1 files changed, 72 insertions, 53 deletions

diff --git a/src/Rahm/Desktop/Layout/List.hs b/src/Rahm/Desktop/Layout/List.hs
index d6ab6ba..787697e 100644
--- a/src/Rahm/Desktop/Layout/List.hs
+++ b/src/Rahm/Desktop/Layout/List.hs
@@ -1,4 +1,5 @@
-{-# LANGUAGE UndecidableInstances, TypeOperators #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE UndecidableInstances #-}
 
 {-
  - This module provides a more powerful version of the "Choose" layout that can
@@ -7,34 +8,36 @@
  - The indexing uses a type-safe zipper to keep track of the currently-selected
  - layout.
  -}
-module Rahm.Desktop.Layout.List (
-  LayoutList,
-  layoutList,
-  LCons,
-  LNil,
-  toNextLayout,
-  toPreviousLayout,
-  toFirstLayout,
-  toIndexedLayout,
-  (|:),
-  nil,
-  layoutListLength,
-  layoutListLengthProxy
-  )where
+module Rahm.Desktop.Layout.List
+  ( LayoutList,
+    layoutList,
+    LCons,
+    LNil,
+    toNextLayout,
+    toPreviousLayout,
+    toFirstLayout,
+    toIndexedLayout,
+    (|:),
+    nil,
+    layoutListLength,
+    layoutListLengthProxy,
+  )
+where
 
 import Control.Applicative ((<|>))
 import Control.Arrow (second, (>>>))
 import Control.Monad.Identity (runIdentity)
-import Data.Maybe (fromMaybe, fromJust)
+import Data.Maybe (fromJust, fromMaybe)
 import Data.Proxy
 import Data.Void
 import GHC.TypeLits
-import XMonad
 import qualified Rahm.Desktop.StackSet as W
+import XMonad
 
 -- Type-level lists. LNil is the final of the list. LCons contains a layout and a
 -- tail.
 data LNil a = LNil deriving (Read, Show)
+
 data LCons l t a = LCons (l a) (t a) deriving (Read, Show)
 
 -- Sel - This defines a structure where either this selected, or some
@@ -55,20 +58,25 @@ data LCons l t a = LCons (l a) (t a) deriving (Read, Show)
 --
 -- Note that a type (Sel End) can only be in the Sel as End may not be
 -- construted (without using undefined).
-data Sel l =
-    Sel |
-    (Selector l) => Skip l
+data Sel l
+  = Sel
+  | (Selector l) => Skip l
+
 deriving instance (Read l, Selector l) => Read (Sel l)
+
 deriving instance (Show l, Selector l) => Show (Sel l)
+
 deriving instance (Eq l, Selector l) => Eq (Sel l)
 
 -- Reimplement Void as End, just to keep the two separate, but End is for all
 -- intents and purposes Void.
 data End
+
 deriving instance Read End
+
 deriving instance Show End
-deriving instance Eq End
 
+deriving instance Eq End
 
 -- Types that constitute a selection. Selections can be moved to the next
 -- selection, moved to the previous selection, optionally there could be a
@@ -118,7 +126,6 @@ instance (Selector t) => Selector (Sel t) where
 -- The End structure (which is equivalent to Void) is the "null" selector; the
 -- basecase that the Sel selector terminates at.
 instance Selector End where
-
   -- Incrementing the End Selector doesn't do anything.
   increment = const Nothing
 
@@ -155,9 +162,12 @@ intToSelector n = incrementCycle $ intToSelector (n - 1)
 data LayoutList l a where
   LayoutList ::
     (LayoutSelect l a, Selector (SelectorFor l)) =>
-      SelectorFor l -> l a -> LayoutList l a
+    SelectorFor l ->
+    l a ->
+    LayoutList l a
 
 deriving instance (LayoutSelect l a) => Show (LayoutList l a)
+
 deriving instance (LayoutSelect l a) => Read (LayoutList l a)
 
 -- Type family to get the LengthOf a ConsList.
@@ -183,8 +193,10 @@ infixr 5 |:
 -- Constructs a LayoutList. This function enforces that the SelectorFor l
 -- is a 'Sel' type. Essentially this enforces that there must be at least one
 -- underlying layout, otherwise a LayoutList cannot be constructed.
-layoutList :: (LayoutSelect l a, SelectorFor l ~ Sel n) =>
-  l a -> LayoutList l a
+layoutList ::
+  (LayoutSelect l a, SelectorFor l ~ Sel n) =>
+  l a ->
+  LayoutList l a
 layoutList = LayoutList Sel
 
