import System.Environment
import Control.Monad (forM_)
import Text.ParserCombinators.Parsec
import qualified Text.ParserCombinators.Parsec.Number as Numbers
expr = chainl1 int infixOp
int = Numbers.int
infixOp = do
spaces
char '+'
spaces
return (+)
runExpr = runParser expr 0 "<input>"
showResult (Left a) = "Error: " ++ show a
showResult (Right a) = show a
main = do
putStrLn "args:"
args <- System.Environment.getArgs
args `forM_` ((\s -> putStr " - " >> putStrLn s) . showResult . runExpr)
putStrLn ""