147 lines
4.2 KiB
Python
147 lines
4.2 KiB
Python
# Access WeakSet through the weakref module.
|
|
# This code is separated-out because it is needed
|
|
# by abc.py to load everything else at startup.
|
|
|
|
from _weakref import ref
|
|
|
|
__all__ = ['WeakSet']
|
|
|
|
class WeakSet:
|
|
def __init__(self, data=None):
|
|
self.data = set()
|
|
def _remove(item, selfref=ref(self)):
|
|
self = selfref()
|
|
if self is not None:
|
|
self.data.discard(item)
|
|
self._remove = _remove
|
|
if data is not None:
|
|
self.update(data)
|
|
|
|
def __iter__(self):
|
|
for itemref in self.data:
|
|
item = itemref()
|
|
if item is not None:
|
|
yield item
|
|
|
|
def __len__(self):
|
|
return sum(x() is not None for x in self.data)
|
|
|
|
def __contains__(self, item):
|
|
return ref(item) in self.data
|
|
|
|
def __reduce__(self):
|
|
return (self.__class__, (list(self),),
|
|
getattr(self, '__dict__', None))
|
|
|
|
def add(self, item):
|
|
self.data.add(ref(item, self._remove))
|
|
|
|
def clear(self):
|
|
self.data.clear()
|
|
|
|
def copy(self):
|
|
return self.__class__(self)
|
|
|
|
def pop(self):
|
|
while True:
|
|
try:
|
|
itemref = self.data.pop()
|
|
except KeyError:
|
|
raise KeyError('pop from empty WeakSet')
|
|
item = itemref()
|
|
if item is not None:
|
|
return item
|
|
|
|
def remove(self, item):
|
|
self.data.remove(ref(item))
|
|
|
|
def discard(self, item):
|
|
self.data.discard(ref(item))
|
|
|
|
def update(self, other):
|
|
if isinstance(other, self.__class__):
|
|
self.data.update(other.data)
|
|
else:
|
|
for element in other:
|
|
self.add(element)
|
|
def __ior__(self, other):
|
|
self.update(other)
|
|
return self
|
|
|
|
# Helper functions for simple delegating methods.
|
|
def _apply(self, other, method):
|
|
if not isinstance(other, self.__class__):
|
|
other = self.__class__(other)
|
|
newdata = method(other.data)
|
|
newset = self.__class__()
|
|
newset.data = newdata
|
|
return newset
|
|
|
|
def difference(self, other):
|
|
return self._apply(other, self.data.difference)
|
|
__sub__ = difference
|
|
|
|
def difference_update(self, other):
|
|
if self is other:
|
|
self.data.clear()
|
|
else:
|
|
self.data.difference_update(ref(item) for item in other)
|
|
def __isub__(self, other):
|
|
if self is other:
|
|
self.data.clear()
|
|
else:
|
|
self.data.difference_update(ref(item) for item in other)
|
|
return self
|
|
|
|
def intersection(self, other):
|
|
return self._apply(other, self.data.intersection)
|
|
__and__ = intersection
|
|
|
|
def intersection_update(self, other):
|
|
self.data.intersection_update(ref(item) for item in other)
|
|
def __iand__(self, other):
|
|
self.data.intersection_update(ref(item) for item in other)
|
|
return self
|
|
|
|
def issubset(self, other):
|
|
return self.data.issubset(ref(item) for item in other)
|
|
__lt__ = issubset
|
|
|
|
def __le__(self, other):
|
|
return self.data <= set(ref(item) for item in other)
|
|
|
|
def issuperset(self, other):
|
|
return self.data.issuperset(ref(item) for item in other)
|
|
__gt__ = issuperset
|
|
|
|
def __ge__(self, other):
|
|
return self.data >= set(ref(item) for item in other)
|
|
|
|
def __eq__(self, other):
|
|
if not isinstance(other, self.__class__):
|
|
return NotImplemented
|
|
return self.data == set(ref(item) for item in other)
|
|
|
|
def symmetric_difference(self, other):
|
|
return self._apply(other, self.data.symmetric_difference)
|
|
__xor__ = symmetric_difference
|
|
|
|
def symmetric_difference_update(self, other):
|
|
if self is other:
|
|
self.data.clear()
|
|
else:
|
|
self.data.symmetric_difference_update(ref(item) for item in other)
|
|
def __ixor__(self, other):
|
|
if self is other:
|
|
self.data.clear()
|
|
else:
|
|
self.data.symmetric_difference_update(ref(item) for item in other)
|
|
return self
|
|
|
|
def union(self, other):
|
|
return self._apply(other, self.data.union)
|
|
__or__ = union
|
|
|
|
def isdisjoint(self, other):
|
|
return len(self.intersection(other)) == 0
|