// implement SargExpr
public SargIntervalSequence evaluate() {
if (setOp == SargSetOperator.COMPLEMENT) {
assert (children.size() == 1);
SargExpr child = children.get(0);
return child.evaluateComplemented();
}
List<SargIntervalSequence> list = evaluateChildren(this);
switch (setOp) {
case UNION:
return evaluateUnion(list);
case INTERSECTION:
return evaluateIntersection(list);
default:
throw Util.newInternal(setOp.toString());
}
}
// implement SargExpr
public SargIntervalSequence evaluateComplemented() {
if (setOp == SargSetOperator.COMPLEMENT) {
// Double negation is a nop
return children.get(0).evaluate();
}
// Use DeMorgan's Law: complement of union is intersection of
// complements, and vice versa
List<SargIntervalSequence> list = new ArrayList<SargIntervalSequence>();
for (SargExpr child : children) {
SargIntervalSequence newSeq = child.evaluateComplemented();
list.add(newSeq);
}
switch (setOp) {
case INTERSECTION:
return evaluateUnion(list);
case UNION:
return evaluateIntersection(list);
default:
throw Util.newInternal(setOp.toString());
}
}