refactoring for lineSeparator.

Language/Haskell/GhcMod/Utils.hs

@@ -3,3 +3,13 @@ module Language.Haskell.GhcMod.Utils where
 -- dropWhileEnd is not provided prior to base 4.5.0.0.
 dropWhileEnd :: (a -> Bool) -> [a] -> [a]
 dropWhileEnd p = foldr (\x xs -> if p x && null xs then [] else x : xs) []
+
+-- |
+--
+-- >>> replace '"' "\\\"" "foo\"bar"
+-- "foo\\\"bar"
+replace :: Char -> String -> String -> String
+replace _ _  [] = []
+replace c cs (x:xs)
+  | x == c    = cs ++ replace c cs xs
+  | otherwise = x   : replace c cs xs