X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=src%2Flibpspp%2FChangeLog;h=9e965630829ae180a53e91db9e02aff9b3f6d2a5;hb=522f263565607b97b83d26bff49b5fa44704df33;hp=c125ac413bf7661bfd7edd384c3fa083e4b258e5;hpb=24b37bba66595150594008c350944a14ab654a52;p=pspp

diff --git a/src/libpspp/ChangeLog b/src/libpspp/ChangeLog
index c125ac413b..9e96563082 100644
--- a/src/libpspp/ChangeLog
+++ b/src/libpspp/ChangeLog
@@ -1,5 +1,23 @@
 2007-06-03  Ben Pfaff  <blp@gnu.org>
 
+	Add ability for reverse iteration to tower code.
+	
+	* tower.c (tower_last): New function.
+	(tower_prev): New function.
+	(abt_to_tower_node): New function.
+	(first_node): Use abt_to_tower_node.
+	(last_node): New function.
+	(next_ndoe): Use abt_to_tower_node.
+	(prev_node): New function.
+
+2007-06-03  Ben Pfaff  <blp@gnu.org>
+
+	* tower.c: Cache repeated lookups of a single tower element.  This
+	turns such lookups into O(1) operations without harming the big-O
+	of other operations.
+
+	* tower.h (struct tower): Add members for caching.
+
 	* range-set.c (range_set_clone): New function.
 
 	* array.c (insert_range): New function.