List files in a directory recursively

list_dir.hs

module ListFiles where

import System.Directory
import System.FilePath.Posix

split:: [a] -> [Bool] -> ([a], [a])
split xs bs = foldr s ([], []) (zip xs bs)
    where s (d, i) (y, z) = if i then (d:y, z) else (y, d:z)

isSpecialFile :: FilePath -> Bool
isSpecialFile f = f `elem` [".", ".."]

filesComletePath :: FilePath -> [FilePath] -> [FilePath]
filesComletePath base files = map (base </>) . filter (not . isSpecialFile) $ files

getDirs :: FilePath -> IO [FilePath]
getDirs base = do c <- filesComletePath base <$> getDirectoryContents base
                  (dirs, files) <- split c <$> mapM doesDirectoryExist c
                  sub_files <- concat <$> mapM getDirs dirs
                  return $ files ++ sub_files

main :: IO()
main = do filepath <- getCurrentDirectory
          file_list <- getDirs filepath
          mapM_ putStrLn file_list