[Zope3-checkins] SVN: Zope3/trunk/src/zope/app/uniqueid/ Added __hash__ to IReference and updated ReferenceToPersistent to implement it.

[Gintautas Miliauskas]

Log message for revision 25341:
Added __hash__ to IReference and updated ReferenceToPersistent to implement it.



-=-
Modified: Zope3/trunk/src/zope/app/uniqueid/__init__.py
===================================================================
--- Zope3/trunk/src/zope/app/uniqueid/__init__.py	2004-06-10 18:36:08 UTC (rev 25340)
+++ Zope3/trunk/src/zope/app/uniqueid/__init__.py	2004-06-11 09:50:19 UTC (rev 25341)
@@ -96,11 +96,14 @@
     def __call__(self):
         return self.object
 
+    def __hash__(self):
+        return self.object._p_oid
+
     def __cmp__(self, other):
         if not isinstance(other, ReferenceToPersistent):
             raise TypeError("Cannot compare ReferenceToPersistent with %r" %
                             (other,))
-        return cmp(self.object._p_oid, other.object._p_oid)
+        return cmp(self.__hash__(), other.__hash__())
 
 
 def connectionOfPersistent(ob):

Modified: Zope3/trunk/src/zope/app/uniqueid/interfaces.py
===================================================================
--- Zope3/trunk/src/zope/app/uniqueid/interfaces.py	2004-06-10 18:36:08 UTC (rev 25340)
+++ Zope3/trunk/src/zope/app/uniqueid/interfaces.py	2004-06-11 09:50:19 UTC (rev 25341)
@@ -7,16 +7,18 @@
 
 
 class IReference(Interface):
-    """A reference to an object (like a weak ref)
+    """A reference to an object (similar to a weak reference).
 
-    Have to be orderable.  The references are only equal if they
-    reference the same object.
+    The references are compared by their hashes.
     """
 
     def __call__():
-        """Get the object this reference is linking to"""
+        """Get the object this reference is linking to."""
 
+    def __hash__():
+        """Get a unique identifier of the referenced object."""
 
+
 class IUniqueIdUtilityQuery(Interface):
 
     def getObject(uid):