/**
* Instantiates the domain of <code>this</code> to <code>value</code>. The instruction comes from
* <code>propagator</code>.
*
* <ul>
* <li>If the domain of <code>this</code> is already instantiated to <code>value</code>, nothing
* is done and the return value is <code>false</code>,
* <li>If the domain of <code>this</code> is already instantiated to another value, then a
* <code>ContradictionException</code> is thrown,
* <li>Otherwise, the domain of <code>this</code> is restricted to <code>value</code> and the
* observers are notified and the return value is <code>true</code>.
* </ul>
*
* @param value instantiation value (int)
* @param cause instantiation releaser
* @param informCause
* @return true if the instantiation is done, false otherwise
* @throws solver.exception.ContradictionException if the domain become empty due to this action
*/
public boolean instantiateTo(int value, ICause cause, boolean informCause)
throws ContradictionException {
// BEWARE: THIS CODE SHOULD NOT BE MOVED TO THE DOMAIN TO NOT DECREASE PERFORMANCES!
solver
.getExplainer()
.instantiateTo(
this, value,
cause); // the explainer is informed before the actual instantiation is performed
if (informCause) {
cause = Cause.Null;
}
if (this.instantiated()) {
if (value != this.getValue()) {
this.contradiction(cause, MSG_INST);
}
return false;
} else if (contains(value)) {
int aValue = value - OFFSET;
if (reactOnRemoval) {
int i = VALUES.nextSetBit(this.LB.get());
for (; i < aValue; i = VALUES.nextSetBit(i + 1)) {
delta.add(i + OFFSET);
}
i = VALUES.nextSetBit(aValue + 1);
for (; i >= 0; i = VALUES.nextSetBit(i + 1)) {
delta.add(i + OFFSET);
}
}
this.VALUES.clear();
this.VALUES.set(aValue);
this.LB.set(aValue);
this.UB.set(aValue);
this.SIZE.set(1);
if (VALUES.isEmpty()) {
this.contradiction(cause, MSG_EMPTY);
}
this.notifyPropagators(EventType.INSTANTIATE, cause);
return true;
} else {
this.contradiction(cause, MSG_UNKNOWN);
return false;
}
}
/**
* Updates the lower bound of the domain of <code>this</code> to <code>value</code>. The
* instruction comes from <code>propagator</code>.
*
* <ul>
* <li>If <code>value</code> is smaller than the lower bound of the domain, nothing is done and
* the return value is <code>false</code>,
* <li>if updating the lower bound to <code>value</code> leads to a dead-end (domain wipe-out),
* a <code>ContradictionException</code> is thrown,
* <li>otherwise, if updating the lower bound to <code>value</code> can be done safely, the
* event type is created (the original event can be promoted) and observers are notified and
* the return value is <code>true</code>
* </ul>
*
* @param value new lower bound (included)
* @param cause updating releaser
* @param informCause
* @return true if the lower bound has been updated, false otherwise
* @throws solver.exception.ContradictionException if the domain become empty due to this action
*/
public boolean updateLowerBound(int value, ICause cause, boolean informCause)
throws ContradictionException {
boolean change;
ICause antipromo = cause;
if (informCause) {
cause = Cause.Null;
}
int old = this.getLB();
if (old < value) {
if (this.getUB() < value) {
solver.getExplainer().updateLowerBound(this, old, value, antipromo);
this.contradiction(cause, MSG_LOW);
} else {
EventType e = EventType.INCLOW;
int aValue = value - OFFSET;
if (reactOnRemoval) {
// BEWARE: this loop significantly decreases performances
for (int i = old - OFFSET; i < aValue; i = VALUES.nextSetBit(i + 1)) {
delta.add(i + OFFSET);
}
}
VALUES.clear(old - OFFSET, aValue);
LB.set(VALUES.nextSetBit(aValue));
int _size = SIZE.get();
int card = VALUES.cardinality();
SIZE.set(card);
change = _size - card > 0;
if (instantiated()) {
e = EventType.INSTANTIATE;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
}
assert (change);
this.notifyPropagators(e, cause);
solver.getExplainer().updateLowerBound(this, old, value, antipromo);
return change;
}
}
return false;
}
/**
* Removes <code>value</code>from the domain of <code>this</code>. The instruction comes from
* <code>propagator</code>.
*
* <ul>
* <li>If <code>value</code> is out of the domain, nothing is done and the return value is
* <code>false</code>,
* <li>if removing <code>value</code> leads to a dead-end (domain wipe-out), a <code>
* ContradictionException</code> is thrown,
* <li>otherwise, if removing <code>value</code> from the domain can be done safely, the event
* type is created (the original event can be promoted) and observers are notified and the
* return value is <code>true</code>
* </ul>
*
* @param value value to remove from the domain (int)
* @param cause removal releaser
* @param informCause
* @return true if the value has been removed, false otherwise
* @throws solver.exception.ContradictionException if the domain become empty due to this action
*/
public boolean removeValue(int value, ICause cause, boolean informCause)
throws ContradictionException {
// BEWARE: THIS CODE SHOULD NOT BE MOVED TO THE DOMAIN TO NOT DECREASE PERFORMANCES!
boolean change = false;
ICause antipromo = cause;
if (informCause) {
cause = Cause.Null;
}
int inf = getLB();
int sup = getUB();
if (value == inf && value == sup) {
solver.getExplainer().removeValue(this, value, antipromo);
this.contradiction(cause, MSG_REMOVE);
} else {
if (inf <= value && value <= sup) {
EventType e = EventType.REMOVE;
int aValue = value - OFFSET;
change = VALUES.get(aValue);
this.VALUES.set(aValue, false);
if (change) {
this.SIZE.add(-1);
if (reactOnRemoval) {
delta.add(aValue + OFFSET);
}
}
if (value == inf) {
LB.set(VALUES.nextSetBit(aValue));
e = EventType.INCLOW;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
} else if (value == sup) {
UB.set(VALUES.prevSetBit(aValue));
e = EventType.DECUPP;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
}
if (change && !VALUES.isEmpty()) {
if (this.instantiated()) {
e = EventType.INSTANTIATE;
if (cause.reactOnPromotion()) {
cause = Cause.Null;
}
}
this.notifyPropagators(e, cause);
} else {
if (VALUES.isEmpty()) {
solver.getExplainer().removeValue(this, value, antipromo);
this.contradiction(cause, MSG_EMPTY);
}
}
}
}
if (change) {
solver.getExplainer().removeValue(this, value, antipromo);
}
return change;
}