integrating hlint.

Lint.hs

@@ -0,0 +1,20 @@
+module Lint where
+
+import Control.Applicative
+import Data.List
+import System.IO
+import System.Process
+import Types
+
+lintSyntax :: Options -> String -> IO String
+lintSyntax cmd file = pretty <$> lint cmd file
+  where
+    pretty = unlines . map (concat . intersperse "\0")
+           . filter (\x -> length x > 1)
+           . groupBy (\a b -> a /= "" && b /= "") 
+           . lines
+
+lint :: Options -> String -> IO String
+lint cmd file = do
+  (_,hout,_,_) <- runInteractiveProcess (hlint cmd) [file] Nothing Nothing
+  hGetContents hout