RE: [Axiom-math] Can I decompose a domain ?

[Page, Bill]

On Monday, March 20, 2006 7:53 PM William Sit wrote:
> 
> Francois Maltey wrote:
> > 
> > Myfunction (a : Expression ...) : String ==
> >   is a an Expression Integer => "Integer"
> >   -- or an other calculus.
> >   is a an Expression Franction Integer => "Rationnal"
> >   is a an Expression Complex ... => "Complex"
> >   -- so I can use real and imag.
> >   is a an Expression Float => "Float"
> >   "A rare domain".
> > 
> 
> This is a bit tricky, since any function in Axiom must have
> a specific domain as source. The Axiom domain ANY is a
> coverall. Here is a try:
> 
> Myfunction(a:Any):String ==
>   aDom := unparse ((domainOf a)::InputForm)
>   substring?("Expression",aDom,1)=>delete(aDom, 1..11)
>   "A rare domain"
> 
> To use the function, coerce the input to Any, such as:
> 
> Myfunction(resInteger::Any)
> 

I thought this was an interesting question so I prepared a
simple example based (more or less) on the idea of William Sit
above:

http://wiki.axiom-developer.org/SandBoxManipulatingDomains

Instead of manipulating strings, I think it is better to
work with S-expressions. This is both more efficient and
more specific. For this purpose the ANY domain provides a
function named 'dom' that is similar to 'domainOf'.

Regards,
Bill Page.