=== modified file 'lib2to3/pytree.py'
--- lib2to3/pytree.py	2008-06-10 04:12:51 +0000
+++ lib2to3/pytree.py	2008-07-15 03:54:41 +0000
@@ -653,29 +653,40 @@
                     r[self.name] = nodes[:count]
                 yield count, r
         else:
-            for count, r in self._recursive_matches(nodes, 0):
+            for count, r in self._iterative_matches(nodes):
                 if self.name:
                     r[self.name] = nodes[:count]
                 yield count, r
 
-    def _recursive_matches(self, nodes, count):
-        """Helper to recursively yield the matches."""
-        assert self.content is not None
-        if count >= self.min:
-            r = {}
-            if self.name:
-                r[self.name] = nodes[:0]
-            yield 0, r
-        if count < self.max:
-            for alt in self.content:
-                for c0, r0 in generate_matches(alt, nodes):
-                    for c1, r1 in self._recursive_matches(nodes[c0:], count+1):
-                        r = {}
-                        r.update(r0)
-                        r.update(r1)
-                        yield c0 + c1, r
-
-
+    def _iterative_matches(self, nodes):
+        """Helper to iteratively yield the matches."""
+        nodelen = len(nodes)
+        if 0 >= self.min:
+            yield 0, {}
+
+        results = []
+        # generate matches that use just one alt from self.content
+        for alt in self.content:
+            for c, r in generate_matches(alt, nodes):
+                yield c, r
+                results.append((c, r))
+
+        # for each match, iterate down the nodes
+        while len(results):
+            new_results = []
+            for c0, r0 in results:
+                # stop if the entire set of nodes has been matched
+                if c0 < nodelen and c0 <= self.max:
+                    for alt in self.content:
+                        for c1, r1 in generate_matches(alt, nodes[c0:]):
+                            if c1 > 0:
+                                r = {}
+                                r.update(r0)
+                                r.update(r1)
+                                yield c0 + c1, r
+                                new_results.append((c0 + c1, r))
+            results = new_results
+    
 class NegatedPattern(BasePattern):
 
     def __init__(self, content=None):

=== modified file 'lib2to3/tests/test_pytree.py'
--- lib2to3/tests/test_pytree.py	2008-06-10 04:12:51 +0000
+++ lib2to3/tests/test_pytree.py	2008-07-15 03:43:46 +0000
@@ -428,7 +428,7 @@
                                      [pa, pb], [pc, pd], [pe, pf]],
                                     min=1, max=4, name="pw")
         self.assertEqual([x[0] for x in pw.generate_matches(leaves)],
-                         [3, 5, 2, 4, 6])
+                         [3, 2, 5, 4, 6])
         pr = pytree.NodePattern(type=1000, content=[pw], name="pr")
         matches = list(pytree.generate_matches([pr], [root]))
         self.assertEqual(len(matches), 1)