From 9fafa995c7fa00781359b99ffba3714c1697a3f4 Mon Sep 17 00:00:00 2001
From: Don Stewart <dons@cse.unsw.edu.au>
Date: Mon, 30 Apr 2007 02:45:25 +0000
Subject: [PATCH] shrink 'rotate' a little

---
 StackSet.hs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/StackSet.hs b/StackSet.hs
index b052141..73c3bfb 100644
--- a/StackSet.hs
+++ b/StackSet.hs
@@ -143,10 +143,8 @@ rotate :: (Integral i, Eq a) => Ordering -> StackSet i j a -> StackSet i j a
 rotate o w = maybe w id $ do
     f <- M.lookup (current w) (focus w)
     s <- M.lookup (current w) (stacks w)
-    ea <- case o of
-            EQ -> Nothing
-            GT -> elemAfter f s
-            LT -> elemAfter f (reverse s)
+    ea <- case o of EQ -> Nothing
+                    _  -> elemAfter f (if o == GT then s else reverse s)
     return $ w { focus = M.insert (current w) ea (focus w) }
 
 -- | /O(log n)/. shift. move the client on top of the current stack to