On Fri, Jun 20, 2008 at 11:51:40AM +0100, Adrian Hey wrote:
2) Don't use Int# , looks like a premature optimization to me. Furthermore, I'd change the queer addSize to simply
size :: map a -> Int
This does exist (see above), but it's not a class method. One could argue that is was unnecessary to make unboxing explicit. It's something I got into the habit of doing because it's way easier to do that than is inspecting ghc's output to make it's done it on its own (and figuring out what to do about it if it hasn't). Also, because of the nested nature generalised tries addSize is more convenient for implementors than size IMO.
I agree that using Int# is a bad idea. It makes the package unportable, and it forces all the packages that implement the class to write code using Int#. Thanks Ian