An incomplete snippet of Haskell study

sort.hs

module Sort
where

import IO

cat = bracket 
    (openFile "a.txt" ReadMode)
    hClose
    (\h -> docatloop h)
    where docatloop h = do
           iseof <- hIsEOF h
           case iseof of
             True -> return ()
             False -> do
               line <- hGetLine h
               putStr (line ++ "\n")
               docatloop h
               

getfile = bracket 
    (openFile "a.txt" ReadMode)
    hClose
    (\h -> dogetfileloop h)
    where
      dogetfileloop::h->[a]->[a]
      dogetfileloop h [] = []
      dogetfileloop h (xs) = let io = getoneline h
                             in case io of
                               Nothing -> xs
                               _       -> 
      getoneline h = do
           iseof <- hIsEOF h
           case iseof of
             True -> Nothing
             False -> hGetLine h
      
           case iseof of
             True -> xs
             False -> do
               dogetfileloop h (line:xs)
               
   
askname = do
  putStrLn "Entrez votre nom:"
  name <- getLine
  case name of
     "Simon" -> do putStrLn "Haskell c'est bon"
     "Koen" -> do putStrLn "debugging Haskel is fun"
     _ -> do putStrLn "How do you do "