On Mon, 14 Feb 2005 11:07:48 +0100, Daniel Fischer > And could one define
> \f g h x y -> f (g x) (h y)
> > point-free?
sure,
((flip . ((.) .)) .) . (.)
That occurence of flip cannot (AFAIK) be removed, indicating that as far as natural composition is concerned, that function above is not quite 'right'. On the other hand
\f g x h y -> f (g x) (h y) corresponds to (((.) .) .) . (.) Clearly better, no? ;-)
Reducing the 'complexity' by one level, the symmetric version ((.) .) . (. (.)) has the same type as \f g h x -> f (\f1 y -> g (f1 y)) (h x)
I am curious if the function above has been 'seen' in an application before?
Jacques _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
