gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/filter/AndStep.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.tinkerpop.gremlin.process.traversal.step.filter;

import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
import org.apache.tinkerpop.gremlin.process.traversal.Traverser;
import org.apache.tinkerpop.gremlin.process.traversal.util.TraversalUtil;

import java.util.NoSuchElementException;

/**
 * @author Marko A. Rodriguez (http://markorodriguez.com)
 */
public final class AndStep<S> extends ConnectiveStep<S> {

    public AndStep(final Traversal.Admin traversal, final Traversal<S, ?>... traversals) {
        super(traversal, traversals);
    }

    @Override
    protected Traverser.Admin<S> processNextStart() throws NoSuchElementException {
        while (true) {
            final Traverser.Admin<S> start = this.starts.next();
            boolean alive = true;
            for (final Traversal.Admin<S, ?> traversal : this.traversals) {
                if (!TraversalUtil.test(start, traversal)) {
                    alive = false;
                    break;
                }
            }
            if (alive)
                return start;
        }
    }
}