[gecode-users] Gecode 3.0.0: What we will do. What do you want?

[Filip Konvička]

Hi,

> In more detail, Gecode 3.0.0 will feature:
>  - a complete rework of branching, including randomization and support for
> tie-breaking (already finished)
>  - abstractions for cost-based optimization (just define a cost function,
> done)
>  - a first shot at parallel search (working really great, but integration
> and legal aspects are not yet resolved)

Well actually there's a couple of things :-)

Recently we've been dealing with some constraint systems using Gecode 
and we tried to tweak our heuristics, and while doing that, I found out 
that I still remember seeing things like backjumping when I first met 
CP. So when you mention tie-breaking, randomization - is this somehow 
related to that? And (if not) do you think that it's possible to define 
some abstractions that would help re-shape the search tree dynamically? 
I'm thinking about some "agents" - like actors, but living in the search 
engine - that would try to identify the conflicting decisions in the 
search tree...


Another thing is a rather technical aspect of parallel search. I was 
thinking of using external solvers for efficient consistency-checking of 
some special constraint systems. I don't want to go in too much detail 
now, the thing is that it would be great if the space created for a new 
thread by the parallel-search engine received some sort of thread ID (an 
int identifying the thread in the pool would be OK) during the cloning 
operation.

> The later versions of Gecode 3.* will gradually improve the search
> capabilities, including a better LDS, abstractions for large neighborhood
> search, automatic configuration of recomputation, etc...

Well then maybe my wishes fit here...

> The long term vision is that Gecode 4.0.0 will be something that is fully
> backed up with high-quality documentation, has very advanced parallel search
> facilities, and might have unique inference modules (elimination of
> redundant propagators, automatic choice of consistency level, SAC, ...).

...and maybe here as well :-)

Cheers,
Filip