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goulash.set module

goulash.set

""" goulash.set

"""
import collections

# SOURCE:
#   Ordered set implementation adapted from original at:
#   http://code.activestate.com/recipes/576694/
class OrderedSet(collections.MutableSet, list):

    def __init__(self, iterable=None):
        self.end = end = []
        end += [None, end, end]  #  sentinel node for doubly linked list
        self.map = {}            #  key --> [key, prev, next]
        if iterable is not None:
            self |= iterable

    def __len__(self):
        return len(self.map)

    def __contains__(self, key):
        return key in self.map

    def add(self, key):
        if key not in self.map:
            end = self.end
            curr = end[1]
            curr[2] = end[1] = self.map[key] = [key, curr, end]
    append = add

    def __getitem__(self, *args):
        return list(self).__getitem__(*args)

    def insert(self, i, x):
        tmp = list(self)
        tmp.insert(i, x)
        for x in self:
            self.remove(x)
        self.__init__(tmp)

    def discard(self, key):
        if key in self.map:
            key, prev, next = self.map.pop(key)
            prev[2] = next
            next[1] = prev

    def __iter__(self):
        end = self.end
        curr = end[2]
        while curr is not end:
            yield curr[0]
            curr = curr[2]

    def __reversed__(self):
        end = self.end
        curr = end[1]
        while curr is not end:
            yield curr[0]
            curr = curr[1]

    def pop(self, last=True):
        if not self:
            raise KeyError('set is empty')
        key = self.end[1][0] if last else self.end[2][0]
        self.discard(key)
        return key

    def __repr__(self):
        if not self:
            return '%s()' % (self.__class__.__name__,)
        return '%s(%r)' % (self.__class__.__name__, list(self))

    def __eq__(self, other):
        if isinstance(other, OrderedSet):
            return len(self) == len(other) and list(self) == list(other)
        return set(self) == set(other)

Classes

class OrderedSet

class OrderedSet(collections.MutableSet, list):

    def __init__(self, iterable=None):
        self.end = end = []
        end += [None, end, end]  #  sentinel node for doubly linked list
        self.map = {}            #  key --> [key, prev, next]
        if iterable is not None:
            self |= iterable

    def __len__(self):
        return len(self.map)

    def __contains__(self, key):
        return key in self.map

    def add(self, key):
        if key not in self.map:
            end = self.end
            curr = end[1]
            curr[2] = end[1] = self.map[key] = [key, curr, end]
    append = add

    def __getitem__(self, *args):
        return list(self).__getitem__(*args)

    def insert(self, i, x):
        tmp = list(self)
        tmp.insert(i, x)
        for x in self:
            self.remove(x)
        self.__init__(tmp)

    def discard(self, key):
        if key in self.map:
            key, prev, next = self.map.pop(key)
            prev[2] = next
            next[1] = prev

    def __iter__(self):
        end = self.end
        curr = end[2]
        while curr is not end:
            yield curr[0]
            curr = curr[2]

    def __reversed__(self):
        end = self.end
        curr = end[1]
        while curr is not end:
            yield curr[0]
            curr = curr[1]

    def pop(self, last=True):
        if not self:
            raise KeyError('set is empty')
        key = self.end[1][0] if last else self.end[2][0]
        self.discard(key)
        return key

    def __repr__(self):
        if not self:
            return '%s()' % (self.__class__.__name__,)
        return '%s(%r)' % (self.__class__.__name__, list(self))

    def __eq__(self, other):
        if isinstance(other, OrderedSet):
            return len(self) == len(other) and list(self) == list(other)
        return set(self) == set(other)

Ancestors (in MRO)

  • OrderedSet
  • _abcoll.MutableSet
  • _abcoll.Set
  • _abcoll.Sized
  • _abcoll.Iterable
  • _abcoll.Container
  • __builtin__.list
  • __builtin__.object

Instance variables

var map

Methods

def __init__(

self, iterable=None)

def __init__(self, iterable=None):
    self.end = end = []
    end += [None, end, end]  #  sentinel node for doubly linked list
    self.map = {}            #  key --> [key, prev, next]
    if iterable is not None:
        self |= iterable

def add(

self, key)

def add(self, key):
    if key not in self.map:
        end = self.end
        curr = end[1]
        curr[2] = end[1] = self.map[key] = [key, curr, end]

def append(

self, key)

def add(self, key):
    if key not in self.map:
        end = self.end
        curr = end[1]
        curr[2] = end[1] = self.map[key] = [key, curr, end]

def clear(

self)

This is slow (creates N new iterators!) but effective.

def clear(self):
    """This is slow (creates N new iterators!) but effective."""
    try:
        while True:
            self.pop()
    except KeyError:
        pass

def discard(

self, key)

def discard(self, key):
    if key in self.map:
        key, prev, next = self.map.pop(key)
        prev[2] = next
        next[1] = prev

def insert(

self, i, x)

def insert(self, i, x):
    tmp = list(self)
    tmp.insert(i, x)
    for x in self:
        self.remove(x)
    self.__init__(tmp)

def isdisjoint(

self, other)

Return True if two sets have a null intersection.

def isdisjoint(self, other):
    'Return True if two sets have a null intersection.'
    for value in other:
        if value in self:
            return False
    return True

def pop(

self, last=True)

def pop(self, last=True):
    if not self:
        raise KeyError('set is empty')
    key = self.end[1][0] if last else self.end[2][0]
    self.discard(key)
    return key

def remove(

self, value)

Remove an element. If not a member, raise a KeyError.

def remove(self, value):
    """Remove an element. If not a member, raise a KeyError."""
    if value not in self:
        raise KeyError(value)
    self.discard(value)