forked from bton/matekasse
43 lines
1.1 KiB
Python
43 lines
1.1 KiB
Python
# Copyright 2009-2022 Joshua Bronson. All rights reserved.
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#
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# This Source Code Form is subject to the terms of the Mozilla Public
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# License, v. 2.0. If a copy of the MPL was not distributed with this
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# file, You can obtain one at http://mozilla.org/MPL/2.0/.
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"""Provide typing-related objects."""
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from __future__ import annotations
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from enum import Enum
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import typing as t
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if t.TYPE_CHECKING:
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from typing_extensions import TypeAlias as TypeAlias
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else:
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TypeAlias = 'TypeAlias'
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KT = t.TypeVar('KT')
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VT = t.TypeVar('VT')
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Items: TypeAlias = 't.Iterable[tuple[KT, VT]]'
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MapOrItems: TypeAlias = 't.Mapping[KT, VT] | Items[KT, VT]'
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ItemsIter: TypeAlias = 't.Iterator[tuple[KT, VT]]'
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class MissingT(Enum):
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"""Sentinel used to represent none/missing when None itself can't be used."""
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MISSING = 'MISSING'
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def __repr__(self) -> str:
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return '<MISSING>'
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MISSING: t.Final[MissingT] = MissingT.MISSING
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OKT: TypeAlias = 'KT | MissingT' #: optional key type
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OVT: TypeAlias = 'VT | MissingT' #: optional value type
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DT = t.TypeVar('DT') #: for default arguments
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ODT: TypeAlias = 'DT | MissingT' #: optional default arg type
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