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Open-source constraint solver.
/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2022, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.solver.constraints.set;
import org.chocosolver.solver.constraints.Propagator;
import org.chocosolver.solver.constraints.PropagatorPriority;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.variables.IntVar;
import org.chocosolver.solver.variables.SetVar;
import org.chocosolver.solver.variables.Variable;
import org.chocosolver.solver.variables.delta.ISetDeltaMonitor;
import org.chocosolver.solver.variables.events.IntEventType;
import org.chocosolver.solver.variables.events.SetEventType;
import org.chocosolver.util.ESat;
import org.chocosolver.util.procedure.IntProcedure;
/**
* Propagator for Member constraint: iv is in set
* @since 14/01/13
* @author Charles Prud'homme
*/
public class PropIntEnumMemberSet extends Propagator {
//***********************************************************************************
// VARIABLES
//***********************************************************************************
private IntVar iv;
private final SetVar set;
private final ISetDeltaMonitor sdm;
private final IntProcedure elemRem;
//***********************************************************************************
// CONSTRUCTORS
//***********************************************************************************
/**
* Propagator for Member constraint
* val(intVar) is in setVar
*
* @param setVar a set variable
* @param intVar an integer variable
*/
public PropIntEnumMemberSet(SetVar setVar, IntVar intVar) {
super(new Variable[]{setVar, intVar}, PropagatorPriority.BINARY, true);
assert intVar.hasEnumeratedDomain() : iv.toString() + " does not an enumerated domain";
this.set = (SetVar) vars[0];
this.iv = (IntVar) vars[1];
this.sdm = set.monitorDelta(this);
elemRem = i -> iv.removeValue(i, this);
}
//***********************************************************************************
// METHODS
//***********************************************************************************
@Override
public int getPropagationConditions(int vIdx) {
if (vIdx == 0) {
return SetEventType.REMOVE_FROM_ENVELOPE.getMask();
} else {
return IntEventType.INSTANTIATE.getMask();
}
}
@Override
public void propagate(int evtmask) throws ContradictionException {
if (iv.isInstantiated()) {
set.force(iv.getValue(), this);
setPassive();
return;
}
int ub = iv.getUB();
for (int i = iv.getLB(); i <= ub; i = iv.nextValue(i)) {
if (!set.getUB().contains(i)) {
iv.removeValue(i, this);
}
}
// now iv \subseteq set
if (iv.isInstantiated()) {
set.force(iv.getValue(), this);
setPassive();
}
sdm.startMonitoring();
}
@Override
public void propagate(int i, int mask) throws ContradictionException {
if (i == 0) {
sdm.forEach(elemRem, SetEventType.REMOVE_FROM_ENVELOPE);
}
if (iv.isInstantiated()) {
set.force(iv.getValue(), this);
setPassive();
}
}
@Override
public ESat isEntailed() {
if (iv.isInstantiated()) {
if (!set.getUB().contains(iv.getValue())) {
return ESat.FALSE;
} else {
if (set.getLB().contains(iv.getValue())) {
return ESat.TRUE;
} else {
return ESat.UNDEFINED;
}
}
} else {
int minVal = iv.getLB();
int maxVal = iv.getUB();
boolean all = true;
for (int i = minVal; i <= maxVal; i = iv.nextValue(i)) {
if (!set.getLB().contains(i)) {
all = false;
break;
}
}
if (all) {
return ESat.TRUE;
}
for (int i = minVal; i <= maxVal; i = iv.nextValue(i)) {
if (set.getUB().contains(i)) {
return ESat.UNDEFINED;
}
}
return ESat.FALSE;
}
}
}