# HG changeset patch
# User Lucas Moscovicz <lmoscovicz@fb.com>
# Date 2014-03-11 23:52:15
# Node ID c152e538b85b099ce20b51104b8b7dd3666aad7c
# Parent  b95490cf8abd24e7c7a157c5d066b6c6ee8d7d62

revset: added ascending attribute to addset class

In case both collections are in an ascending/descending order then we will be
able to iterate them lazily while keeping the order.

diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -2312,13 +2312,18 @@ class _addset(object):
     Wrapper structure for lazily adding two structures without losing much
     performance on the __contains__ method
 
+    If the ascending attribute is set, that means the two structures are
+    ordered in either an ascending or descending way. Therefore, we can add
+    them mantaining the order by iterating over both at the same time
+
     This class does not duck-type baseset and it's only supposed to be used
     internally
     """
-    def __init__(self, revs1, revs2):
+    def __init__(self, revs1, revs2, ascending=None):
         self._r1 = revs1
         self._r2 = revs2
         self._iter = None
+        self._ascending = ascending
 
     def _iterator(self):
         if not self._iter: