mercurial/interfaces/util.py
author Martin von Zweigbergk <martinvonz@google.com>
Thu, 10 Oct 2019 22:34:16 -0700
changeset 43244 c5adf480de0f
parent 43077 687b865b95ad
child 48875 6000f5b25c9b
permissions -rw-r--r--
widening: remove always-true condition in widening code The function is now specifically about widening, so we don't need to check if we're widening. Differential Revision: https://phab.mercurial-scm.org/D7094

# util.py - Utilities for declaring interfaces.
#
# Copyright 2018 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

# zope.interface imposes a run-time cost due to module import overhead and
# bookkeeping for declaring interfaces. So, we use stubs for various
# zope.interface primitives unless instructed otherwise.

from __future__ import absolute_import

from .. import encoding

if encoding.environ.get(b'HGREALINTERFACES'):
    from ..thirdparty.zope import interface as zi

    Attribute = zi.Attribute
    Interface = zi.Interface
    implementer = zi.implementer
else:

    class Attribute(object):
        def __init__(self, __name__, __doc__=b''):
            pass

    class Interface(object):
        def __init__(
            self, name, bases=(), attrs=None, __doc__=None, __module__=None
        ):
            pass

    def implementer(*ifaces):
        def wrapper(cls):
            return cls

        return wrapper