private Iterable<LookupElement> liftShorterElements(
final Iterable<LookupElement> source,
@Nullable final THashSet<LookupElement> lifted,
final ProcessingContext context) {
final Set<LookupElement> srcSet =
newIdentityTroveSet(source instanceof Collection ? ((Collection) source).size() : myCount);
ContainerUtil.addAll(srcSet, source);
if (srcSet.size() < 2) {
return myNext.classify(source, context);
}
return new LiftingIterable(srcSet, context, source, lifted);
}
@Override
public Iterator<LookupElement> iterator() {
final Set<LookupElement> processed = newIdentityTroveSet(mySrcSet.size());
final Set<Collection<LookupElement>> arraysProcessed = newIdentityTroveSet();
final Iterable<LookupElement> next = myNext.classify(mySource, myContext);
Iterator<LookupElement> base =
FilteringIterator.create(next.iterator(), element -> processed.add(element));
return new FlatteningIterator<LookupElement, LookupElement>(base) {
@Override
protected Iterator<LookupElement> createValueIterator(LookupElement element) {
List<LookupElement> shorter = addShorterElements(myToLift.get(element));
List<LookupElement> singleton = Collections.singletonList(element);
if (shorter != null) {
if (myLifted != null) {
myLifted.addAll(shorter);
}
Iterable<LookupElement> lifted = myNext.classify(shorter, myContext);
return (myLiftBefore
? ContainerUtil.concat(lifted, singleton)
: ContainerUtil.concat(singleton, lifted))
.iterator();
}
return singleton.iterator();
}
@Nullable
private List<LookupElement> addShorterElements(@Nullable Collection<LookupElement> from) {
List<LookupElement> toLift = null;
if (from == null) {
return null;
}
if (arraysProcessed.add(from)) {
for (LookupElement shorterElement : from) {
if (mySrcSet.contains(shorterElement) && processed.add(shorterElement)) {
if (toLift == null) {
toLift = new ArrayList<>();
}
toLift.add(shorterElement);
}
}
}
return toLift;
}
};
}