Re: [Haskell-cafe] Newbie Question on type constructors

On Mon, 1 Nov 2004, Ben Rudiak-Gould wrote:

In particular, one cannot write an invert :: (a->b) -> Maybe (b->a) which never returns a wrong answer, except for invert = const Nothing

How about: invert = undefined This never returns an answer at all, so it can't return a wrong one! Finn