[pypy-commit] pypy default: Re-add an optimization that was incorrectly implemented and

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r54145:4767e4614bfa
Date: 2012-04-02 11:20 +0200
http://bitbucket.org/pypy/pypy/changeset/4767e4614bfa/

Log:	Re-add an optimization that was incorrectly implemented and so
	killed by the merge of list strategies.

diff --git a/pypy/objspace/descroperation.py b/pypy/objspace/descroperation.py
--- a/pypy/objspace/descroperation.py
+++ b/pypy/objspace/descroperation.py
@@ -43,6 +43,13 @@
     return w_eq
 type_eq._annspecialcase_ = 'specialize:memo'
 
+def list_iter(space):
+    "Utility that returns the app-level descriptor list.__iter__."
+    w_src, w_iter = space.lookup_in_type_where(space.w_list,
+                                               '__iter__')
+    return w_iter
+list_iter._annspecialcase_ = 'specialize:memo'
+
 def raiseattrerror(space, w_obj, name, w_descr=None):
     w_type = space.type(w_obj)
     typename = w_type.getname(space)
diff --git a/pypy/objspace/std/objspace.py b/pypy/objspace/std/objspace.py
--- a/pypy/objspace/std/objspace.py
+++ b/pypy/objspace/std/objspace.py
@@ -439,6 +439,8 @@
             t = w_obj.getitems()
         elif isinstance(w_obj, W_AbstractTupleObject):
             t = w_obj.getitems_copy()
+        elif isinstance(w_obj, W_ListObject) and self._uses_list_iter(w_obj):
+            t = w_obj.getitems()
         else:
             return ObjSpace.unpackiterable(self, w_obj, expected_length)
         if expected_length != -1 and len(t) != expected_length:
@@ -456,6 +458,8 @@
             return w_obj.listview_str()
         if isinstance(w_obj, W_StringObject):
             return w_obj.listview_str()
+        if isinstance(w_obj, W_ListObject) and self._uses_list_iter(w_obj):
+            return w_obj.getitems_str()
         return None
 
     def listview_int(self, w_obj):
@@ -465,8 +469,14 @@
             return w_obj.listview_int()
         if type(w_obj) is W_SetObject or type(w_obj) is W_FrozensetObject:
             return w_obj.listview_int()
+        if isinstance(w_obj, W_ListObject) and self._uses_list_iter(w_obj):
+            return w_obj.getitems_int()
         return None
 
+    def _uses_list_iter(self, w_obj):
+        from pypy.objspace.descroperation import list_iter
+        return self.lookup(w_obj, '__iter__') is list_iter(self)
+
     def sliceindices(self, w_slice, w_length):
         if isinstance(w_slice, W_SliceObject):
             a, b, c = w_slice.indices3(self, self.int_w(w_length))
diff --git a/pypy/objspace/std/test/test_listobject.py b/pypy/objspace/std/test/test_listobject.py
--- a/pypy/objspace/std/test/test_listobject.py
+++ b/pypy/objspace/std/test/test_listobject.py
@@ -1186,14 +1186,23 @@
         # of dicts, because the OrderedDict in the stdlib relies on this.
         # we extend the use case to lists and sets, i.e. all types that have
         # strategies, to avoid surprizes depending on the strategy.
-        for base, arg in [(list, []), (list, [5]), (list, ['x']),
-                          (set, []),  (set,  [5]), (set,  ['x']),
-                          (dict, []), (dict, [(5,6)]), (dict, [('x',7)])]:
+        class X: pass
+        for base, arg in [
+                (list, []), (list, [5]), (list, ['x']), (list, [X]),
+                (set, []),  (set,  [5]), (set,  ['x']), (set, [X]),
+                (dict, []), (dict, [(5,6)]), (dict, [('x',7)]), (dict, [(X,8)]),
+                ]:
             print base, arg
             class SubClass(base):
                 def __iter__(self):
                     return iter("foobar")
             assert list(SubClass(arg)) == ['f', 'o', 'o', 'b', 'a', 'r']
+            class Sub2(base):
+                pass
+            assert list(Sub2(arg)) == list(base(arg))
+            s = set()
+            s.update(Sub2(arg))
+            assert s == set(base(arg))
 
 class AppTestForRangeLists(AppTestW_ListObject):