src/game/java/net/minecraft/client/searchtree/IntersectionIterator.java

package net.minecraft.client.searchtree;

import com.google.common.collect.AbstractIterator;
import com.google.common.collect.Iterators;
import com.google.common.collect.PeekingIterator;
import java.util.Comparator;
import java.util.Iterator;
import net.minecraftforge.api.distmarker.Dist;
import net.minecraftforge.api.distmarker.OnlyIn;

@OnlyIn(Dist.CLIENT)
public class IntersectionIterator<T> extends AbstractIterator<T> {
    private final PeekingIterator<T> firstIterator;
    private final PeekingIterator<T> secondIterator;
    private final Comparator<T> comparator;

    public IntersectionIterator(Iterator<T> p_235178_, Iterator<T> p_235179_, Comparator<T> p_235180_) {
        this.firstIterator = Iterators.peekingIterator(p_235178_);
        this.secondIterator = Iterators.peekingIterator(p_235179_);
        this.comparator = p_235180_;
    }

    @Override
    protected T computeNext() {
        while (this.firstIterator.hasNext() && this.secondIterator.hasNext()) {
            int i = this.comparator.compare(this.firstIterator.peek(), this.secondIterator.peek());
            if (i == 0) {
                this.secondIterator.next();
                return this.firstIterator.next();
            }

            if (i < 0) {
                this.firstIterator.next();
            } else {
                this.secondIterator.next();
            }
        }

        return this.endOfData();
    }
}