donn: > > On Mar 8, 2008, at 12:33 PM, Henning Thielemann wrote: > > >On Sat, 8 Mar 2008, Denis Bueno wrote: > ... > >>I am also using STUArray from some time-critical code; however, I > >>don't deal with ArrayException, or any exceptions for that matter. > >>What besides an out-of-bounds read or write might throw an > >>ArrayException? If it is out-of-bounds reading or writing, surely > >>that indicates a bug in your program that you'd rather fix than catch > >>the exception, no? > > > >Another instance of mixing up exceptions and errors in the Haskell > >libraries. > > http://www.haskell.org/haskellwiki/Error > > http://www.haskell.org/haskellwiki/Exception > > This seems to me one of the disappointments of Haskell - not just a > detail that was handled in an awkward way, but a fundamental flaw. > I'm not talking about ArrayException, whatever that is, but the notion > that errors encountered in functional code mustn't be handled as > exceptions. > > If your input file is not where you expected it and openFile fails, > or it was > incompletely written out and your input processing fails in a 'head' or > pattern match, the difference is not very important to me. I want to be > able to call your code and manage the risk that it's going to kill my > server. > You may feel that it's your job to write more robust functional code > that > can't run into these errors, but C programmers can be found who insist > that it's the programmer's job to manage heap memory and it isn't all > that hard. A programming language that fails to make it easier to write > more robust code, is not moving us forward. I rejoice that Haskell > isn't > as miserable as C, but with respect to exceptions and errors, it's > behind > for example Python. Languages that can, use exceptions like IndexError. > Evidently, Haskell fundamentally can't. That's too bad.
I don't understand this complaint -- you can handle all these with Control.Exception. xmonad catches all these things for example, in user code, to prevent poorly written modules throwing a pattern match exception, or calling 'error' and making the window manager unstable. Handling exceptions generated from pure code is just another part of making systems more robust -- and of course you can do it in Haskell. -- Don _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
