nptools-0.1: show-non-ascii.hs

import Data.Char
import Data.List
import Control.Applicative

bool :: a -> a -> Bool -> a
bool t e b = if b then t else e

analyseLine :: (Int, String) -> [String]
analyseLine (line, xs) | any (not . isAscii) xs = ["Line " ++ show line,
                                                   "  Orig: " ++ xs,
                                                   "  Mark: " ++ marks xs,
                                                   "  Char: " ++ chars xs]
                       | otherwise              = []
  where marks = reverse . dropWhile isSpace . reverse . map (bool ' ' '^' . isAscii)
        chars = intercalate ", " . map show . filter (not . isAscii)

main :: IO ()
main = do putStrLn "Reading from stdin"
          putStrLn =<< unlines . concatMap analyseLine . zip [1..] . lines <$> getContents