From a05115bb72df3184c491a2b9cebdb18991967868 Mon Sep 17 00:00:00 2001
From: Spencer Janssen <sjanssen@cse.unl.edu>
Date: Thu, 22 Mar 2007 22:15:47 +0000
Subject: [PATCH] Add promote

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

diff --git a/StackSet.hs b/StackSet.hs
index 8103075..8f3493d 100644
--- a/StackSet.hs
+++ b/StackSet.hs
@@ -169,5 +169,11 @@ raiseFocus k w = case M.lookup k (cache w) of
     Nothing -> w
     Just i  -> w { focus = M.insert i k (focus w) }
 
+-- | Move a window to the top of its workspace.
+promote :: Ord a => a -> StackSet a -> StackSet a
+promote k w = case M.lookup k (cache w) of
+    Nothing -> w
+    Just i  -> w { stacks = M.adjust (\ks -> k : filter (/= k) ks) i (stacks w) }
+
 elemAfter :: Eq a => a -> [a] -> Maybe a
 elemAfter w ws = listToMaybe . filter (/= w) . dropWhile (/= w) $ ws ++ ws