private boolean forEachConstraintRecursively(Function4 block) {
Queue4 queue = new NoDuplicatesQueue(new NonblockingQueue());
Iterator4 constrIter = iterateConstraints();
while (constrIter.moveNext()) {
queue.add(constrIter.current());
}
while (queue.hasNext()) {
QCon constr = (QCon) queue.next();
Boolean cancel = (Boolean) block.apply(constr);
if (cancel.booleanValue()) {
return true;
}
Iterator4 childIter = constr.iterateChildren();
while (childIter.moveNext()) {
queue.add(childIter.current());
}
Iterator4 joinIter = constr.iterateJoins();
while (joinIter.moveNext()) {
queue.add(joinIter.current());
}
}
return false;
}
public int nextId() {
return ((Integer) _queue.next()).intValue();
}