Re: [Axiom-developer] CAS for the masses

[Waldek Hebisch]

Martin Rubey wrote:
> Waldek Hebisch <address@hidden> writes:
> > 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.
> 
> although Domains may be mutable in some sense in SPAD and Aldor (since we can
> access and modify their "state") I think that "the way things are meant to be
> done in Axiom/SPAD/Aldor" is to create new domains, instead of modifying old
> ones. Since we have "dependent types", this can be done in an extremely
> flexible manner, as the example "Interpret" shows, which takes a string and
> yields a domain.
> 

Redefinition is probably of little (maybe no) use for end users.  But
domain developers have to modify them.  Ability to modify functions
"on the fly" is claimed to be significant debugging advantage of
"dynamic" language implementations (like Python or Lisp).

NI am _not_ advocating using dynamic capabilities of Axiom.  Rather
I wanted to point out that such capabilities are implemented and
I give my opinion why.
-- 
                              Waldek Hebisch
address@hidden