David Bergman wrote (on 26-11-02 01:29 -0500):
I would like to know if anyone (maybe Mark P) knows the status of "Cartesian classes" in different Haskell implementations. I.e., does anyone implement the suggested functional dependencies or the less general parameterized type classes?
I have need for the multi-variable classes quite often (especially in a genetic algorithm framework I am building in Haskell). Although I would hesitate to extend beyond Haskell 98, if there exist a common view on how to best implement Cartesian classes (read "it will be part of Haskell 2") and/or a stable implementation for it, I am willing to be a bit adventurous...
What do you mean by "cartesian classes"? Do you mean multi-parameter type classes? They're supported by GHC and Hugs, but not NHC98 or HBC. The same goes for functional dependencies. -- Frank