@Override
protected void createUpcomingSelection() {
if (!rightSubSelectionIterator.hasNext()) {
if (!leftSubSelectionIterator.hasNext()) {
upcomingSelection = null;
return;
}
leftSubSelection = leftSubSelectionIterator.next();
if (!leftEqualsRight) {
rightSubSelectionIterator = rightSubSelector.listIterator();
if (!rightSubSelectionIterator.hasNext()) {
upcomingSelection = null;
return;
}
} else {
// Select A-B, A-C, B-C. Do not select B-A, C-A, C-B. Do not select A-A, B-B, C-C.
if (!leftSubSelectionIterator.hasNext()) {
upcomingSelection = null;
return;
}
rightSubSelectionIterator =
rightSubSelector.listIterator(leftSubSelectionIterator.nextIndex());
// rightEntityIterator's first hasNext() always returns true because of the nextIndex()
}
}
SubS rightSubSelection = rightSubSelectionIterator.next();
upcomingSelection = newSwapSelection(leftSubSelection, rightSubSelection);
}
public AbstractOriginalSwapIterator(
ListIterable<SubS> leftSubSelector, ListIterable<SubS> rightSubSelector) {
this.leftSubSelector = leftSubSelector;
this.rightSubSelector = rightSubSelector;
leftEqualsRight = (leftSubSelector == rightSubSelector);
leftSubSelectionIterator = leftSubSelector.listIterator();
rightSubSelectionIterator = IteratorUtils.emptyListIterator();
createUpcomingSelection();
}
