com.tinkerpop.gremlin.process.util.EmptyStep Maven / Gradle / Ivy

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package com.tinkerpop.gremlin.process.util;

import com.tinkerpop.gremlin.process.Step;
import com.tinkerpop.gremlin.process.Traversal;
import com.tinkerpop.gremlin.process.Traverser;

import java.util.Iterator;

/**
 * @author Marko A. Rodriguez (http://markorodriguez.com)
 */
public class EmptyStep implements Step {

    private static final Step INSTANCE = new EmptyStep<>();

    private EmptyStep() {
    }

    public void addStarts(final Iterator> iterator) {

    }

    public void setPreviousStep(final Step step) {

    }

    public Step getPreviousStep() {
        return instance();
    }

    public void setNextStep(final Step step) {

    }

    public Step getNextStep() {
        return instance();
    }

    public  Traversal getTraversal() {
        return EmptyTraversal.instance();
    }

    public Object clone() throws CloneNotSupportedException {
        return instance();
    }

    public String getAs() {
        return Traverser.NO_FUTURE;
    }

    public void setAs(String as) {

    }

    public boolean hasNext() {
        return false;
    }

    public Traverser next() {
        throw FastNoSuchElementException.instance();
    }

    public static  Step instance() {
        return INSTANCE;
    }
}