Improve extended slicing support in builtin types and classes. Specifically:
- Specialcase extended slices that amount to a shallow copy the same way as
is done for simple slices, in the tuple, string and unicode case.
- Specialcase step-1 extended slices to optimize the common case for all
involved types.
- For lists, allow extended slice assignment of differing lengths as long
as the step is 1. (Previously, 'l[:2:1] = []' failed even though
'l[:2] = []' and 'l[:2:None] = []' do not.)
- Implement extended slicing for buffer, array, structseq, mmap and
UserString.UserString.
- Implement slice-object support (but not non-step-1 slice assignment) for
UserString.MutableString.
- Add tests for all new functionality.
diff --git a/Lib/test/test_buffer.py b/Lib/test/test_buffer.py
new file mode 100644
index 0000000..3bede88
--- /dev/null
+++ b/Lib/test/test_buffer.py
@@ -0,0 +1,29 @@
+"""Unit tests for buffer objects.
+
+For now, tests just new or changed functionality.
+
+"""
+
+import unittest
+from test import test_support
+
+class BufferTests(unittest.TestCase):
+
+ def test_extended_getslice(self):
+ # Test extended slicing by comparing with list slicing.
+ s = "".join(chr(c) for c in list(range(255, -1, -1)))
+ b = buffer(s)
+ indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
+ for start in indices:
+ for stop in indices:
+ # Skip step 0 (invalid)
+ for step in indices[1:]:
+ self.assertEqual(b[start:stop:step],
+ s[start:stop:step])
+
+
+def test_main():
+ test_support.run_unittest(BufferTests)
+
+if __name__ == "__main__":
+ test_main()