81 lines
2.7 KiB
Python
81 lines
2.7 KiB
Python
# -*- coding: utf-8 -*-
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# Copyright (C) 2014-2016 Andrey Antukh <niwi@niwi.nz>
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# Copyright (C) 2014-2016 Jesús Espino <jespinog@gmail.com>
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# Copyright (C) 2014-2016 David Barragán <bameda@dbarragan.com>
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# Copyright (C) 2014-2016 Alejandro Alonso <alejandro.alonso@kaleidos.net>
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as
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# published by the Free Software Foundation, either version 3 of the
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# License, or (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Affero General Public License for more details.
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#
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# You should have received a copy of the GNU Affero General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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import collections
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class OrderedSet(collections.MutableSet):
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# Extract from:
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# - https://docs.python.org/3/library/collections.abc.html?highlight=orderedset
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# - https://code.activestate.com/recipes/576694/
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def __init__(self, iterable=None):
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self.end = end = []
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end += [None, end, end] # sentinel node for doubly linked list
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self.map = {} # key --> [key, prev, next]
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if iterable is not None:
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self |= iterable
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def __len__(self):
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return len(self.map)
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def __contains__(self, key):
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return key in self.map
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def add(self, key):
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if key not in self.map:
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end = self.end
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curr = end[1]
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curr[2] = end[1] = self.map[key] = [key, curr, end]
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def discard(self, key):
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if key in self.map:
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key, prev, next = self.map.pop(key)
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prev[2] = next
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next[1] = prev
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def __iter__(self):
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end = self.end
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curr = end[2]
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while curr is not end:
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yield curr[0]
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curr = curr[2]
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def __reversed__(self):
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end = self.end
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curr = end[1]
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while curr is not end:
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yield curr[0]
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curr = curr[1]
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def pop(self, last=True):
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if not self:
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raise KeyError('set is empty')
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key = self.end[1][0] if last else self.end[2][0]
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self.discard(key)
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return key
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def __repr__(self):
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if not self:
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return '%s()' % (self.__class__.__name__,)
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return '%s(%r)' % (self.__class__.__name__, list(self))
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def __eq__(self, other):
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if isinstance(other, OrderedSet):
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return len(self) == len(other) and list(self) == list(other)
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return set(self) == set(other)
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