On Wed, Jan 14, 2004 at 10:38:15AM +0100, Daan Leijen wrote:
No one seems to support Edison. However, there is an important difference between Edison and DData: DData provides implementations of specific structures, while Edison tried to provide general collection interfaces *and* implementations. I believe that designing good generic collection interfaces is very hard and may even be impossible to do "right" in current Haskell's. So, I guess we will be stuck with concrete data structures for a while :-)
It might be sensible to do the generic thing for sequences only: * the generic interface is fairly clear (PreludeList + List + toList, fromList, empty, cons, snoc, lview, rview and a few others -- the only question is whether to reuse the standard names). * the interface fits in Haskell 98, because element types are unconstrained. * no implementation suits all purposes, and you often want to delay the choice.