annotate mercurial/thirdparty/attr/setters.py @ 49643:e1c586b9a43c

attr: vendor 22.1.0

The previous version was 5 years old, and pytype 2022.06.30 started complaining
about various uses (e.g. seeing `mercurial.thirdparty.attr._make._CountingAttr`
instead of `bytearray`).  Hopefully this helps.  Additionally, this has official
python 3.11 support.

The `attrs` package is left out, because it is simply a bunch of *.pyi stubs and
`from attr.X import *`, and that's not how they've been used up to this point.
We'd probably need to customize those anyway to
`from mercurial.thirdparty.attr import *`.

# SPDX-License-Identifier: MIT

"""
Commonly used hooks for on_setattr.
"""


from . import _config
from .exceptions import FrozenAttributeError


def pipe(*setters):
    """
    Run all *setters* and return the return value of the last one.

    .. versionadded:: 20.1.0
    """

    def wrapped_pipe(instance, attrib, new_value):
        rv = new_value

        for setter in setters:
            rv = setter(instance, attrib, rv)

        return rv

    return wrapped_pipe


def frozen(_, __, ___):
    """
    Prevent an attribute to be modified.

    .. versionadded:: 20.1.0
    """
    raise FrozenAttributeError()


def validate(instance, attrib, new_value):
    """
    Run *attrib*'s validator on *new_value* if it has one.

    .. versionadded:: 20.1.0
    """
    if _config._run_validators is False:
        return new_value

    v = attrib.validator
    if not v:
        return new_value

    v(instance, attrib, new_value)

    return new_value


def convert(instance, attrib, new_value):
    """
    Run *attrib*'s converter -- if it has one --  on *new_value* and return the
    result.

    .. versionadded:: 20.1.0
    """
    c = attrib.converter
    if c:
        return c(new_value)

    return new_value


# Sentinel for disabling class-wide *on_setattr* hooks for certain attributes.
# autodata stopped working, so the docstring is inlined in the API docs.
NO_OP = object()