On Thu, Jun 10, 2010 at 8:45 PM, Derek Elkins <[email protected]>wrote:
> Or... one could just use the exceptions that are already built into > the IO monad... > It feels to me like this discussion has a lot of speculation in it. I would like to see concrete examples of the code and the suggested improvements. > 2010/6/10 Yitzchak Gale <[email protected]>: > > Lennart Augustsson wrote: > >> I would not use the continuation monad just for early exit. Sounds > >> like the error monad to me. > > > > I.e., the Either/ErrorT monad. But the mtl/transformers packages > > have an orphan instance for Either that requires the > > exit type to be an instance of the Error class. If that > > doesn't work in your case, use the Exit monad: > > > > http://www.haskell.org/haskellwiki/New_monads/MonadExit > > > > Or use the Maybe monad written additively, i.e. mplus > > in place of >> (more or less). > > > > Regards, > > Yitz > > _______________________________________________ > > Haskell-Cafe mailing list > > [email protected] > > http://www.haskell.org/mailman/listinfo/haskell-cafe > > > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe >
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