You can get nice exception (but not segfault) when trying to fire this code:
{-# OPTIONS_GHC -XRecursiveDo #-}
module Main where
import Control.Concurrent import Control.Monad.Fix
loopChan :: IO (Chan ()) loopChan = mdo chan <- dupChan chan return chan
main = do c <- loopChan writeChan c ()
You just can't use a duplicate of a channel to create itself.
Prelude> :l loop_channel.hs [1 of 1] Compiling LC ( loop_channel.hs, interpreted ) Ok, modules loaded: LC. *LC> :type loopChan loopChan :: IO (Chan ()) *LC> c <- loopChan *** Exception: <>
Still I don't think it's a bug, but merely complicated way to crash
your program.
Haskell is great, but it also has many pitfalls, just like any other language.
Christopher Skrzętnicki
On Sun, Aug 24, 2008 at 00:15, Daniel Fischer
Am Samstag, 23. August 2008 23:17 schrieb Thomas Davie:
I'd be interested to see your other examples -- because that error is not happening in Haskell! You can't argue that Haskell doesn't give you no segfaults, because you can embed a C segfault within Haskell.
Bob
Use ST(U)Arrays, and use unsafeWrite because you do the indexchecking yourself. Then be stupid and confuse two bounds so that you actually write beyond the array bounds. I've had that happen _once_. But if you explicitly say you want it unsafe, you're prepared for it :)
Daniel _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe