C Code:

* Removed the ifilter flag wart by splitting it into two simpler functions.
* Fixed comment tabbing in C code.
* Factored module start-up code into a loop.

Documentation:
* Re-wrote introduction.
* Addede examples for quantifiers.
* Simplified python equivalent for islice().
* Documented split of ifilter().

Sets.py:
* Replace old ifilter() usage with new.

2 files changed, 28 insertions, 9 deletions

diff --git a/Lib/sets.py b/Lib/sets.py
index 4f55515..9604249 100644
--- a/Lib/sets.py
+++ b/Lib/sets.py
@@ -57,7 +57,7 @@ what's tested is actually `z in y'.
 
 
 __all__ = ['BaseSet', 'Set', 'ImmutableSet']
-from itertools import ifilter
+from itertools import ifilter, ifilterfalse
 
 class BaseSet(object):
     """Common base class for mutable and immutable sets."""
@@ -204,9 +204,9 @@ class BaseSet(object):
         value = True
         selfdata = self._data
         otherdata = other._data
-        for elt in ifilter(otherdata.has_key, selfdata, True):
+        for elt in ifilterfalse(otherdata.has_key, selfdata):
             data[elt] = value
-        for elt in ifilter(selfdata.has_key, otherdata, True):
+        for elt in ifilterfalse(selfdata.has_key, otherdata):
             data[elt] = value
         return result
 
@@ -227,7 +227,7 @@ class BaseSet(object):
         result = self.__class__()
         data = result._data
         value = True
-        for elt in ifilter(other._data.has_key, self, True):
+        for elt in ifilterfalse(other._data.has_key, self):
             data[elt] = value
         return result
 
@@ -260,7 +260,7 @@ class BaseSet(object):
         self._binary_sanity_check(other)
         if len(self) > len(other):  # Fast check for obvious cases
             return False
-        for elt in ifilter(other._data.has_key, self, True):
+        for elt in ifilterfalse(other._data.has_key, self):
             return False
         return True
 
@@ -269,7 +269,7 @@ class BaseSet(object):
         self._binary_sanity_check(other)
         if len(self) < len(other):  # Fast check for obvious cases
             return False
-        for elt in ifilter(self._data.has_key, other, True):
+        for elt in ifilterfalse(self._data.has_key, other):
             return False
         return True
 
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index cef1718..09b7d13 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -13,12 +13,19 @@ class TestBasicOps(unittest.TestCase):
         def isEven(x):
             return x%2==0
         self.assertEqual(list(ifilter(isEven, range(6))), [0,2,4])
-        self.assertEqual(list(ifilter(isEven, range(6), True)), [1,3,5])
         self.assertEqual(list(ifilter(None, [0,1,0,2,0])), [1,2])
         self.assertRaises(TypeError, ifilter)
         self.assertRaises(TypeError, ifilter, 3)
         self.assertRaises(TypeError, ifilter, isEven, 3)
-        self.assertRaises(TypeError, ifilter, isEven, [3], True, 4)
+
+    def test_ifilterfalse(self):
+        def isEven(x):
+            return x%2==0
+        self.assertEqual(list(ifilterfalse(isEven, range(6))), [1,3,5])
+        self.assertEqual(list(ifilterfalse(None, [0,1,0,2,0])), [0,0,0])
+        self.assertRaises(TypeError, ifilterfalse)
+        self.assertRaises(TypeError, ifilterfalse, 3)
+        self.assertRaises(TypeError, ifilterfalse, isEven, 3)
 
     def test_izip(self):
         ans = [(x,y) for x, y in izip('abc',count())]
@@ -133,7 +140,19 @@ Samuele
 
 >>> def nth(iterable, n):
 ...     "Returns the nth item"
-...     return islice(iterable, n, n+1).next()
+...     return list(islice(iterable, n, n+1))
+
+>>> def all(pred, seq):
+...     "Returns True if pred(x) is True for every element in the iterable"
+...     return not nth(ifilterfalse(pred, seq), 0)
+
+>>> def some(pred, seq):
+...     "Returns True if pred(x) is True at least one element in the iterable"
+...     return bool(nth(ifilter(pred, seq), 0))
+
+>>> def no(pred, seq):
+...     "Returns True if pred(x) is False for every element in the iterable"
+...     return not nth(ifilter(pred, seq), 0)
 
 """