The simplest solution seems to be to use the utf8-string package from Galois. It provides a drop-in replacement for System.IO
If we use a function from System.IO.UTF8, we should also hide the equivalent one from the Prelude. (Alternatively, we could import the UTF8 module qualified)
> import System.IO.UTF8 > import Prelude hiding (readFile, writeFile) > import System.Environment (getArgs)
The readFile and writeFile functions are the same as before...
> main :: IO () > main = > do args <- getArgs > mapM_ reverseUTF8File args > reverseUTF8File :: FilePath -> IO () > reverseUTF8File f = > do c <- readFile f > writeFile (f ++ ".rev") $ reverseLines c > where > reverseLines = unlines . map reverse . lines