Re: [Axiom-developer] Re: SPAD and Aldor again

[Gabriel Dos Reis]

Martin Rubey <address@hidden> writes:

| Dear Christian, Gaby, Waldek,
| 
| Christian, I'm copying this to you since I think that you have a lot to say
| with respect to features and shortcomings of Aldor. I would like to ask you to
| join the discussion, time permitting.
| 
| Gabriel Dos Reis <address@hidden> writes:
| 
| > I would like to see a discussion about what is necessary to support
| > computational mathematics in Axiom, rather than how closely SPAD should
| > ressemble another language.
| 
| I think that this is beyond a group of a dozen part-time developers, and in
| fact, I believe that this is very likely beyond the abilities of the average
| mathematician. As evidence I'd like to present the "languages" of maple and
| mupad, which I believe to be quite inferior (maple: obviously, mupad: very
| likely) to Aldor.

However, we must be envision beyond today horizon, and define
ideals and must try hard to approximate them.  If you think of Axiom as
just a mere compiler to write today codes, it will not excite, not evolve
and therefore will die.  We must not improve SPAD just for what we
want to write today.  We must improve it to handle construct beyond
what we're doing today.  

[...]

| I did quite a bit of work with Aldor now (within the species project together
| with Ralf), and I'm quite convinced of the features of this language. In
| particular, the semantics of Aldor feel very "sound" to me, i.e., Aldor 
usually
| does what I expect it to do and allows what I would expect it to allow.

except when it does not, then you get depressed :-)


I'm not saying we should not having anything that is in Aldor.  I'm
saying, we should define the goal beyond being a clone of Aldor.
Cloning Aldor is not that much interesting.  People who wants Aldor
know where to get it.  The features should be cloned only when they
support the goals very well and beyond.

[...]

| Gaby pointed out that "==" has different semantics in Aldor and Axiom, but I
| have the feeling that this difference is not so severe: in fact, I don't know

yes, those are "little details" that are easy to fix in principle, but
might consume lot of resource to get right. 

>From my perspective, I would like to support recursive types (get rid
of )abbrev), dependent types, algebraic types.  

| of a way to define a constant in SPAD, currently, other than to define a
| macro. As far as I know, in Axiom "==" can only be used to define functions
| and, in SPAD, types. (Aren't types just a special kind of functions?)

depending on the perspective, yes.

-- Gaby