Support my PEP 649 branch (#412)

Author: JelleZijlstra

CHANGELOG.md

@@ -1,3 +1,8 @@
+# Unreleased
+
+- Preliminary changes for compatibility with the draft implementation
+  of PEP 649 in Python 3.14.
+
 # Release 4.12.0 (May 23, 2024)
 
 This release is mostly the same as 4.12.0rc1 but fixes one more

src/test_typing_extensions.py

@@ -64,10 +64,14 @@
 )
 
 ANN_MODULE_SOURCE = '''\
+import sys
 from typing import List, Optional
 from functools import wraps
 
-__annotations__[1] = 2
+try:
+    __annotations__[1] = 2
+except NameError:
+    assert sys.version_info >= (3, 14)
 
 class C:
 
@@ -77,8 +81,10 @@ class C:
 x: int = 5; y: str = x; f: Tuple[int, int]
 
 class M(type):
-
-    __annotations__['123'] = 123
+    try:
+        __annotations__['123'] = 123
+    except NameError:
+        assert sys.version_info >= (3, 14)
     o: type = object
 
 (pars): bool = True
@@ -1310,7 +1316,10 @@ def tearDownClass(cls):
             del sys.modules[modname]
 
     def test_get_type_hints_modules(self):
-        ann_module_type_hints = {1: 2, 'f': Tuple[int, int], 'x': int, 'y': str}
+        if sys.version_info >= (3, 14):
+            ann_module_type_hints = {'f': Tuple[int, int], 'x': int, 'y': str}
+        else:
+            ann_module_type_hints = {1: 2, 'f': Tuple[int, int], 'x': int, 'y': str}
         self.assertEqual(gth(self.ann_module), ann_module_type_hints)
         self.assertEqual(gth(self.ann_module2), {})
         self.assertEqual(gth(self.ann_module3), {})
@@ -1319,7 +1328,10 @@ def test_get_type_hints_classes(self):
         self.assertEqual(gth(self.ann_module.C, self.ann_module.__dict__),
                          {'y': Optional[self.ann_module.C]})
         self.assertIsInstance(gth(self.ann_module.j_class), dict)
-        self.assertEqual(gth(self.ann_module.M), {'123': 123, 'o': type})
+        if sys.version_info >= (3, 14):
+            self.assertEqual(gth(self.ann_module.M), {'o': type})
+        else:
+            self.assertEqual(gth(self.ann_module.M), {'123': 123, 'o': type})
         self.assertEqual(gth(self.ann_module.D),
                          {'j': str, 'k': str, 'y': Optional[self.ann_module.C]})
         self.assertEqual(gth(self.ann_module.Y), {'z': int})
@@ -2992,7 +3004,7 @@ def meth(self): pass  # noqa: B027
 
         acceptable_extra_attrs = {
             '_is_protocol', '_is_runtime_protocol', '__parameters__',
-            '__init__', '__annotations__', '__subclasshook__',
+            '__init__', '__annotations__', '__subclasshook__', '__annotate__'
         }
         self.assertLessEqual(vars(NonP).keys(), vars(C).keys() | acceptable_extra_attrs)
         self.assertLessEqual(

src/typing_extensions.py

@@ -942,7 +942,13 @@ def __new__(cls, name, bases, ns, *, total=True, closed=False):
                 tp_dict.__orig_bases__ = bases
 
             annotations = {}
-            own_annotations = ns.get('__annotations__', {})
+            if "__annotations__" in ns:
+                own_annotations = ns["__annotations__"]
+            elif "__annotate__" in ns:
+                # TODO: Use inspect.VALUE here, and make the annotations lazily evaluated
+                own_annotations = ns["__annotate__"](1)
+            else:
+                own_annotations = {}
             msg = "TypedDict('Name', {f0: t0, f1: t1, ...}); each t must be a type"
             if _TAKES_MODULE:
                 own_annotations = {
@@ -3104,7 +3110,13 @@ def __new__(cls, typename, bases, ns):
                     raise TypeError(
                         'can only inherit from a NamedTuple type and Generic')
             bases = tuple(tuple if base is _NamedTuple else base for base in bases)
-            types = ns.get('__annotations__', {})
+            if "__annotations__" in ns:
+                types = ns["__annotations__"]
+            elif "__annotate__" in ns:
+                # TODO: Use inspect.VALUE here, and make the annotations lazily evaluated
+                types = ns["__annotate__"](1)
+            else:
+                types = {}
             default_names = []
             for field_name in types:
                 if field_name in ns: