Pointfree Mirror and SomeLayout instances

darcs-hash:20070920211042-a5988-0fcfdaa8b1ecfffe0f1ec5e5584d53d7e31416d7

2 files changed, 4 insertions, 6 deletions

diff --git a/Operations.hs b/Operations.hs
index d18bd99..cedc93a 100644
--- a/Operations.hs
+++ b/Operations.hs
@@ -378,8 +378,8 @@ mirrorRect (Rectangle rx ry rw rh) = (Rectangle ry rx rh rw)
 data Mirror l a = Mirror (l a) deriving (Show, Read)
 
 instance Layout l a => Layout (Mirror l) a where
-    doLayout (Mirror l) r s = do (wrs, ml') <- doLayout l (mirrorRect r) s
-                                 return (map (second mirrorRect) wrs, Mirror `fmap` ml')
+    doLayout (Mirror l) r s = (map (second mirrorRect) *** fmap Mirror)
+                                `fmap` doLayout l (mirrorRect r) s
     modifyLayout (Mirror l) = fmap (fmap Mirror) . modifyLayout l
 
 -- | tile.  Compute the positions for windows using the default 2 pane tiling algorithm.
diff --git a/XMonad.hs b/XMonad.hs
index e611c31..103639e 100644
--- a/XMonad.hs
+++ b/XMonad.hs
@@ -148,10 +148,8 @@ class (Show (layout a), Read (layout a)) => Layout layout a where
     modifyLayout :: layout a -> SomeMessage -> X (Maybe (layout a))
 
 instance Layout SomeLayout a where
-    doLayout (SomeLayout l) r s = do (ars, ml') <- doLayout l r s
-                                     return (ars, SomeLayout `fmap` ml' )
-    modifyLayout (SomeLayout l) m = do ml' <- modifyLayout l m
-                                       return (SomeLayout `fmap` ml')
+    doLayout (SomeLayout l) r s = fmap (fmap $ fmap SomeLayout) $ doLayout l r s
+    modifyLayout (SomeLayout l) = fmap (fmap SomeLayout) . modifyLayout l
 
 runLayout :: Layout l a => l a -> Rectangle -> StackOrNot a -> X ([(a, Rectangle)], Maybe (l a))
 runLayout l r = maybe (return ([], Nothing)) (doLayout l r)