[gecode-users] Custom constraint to external progam

[Pedro Salgueiro]

Ok, I think thats what I want to do.

Is there any examples in Gecode that implement a custom propagator?

Pedro Salgueiro

On Thu, 2008-11-13 at 11:10 +0100, Mauricio Toro wrote:
> Hello,
> 
> 
> I made something similar once.
> My approach was writting a propagator 
> that waits until cvars[0] and cvars[1]
> are assigned. Once they are assigned
> it calls run_something.
> 
> 
> I hope that helps,
> 
> 
> Mauricio
> 
> 2008/11/13 Pedro Salgueiro <pds at di.uevora.pt>
>         Hi!
>         
>         I have been experimenting Gecode for a while, and now I want
>         to make
>         something wich I don't know if its possible:
>         
>         I want to create a new "custom" constraint that allows to
>         relate/constraint a variable with a function that receives two
>         other
>         gecode variables as parameters. This function will be
>         something
>         completely external to gecode, and evan c++, so, by the the
>         this
>         function is called the gecode variables that are used on it
>         should
>         already have some values assigned to it.
>         
>         Here's how it would look:
>         
>         post(this, cvars[0] < 5)
>         post(this, cvars[1] < cvars[0] + 2)
>         post(this, new_constraint(cvars[2], run_something(cvars[0],
>         cvars[1])
>         
>         In this example, we could just assume that the
>         "new_constraint" is used
>         to make sure that cvars[2] "<"
>         run_something(cvars[0],cvars[1]).
>         
>         Is this possible to do? If so, where should I start?
>         
>         Thank you all
>         Pedro Salgueiro
>         
>         
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> 
> 
> -- 
> Mauricio Toro Bermudez
> Estudiante de Ingeniería de Sistemas
> Pontificia Universidad Javeriana, Colombia
> 
> Stagiare à l'Ircam
> 1, place Igor-Stravinsky 75004 Paris, 
> France de 2008 à 2009
>