"Chaddaï Fouché" <[EMAIL PROTECTED]> writes: > > so you need an f so that c `f` x is c (for any c and x) and > > yet (b `f` c) is c for any c and b -- this is impossible (or > > I'm asleep). > > 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. > Still you could "approximate" it, and in fact I believe the [Char] -> > Char requirement is hinting at such a (arguably and IMO ugly) > solution. For example you could assume there would be no "NUL" > character in a string ([Char] is a synonym for String, or vice-versa), > and then get a simple myLast for String in this restrictive case (and > looking exactly like Alexteslin sample). 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. -- Jón Fairbairn [EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
