On Thu, Jul 27, 2006 at 02:57:20PM +0200, Doaitse Swierstra wrote: > On Jul 27, 2006, at 1:35 PM, Niklas Broberg wrote: > >I would really like to see this implemented, and I don't think the > >above is serious enough that we shouldn't. There may be some that > >don't agree though. Speak up now, or forever hold your peace!
Me too, this sounds really cool! > We alreday are at a stage where first year students trying to master > haskell get error messages like > > "Bool is not an instance of the class Num" > > if they accidently write 1 + True (or something equivalent, but less > obvious). I think this is not a language issue so much as a compiler issue, and I don't think it's a sound idea to limit the language or libraries based on the existing poor error messages. If the above gave a message like (+) requires an argument of class Num, but "True" is of type Bool, which is not in class Num. I don't think there would be a problem. In general, I think classes should be used more, rather than less, and if that means we need a SoC project to improve the clarity of error messages, then that's what needs to be done. (I'll admit, I'm unlikely to do this...) > If you want to mess around why not call the function "provided" or > something similar. Or perhaps (?:) or something like that, which could be used infix to evoke the idea of C's e1 ? e2 : e3 syntax. "provided" to me is less clear than "cond" since it has other meanings, and isn't borrowed from any language that I'm familiar with, like "cond" is. -- David Roundy _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe