Author: collin.winter Date: Tue Apr 1 18:27:10 2008 New Revision: 62092 Modified: sandbox/trunk/2to3/lib2to3/pytree.py sandbox/trunk/2to3/lib2to3/tests/test_pytree.py Log: Add get_prev_sibling() to complement pytree's get_next_sibling(). Modified: sandbox/trunk/2to3/lib2to3/pytree.py ============================================================================== --- sandbox/trunk/2to3/lib2to3/pytree.py (original) +++ sandbox/trunk/2to3/lib2to3/pytree.py Tue Apr 1 18:27:10 2008 @@ -167,13 +167,27 @@ return None # Can't use index(); we need to test by identity - for i, sibling in enumerate(self.parent.children): - if sibling is self: + for i, child in enumerate(self.parent.children): + if child is self: try: return self.parent.children[i+1] except IndexError: return None + def get_prev_sibling(self): + """Return the node immediately preceding the invocant in their + parent's children list. If the invocant does not have a previous + sibling, return None.""" + if self.parent is None: + return None + + # Can't use index(); we need to test by identity + for i, child in enumerate(self.parent.children): + if child is self: + if i == 0: + return None + return self.parent.children[i-1] + def get_suffix(self): """Return the string immediately following the invocant node. This is effectively equivalent to node.get_next_sibling().get_prefix()""" Modified: sandbox/trunk/2to3/lib2to3/tests/test_pytree.py ============================================================================== --- sandbox/trunk/2to3/lib2to3/tests/test_pytree.py (original) +++ sandbox/trunk/2to3/lib2to3/tests/test_pytree.py Tue Apr 1 18:27:10 2008 @@ -319,6 +319,24 @@ self.assertEqual(l2.get_next_sibling(), None) self.assertEqual(p1.get_next_sibling(), None) + def testNodePrevSibling(self): + n1 = pytree.Node(1000, []) + n2 = pytree.Node(1000, []) + p1 = pytree.Node(1000, [n1, n2]) + + self.failUnless(n2.get_prev_sibling() is n1) + self.assertEqual(n1.get_prev_sibling(), None) + self.assertEqual(p1.get_prev_sibling(), None) + + def testLeafPrevSibling(self): + l1 = pytree.Leaf(100, "a") + l2 = pytree.Leaf(100, "b") + p1 = pytree.Node(1000, [l1, l2]) + + self.failUnless(l2.get_prev_sibling() is l1) + self.assertEqual(l1.get_prev_sibling(), None) + self.assertEqual(p1.get_prev_sibling(), None) + class TestPatterns(support.TestCase):