Get files recursively inside directories

DirTree.hs

module System.Directory.Tree where

import System.Directory ( doesFileExist, getDirectoryContents )

data DirTree = Directory String [DirTree]
             | File String
             deriving (Show, Eq)

getDirTree :: FilePath -> IO [DirTree]
getDirTree path = getDirectoryContents path
              >>= mapM dirOrFile
                . filter (`notElem` [".", ".."])

    where dirOrFile n = let loc        = path ++ "/" ++ n
                            tree True  = fmap (Directory n) $ getDirTree loc
                            tree False = return $ File n

                        in  doesFileExist loc
                        >>= tree