csv.hs

import Text.Regex
import Data.List

readCSV :: (String,String)->IO [[String]]
readCSV (fileName,delimiter) = do        
        text <- (readFile fileName)
        let column = lines text::[String]
            elements = map (splitRegex (mkRegex delimiter)) column
        return elements

writeCSV :: (String,String) -> [[String]] ->IO ()
writeCSV (fileName,delimiter) csv = do
        let column = map (intercalate (delimiter)) csv
            text   = unlines column
        writeFile fileName text