RE: [Axiom-developer] categorical design, aldor, and the type system

[Bill Page]

Tim,

On Thursday, October 09, 2003 10:20 AM you wrote:
> 
> re: Aldor rewrite. 
> 
> Many people, including myself, have tried to reconstruct 
> and/or rewrite the Axiom type system in Aldor. This is 
> unlikely for at least 4 reasons.
>

I agree that this is probably not a reasonable prospect. On
the other hand, I have contemplated the opposite possibility,
that is to re-import back into Axiom the new Aldor type
library. This might be a much smaller project since the new
Aldor type library was re-designed recently (last year?)
and is still quite primative and limited compared to Axiom
as a whole.

Last time I mentioned this you gave a muffled answer which
I took to mean either of two things: 1) you weren't interested
or thought it not worthwhile, or 2) there has been some
discussions with people working on the Aldor project about
this possibility and so far there is "not good agreement".

Since I think that the relationship between Axiom and Aldor
is an interesting subject, I would be glad to hear more
about this situtation when you feel you can or when you
have time to discuss it.
 
> First, ...
> 
> Second, ...
> 
> Third, an Aldor implementation would be a library not an 
> interpreter/compiler combination so the user would have to 
> perform type coercion and simplification, which is very hard 
> to get right.

I am not sure I understand your point. As you have pointed
out, Axiom also compiles it's library (It was from this that
the notion of Aldor as a separte compiler originally arose,
right?). And Axiom also usually (when it can) compiles the
functions provided by the user at "run- time". I understand
that it some cases Axiom is not able to compile user provided
code and then resorts to "interpreter" mode. I take this to
mean that it attempts to delay resolution of types until the
function is actually applied. This sort of interpreter mode
is still unique to Axiom, I think.

> 
> Fourth, ...
> 
> Aldor is a great language and it is a very seductive idea to 
> do Axiom over and try to "get it right" but that implies 
> covering a LOT of old ground before you develop new work. 
> Plus we don't even know or agree about what is "right".
> ...

"Uncle". You've convinced me! <grin>  But seriously I never
was actually quite thinking along these lines. I have become
convinced that it is probably possible to work from "within"
Axiom to extend and change it more gradually along certain
lines with a true or at least more "categorial implementation"
only as a longer term goal.
 
Cheers,
Bill Page.