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Open-source constraint solver.
/**
* Copyright (c) 2016, 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:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the .
* 4. Neither the name of the 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 ''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 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 org.chocosolver.solver.variables.view;
import org.chocosolver.solver.ICause;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.explanations.RuleStore;
import org.chocosolver.solver.variables.BoolVar;
import org.chocosolver.solver.variables.IntVar;
import org.chocosolver.solver.variables.Variable;
import org.chocosolver.solver.variables.delta.IIntDeltaMonitor;
import org.chocosolver.solver.variables.delta.NoDelta;
import org.chocosolver.solver.variables.events.IEventType;
import org.chocosolver.solver.variables.events.IntEventType;
import org.chocosolver.util.ESat;
import org.chocosolver.util.objects.setDataStructures.iterable.IntIterableSet;
/**
* A view for boolean variable, that enforce not(b).
*
*
* @author Charles Prud'homme
* @since 31/07/12
*/
public final class BoolNotView extends IntView implements BoolVar {
/**
* Variable to observe
*/
private final BoolVar var;
/**
* Create a not view based on var
* @param var a boolean variable
*/
public BoolNotView(BoolVar var) {
super("not(" + var.getName() + ")", var);
this.var = var;
}
@Override
public ESat getBooleanValue() {
return ESat.not(var.getBooleanValue());
}
@Override
public boolean setToTrue(ICause cause) throws ContradictionException {
if (var.setToFalse(this)) {
notifyPropagators(IntEventType.INSTANTIATE, cause);
return true;
}
return false;
}
@Override
public boolean setToFalse(ICause cause) throws ContradictionException {
if (var.setToTrue(this)) {
notifyPropagators(IntEventType.INSTANTIATE, cause);
return true;
}
return false;
}
@Override
public boolean removeValue(int value, ICause cause) throws ContradictionException {
return contains(value) && instantiateTo(1 - value, cause);
}
@Override
public boolean removeValues(IntIterableSet values, ICause cause) throws ContradictionException {
boolean hasChanged = false;
if (values.contains(0)) {
hasChanged = instantiateTo(1, cause);
}
if (values.contains(1)) {
hasChanged = instantiateTo(0, cause);
}
return hasChanged;
}
@Override
public boolean removeAllValuesBut(IntIterableSet values, ICause cause) throws ContradictionException {
boolean hasChanged = false;
if (!values.contains(0)) {
hasChanged = instantiateTo(1, cause);
}
if (!values.contains(1)) {
hasChanged = instantiateTo(0, cause);
}
return hasChanged;
}
@Override
public boolean removeInterval(int from, int to, ICause cause) throws ContradictionException {
boolean hasChanged = false;
if (from <= to && from <= 1 && to >= 0) {
if (from == 1) {
hasChanged = instantiateTo(1, cause);
} else if (to == 0) {
hasChanged = instantiateTo(0, cause);
} else {
instantiateTo(2, cause);
}
}
return hasChanged;
}
@Override
public boolean instantiateTo(int value, ICause cause) throws ContradictionException {
model.getSolver().getExplainer().instantiateTo(this, value, cause, getLB(), getUB());
if (var.instantiateTo(1 - value, this)) {
notifyPropagators(IntEventType.INSTANTIATE, cause);
return true;
}else{
model.getSolver().getExplainer().undo();
}
return false;
}
@Override
public boolean updateLowerBound(int value, ICause cause) throws ContradictionException {
if (value > 0) {
model.getSolver().getExplainer().updateLowerBound(this, value, getLB(), cause);
if (var.instantiateTo(1 - value, this)) {
notifyPropagators(IntEventType.INSTANTIATE, cause);
return true;
}else{
model.getSolver().getExplainer().undo();
}
}
return false;
}
@Override
public boolean updateUpperBound(int value, ICause cause) throws ContradictionException {
if (value < 1) {
model.getSolver().getExplainer().updateUpperBound(this, value, getUB(), cause);
if (var.instantiateTo(1 - value, this)) {
notifyPropagators(IntEventType.INSTANTIATE, cause);
return true;
}else{
model.getSolver().getExplainer().undo();
}
}
return false;
}
@Override
public boolean updateBounds(int lb, int ub, ICause cause) throws ContradictionException {
boolean hasChanged = false;
if (lb > 1) {
var.instantiateTo(-1, cause);
} else if (ub < 0) {
var.instantiateTo(2, cause);
} else {
if (lb == 1) {
hasChanged = instantiateTo(1, cause);
} else if (ub == 0) {
hasChanged = instantiateTo(0, cause);
}
}
return hasChanged;
}
@Override
public boolean contains(int value) {
return var.contains(1 - value);
}
@Override
public boolean isInstantiatedTo(int value) {
return var.isInstantiatedTo(1 - value);
}
@Override
public int getValue() {
int v = var.getValue();
return 1 - v;
}
@Override
public int getLB() {
if (var.isInstantiated()) {
return getValue();
} else return 0;
}
@Override
public int getUB() {
if (var.isInstantiated()) {
return getValue();
} else return 1;
}
@Override
public int nextValue(int v) {
if (v < 0 && contains(0)) {
return 0;
}
return v <= 0 && contains(1) ? 1 : Integer.MAX_VALUE;
}
@Override
public int nextValueOut(int v) {
if(var.isInstantiated() && v == getValue() - 1){
return getValue() + 1;
}else if(-1 <= v && v <= 1){
return 2;
}
return v + 1;
}
@Override
public int previousValue(int v) {
if (v > 1 && contains(1)) {
return 1;
}
return v >= 1 && contains(0) ? 0 : Integer.MIN_VALUE;
}
@Override
public int previousValueOut(int v) {
if(var.isInstantiated() && v == getValue() + 1){
return getValue() - 1;
}else if(0 <= v && v <= 2){
return -1;
}
return v - 1;
}
@Override
public IIntDeltaMonitor monitorDelta(ICause propagator) {
var.createDelta();
if (var.getDelta() == NoDelta.singleton) {
return IIntDeltaMonitor.Default.NONE;
}
return new ViewDeltaMonitor((IIntDeltaMonitor) var.monitorDelta(propagator)) {
@Override
protected int transform(int value) {
return 1 - value;
}
};
}
public String toString() {
return "not(" + var.getName() + ")";
}
@Override
public BoolVar not() {
return var;
}
@Override
public void _setNot(BoolVar not) {
assert not == var;
}
@Override
public boolean hasNot() {
return true;
}
@Override
public boolean isLit() {
return true;
}
@Override
public boolean isNot() {
return !var.isNot();
}
@Override
public void setNot(boolean isNot) {
assert isNot;
}
@Override
public int getTypeAndKind() {
return Variable.VIEW | Variable.BOOL;
}
@Override
public boolean why(RuleStore ruleStore, IntVar modifiedVar, IEventType evt, int value) {
assert modifiedVar == this.var;
return ruleStore.addFullDomainRule(this);
}
@Override
public int transformValue(int value) {
assert value == 0 || value == 1;
return 1- value;
}
@Override
public void justifyEvent(IntVar var, ICause cause, IntEventType mask, int one, int two, int three) {
assert mask == IntEventType.INSTANTIATE;
model.getSolver().getExplainer().instantiateTo(this, 1 - one, var, 0, 1);
}
}