On 4 September 2010 08:50, Ivan Lazar Miljenovic
3) Am I wasting my time with this?
Not at all. Many people want a good containers API, and many people want a cleaned up version of the categorical classes which isn't quite as involved as category-extras. Go for it!
*sigh* I was almost wishing people would say I _was_ wasting my time with this... ;-)
Hi Ivan Okay, I'll bite... Its good someone is looking into arity versions of Monad, Applicative etc. I think previously pointed you to Conor McBride's message on the subject: http://www.haskell.org/pipermail/haskell-cafe/2008-June/044011.html But, I don't know that work on this will lead to a better API for collection classes... Supposing classes is the way to go, I think there's still a lot of design work to be done on what the classes should be rather than how they are implemented. The current design space (ListLike and your Data.Containers) looks like a factoring of the operations from Data.List and Data.Sequence, personally I have serious doubts that this will lead to a nice API. If I was looking at it myself, I'd start from Chris Okasaki and Ralf Hinze's observations that data structures have analogies to numerical representations. So, I would try to build classes upwards from that (monoid is obviously already in place), rather than design by factoring what List already has. As an example, I think someone has pointed out on the Cafe that C++ has a container library following the analogy to numerical representations. As an aside I thought someone added an implementation of Simon Peyton Jones's "Bulk Types with Class" to Hackage recently? If they did they didn't give it a findable description. Best wishes Stephen