highlightRange

highlightRange.hs

import System.Console.ANSI
import qualified Data.ByteString.Lazy.Char8 as BS
import Text.Regex.PCRE
import Text.Regex.PCRE.ByteString
import Data.Int

hlCode = setSGRCode [SetColor Foreground Vivid Red]
hlReset = setSGRCode [Reset]

d = map BS.pack [
    "foo",
    "bar",
    "baz",
    "----",
    "hoge",
    "piyo" ]

highlightRange :: BS.ByteString -> Int64 -> Int64 -> BS.ByteString
highlightRange str start len =
    BS.concat [ (BS.take start str), (BS.pack hlCode) ,
                (BS.take len $ BS.drop start str), (BS.pack hlReset) ,
                (BS.drop (start+len) str)]

main = BS.putStrLn $ highlightRange (BS.concat d) 6 9