/**
* Copyright (c) 1999-2014, Ecole des Mines de Nantes
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Ecole des Mines de Nantes nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package solver.constraints.set;
import gnu.trove.map.hash.THashMap;
import solver.Solver;
import solver.constraints.Propagator;
import solver.constraints.PropagatorPriority;
import solver.exception.ContradictionException;
import solver.variables.SetVar;
import util.ESat;
/**
* Restricts the set var not to be empty
*
* @author Jean-Guillaume Fages
*/
public class PropNotEmpty extends Propagator<SetVar> {
//***********************************************************************************
// CONSTRUCTORS
//***********************************************************************************
public PropNotEmpty(SetVar set) {
super(new SetVar[]{set}, PropagatorPriority.UNARY, false);
}
//***********************************************************************************
// METHODS
//***********************************************************************************
@Override
public void propagate(int evtmask) throws ContradictionException {
int e = vars[0].getEnvelopeSize();
if(e==0){
contradiction(vars[0],"");
}else if(e==1){
vars[0].addToKernel(vars[0].getEnvelopeFirst(),aCause);
}
if(vars[0].getKernelSize()>0){
setPassive();
}
}
@Override
public ESat isEntailed() {
if(vars[0].getEnvelopeSize()==0){
return ESat.FALSE;
}
if(vars[0].getKernelSize()>0){
return ESat.TRUE;
}
return ESat.UNDEFINED;
}
@Override
public void duplicate(Solver solver, THashMap<Object, Object> identitymap) {
if (!identitymap.containsKey(this)) {
vars[0].duplicate(solver, identitymap);
SetVar S = (SetVar) identitymap.get(vars[0]);
identitymap.put(this, new PropNotEmpty(S));
}
}
}