16 Aug 2007 10:11:24 +0100, Jon Fairbairn <[EMAIL PROTECTED]>: > snip my quote > > I certainly wouldn't count such a thing as a valid > solution. It's always amazed me that C uses as standard a > mechanism of ending strings that is so obviously an > error-prone hack.
I'm completely with you on that ! Which is why I don't like the suggestion of doing it only for Char... > > Well, it isn't "impossible" but quite hard (and not even standard H98 > > if I'm not mistaken) > > If it is possible, I'm very sad that we've allowed things to > get into the language that make that kind of reasoning > faulty. I spoke too fast on this one, it _is_ impossible (I think ?), but you can use the same trick as for Char to get a polymorphic function, arguably a little bit more useful than the Char one, since if you have a undefined as the last element of your list, there's a good chance anyway that your program is already in a bad state. Still it's an ugly hack altogether... Your suggestion is of course the right answer if there is an obligation to use a foldr and not just any fold. -- Jedaï _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
