Re: New gp features

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Sun, Aug 13, 2023 at 08:39:18PM +0200, hermann@stamm-wilbrandt.de wrote:
> Few questions:
> 
> A) foreach cannot be redefined?
> 
> foreach2(a,b,c) = foreach(a,b,c);

This does not work, because user GP functions are 'strict': 
b and c are evaluated before foreach2 is evaluated to a closure.

Instead you can do
foreach2(a,c) = foreach(a,b,c(b))
and then
foreach2(a,t->printf("%d ",t[1]))

> B) foreach variable cannot be multi assignment tuple?
> 
> ? foreach(rsa,[l,n],printf("%d ",l));
>   ***   variable name expected: foreach(rsa,[l,n],printf("%d ",l));
>   ***                                       ^-----------------------

No, this is not supported.

> C) holes only allowed on LHS, not on RHS?
> 
> ? [a,b,c] = [1,2]
>   ***   at top-level: [a,b,c]=[1,2]
>   ***                      ^--------
>   ***   nonexistent component: index > 2

c would not be defined.

Cheers,
Bill