Capitalise text in Haskell

gistfile1.hs

module Lorem where

import Control.Monad(replicateM_)

import System.Environment(getArgs)
import qualified System.IO as SIO

import qualified Data.Char as C
import qualified Data.ByteString.Char8 as BC

import qualified Data.Word8 as W8
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL

genText filename n = do 
  outh <- SIO.openFile filename SIO.WriteMode
  replicateM_ n $ BC.hPutStrLn outh lorem
  
  where lorem = BC.pack "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."

processC file = do
  str <- BC.readFile file
  BC.putStr $ title str
  where title bs =
          snd $ BC.mapAccumL (\prev c -> (c, if C.isSpace prev then C.toUpper c else c)) ' ' bs

processB file = do
  str <- B.readFile file
  B.putStr $ title str
  where title bs =
          snd $ B.mapAccumL (\prev c -> (c, if W8.isSpace prev then W8.toUpper c else c)) W8._space bs

processBL file = do
  str <- BL.readFile file
  BL.putStr $ title str
  where title bs =
          snd $ BL.mapAccumL (\prev c -> (c, if W8.isSpace prev then W8.toUpper c else c)) W8._space bs


main :: IO()
main = do
  args <- getArgs
  case args of
    ["-g", f, n] -> genText f (read n)
    ["-c", f] -> processC f 
    ["-b", f] -> processB f 
    ["-l", f] -> processBL f