RE: [Axiom-developer] Value stack overflow bug

[Bill Page]

Tim,

On Sunday, June 08, 2003 3:39 PM you wrote:
> 
> Sorry for the delay but I've been heads-down trying to get
> a runnable Axiom version.

No problem. I am glad you are taking this route and very
much look forward to the result. It is not my intention to
distract you from this efffort!

> ...
>> It seems to me that it is conceivable that one might always
>> need a running Axiom system in order to (conveniently) build
>> a runnable Axiom system. This is essentially the case with any
>> compiler that compiles itself. Most higher level languages are
>> in this sort of situation today, e.g. the GNU C compiler (gcc)
>> is written in gcc, right?
>> ...
> 
> Technically Axiom can't be built from scratch at several 
> levels because it needs a Meta compiler, a Boot compiler, and 
> an Axiom compiler (and also a C and a Lisp compiler but they 
> come free). However, I've worked around most of the problems 
> associated with bootstrapping the system. Having such 
> circularity is less than ideal for several reasons not the 
> least of which is that you wouldn't be able to download 
> sources and type 'make'.

But this is the *normal* situation for most high level
languages. I cannot just download gcc and type make -
I first must already have a running gcc (presumably older
version) on my system. So I don't see why we should not
expect this of Axiom as well.

> The whole system is very close to being built from scratch.

By "scratch" you mean starting with a running C compiler and
various source codes. First compile GCL, then bootsys, then ...
etc.

Could you (briefly) describe how this process would be
different if you could presume that there was already a
running Axiom system available? Say, for example, that
there was a new version of (some part of) Axiom available
in source code format from CVS plus a running C compiler,
GCL already compiled and running *and* an older version of
Axiom running on the system. What would be the most
convenient and/or most efficient steps to take to compile
and install the new version of the Axiom code?

> ... 
> If we were to pursue the aldor route I'd consider scrapping 
> the axiom interpreter and going to a compile-time only 
> environment.  This has been discussed several times and
> it is very, very hard.  Manuel Bronstein has done some work
> on this path before.  I don't know of anyone that would fund
> such an effort and I don't believe we would get the research-
> level expertise for free.

Perhaps a joint effort with the Aldor people? It is truly
amazing what one can get for free these days ...

> 
> But if I were to even entertain such a huge job (which, 
> believe me, I'm not) I'd go the other way and grind it
> all into common lisp syntax. The ability of a program to
> read another program as data gives a "second order" power
> that is hard in Axiom.
> 

You mean that this is not possible in Axiom, i.e. programs
as data? This is not such a foreign idea in high level
languages any more. For example it is fundamental to
Python and other languages of that genre. You can even find
it in Maple's programming language.

I have nothing against lisp as such. But lisp has been
around a long time and for a lot of different reasons
it has yet to reach it's full potential. I think there
are good reasons why people are still searching for better
higher level languages. Axiom (and Aldor) seem to be moving
in the right direction to me. To return to "just lisp"
seems like a backward step, no?

Cheers,
Bill Page.