On 17/03/2010, at 03:16, Louis Wasserman wrote:
I'm not willing to do this sort of typeclass wrapper thing, primarily because nothing else in containers does -- even though we might have a Mapping type class that handles both IntMap and Map, we don't.
I'm inclined to let that design choice stand, as far as containers is concerned. It would make perfect sense to write a new package with such a type class and offering instances for the containers priority queue implementations, but I prefer to stick with the style that containers already seems to use -- that is, exporting separate modules without a unifying type class, but with nearly-identical method signatures.
FWIW, vector does both. It defines most vector operations generically and then exports appropriate specialisations for each concrete vector type. I think this is the most flexible and convenient approach. I just wish Haskell had some kind of support for it. Roman