Add GreedyView

GreedyView.hs

@@ -0,0 +1,25 @@
+-- greedyView is an alternative to standard workspace switching.  When a
+-- workspace is already visible on another screen, greedyView swaps the
+-- contents of that other screen with the current screen.
+
+module XMonadContrib.GreedyView (greedyView) where
+
+import StackSet as W
+import XMonad
+import Operations
+import Data.List (find)
+
+greedyView :: WorkspaceId -> X ()
+greedyView = windows . greedyView'
+
+greedyView' :: WorkspaceId -> WindowSet -> WindowSet
+greedyView' w ws
+ | any wTag (hidden ws)                             = W.view w ws
+ | (Just s) <- find (wTag . workspace) (visible ws) = ws { current = setScreen s (screen $ current ws)
+                                                         , visible = setScreen (current ws) (screen s)
+                                                                   : filter (not . wTag . workspace) (visible ws)
+                                                         }
+ | otherwise                                        = ws
+ where
+    setScreen s i = s { screen = i }
+    wTag = (w == ) . tag