On Tue, Sep 09, 2008 at 11:06:43PM +0200, Pieter Laeremans wrote:
This : Prelude> let f = (\x -> return "something went wrong") :: IOError -> IO String Prelude> let t = return $ show $ "too short list" !! 100 :: IO String Prelude> catch t f "*** Exception: Prelude.(!!): index too large
How about:
module Main where
import Control.Exception import Prelude hiding (catch)
f :: Exception -> IO String f = const $ return "sthg went wrong"
g :: String g = show $ "too short list" !! 100
h :: IO String h = do print $ head [0 .. -1] return "huh?"
main = do mapM_ print =<< sequence [ h `catch` f , evaluate g `catch` f , (return $! g) `catch` f , (return g) `catch` f ]
Output: kokr@copper:/tmp$ runhaskell test.lhs "sthg went wrong" "sthg went wrong" "sthg went wrong" "test.lhs: Prelude.(!!): index too large Check documentation of catch and evaluate functions in Control.Exception. Regards, -- Krzysztof Kościuszkiewicz Skype: dr.vee, Gadu: 111851, Jabber: kokr@jabster.pl "Simplicity is the ultimate sophistication" -- Leonardo da Vinci