Implement and apply PEP 322, reverse iteration

1 files changed, 19 insertions, 1 deletions

diff --git a/Lib/test/test_enumerate.py b/Lib/test/test_enumerate.py
index 88e24e8..b073606 100644
--- a/Lib/test/test_enumerate.py
+++ b/Lib/test/test_enumerate.py
@@ -124,9 +124,27 @@ class TestBig(EnumerateTestCase):
     seq = range(10,20000,2)
     res = zip(range(20000), seq)
 
+class TestReversed(unittest.TestCase):
+
+    def test_simple(self):
+        class A:
+            def __getitem__(self, i):
+                if i < 5:
+                    return str(i)
+                raise StopIteration
+            def __len__(self):
+                return 5
+        for data in 'abc', range(5), tuple(enumerate('abc')), A(), xrange(1,17,5):
+            self.assertEqual(list(data)[::-1], list(reversed(data)))
+        self.assertRaises(TypeError, reversed, {})
+
+    def test_xrange_optimization(self):
+        x = xrange(1)
+        self.assertEqual(type(reversed(x)), type(iter(x)))
 
 def test_main(verbose=None):
-    testclasses = (EnumerateTestCase, SubclassTestCase, TestEmpty, TestBig)
+    testclasses = (EnumerateTestCase, SubclassTestCase, TestEmpty, TestBig,
+                   TestReversed)
     test_support.run_unittest(*testclasses)
 
     # verify reference counting