[gecode-users] Custom constraint to external progam

[Pedro Salgueiro]

Hi!
        
With the help that Tias Guns give it builds ok:

> Note that in the example the 'propagate' function misses the ModEventDelta  
> parameter:
> line 57 should be:     virtual ExecStatus propagate(Space* home,  
> ModEventDelta);
> line 93 should be:   DisEq<View>::propagate(Space* home, ModEventDelta) {

Thank you all so much. Now I will work on it to understand how it works
and solve my problem.

Pedro Salgueiro

On Thu, 2008-11-13 at 12:30 +0000, Pedro Salgueiro wrote:
> Hi!
> 
> That example seems very help-full and I think now I can do what I want. 
> 
> Any way, I am not beeing able to build your example:
> 
> teste1.cc: In static member function ‘static Gecode::ExecStatus Extra::DisEq<View>::post(Gecode::Space*, View, View, View) [with View = Gecode::Int::IntView]’:
> teste1.cc:115:   instantiated from here
> teste1.cc:70: error: cannot allocate an object of abstract type ‘Extra::DisEq<Gecode::Int::IntView>’
> teste1.cc:41: note:   because the following virtual functions are pure within ‘Extra::DisEq<Gecode::Int::IntView>’:
> /usr/local/include/gecode/kernel/core.icc:719: note: 	virtual Gecode::ExecStatus Gecode::Propagator::propagate(Gecode::Space*, Gecode::ModEventDelta)
> make: *** [teste1] Error 1
> 
> 
> If I comment the following line in post method, it builds ok, but
> obviously it would not work ok:
> 
>     //(void) new (home) DisEq<View>(home,x0,x1,x2);
> 
> What am I doing wrong?
> 
> Thank you.
> Pedro Salgueiro
> 
> 
> 
> On Thu, 2008-11-13 at 12:05 +0100, Mikael Zayenz Lagerkvist wrote:
> > Hi,
> > 
> > There are no examples currently in Gecode that implement custom propagators.
> > 
> > There is an old post in the mailinglist with a custom
> > propagator-example [1]. Note that there is a bug in the logic, the
> > line
> >     GECODE_ME_CHECK(x1.inter_r(home, u12, false));
> > should be
> >     GECODE_ME_CHECK(x0.inter_r(home, u12, false));
> > I missed that on a variable-renaming before posting it.
> > 
> > Hope that helps,
> > Mikael
> > 
> > [1] http://article.gmane.org/gmane.comp.lib.gecode.user/1276/
> > 
> > 
> > On Thu, Nov 13, 2008 at 11:51 AM, Pedro Salgueiro <pds at di.uevora.pt> wrote:
> > > 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
> > >>
> > >>
> > >>         _______________________________________________
> > >>         Gecode users mailing list
> > >>         users at gecode.org
> > >>         https://www.gecode.org/mailman/listinfo/gecode-users
> > >>
> > >>
> > >>
> > >> --
> > >> 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
> > >>
> > >
> > >
> > > _______________________________________________
> > > Gecode users mailing list
> > > users at gecode.org
> > > https://www.gecode.org/mailman/listinfo/gecode-users
> > >
> > 
> > 
> > 
> 
> 
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