Re: [Axiom-developer] interpreter and with-expression

[Martin Rubey]

Dear all,

Gabriel Dos Reis <address@hidden> writes:

>   The interpreter (in particular pf2Sex) does not handle category
> definitions (with-expression).  

This sounds as if the interpreter would allow the definition of new
domains. However, from my experience, this is not the case.

I believe that both

>    Foo == Record(f: Integer, b: Boolean)
> 
> or
> 
>    Bar := Record(f: Integer, b: Boolean)

do not "really" define new domains. Foo is a macro that expands to
Record(f...), while Bar is a variable that is assigned Record(f...). However,
Record(f...) is an already defined domain, in fact, a very special one since it
is built in to the spad language (same holds for aldor, as far as I know).

For example, I get

(1) -> F: CoercibleTo OutputForm == add (Rep := Integer; coerce x == 
1::OutputForm)
   Internal Error
   Unexpected error in call to system function pf2Sex1 

Martin

> In case it is by design, what is the rationale?

Looking at the aldor interpreter (where both is possible), it seems that it is
quite difficult. It is the bit where I experienced most segfaults...