At 2001-05-16 00:18, Wojciech Moczydlowski, Jr wrote:

...

I think multiparameter type classes or other extensions to Haskell 98 are really needed to solve these kinds of problems in a simple and elegant way.

The right solution, IMHO, is to extend nhc and other Haskell compilers to support multiparameter type classes, not to try to shoehorn things that don't fit into Haskell 98.

I don't like the idea of a program working which compiles only under compilers which have certain language extensions built in.

If I understand things correctly, there is a list of language extensions (FFI for example), which has been accepted by all Haskell compilers developers. If multiparameter type classes were in that list, I would agree.

I tend to share Fergus Henderson's viewpoint. I see a Haskell with multiparameter type classes as a language I want to work with, and it would be great to have libraries written for that. I'm less interested in Haskell 98, since it means muckier solutions to the same problems. -- Ashley Yakeley, Seattle WA