Re: [Axiom-developer] CAS for the masses

[Waldek Hebisch]

Bill Page wrote:
> You are right that I did not state this properly. Of course we can
> evaluate expressions (including functions) that return domains
> and categories. What I was trying to say is that domains in Spad
> and Aldor are immutable during run-time. Once constructed their
> "value" is constant and can not be changed. For example we
> can not insert or remove anything in the list of exports or even
> replace one exported function with another during the execution
> of the program. This is possible in Python.
> 
> Note: I am not talking about the post facto library extension feature
> in Aldor. 'extend' is a compile-time operation.
>

I want comment about Alder, but in current Axiom runtime domains are
mutable.  In fact I think that ability to redefine domain at runtime
was an important design goal (otherwise a sigificant part of Axiom
runtime activities would be useless).

I think that biggest problem in impementing 'extend' is to provide
sane behaviour during redefinition.

-- 
                              Waldek Hebisch
address@hidden