comments. and stop tracing events to stderr

Operations.hs

@@ -42,12 +42,13 @@ import qualified StackSet as W
 refresh :: X ()
 refresh = do
     XState { workspace = ws, layoutDescs = fls } <- get
-    XConf  { xineScreens = xinesc, display = d } <- ask
+    XConf  { xineScreens = xinesc, display = d } <- ask -- neat, eh?
 
     flip mapM_ (M.assocs (W.screen2ws ws)) $ \(scn, n) -> do
         let sc =  genericIndex xinesc scn -- temporary coercion!
             fl = M.findWithDefault defaultLayoutDesc n fls
         mapM_ (\(w, rect) -> io $ moveWindowInside d w rect) $
+            -- likely this should just dispatch on the current layout algo
             case layoutType fl of
                 Full -> fmap (flip (,) sc) $ maybeToList $ W.peekStack n ws
                 Tall -> tile  (tileFraction fl) sc $ W.index n ws
@@ -63,11 +64,16 @@ clearEnterEvents = do
     io $ sync d False
     io $ allocaXEvent $ \p -> fix $ \again -> do
         more <- checkMaskEvent d enterWindowMask p
-        when more again
+        when more again -- beautiful
 
 -- | tile.  Compute the positions for windows in horizontal layout
 -- mode.
 --
+-- Tiling algorithms in the core should satisify the constraint that
+--
+--  * no windows overlap
+--  * no gaps exist between windows.
+--
 tile :: Rational -> Rectangle -> [Window] -> [(Window, Rectangle)]
 tile _ _ []    = []
 tile _ d [w]   = [(w, d)]
@@ -117,8 +123,7 @@ windows :: (WindowSet -> WindowSet) -> X ()
 windows f = do
     modify $ \s -> s { workspace = f (workspace s) }
     refresh
-    ws <- gets workspace
-    trace (show ws) -- log state changes to stderr
+    -- gets workspace >>= trace . show -- log state changes to stderr
 
 -- | hide. Hide a window by moving it offscreen.
 hide :: Window -> X ()

XMonad.hs

@@ -65,6 +65,11 @@ newtype ScreenId    = S Int deriving (Eq,Ord,Show,Enum,Num,Integral,Real)
 
 -- | The X monad, a StateT transformer over IO encapsulating the window
 -- manager state
+--
+-- Dynamic components may be retrieved with 'get', static components
+-- with 'ask'. With newtype deriving we get readers and state monads
+-- instantiated on XConf and XState automatically.
+--
 newtype X a = X (ReaderT XConf (StateT XState IO) a)
     deriving (Functor, Monad, MonadIO, MonadState XState, MonadReader XConf)
 
@@ -96,8 +101,7 @@ rotateLayout x = if x == maxBound then minBound else succ x
 
 -- | A full description of a particular workspace's layout parameters.
 data LayoutDesc = LayoutDesc { layoutType   :: !Layout
-                             , tileFraction :: !Rational
-                             }
+                             , tileFraction :: !Rational }
 
 -- ---------------------------------------------------------------------
 -- Utilities