On 2006-05-16, Ashley Yakeley
Aaron Denney wrote (on the Haskell' list):
Meh. I'd really like a revised numeric prelude to be able to use MPTCs with FDs.
Do you have some ideas for this?
Not well put together. There was some discussion earlier on haskell-cafe under "Proposal for restructuring Number classes"
There's no reason why such an effort shouldn't start right now; I daresay even if we used FDs while Haskell eventually goes with ATs it might still be useful.
I know there's the Basic Algebra proposal, but there's probably been some other work done here.
The basic algebra proposal sounded reasonable, on some descriptions, but was actually awful to try to use. http://cvs.haskell.org/darcs/numericprelude/ is a reasonable start. I have some quibbles with the hierarchy, and with the names. For instance, I think supplying gcd for all principle ideal domains is silly, as it cannot always be done efficiently, and it's also silly to provide them for say, finite fields, where they do nothing useful. I would also want (*) available in a seperate Multiplicative class, rather than only as part of Num (which seems to be trying to capture Ring). -- Aaron Denney -><-