/**
* To find in the union, find in the components, concatenate the results, and omit duplicates.
* That last is a performance penalty, but I see no way to remove it unless we know the graphs do
* not overlap.
*/
@Override
public ExtendedIterator<Triple> graphBaseFind(final TripleMatch t) {
Set<Triple> seen = CollectionFactory.createHashedSet();
return recording(L.find(t), seen).andThen(rejecting(R.find(t), seen));
// return L.find( t ) .andThen( rejecting( R.find( t ), L ) );
}
/** To remove a triple, remove it from <i>both</i> operands. */
@Override
public void performDelete(Triple t) {
L.delete(t);
R.delete(t);
}
@Override
public boolean graphBaseContains(Triple t) {
return L.contains(t) || R.contains(t);
}
/** To add a triple to the union, add it to the left operand; this is asymmetric. */
@Override
public void performAdd(Triple t) {
L.add(t);
}