define defaultLayout in Config.hs.

Config.hs

@@ -90,8 +90,19 @@ borderWidth :: Dimension
 borderWidth = 1
 
 -- |
--- The default set of tiling algorithms
+-- A list of layouts which, in addition to the defaultLayouts, xmonad can
+-- deserialize.
+possibleLayouts :: [SomeLayout Window]
+possibleLayouts = [defaultLayout
+                  -- Extension-provided layouts
+                  ] ++ defaultLayouts
+
+-- |
+-- The default tiling algorithm
 --
+defaultLayout :: SomeLayout Window
+defaultLayout = SomeLayout $ LayoutSelection defaultLayouts
+
 defaultLayouts :: [SomeLayout Window]
 defaultLayouts = [ SomeLayout tiled
                  , SomeLayout $ Mirror tiled
@@ -142,7 +153,7 @@ keys = M.fromList $
     , ((modMask .|. shiftMask, xK_c     ), kill) -- %! Close the focused window
 
     , ((modMask,               xK_space ), sendMessage NextLayout) -- %! Rotate through the available layout algorithms
-    , ((modMask .|. shiftMask, xK_space ), setLayout $ SomeLayout $ LayoutSelection defaultLayouts) -- %! Reset the layouts on the current workspace to default
+    , ((modMask .|. shiftMask, xK_space ), setLayout defaultLayout) -- %!  Reset the layouts on the current workspace to default
 
     , ((modMask,               xK_n     ), refresh) -- %! Resize viewed windows to the correct size
 

Config.hs-boot

@@ -6,4 +6,4 @@ borderWidth :: Dimension
 logHook     :: X ()
 numlockMask :: KeyMask
 workspaces :: [WorkspaceId]
-defaultLayouts, otherPossibleLayouts :: [SomeLayout Window]
+possibleLayouts :: [SomeLayout Window]

Main.hs

@@ -53,10 +53,8 @@ main = do
     let winset | ("--resume" : s : _) <- args
                , [(x, "")]            <- reads s = W.ensureTags defaultLayout workspaces x
                | otherwise = new defaultLayout workspaces $ zipWith SD xinesc gaps
-        defaultLayout = SomeLayout $ LayoutSelection safeLayouts
         gaps = take (length xinesc) $ defaultGaps ++ repeat (0,0,0,0)
 
-        safeLayouts = if null defaultLayouts then [SomeLayout Full] else defaultLayouts
         cf = XConf
             { display       = dpy
             , theRoot       = rootw

Operations.hs

@@ -20,7 +20,7 @@ module Operations where
 
 import XMonad
 import qualified StackSet as W
-import {-# SOURCE #-} Config (borderWidth,logHook,numlockMask,defaultLayouts,otherPossibleLayouts)
+import {-# SOURCE #-} Config (borderWidth,logHook,numlockMask,possibleLayouts)
 
 import Data.Maybe
 import Data.List            (nub, (\\), find, partition)
@@ -351,10 +351,10 @@ data ChangeLayout = NextLayout | PrevLayout | JumpToLayout String
 instance Message ChangeLayout
 
 instance ReadableSomeLayout Window where
-    defaults = SomeLayout (LayoutSelection defaultLayouts) :
+    defaults = SomeLayout (LayoutSelection []) :
                SomeLayout Full : SomeLayout (Tall 1 0.1 0.5) :
                SomeLayout (Mirror $ Tall 1 0.1 0.5) :
-               defaultLayouts ++ otherPossibleLayouts
+               possibleLayouts
 
 data LayoutSelection a = LayoutSelection [SomeLayout a]
                          deriving ( Show, Read )