gistfile1.hs

{-# LANGUAGE OverloadedStrings #-}
import qualified Data.Text as T
import Data.Char (isDigit)
import System.IO
import Data.List (partition, intersperse)
import System.Environment (getArgs)

main = do
	args <- getArgs
	content <- readFile(args !! 0)
	let l = lines content
	let lf = filter (\x -> length x > 0) l
	mapM_ (putStrLn . arrange) lf 

tokens :: String -> [String]
tokens [] = []
tokens s = 
	case break(== ',') s of
	(x, []) -> [x]
	(x, _:xs) -> x:tokens xs


untokens :: [String] -> String
untokens l = concat . intersperse "," $ l

isANumber :: String -> Bool
isANumber = all isDigit

-- ["i", "am", "the", "12", "light"] 
separate :: [String] -> ([String], [String])
separate l = partition (not . isANumber) l


generateSentence :: ([String], [String]) -> String
generateSentence (xa, []) = untokens xa
generateSentence ([], xb) = untokens xb
generateSentence (xa, xb) = untokens xa ++ "|" ++ untokens xb

arrange :: String -> String
arrange = generateSentence . separate . tokens