On Mon, Dec 26, 2011 at 12:32:13PM +0400, Eugene Kirpichov wrote: > 2011/12/26 Gábor Lehel <illiss...@gmail.com> > > > On Sun, Dec 25, 2011 at 9:19 PM, Eugene Kirpichov <ekirpic...@gmail.com> > > wrote: > > > Hello Heinrich, > > > > > > Thanks, that's sure some food for thought! > > > > > > A few notes: > > > * This is indeed analogous to Iteratees. I tried doing the same with > > > Iteratees but failed, so I decided to put together something simple of my > > > own. > > > * The Applicative structure over this stuff is very nice. I was thinking, > > > what structure to put on - and Applicative seems the perfect fit. It's > > also > > > possible to implement Arrows - but I once tried and failed; however, I > > was > > > trying that for a more complex stream transformer datatype (a hybrid of > > > Iteratee and Enumerator). > > > * StreamSummary is trivially a bifunctor. I actually wanted to make it an > > > instance of Bifunctor, but it was in the category-extras package and I > > > hesitated to reference this giant just for this purpose :) Probably > > > bifunctors should be in prelude. > > > > Edward Kmett has been splitting that up into a variety of smaller > > packages, for instance: > > > > http://hackage.haskell.org/package/bifunctors > > Actually it's not a bifunctor - it's a functor in one argument and > contrafunctor in the other. > Is there a name for such a structure?
"Bifunctor" is usually used for such things as well. Data.Bifunctor only covers bifunctors which are covariant in both arguments. -Brent _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
