Author: Lukas Diekmann <[email protected]>
Branch: set-strategies
Changeset: r49163:a9c59d68f3ac
Date: 2011-05-18 15:42 +0200
http://bitbucket.org/pypy/pypy/changeset/a9c59d68f3ac/
Log: added intelligent way to treat the different strategies in
W_SetObject.difference
diff --git a/pypy/objspace/std/setobject.py b/pypy/objspace/std/setobject.py
--- a/pypy/objspace/std/setobject.py
+++ b/pypy/objspace/std/setobject.py
@@ -391,34 +391,50 @@
return True
def difference(self, w_set, w_other):
- #XXX return clone if other is Empty
- result = w_set._newobj(self.space, None)
if not isinstance(w_other, W_BaseSetObject):
w_other = w_set._newobj(self.space, w_other)
- # lookup is faster when w_other is set
- for w_key in w_set.getkeys():
- if not w_other.has_key(w_key):
- result.add(w_key)
+
+ if w_other.strategy is self.space.fromcache(ObjectSetStrategy):
+ return self.difference_wrapped(w_set, w_other)
+
+ if w_set.strategy is not w_other.strategy:
+ return w_set.copy()
+
+ return self.difference_unwrapped(w_set, w_other)
+
+ def difference_wrapped(self, w_set, w_other):
+ result = w_set._newobj(self.space, None)
+ w_iter = self.space.iter(w_set)
+ while True:
+ try:
+ w_item = self.space.next(w_iter)
+ if not w_other.has_key(w_key):
+ result.add(w_key)
+ except OperationError, e:
+ if not e.match(self.space, self.space.w_StopIteration):
+ raise
+ return
+ return result
+
+ def difference_unwrapped(self, w_set, w_other):
+ if not isinstance(w_other, W_BaseSetObject):
+ w_other = w_set._newobj(self.space, w_other)
+ iterator = self.cast_from_void_star(w_set.sstorage).iterkeys()
+ other_dict = self.cast_from_void_star(w_other.sstorage)
+ result_dict = self.get_empty_dict()
+ for key in iterator:
+ if key not in other_dict:
+ result_dict[key] = None
+ result = w_set._newobj(self.space, None)
+ result.strategy = self
+ result.sstorage = self.cast_to_void_star(result_dict)
return result
def difference_update(self, w_set, w_other):
- if w_other.strategy is EmptySetStrategy:
- return
- if w_set is w_other:
- w_set.clear() # for the case 'a.difference_update(a)'
- else:
- w_iter = self.space.iter(w_other)
- while True:
- try:
- w_item = self.space.next(w_iter)
- try:
- self.delitem(w_set, w_item)
- except KeyError:
- pass
- except OperationError, e:
- if not e.match(self.space, self.space.w_StopIteration):
- raise
- return
+ #XXX this way we unnecessarily create a new set
+ result = self.difference(w_set, w_other)
+ w_set.strategy = result.strategy
+ w_set.sstorage = result.sstorage
def symmetric_difference(self, w_set, w_other):
#XXX no wrapping when strategies are equal
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