Revised Numeric Prelude

[Aaron Denney]

On 2006-05-16, Ashley Yakeley <ashley at semantic.org> wrote:
> 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
-><-