annotate mercurial/typelib.py @ 51864:1c5810ce737e

typing: add `from __future__ import annotations` to remaining source files

Most of these look newer than when the original imports referenced in the
previous commit were dropped, so these weren't covered by the backout.  These
were found with:

    hg files mercurial hgext hgext3rd -I '**.py' -X '**/thirdparty' \
        | xargs grep -L 'from __future__ import annotations'

All of the `__init__.py` files that finds are empty, so those were ignored and
the rest manually edited.

# typelib.py - type hint aliases and support
#
# Copyright 2022 Matt Harbison <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import annotations

import typing

from typing import (
    Callable,
)

# Note: this is slightly different from pycompat.TYPE_CHECKING, as using
# pycompat causes the BinaryIO_Proxy type to be resolved to ``object`` when
# used as the base class during a pytype run.
TYPE_CHECKING = typing.TYPE_CHECKING


# The BinaryIO class provides empty methods, which at runtime means that
# ``__getattr__`` on the proxy classes won't get called for the methods that
# should delegate to the internal object.  So to avoid runtime changes because
# of the required typing inheritance, just use BinaryIO when typechecking, and
# ``object`` otherwise.
if TYPE_CHECKING:
    from typing import (
        BinaryIO,
        Union,
    )

    from . import (
        node,
        posix,
        windows,
    )

    BinaryIO_Proxy = BinaryIO
    CacheStat = Union[posix.cachestat, windows.cachestat]
    NodeConstants = node.sha1nodeconstants
else:
    from typing import Any

    BinaryIO_Proxy = object
    CacheStat = Any
    NodeConstants = Any

# scmutil.getuipathfn() related callback.
UiPathFn = Callable[[bytes], bytes]