diff options
Diffstat (limited to 'Wm.hs')
| -rw-r--r-- | Wm.hs | 35 |
1 files changed, 24 insertions, 11 deletions
@@ -1,4 +1,17 @@ -{-# OPTIONS_GHC -fglasgow-exts #-} +----------------------------------------------------------------------------- +-- | +-- Module : Wm.hs +-- Copyright : (c) Spencer Janssen 2007 +-- License : BSD3-style (see LICENSE) +-- +-- Maintainer : sjanssen@cse.unl.edu +-- Stability : unstable +-- Portability : not portable, uses cunning newtype deriving +-- +----------------------------------------------------------------------------- +-- +-- The Wm monad, a state monad transformer over IO, for the window manager state. +-- module Wm where @@ -7,12 +20,12 @@ import Control.Monad.State import System.IO (hFlush, hPutStrLn, stderr) import Graphics.X11.Xlib -data WmState = WmState - { display :: Display - , screenWidth :: Int - , screenHeight :: Int - , windows :: Seq Window - } +data WmState = WmState + { display :: Display + , screenWidth :: !Int + , screenHeight :: !Int + , windows :: Seq Window + } newtype Wm a = Wm (StateT WmState IO a) deriving (Monad, MonadIO{-, MonadState WmState-}) @@ -20,17 +33,17 @@ newtype Wm a = Wm (StateT WmState IO a) runWm :: Wm a -> WmState -> IO (a, WmState) runWm (Wm m) = runStateT m -l :: IO a -> Wm a -l = liftIO +io :: IO a -> Wm a +io = liftIO -trace msg = l $ do +trace msg = io $ do hPutStrLn stderr msg hFlush stderr withIO :: (forall b. (a -> IO b) -> IO b) -> (a -> Wm c) -> Wm c withIO f g = do s <- Wm get - (y, s') <- l $ f $ \x -> runWm (g x) s + (y, s') <- io $ f $ \x -> runWm (g x) s Wm (put s') return y |