[Aldor-l] [fricas-devel] Re: leftover from allowing functions to return types

[Bill Page]

On Thu, Nov 13, 2008 at 2:11 PM, Ralf Hemmecke wrote:
>Bill Page wrote:
>> Could you explain why you prefer these to be pre-defined macros
>> rather than being builtin as Gaby has done in OpenAxiom and Aldor?
>
> You should (currently) delete "and Aldor" from the last sentence.
>
> https://svn.origo.ethz.ch/algebraist/trunk/aldor/lib/aldor/include/aldor.as
>

Thanks. Point accepted. Of course, almost everything is added-on to
Aldor because really the core language itself is quite small. Still,
rep and per could be local functions instead of macros. I simply
wonder why one is preferable to the other.

> Of course, one can make these things into a language defined concept.
> However, one can also consider them to be just a convention.
>

If one wants to argue that Axiom (and Aldor) are fully typed
languages, then it seems to me that one is obliged to claim that it is
"part of the language".

> This % thing is rather driven by the concept of universal algebra where
> Rep refers to the carrier set. It's in some sense nice, since universal
> algebra comprises a lot of cases, but take, for example, zero?: % ->
> Boolean. Strictly speaking, this function cannot live in a universal
> algebra, since Boolean is not the carrier set.
>

Honestly, I do not see the need for any of this discussion of
universal algebra in the context of Axiom/Aldor. To me % is just a
convenient name for "this domain". Many other languages including Java
and Python have names like "this" or "self", or whatever. In
Axiom/Aldor it is just %.

Could you summarize again why you think it is important?

> ...

Regards,
Bill Page.