Toot-Mastodon-CLI-TUI-clien.../toot/typing_compat.py

148 lines
5.4 KiB
Python
Raw Normal View History

2023-02-14 11:31:30 +01:00
# Taken from https://github.com/rossmacarthur/typing-compat/
# TODO: Remove once the minimum python version is increased to 3.8
#
# Licensed under the MIT license
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
# flake8: noqa
import collections
import typing
__all__ = ['get_args', 'get_origin']
__title__ = 'typing-compat'
__version__ = '0.1.0'
__url__ = 'https://github.com/rossmacarthur/typing-compat'
__author__ = 'Ross MacArthur'
__author_email__ = 'ross@macarthur.io'
__description__ = 'Python typing compatibility library'
try:
# Python >=3.8 should have these functions already
2023-06-26 16:42:23 +02:00
from typing import get_args as _get_args # novermin
from typing import get_origin as _get_origin # novermin
2023-02-14 11:31:30 +01:00
except ImportError:
if hasattr(typing, '_GenericAlias'): # Python 3.7
def _get_origin(tp):
"""Copied from the Python 3.8 typing module"""
if isinstance(tp, typing._GenericAlias):
return tp.__origin__
if tp is typing.Generic:
return typing.Generic
return None
def _get_args(tp):
"""Copied from the Python 3.8 typing module"""
if isinstance(tp, typing._GenericAlias):
res = tp.__args__
if (
get_origin(tp) is collections.abc.Callable
and res[0] is not Ellipsis
):
res = (list(res[:-1]), res[-1])
return res
return ()
else: # Python <3.7
def _resolve_via_mro(tp):
if hasattr(tp, '__mro__'):
for t in tp.__mro__:
if t.__module__ in ('builtins', '__builtin__') and t is not object:
return t
return tp
def _get_origin(tp):
"""Emulate the behaviour of Python 3.8 typing module"""
if isinstance(tp, typing._ClassVar):
return typing.ClassVar
elif isinstance(tp, typing._Union):
return typing.Union
elif isinstance(tp, typing.GenericMeta):
if hasattr(tp, '_gorg'):
return _resolve_via_mro(tp._gorg)
else:
while tp.__origin__ is not None:
tp = tp.__origin__
return _resolve_via_mro(tp)
2023-06-26 16:42:23 +02:00
elif hasattr(typing, '_Literal') and isinstance(tp, typing._Literal): # novermin
return typing.Literal # novermin
2023-02-14 11:31:30 +01:00
def _normalize_arg(args):
if isinstance(args, tuple) and len(args) > 1:
base, rest = args[0], tuple(_normalize_arg(arg) for arg in args[1:])
if isinstance(base, typing.CallableMeta):
return typing.Callable[list(rest[:-1]), rest[-1]]
elif isinstance(base, (typing.GenericMeta, typing._Union)):
return base[rest]
return args
def _get_args(tp):
"""Emulate the behaviour of Python 3.8 typing module"""
if isinstance(tp, typing._ClassVar):
return (tp.__type__,)
elif hasattr(tp, '_subs_tree'):
tree = tp._subs_tree()
if isinstance(tree, tuple) and len(tree) > 1:
if isinstance(tree[0], typing.CallableMeta) and len(tree) == 2:
return ([], _normalize_arg(tree[1]))
return tuple(_normalize_arg(arg) for arg in tree[1:])
return ()
def get_origin(tp):
"""
Get the unsubscripted version of a type.
This supports generic types, Callable, Tuple, Union, Literal, Final and
ClassVar. Returns None for unsupported types.
Examples:
get_origin(Literal[42]) is Literal
get_origin(int) is None
get_origin(ClassVar[int]) is ClassVar
get_origin(Generic) is Generic
get_origin(Generic[T]) is Generic
get_origin(Union[T, int]) is Union
get_origin(List[Tuple[T, T]][int]) == list
"""
return _get_origin(tp)
def get_args(tp):
"""
Get type arguments with all substitutions performed.
For unions, basic simplifications used by Union constructor are performed.
Examples:
get_args(Dict[str, int]) == (str, int)
get_args(int) == ()
get_args(Union[int, Union[T, int], str][int]) == (int, str)
get_args(Union[int, Tuple[T, int]][str]) == (int, Tuple[str, int])
get_args(Callable[[], T][int]) == ([], int)
"""
return _get_args(tp)