[pypy-commit] pypy release-5.x: Probable fix for issue #2383: have 'list(S())' call 'S.__getitem__' if S

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: release-5.x
Changeset: r86978:eacdeb58a9ec
Date: 2016-08-29 20:32 +0200
http://bitbucket.org/pypy/pypy/changeset/eacdeb58a9ec/

Log:	Probable fix for issue #2383: have 'list(S())' call 'S.__getitem__'
	if S is a subclass of str with a custom __getitem__. (grafted from
	990f5b2322e124bbbfd7d9ab56d44a77f0085a8a)

diff --git a/pypy/objspace/descroperation.py b/pypy/objspace/descroperation.py
--- a/pypy/objspace/descroperation.py
+++ b/pypy/objspace/descroperation.py
@@ -58,6 +58,20 @@
     return w_iter
 tuple_iter._annspecialcase_ = 'specialize:memo'
 
+def str_getitem(space):
+    "Utility that returns the app-level descriptor str.__getitem__."
+    w_src, w_iter = space.lookup_in_type_where(space.w_str,
+                                               '__getitem__')
+    return w_iter
+str_getitem._annspecialcase_ = 'specialize:memo'
+
+def unicode_getitem(space):
+    "Utility that returns the app-level descriptor unicode.__getitem__."
+    w_src, w_iter = space.lookup_in_type_where(space.w_unicode,
+                                               '__getitem__')
+    return w_iter
+unicode_getitem._annspecialcase_ = 'specialize:memo'
+
 def raiseattrerror(space, w_obj, name, w_descr=None):
     if w_descr is None:
         raise oefmt(space.w_AttributeError,
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
@@ -445,7 +445,7 @@
             return w_obj.listview_bytes()
         if type(w_obj) is W_SetObject or type(w_obj) is W_FrozensetObject:
             return w_obj.listview_bytes()
-        if isinstance(w_obj, W_BytesObject) and self._uses_no_iter(w_obj):
+        if isinstance(w_obj, W_BytesObject) and self._str_uses_no_iter(w_obj):
             return w_obj.listview_bytes()
         if isinstance(w_obj, W_ListObject) and self._uses_list_iter(w_obj):
             return w_obj.getitems_bytes()
@@ -460,7 +460,7 @@
             return w_obj.listview_unicode()
         if type(w_obj) is W_SetObject or type(w_obj) is W_FrozensetObject:
             return w_obj.listview_unicode()
-        if isinstance(w_obj, W_UnicodeObject) and self._uses_no_iter(w_obj):
+        if isinstance(w_obj, W_UnicodeObject) and self._uni_uses_no_iter(w_obj):
             return w_obj.listview_unicode()
         if isinstance(w_obj, W_ListObject) and self._uses_list_iter(w_obj):
             return w_obj.getitems_unicode()
@@ -504,8 +504,15 @@
         from pypy.objspace.descroperation import tuple_iter
         return self.lookup(w_obj, '__iter__') is tuple_iter(self)
 
-    def _uses_no_iter(self, w_obj):
-        return self.lookup(w_obj, '__iter__') is None
+    def _str_uses_no_iter(self, w_obj):
+        from pypy.objspace.descroperation import str_getitem
+        return (self.lookup(w_obj, '__iter__') is None and
+                self.lookup(w_obj, '__getitem__') is str_getitem(self))
+
+    def _uni_uses_no_iter(self, w_obj):
+        from pypy.objspace.descroperation import unicode_getitem
+        return (self.lookup(w_obj, '__iter__') is None and
+                self.lookup(w_obj, '__getitem__') is unicode_getitem(self))
 
     def sliceindices(self, w_slice, w_length):
         if isinstance(w_slice, W_SliceObject):
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
@@ -432,7 +432,7 @@
 
 
 class AppTestListObject(object):
-    spaceconfig = {"objspace.std.withliststrategies": True}  # it's the default
+    #spaceconfig = {"objspace.std.withliststrategies": True}  # it's the default
 
     def setup_class(cls):
         import platform
@@ -1518,6 +1518,16 @@
             def __iter__(self):
                 yield "ok"
         assert list(U(u"don't see me")) == ["ok"]
+        #
+        class S(str):
+            def __getitem__(self, index):
+                return str.__getitem__(self, index).upper()
+        assert list(S("abc")) == list("ABC")
+        #
+        class U(unicode):
+            def __getitem__(self, index):
+                return unicode.__getitem__(self, index).upper()
+        assert list(U(u"abc")) == list(u"ABC")
 
     def test_extend_from_nonempty_list_with_subclasses(self):
         l = ["hi!"]
@@ -1543,6 +1553,20 @@
         l.extend(U(u"don't see me"))
         #
         assert l == ["hi!", "okT", "okL", "okL", "okS", "okU"]
+        #
+        class S(str):
+            def __getitem__(self, index):
+                return str.__getitem__(self, index).upper()
+        l = []
+        l.extend(S("abc"))
+        assert l == list("ABC")
+        #
+        class U(unicode):
+            def __getitem__(self, index):
+                return unicode.__getitem__(self, index).upper()
+        l = []
+        l.extend(U(u"abc"))
+        assert l == list(u"ABC")
 
     def test_no_len_on_range_iter(self):
         iterable = range(10)