Re: [Axiom-developer] pointers

[William Sit]

Gabriel:

Thanks for the response. Your script shows how to get the 
parameters, not the constructor. I do not have OpenAxiom 
installed (sorry). The question is whether I can test that 
the constructor is Fraction, or otherwise (like 
FiniteField) when the domain belongs to the category 
Field.

I came across this requirement in algorithms that may take 
advantage of special knowledge of how the coefficient 
field is constructed.

William

On Mon, 9 Nov 2009 21:21:28 -0600
 Gabriel Dos Reis <address@hidden> wrote:
> On Mon, Nov 9, 2009 at 7:09 PM, William Sit 
> <address@hidden> wrote:
> > Tim:
> >
> > Interesting. Is there a similar function that is more 
> > structural? say, can I
> > test whether some domain (which may be passed as a 
> > parameter of type Field)
> > is of the form Fraction(something) and if so, extract 
> > "something" (that is,
> > assign it to a variable and further test it), sort of a 
> > deconstruction?
>
> William --
>
>    In OpenAxiom, when you get a domain, you can reify 
> it, and
> ask for the arguments that were used to instantiate it:
>
> (1) -> reify Fraction Integer
>    (1)  Fraction Integer
>                                       Type: 
> ConstructorCall DomainConstructor
> (2) -> arguments reify Fraction Integer
>    (2)  [(Integer)]
>                                                           
>  Type: List Syntax

William Sit, Professor Emeritus
Mathematics, City College of New York                  
Office: R6/202C Tel: 212-650-5179
Home Page: http://scisun.sci.ccny.cuny.edu/~wyscc/