Re: new GP language feature: simultaneous affectations

[John Cremona <john.cremona@gmail.com>]

This sounds useful!

Before this gets into the documentation, you should know that
"affectation" means something completely different in English.  I
think you mean "assignment" (in the sense that a value gets assigned
to a variable),  or possibly "application" (in the sense that a
function gets applied to its arguments).

John

On 7 May 2012 20:55, Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr> wrote:
> On Sat, Apr 28, 2012 at 04:20:36PM +0200, Bill Allombert wrote:
>> Dear PARI developpers,
>>
>> I have created a GIT branch 'bill-multi_affect'
>> which allow to affect several values at once:
>>
>> ? [a,b,c]=[1..5]
>> %1 = [1,2,3,4,5]
>> ? [a,b,c]
>> %2 = [1,2,3]
>> ? [a,b]=[b,a]
>> %3 = [2,1]
>> ? [a,b,c]=[1..2]
>>   ***   at top-level: [a,b,c]=[1..2]
>>   ***                      ^---------
>>   ***   array index (3) out of allowed range [1-2].
>>
>> Currently, affecting to components (a[i] etc.) is not supported.
>
> I hae just updated the branch with a version which allows
> arbitrary components:
>
> ? M=matrix(5,5);
> ? [M[1,1],M[2,],M[,4]]=[4,[1..5],[6..10]~]
> %6 = [4, [1, 2, 3, 4, 5], [6, 7, 8, 9, 10]~]
> ? M
> %7 =
> [4 0 0  6 0]
>
> [1 2 3  7 5]
>
> [0 0 0  8 0]
>
> [0 0 0  9 0]
>
> [0 0 0 10 0]
>
> Please tell me if you find any problems.
>
> Cheers,
> Bill.
>