Add CHECK_VERSION for type param lists

JelleZijlstra · JelleZijlstra · commit f4ea500baf44 · 2023-04-29T20:10:03.000-07:00
diff --git a/Grammar/python.gram b/Grammar/python.gram
@@ -640,7 +640,8 @@ type_alias[stmt_ty]:
 # Type parameter declaration
 # --------------------------
 
-type_params[asdl_typeparam_seq*]: '[' t=type_param_seq  ']' { t }
+type_params[asdl_typeparam_seq*]: '[' t=type_param_seq  ']' {
+        CHECK_VERSION(asdl_typeparam_seq *, 12, "Type parameter lists are", t) }
 
 type_param_seq[asdl_typeparam_seq*]: a[asdl_typeparam_seq*]=','.type_param+ [','] { a }
 
diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
@@ -802,6 +802,18 @@ def test_exception_groups_feature_version(self):
         with self.assertRaises(SyntaxError):
             ast.parse(code, feature_version=(3, 10))
 
+    def test_type_params_feature_version(self):
+        samples = [
+            "type X = int",
+            "class X[T]: pass",
+            "def f[T](): pass",
+        ]
+        for sample in samples:
+            with self.subTest(sample):
+                ast.parse(sample)
+                with self.assertRaises(SyntaxError):
+                    ast.parse(sample, feature_version=(3, 11))
+
     def test_invalid_major_feature_version(self):
         with self.assertRaises(ValueError):
             ast.parse('pass', feature_version=(2, 7))
diff --git a/Parser/parser.c b/Parser/parser.c
