On 8 February 2011 09:57, John Lato
I think the real problem we have with container classes has a lot more to do with what we would use them for. That is, Haskell already has Monoid, Foldable and Traversable. These three (especially Foldable) cover nearly everything OOP programmers would expect out of generic container operations.
That was what my rewrite was going to be using. The problem, however, is two-fold: * Dealing with types of kind * vs kind * -> * * Dealing with types of kind * -> * that have a restriction on the type parameter (e.g. Set). I was basing my approach on Ganesh's rmonad [1] library whilst taking into account the Functor => Applicative => Monad hierarchy when re-defining the classes, but the approach was very quickly becoming unwieldy. [1]: http://hackage.haskell.org/package/rmonad -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com