Re: [Axiom-developer] Re: noweb / Lisp Skills

[Martin Rubey]

"Page, Bill" <address@hidden> writes:

> On Thursday, May 04, 2006 10:47 AM Martin Rubey wrote:
> > ... 
> > Things to do on the interpreter side needed for the 
> > axiom-combinat project:
> > 
> > * make it understand Aldor:
> > 
> >   * dependent types
> >   * extend
> >   * creating domains on the command line
> >
> 
> Is what you are suggesting the same thing as making library
> programming possible at the level of the interpreter? 

Yes. In aldor -gloop this is possible.

In fact, maybe it would be better to try to integrate the type guessing
mechanism of Axiom into the Aldor interpreter. That is, throw away the axiom
interpreter and replace it by aldor -gloop.

Again, I said already that I'm unskilled in the art of interpreter and compiler
writing. I only try to state what would be important to me from a
mathematicians point of view.

> If so, they I supose that you realize that this is already an issue at the
> level of SPAD and is not really an Aldor specific problem. It seems to me
> that the differences between the interpreter and library compiler
> environments were largely built-in as part of the original design of Axiom. I
> think the designers decided that the interpreter *should* behave differently
> than the compiler and that some of the things the compiler does should
> specifically not be available to the interactive user.

If this was intentional, it was a mistake. But I'm pretty sure that it was due
to limitations of time and money, rather than intention.

> It is certainly possible right now to use dependent types and the Aldor
> 'extend' functionality in Axiom right now so long as you remain within the
> Aldor library code. The problem is that neither of these can currently be
> "exposed" the the interactive user through the Axiom interpreter.

Yes. This is the way we are going to work around these problems, in fact. But
it's dead ugly.

> I think however that these two cases a rather different.  I think it should
> be possible to implement dependent types in the interpreter and the fact that
> it doesn't currently work is apparently already considers a bug by Peter
> Broadbery.

I believe so too, and I think that supporting dependent types would make for a
very good start. It doesn't need to be super clean, since in the long run we
will have to rewrite the interpreter from scratch anyway (or use aldor -gloop),
but it would make the transition a lot easier.

> But the the 'extend' functionality is another issue because that whould
> require providing the equivalent of the library compiler at the interpreter
> level.

Yes, this might have been wrong on my side. It seems that extend does not even
work in aldor -gloop. However, I think it should.

Is it already possible to extend Axiom domains with Aldor code? (I should check
this)

Martin