 -- The termination of a layout zipper.
@@ -193,11 +205,11 @@ nil = LNil
 
 -- Message to navigate to a layout.
 newtype NavigateLayout =
-          -- Sets the layout based on the given function.
-          NavigateLayout {
-            changeLayoutFn :: forall c. (Selector c) => c -> c
-          }
-          deriving (Typeable)
+  -- Sets the layout based on the given function.
+  NavigateLayout
+  { changeLayoutFn :: forall c. (Selector c) => c -> c
+  }
+  deriving (Typeable)
 
 -- NavigateLayout instance to move to the next layout, circularly.
 toNextLayout :: NavigateLayout
@@ -213,28 +225,34 @@ toFirstLayout = NavigateLayout (`fromMaybe` initial)
 
 -- NavigateLayout instance to go to an indexed layout.
 toIndexedLayout :: Int -> NavigateLayout
-toIndexedLayout i = NavigateLayout $
-  (`fromMaybe` initial) >>> addSelector (intToSelector i)
+toIndexedLayout i =
+  NavigateLayout $
+    (`fromMaybe` initial) >>> addSelector (intToSelector i)
 
-instance Message NavigateLayout where
+instance Message NavigateLayout
 
 -- LayoutSelect class Describes a type that can be used to select a layout using
 -- the associated type SelectorFor.
 --
 -- Instances of this class are LCons and LNil.
-class (Show (l a),
-       Read (l a),
-       Read (SelectorFor l),
-       Show (SelectorFor l),
-       Selector (SelectorFor l)) => LayoutSelect l a where
-
+class
+  ( Show (l a),
+    Read (l a),
+    Read (SelectorFor l),
+    Show (SelectorFor l),
+    Selector (SelectorFor l)
+  ) =>
+  LayoutSelect l a
+  where
   -- The selector that is used to update the layout corresponding to the
   -- selector. This selector must be an instance of the Selector class.
   type SelectorFor l :: *
 
   -- Update applies a functor to the selected layout and maybe returns a result
   -- and an updated layout.
-  update :: forall r m. (Monad m) =>
+  update ::
+    forall r m.
+    (Monad m) =>
     -- The selector for this type. Determines which layout the function is
     -- applied to.
     SelectorFor l ->
@@ -243,18 +261,19 @@ class (Show (l a),
     -- Higher-ordered function to generically apply to the Layout associated
     -- with the Selector. Works on all LayoutClass's.
     (forall l'. (LayoutClass l' a) => l' a -> m (r, Maybe (l' a))) ->
-
     -- Returns a result r, and an updated LayoutSelect.
     m (Maybe (r, l a))
 
 -- Instance for LayoutSelect for cons
-instance (Read (l a),
-          LayoutClass l a,
-          LayoutSelect t a,
-          Show (SelectorFor t),
-          Read (SelectorFor t)) =>
-    LayoutSelect (LCons l t) a where
-
+instance
+  ( Read (l a),
+    LayoutClass l a,
+    LayoutSelect t a,
+    Show (SelectorFor t),
+    Read (SelectorFor t)
+  ) =>
+  LayoutSelect (LCons l t) a
+  where
   -- The SelectorFor Cons is Sel (SelectorFor t). This creates the structure
   -- Sel (Sel (Sel ( ... (Sel End) .. ))) where the number of Sel's match the
   -- number of Cons in this structure enforcing safe selection.
@@ -278,19 +297,19 @@ instance LayoutSelect LNil a where
 -- Instance of layout class for LayoutList. The implementation for this
 -- just delegates to the underlying LayoutSelect class using the generic
 -- update method.
-instance (Show (l a), Typeable l, LayoutSelect l a) =>
-    LayoutClass (LayoutList l) a where
-
+instance
+  (Show (l a), Typeable l, LayoutSelect l a) =>
+  LayoutClass (LayoutList l) a
+  where
   runLayout (W.Workspace i (LayoutList idx l) ms) r = do
     r <- update idx l $ \layout ->
-            runLayout (W.Workspace i layout ms) r
+      runLayout (W.Workspace i layout ms) r
     case r of
       Nothing -> return ([], Nothing)
       Just (r, la) -> return (r, Just (LayoutList idx la))
 
   handleMessage (LayoutList idx l) (fromMessage -> Just (NavigateLayout fn)) =
     return $ Just (LayoutList (fn idx) l)
-
   handleMessage (LayoutList idx l) m = do
     r <- update idx l $ \layout -> ((),) <$> handleMessage layout m
     return $ LayoutList idx . snd <$> r