: int) -> hints.Hresult: ...
         def SetPath(self, pszFile: str) -> hints.Hresult: ...

comtypes/tools/codegenerator/typeannotator.py

@@ -1,19 +1,19 @@
 import abc
 import keyword
-from typing import Any, Generic, TypeVar, TYPE_CHECKING
+from typing import Any, Generic, Protocol, TypeVar
 from typing import Dict, List, Optional, Sequence, Tuple
 from typing import Iterable, Iterator
 
 from comtypes.tools import typedesc
 
-if TYPE_CHECKING:
-    from comtypes import hints
 
+class _MethodTypeDesc(Protocol):
+    arguments: List[Tuple[Any, str, List[str], Optional[Any]]]
+    idlflags: List[str]
+    name: str
 
-if TYPE_CHECKING:
-    _T_MTD = TypeVar("_T_MTD", bound=hints._MethodTypeDesc)
-else:
-    _T_MTD = TypeVar("_T_MTD")
+
+_T_MTD = TypeVar("_T_MTD", bound=_MethodTypeDesc)
 
 
 class _MethodAnnotator(abc.ABC, Generic[_T_MTD]):