Re: [eclipse-clp-users] Possible bug in nth1/3?

[Joachim S. <jsc...@co...>]

On 13/05/2019 19:31, Panagiotis Stamatopoulos wrote:
> Hello,
> 
> Is there any explanation for the following behaviour?
...
> [eclipse 3]: nth1(9,[a,b,c,d,e,f,g,h,i,j,k],V).
> 
> V = V


Hi Panagiotis,

this was a regression that unfortunately slipped into version 7.0#45
(only this exact version), and has since been fixed.  My apologies
to everyone who was affected by this and spent time debugging.

If you want to avoid installing a completely fresh version, you can
download the single file listut.pl from

https://sourceforge.net/p/eclipse-clp/git/ci/builds_7_0/tree/Contrib/listut.pl?format=raw

and place it in the lib_public/ directory of your existing installation.

As a small consolation, the family of nth-predicates has become quite
a bit faster...

Regards,
Joachim

PS: if you do a lot of indexed access, consider using arrays instead of lists.