py2/py3: define OrderableList that uses legacy cmp for ordering.

product/ERP5Type/Utils.py

@@ -144,6 +144,26 @@ else:
 # Generic sort method
 #####################################################
 
+class OrderableList(object):
+  def __init__(self, *args):
+    self.__slots__ = args
+
+  def __lt__(self, other):
+    for i, v in enumerate(self.__slots__):
+      try:
+        other_v = other.__slots__[i]
+      except IndexError:
+        return False
+      c = cmp(v, other_v)
+      if c == -1:
+        return True
+      elif c == 1:
+        return False
+    return True
+
+  def __repr__(self):
+    return repr(self.__slots__)
+
 sort_kw_cache = {}
 
 def sortValueList(value_list, sort_on=None, sort_order=None, **kw):
@@ -201,7 +221,10 @@ def sortValueList(value_list, sort_on=None, sort_order=None, **kw):
               except TypeError:
                 pass
             value_list.append(x)
-          return value_list
+          if six.PY2:
+            return value_list
+          else:
+            return OrderableList(*value_list)
         sort_kw = {'key':sortValue, 'reverse':reverse}
         sort_kw_cache[(sort_on, sort_order)] = sort_kw
       else:

product/ERP5Type/tests/testERP5Type.py

@@ -38,7 +38,7 @@ from Acquisition import aq_base
 from Products.ERP5Type.tests.ERP5TypeTestCase import ERP5TypeTestCase
 from AccessControl.ZopeGuards import guarded_import
 from Products.ERP5Type.tests.utils import LogInterceptor, createZODBPythonScript
-from Products.ERP5Type.Utils import cmp
+from Products.ERP5Type.Utils import OrderableList, cmp
 
 class TestERP5Type(ERP5TypeTestCase, LogInterceptor):
     """
@@ -296,6 +296,16 @@ class TestERP5Type(ERP5TypeTestCase, LogInterceptor):
       self.assertEqual(cmp(None, ''), -1)
       self.assertEqual(cmp(0, ''), -1)
 
+    def test_OrderableList(self):
+      o1 = OrderableList(None, 1)
+      o2 = OrderableList(0, 0)
+      self.assertEqual(sorted([o1, o2]), [o1, o2])
+      self.assertEqual(sorted([o2, o1]), [o1, o2])
+      o3 = OrderableList(1,2,3)
+      o4 = OrderableList(1,2,3,4)
+      self.assertEqual(sorted([o3, o4]), [o3, o4])
+      self.assertEqual(sorted([o4, o3]), [o3, o4])
+
 def test_suite():
   suite = unittest.TestSuite()
   suite.addTest(unittest.makeSuite(TestERP5Type))