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