[Axiom-developer] Re: [sage-devel] Categories for the working programmer

[Nicolas M. Thiery]

        Dear Tim,

On Sun, Nov 09, 2008 at 04:21:56PM -0500, root wrote:
> There are at least two possible paths toward a category hierarchy in Sage,
> adopting Axiom's version or designing a new one.
> 
> The key advantage of adopting the Axiom category hierarchy is the Sage
> system could reuse a lot of the algorithms in Axiom. The Spad language
> used in Axiom is similar in style and spirit to the Sage python language.
> If the same categories were available it should be possible to use the
> algorithms in Axiom's domains as written.
> 
> The temptation to re-design is very seductive but not very productive.

Of course!

Don't worry: I am bound to be productive into translating code from
MuPAD to Sage :-) And the MuPAD's category hierarchy is quite similar
(since inspired from) Axiom's.

For the mathematical categories (Groups, Algebras, ...), the hierarchy
is anyway constrained by the mathematics behind. There are many
categories that are in MuPAD-Combinat but not in Axiom, and
reciprocally. So, there will be some merging of the two hierarchies
(and of others) but it should be straightforward and should not affect
the way algorithms are written.

Some other categories of Axiom are really more about computer science,
not mathematics. My feeling is that those would better be translated
into just a hierarchy of Python "abstract" classes. However we can try
to ensure compatibility whenever possible (names, hierarchy, ...), so
as to ease the translation of algorithms.

All the best,
                                Nicolas
--
Nicolas M. Thiéry "Isil" <address@hidden>
http://Nicolas.Thiery.name/