543cf78a6f
Fixes bug 1445827 Depends-On: I02e3c9aacef0b295a2f823a5cbaf11768a90cb82 Change-Id: I1db681803598ac1bc917fd74a99458bc61edf3f1
137 lines
4.0 KiB
Python
137 lines
4.0 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
# Copyright (C) 2015 Yahoo! Inc. All Rights Reserved.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
import collections
|
|
import itertools
|
|
|
|
import six
|
|
|
|
|
|
# Used for values that don't matter in sets backed by dicts...
|
|
_sentinel = object()
|
|
|
|
|
|
def _merge_in(target, iterable=None, sentinel=_sentinel):
|
|
"""Merges iterable into the target and returns the target."""
|
|
if iterable is not None:
|
|
for value in iterable:
|
|
target.setdefault(value, sentinel)
|
|
return target
|
|
|
|
|
|
class OrderedSet(collections.Set, collections.Hashable):
|
|
"""A read-only hashable set that retains insertion/initial ordering.
|
|
|
|
It should work in all existing places that ``frozenset`` is used.
|
|
|
|
See: https://mail.python.org/pipermail/python-ideas/2009-May/004567.html
|
|
for an idea thread that *may* eventually (*someday*) result in this (or
|
|
similar) code being included in the mainline python codebase (although
|
|
the end result of that thread is somewhat discouraging in that regard).
|
|
"""
|
|
|
|
__slots__ = ['_data']
|
|
|
|
def __init__(self, iterable=None):
|
|
self._data = _merge_in(collections.OrderedDict(), iterable)
|
|
|
|
def __hash__(self):
|
|
return self._hash()
|
|
|
|
def __contains__(self, value):
|
|
return value in self._data
|
|
|
|
def __len__(self):
|
|
return len(self._data)
|
|
|
|
def __iter__(self):
|
|
for value in six.iterkeys(self._data):
|
|
yield value
|
|
|
|
def __setstate__(self, items):
|
|
self.__init__(iterable=iter(items))
|
|
|
|
def __getstate__(self):
|
|
return tuple(self)
|
|
|
|
def __repr__(self):
|
|
return "%s(%s)" % (type(self).__name__, list(self))
|
|
|
|
def copy(self):
|
|
"""Return a shallow copy of a set."""
|
|
it = iter(self)
|
|
c = self._from_iterable(it)
|
|
return c
|
|
|
|
def intersection(self, *sets):
|
|
"""Return the intersection of two or more sets as a new set.
|
|
|
|
(i.e. elements that are common to all of the sets.)
|
|
"""
|
|
def absorb_it(sets):
|
|
for value in iter(self):
|
|
matches = 0
|
|
for s in sets:
|
|
if value in s:
|
|
matches += 1
|
|
else:
|
|
break
|
|
if matches == len(sets):
|
|
yield value
|
|
it = absorb_it(sets)
|
|
c = self._from_iterable(it)
|
|
return c
|
|
|
|
def issuperset(self, other):
|
|
"""Report whether this set contains another set."""
|
|
for value in other:
|
|
if value not in self:
|
|
return False
|
|
return True
|
|
|
|
def issubset(self, other):
|
|
"""Report whether another set contains this set."""
|
|
for value in iter(self):
|
|
if value not in other:
|
|
return False
|
|
return True
|
|
|
|
def difference(self, *sets):
|
|
"""Return the difference of two or more sets as a new set.
|
|
|
|
(i.e. all elements that are in this set but not the others.)
|
|
"""
|
|
def absorb_it(sets):
|
|
for value in iter(self):
|
|
seen = False
|
|
for s in sets:
|
|
if value in s:
|
|
seen = True
|
|
break
|
|
if not seen:
|
|
yield value
|
|
it = absorb_it(sets)
|
|
c = self._from_iterable(it)
|
|
return c
|
|
|
|
def union(self, *sets):
|
|
"""Return the union of sets as a new set.
|
|
|
|
(i.e. all elements that are in either set.)
|
|
"""
|
|
it = itertools.chain(iter(self), *sets)
|
|
return self._from_iterable(it)
|