On Mon, Jan 29, 2007 at 10:08:59AM +0100, Andres Loeh wrote: > > >I didn't fully understand this requirement. If Haskell-prime gets > > >rank-2 or rank-n types, then do we need to restrict constructors in this > > >way? > > Ok, this really boils down to the question of whether we do rank-2 or > rank-n types. I'm biased, because I actually use rank-n types > frequently, and feel somewhat limited by the rank-2 restrictions. I > don't know how many people actually do, though. I can understand > Iavor's points that rank-2 might be easier to explain, but at least > GHC's rank-n extension has a very detailed paper explaining it, so I > guess it's one of the better documented extensions.
I would say there is not much point in doing just rank-2. Once you know how to do rank-n (and we do, thanks to SPJ's great paper) then it is just as easy to implement as rank-2. Perhaps even moreso since it is a rather elegant general change to the type inferencer rather than a special case. John -- John Meacham - ⑆repetae.net⑆john⑈ _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime