Untitled

import Control.Monad
import Control.Monad.Cont

forever x = x >> forever x

processChar k =
    do c <- liftIO getChar
       if c == ' '
          then k c
          else liftIO (putStr [c])

demo = callCC (\k -> forever (processChar k))

demo' :: IO Char 
demo' = runContT demo return