Re: [Axiom-developer] A{ld,xi}o{r,m}-Combinat

[Nicolas M. Thiery]

> Actually, I must thank Nicolas quite a bit. He showed in his talks
> how useful recursion is. And how this is currently done in
> MuPAD. Basically, in MuPAD-combinat it is of importance that one
> should be able to define combinatorial classes via a
> grammer. MuPAD-combinat then computes a fixed point for this grammar
> in order to get the combinatorial classes.  And as I understood
> Nicolas, that code is quite huge and complicated.

To be exact: the MuPAD-Combinat code that deals with decomposable
classes is monolithic. The distributed approach that we just used in
Aldor, and that we plan to use in the future for MuPAD-Combinat, will
be more natural, more modular, and easier to maintain and to
extend. It will also deprecate the grammar-analysis code.

Now for the code size itself ... If we want to keep all the features,
there is still some work to do. I don't expect much more than 10% code
reduction thanks to the distributed approach, and maybe another 10%
thanks to the quality of the Aldor language.

> >I hope we somehow find it possible to arrange more (and more frequent)
> > such "sprints" on all sorts of Axiom subjects.
> I'm all for it. We had lot's of fun, too. ;-)

Definitely.

> Nicolas, am I wrong if I say that you and perhaps your "team" now
> more seriously consider Aldor/Axiom as an option? Of course, that
> all depends on the availablility of Aldor.

I definitely loved that language (I also love typing, but I am still
not 100% sure whether in practice it would not go in the way for our
kind of usage, namely rapid development of experimentation code for
research. The flexibility of the MuPAD language definitely saved us a
lot of time in many occasions).

So, an exact sentence would be:
 - If Aldor was completely free
 - If the Axiom and Aldor community where merged with ongoing work to
   unify their libraries
 - If I was to restart from scratch a project like MuPAD-Combinat
I would definitely hop in and choose that direction.

Now, the MuPAD-Combinat code and community can't be moved that easily;
it took five years to build them, and we still haven't completed the
transition from Maple!

So, the current status is that I will follow very closely what you
guys are doing. And help you whenever I can (but, badly enough,
without being able to put much work power in that). And try to make
sure that we keep things synchronized. Go ahead: please steal whatever
code/doc/tests you can!

Thanks Martin and Ralf for that very fun workshop!

                                                Nicolas

PS: I will put the slides of my talk on the MuPAD-Combinat web page
shortly: http://mupad-combinat.sf.net/


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