diff options
| author | Jed Barber <jjbarber@y7mail.com> | 2014-02-21 23:51:29 +1100 |
|---|---|---|
| committer | Jed Barber <jjbarber@y7mail.com> | 2014-02-21 23:51:29 +1100 |
| commit | e25b703805a6d5b20ddcb70e406830ca8d16cd22 (patch) | |
| tree | 8b54e49e2cd6a04d3f0958e8395651dbf607dc7d | |
| parent | 50958fc5f2aad6f72fa8b948f8fa33713beb91a1 (diff) | |
Revised programming style
| -rw-r--r-- | fractran.hs | 15 | ||||
| -rw-r--r-- | makefile | 4 | ||||
| -rw-r--r-- | thue.hs | 15 |
3 files changed, 10 insertions, 24 deletions
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 ()) ] @@ -21,8 +21,8 @@ testprog: ghc --make test.hs -o ${OUTPUTDIR}/test fractranprog: - ghc -XDeriveDataTypeable --make fractran.hs -o ${OUTPUTDIR}/fractran + ghc --make fractran.hs -o ${OUTPUTDIR}/fractran thueprog: - ghc -XDeriveDataTypeable --make thue.hs -o ${OUTPUTDIR}/thue + ghc --make thue.hs -o ${OUTPUTDIR}/thue @@ -1,16 +1,11 @@ import System.Environment( getArgs ) import Data.Typeable -import qualified Control.Exception +import Control.Exception( ErrorCall(..), Handler(..), catches ) import Thue.Parser import Thue.Interpreter -data ThueException = ThueException { errString :: String } - deriving (Show, Typeable) - -instance Control.Exception.Exception ThueException - usageString :: String @@ -22,7 +17,7 @@ program :: IO () program = do args <- getArgs fileContents <- if (length args /= 1) - then Control.Exception.throw (ThueException usageString) + then error usageString else readFile (head args) case (parseThue fileContents) of @@ -31,8 +26,6 @@ program = do -main = Control.Exception.catch program handler - where - handler :: ThueException -> IO () - handler err = putStrLn (errString err) +main = catches program + [ Handler ((\e -> putStrLn . show $ e) :: ErrorCall -> IO ()) ] |