Tidied up the implementations of reversed (including the custom ones
for xrange and list objects).
* list.__reversed__ now checks the length of the sequence object before
calling PyList_GET_ITEM() because the mutable could have changed length.
* all three implementations are now tranparent with respect to length and
maintain the invariant len(it) == len(list(it)) even when the underlying
sequence mutates.
* __builtin__.reversed() now frees the underlying sequence as soon
as the iterator is exhausted.
* the code paths were rearranged so that the most common paths
do not require a jump.
diff --git a/Lib/test/test_enumerate.py b/Lib/test/test_enumerate.py
index 34bc71d..200779f 100644
--- a/Lib/test/test_enumerate.py
+++ b/Lib/test/test_enumerate.py
@@ -143,8 +143,8 @@
def test_len(self):
# This is an implementation detail, not an interface requirement
- s = 'hello'
- self.assertEqual(len(reversed(s)), len(s))
+ for s in ('hello', tuple('hello'), list('hello'), xrange(5)):
+ self.assertEqual(len(reversed(s)), len(s))
def test_main(verbose=None):
testclasses = (EnumerateTestCase, SubclassTestCase, TestEmpty, TestBig,