Alexey Karakulov
(Ord b) must be deduced from (Functor (Set b)) but it doesn't. I don't know whether it's my mistake somewhere or ghc problem.
I've come across this problem as well; the best solution I've seen so far is the one taken by Ganesh in his rmonad library: http://hackage.haskell.org/package/rmonad
Thanks for the link, but RFunctor typeclass is still (more or less) polymorphic, so I couldn't write ByteString instance for it. (Really I don't care about ByteString, but it's good example). However, I could try to use Suitable+Constraints concept for non-polymorphic functors.
Yeah, I'm working on something like this at the moment, but I'm currently stuck on naming: if I want to have Functor for kind * -> *, what's a good name for a type class for kind *? Also, is there any type for which having a map a -> a _doesn't_ make sense? Bloomfilters maybe? -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com