[Axiom-math] Re: [open-axiom-devel] [fricas-devel] Re: [fricas-devel] Re: iterators and cartesian product.

[Ralf Hemmecke]

On 10/31/2007 07:42 PM, Bill Page wrote:
> On 31 Oct 2007 19:23:44 +0100, Francois Maltey wrote:
> > And what do you think about a map as :
> >
> > map (t +-> [|wholePart t, sin t|], [1.1,2.2,3.3])
> >
> > where [|....|]creates a makeprod with right types.
>
> It's ok, but way should we require the dummy variable 't' when we can
> operate directly on functions with the higher-order function
> 'product'? I think
>
>    t +-> [|wholePart t, sin t|]
>
> is just a slightly awkward way to write:
>
>   product(wholePart,sin)

Exactly.

> Maybe there should be both 'Record' and 'Record!' where as usual the !
> denotes mutability?

Oh, as far as I know "!" stands for "be aware that something strange can 
happen" or "if I use this function, I know what I do". Usually, of 
course, it is connected to destructive operations and thus to 
mutability, but I wouldn't say that could be the only purpose.

And additionally, the ! is a *convention*, that should not be build-in 
into the language. I rather live with Cross and Record than with Record 
and Recort!.

Ralf