F, FD, FC, AT, SPJ ;) WTH does it mean?
On Wed, Mar 07, 2007 at 10:12:11AM +0100, [EMAIL PROTECTED] wrote: > Claus Reinke wrote: > >>> ps. i was somewhat shocked to read that SPJ wants FDs gone. > >> > >> Why? Simon has good taste. :) > > > > de gustibus non est disputandum ;) > > > > FD have uses and problems and AT have uses and problems. starting anew > > with the latter doesn't fix the problems, it just changes their form. > > Well, the choice between FD and AT (and maybe yet undiscovered > alternatives) is entirely a matter of "convenience" as much as > everything related to type inference is. The same goes for type classes > or subtyping: all these can be translated to system F (or FC for FD and > AT) so they don't add abstraction power at run-time. Their only but > important purpose is to auto-infer code. > > FD are pretty much type-level programming in a kind of mini-prolog. Of > course, AT are type-level programming as well, but functional in style, > which is arguably more compelling for a functional base language. At > least, I think that FD are somehow ugly. > > > in particular, many of the problems with FD are ambiguities in > > interpreting interactions with other popular features, such as overlap > > resolution. it took half a decade of practical experience to expose > > such issues for FD, and i don't see the fact that AT haven't reached > > that stage yet as any advantage. > > Quite telling that it took half a decade to shed light on the semantics > of the many FD variants, isn't it? :) > > I guess that AT will come with semantics included because it's otherwise > unclear how to implement them. Implementing FD is simply easier as type > inference already is a kind of mini-prolog. Of course, that doesn't > simplify their semantics at all. In a sense, knowing AT is knowing how > much functional in style type inference can be. > > Regards, > apfelmus > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe