[3.13] Rename typing._collect_parameters (GH-118900) (#118917)

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Lib/test/test_typing.py

@@ -45,7 +45,7 @@ import typing
 import weakref
 import types
 
-from test.support import captured_stderr, cpython_only, infinite_recursion, requires_docstrings
+from test.support import captured_stderr, cpython_only, infinite_recursion, requires_docstrings, import_helper
 from test.typinganndata import ann_module695, mod_generics_cache, _typed_dict_helper
 
 
@@ -6325,6 +6325,8 @@ class ForwardRefTests(BaseTestCase):
         self.assertEqual(X | "x", Union[X, "x"])
         self.assertEqual("x" | X, Union["x", X])
 
+
+class InternalsTests(BaseTestCase):
     def test_deprecation_for_no_type_params_passed_to__evaluate(self):
         with self.assertWarnsRegex(
             DeprecationWarning,
@@ -6350,6 +6352,15 @@ class ForwardRefTests(BaseTestCase):
 
         self.assertEqual(cm.filename, __file__)
 
+    def test_collect_parameters(self):
+        typing = import_helper.import_fresh_module("typing")
+        with self.assertWarnsRegex(
+            DeprecationWarning,
+            "The private _collect_parameters function is deprecated"
+        ) as cm:
+            typing._collect_parameters
+        self.assertEqual(cm.filename, __file__)
+
 
 @lru_cache()
 def cached_func(x, y):

Lib/typing.py

@@ -257,15 +257,15 @@ def _type_repr(obj):
     return repr(obj)
 
 
-def _collect_parameters(args, *, enforce_default_ordering: bool = True):
-    """Collect all type variables and parameter specifications in args
+def _collect_type_parameters(args, *, enforce_default_ordering: bool = True):
+    """Collect all type parameters in args
     in order of first appearance (lexicographic order).
 
     For example::
 
         >>> P = ParamSpec('P')
         >>> T = TypeVar('T')
-        >>> _collect_parameters((T, Callable[P, T]))
+        >>> _collect_type_parameters((T, Callable[P, T]))
         (~T, ~P)
     """
     # required type parameter cannot appear after parameter with default
@@ -281,7 +281,7 @@ def _collect_parameters(args, *, enforce_default_ordering: bool = True):
             # `t` might be a tuple, when `ParamSpec` is substituted with
             # `[T, int]`, or `[int, *Ts]`, etc.
             for x in t:
-                for collected in _collect_parameters([x]):
+                for collected in _collect_type_parameters([x]):
                     if collected not in parameters:
                         parameters.append(collected)
         elif hasattr(t, '__typing_subst__'):
@@ -321,7 +321,7 @@ def _check_generic_specialization(cls, arguments):
         if actual_len < expected_len:
             # If the parameter at index `actual_len` in the parameters list
             # has a default, then all parameters after it must also have
-            # one, because we validated as much in _collect_parameters().
+            # one, because we validated as much in _collect_type_parameters().
             # That means that no error needs to be raised here, despite
             # the number of arguments being passed not matching the number
             # of parameters: all parameters that aren't explicitly
@@ -1256,7 +1256,7 @@ def _generic_init_subclass(cls, *args, **kwargs):
     if error:
         raise TypeError("Cannot inherit from plain Generic")
     if '__orig_bases__' in cls.__dict__:
-        tvars = _collect_parameters(cls.__orig_bases__)
+        tvars = _collect_type_parameters(cls.__orig_bases__)
         # Look for Generic[T1, ..., Tn].
         # If found, tvars must be a subset of it.
         # If not found, tvars is it.
@@ -1418,7 +1418,7 @@ class _GenericAlias(_BaseGenericAlias, _root=True):
         self.__args__ = tuple(... if a is _TypingEllipsis else
                               a for a in args)
         enforce_default_ordering = origin in (Generic, Protocol)
-        self.__parameters__ = _collect_parameters(
+        self.__parameters__ = _collect_type_parameters(
             args,
             enforce_default_ordering=enforce_default_ordering,
         )
@@ -3789,6 +3789,16 @@ def __getattr__(attr):
     elif attr in {"ContextManager", "AsyncContextManager"}:
         import contextlib
         obj = _alias(getattr(contextlib, f"Abstract{attr}"), 2, name=attr, defaults=(bool | None,))
+    elif attr == "_collect_parameters":
+        import warnings
+
+        depr_message = (
+            "The private _collect_parameters function is deprecated and will be"
+            " removed in a future version of Python. Any use of private functions"
+            " is discouraged and may break in the future."
+        )
+        warnings.warn(depr_message, category=DeprecationWarning, stacklevel=2)
+        obj = _collect_type_parameters
     else:
         raise AttributeError(f"module {__name__!r} has no attribute {attr!r}")
     globals()[attr] = obj