Re: forpart() behavior

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

On Sat, Feb 24, 2018 at 09:16:03PM +0100, Bill Allombert wrote:
> On Sat, Feb 24, 2018 at 12:06:39PM -0500, Max Alekseyev wrote:
> > Hello!
> > 
> > In PARI/GP version Version 2.10.0 (development 21603-bef585b) I observe:
> > 
> > ===
> > ? forpart(p=1,print(p),[0,5],3)
> > Vecsmall([0, 0, 1])
> > ? forpart(p=0,print(p),[0,5],3)
> > ? forpart(p=1,print(p),[0,5],[3,4])
> > Vecsmall([0, 1, 1, -1])
> > ===
> > 
> > I believe "forpart(p=0,print(p),[0,5],3)" should produce "Vecsmall([0, 0, 0])",
> > and "forpart(p=1,print(p),[0,5],[3,4])" should produce "Vecsmall([0,
> > 0, 1])" and "Vecsmall([0, 0, 0, 1])".

No, see below:

> It is a bug I introduced a long time ago in commit 941833e2
> 
> Older version give correctly:
> ? partitions(1,[0,5],[3,4])
> %3 = [Vecsmall([0,0,0,1])]

Actually, this is wrong too. The doc says:
the length is the number of nonzero entries.
So the correct result is [].

Cheers,
Bill.