See :pep:`484` for details and comparison with other typing semantics.
+ .. versionchanged:: 3.11
+ Overloaded functions can now be introspected at runtime using
+ :func:`get_overloads`.
+
+
+.. function:: get_overloads(func)
+
+ Return a sequence of :func:`@overload <overload>`-decorated definitions for
+ *func*. *func* is the function object for the implementation of the
+ overloaded function. For example, given the definition of ``process`` in
+ the documentation for :func:`@overload <overload>`,
+ ``get_overloads(process)`` will return a sequence of three function objects
+ for the three defined overloads. If called on a function with no overloads,
+ ``get_overloads`` returns an empty sequence.
+
+ ``get_overloads`` can be used for introspecting an overloaded function at
+ runtime.
+
+ .. versionadded:: 3.11
+
+
+.. function:: clear_overloads()
+
+ Clear all registered overloads in the internal registry. This can be used
+ to reclaim the memory used by the registry.
+
+ .. versionadded:: 3.11
+
+
.. decorator:: final
A decorator to indicate to type checkers that the decorated method
import contextlib
import collections
+from collections import defaultdict
from functools import lru_cache
import inspect
import pickle
import sys
import warnings
from unittest import TestCase, main, skipUnless, skip
+from unittest.mock import patch
from copy import copy, deepcopy
from typing import Any, NoReturn, Never, assert_never
+from typing import overload, get_overloads, clear_overloads
from typing import TypeVar, TypeVarTuple, Unpack, AnyStr
from typing import T, KT, VT # Not in __all__.
from typing import Union, Optional, Literal
self.assertEqual("x" | X, Union["x", X])
+@lru_cache()
+def cached_func(x, y):
+ return 3 * x + y
+
+
+class MethodHolder:
+ @classmethod
+ def clsmethod(cls): ...
+ @staticmethod
+ def stmethod(): ...
+ def method(self): ...
+
+
class OverloadTests(BaseTestCase):
def test_overload_fails(self):
- from typing import overload
-
with self.assertRaises(RuntimeError):
@overload
blah()
def test_overload_succeeds(self):
- from typing import overload
-
@overload
def blah():
pass
blah()
+ def set_up_overloads(self):
+ def blah():
+ pass
+
+ overload1 = blah
+ overload(blah)
+
+ def blah():
+ pass
+
+ overload2 = blah
+ overload(blah)
+
+ def blah():
+ pass
+
+ return blah, [overload1, overload2]
+
+ # Make sure we don't clear the global overload registry
+ @patch("typing._overload_registry",
+ defaultdict(lambda: defaultdict(dict)))
+ def test_overload_registry(self):
+ # The registry starts out empty
+ self.assertEqual(typing._overload_registry, {})
+
+ impl, overloads = self.set_up_overloads()
+ self.assertNotEqual(typing._overload_registry, {})
+ self.assertEqual(list(get_overloads(impl)), overloads)
+
+ def some_other_func(): pass
+ overload(some_other_func)
+ other_overload = some_other_func
+ def some_other_func(): pass
+ self.assertEqual(list(get_overloads(some_other_func)), [other_overload])
+
+ # Make sure that after we clear all overloads, the registry is
+ # completely empty.
+ clear_overloads()
+ self.assertEqual(typing._overload_registry, {})
+ self.assertEqual(get_overloads(impl), [])
+
+ # Querying a function with no overloads shouldn't change the registry.
+ def the_only_one(): pass
+ self.assertEqual(get_overloads(the_only_one), [])
+ self.assertEqual(typing._overload_registry, {})
+
+ def test_overload_registry_repeated(self):
+ for _ in range(2):
+ impl, overloads = self.set_up_overloads()
+
+ self.assertEqual(list(get_overloads(impl)), overloads)
+
# Definitions needed for features introduced in Python 3.6
from abc import abstractmethod, ABCMeta
import collections
+from collections import defaultdict
import collections.abc
import contextlib
import functools
'assert_type',
'assert_never',
'cast',
+ 'clear_overloads',
'final',
'get_args',
'get_origin',
+ 'get_overloads',
'get_type_hints',
'is_typeddict',
'LiteralString',
"by an implementation that is not @overload-ed.")
+# {module: {qualname: {firstlineno: func}}}
+_overload_registry = defaultdict(functools.partial(defaultdict, dict))
+
+
def overload(func):
"""Decorator for overloaded functions/methods.
def utf8(value: str) -> bytes: ...
def utf8(value):
# implementation goes here
+
+ The overloads for a function can be retrieved at runtime using the
+ get_overloads() function.
"""
+ # classmethod and staticmethod
+ f = getattr(func, "__func__", func)
+ try:
+ _overload_registry[f.__module__][f.__qualname__][f.__code__.co_firstlineno] = func
+ except AttributeError:
+ # Not a normal function; ignore.
+ pass
return _overload_dummy
+def get_overloads(func):
+ """Return all defined overloads for *func* as a sequence."""
+ # classmethod and staticmethod
+ f = getattr(func, "__func__", func)
+ if f.__module__ not in _overload_registry:
+ return []
+ mod_dict = _overload_registry[f.__module__]
+ if f.__qualname__ not in mod_dict:
+ return []
+ return list(mod_dict[f.__qualname__].values())
+
+
+def clear_overloads():
+ """Clear all overloads in the registry."""
+ _overload_registry.clear()
+
+
def final(f):
"""A decorator to indicate final methods and final classes.
projects / thirdparty / Python / cpython.git / commitdiff
