From e25b703805a6d5b20ddcb70e406830ca8d16cd22 Mon Sep 17 00:00:00 2001 From: Jed Barber Date: Fri, 21 Feb 2014 23:51:29 +1100 Subject: Revised programming style --- fractran.hs | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) (limited to 'fractran.hs') diff --git a/fractran.hs b/fractran.hs index 7f3946f..964a095 100644 --- a/fractran.hs +++ b/fractran.hs @@ -1,16 +1,11 @@ import System.Environment( getArgs ) import Data.Typeable -import qualified Control.Exception +import Control.Exception( ErrorCall(..), Handler(..), catches ) import Fractran.Parser import Fractran.Interpreter -data FractranException = FractranException { errString :: String } - deriving (Show, Typeable) - -instance Control.Exception.Exception FractranException - usageString :: String @@ -22,7 +17,7 @@ program :: IO () program = do args <- getArgs fileContents <- if (length args /= 1) - then Control.Exception.throw (FractranException usageString) + then error usageString else readFile (head args) case (parseFractran fileContents) of @@ -31,8 +26,6 @@ program = do -main = Control.Exception.catch program handler - where - handler :: FractranException -> IO () - handler err = putStrLn (errString err) +main = catches program + [ Handler ((\e -> putStrLn . show $ e) :: ErrorCall -> IO ()) ] -- cgit