/*
 * 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.camel;

import java.util.List;

/**
 * Implementations support navigating a graph where you can traverse forward and each next returns a {@link List} of
 * outputs of type <tt>T</tt> that can contain <tt>0..n</tt> nodes.
 */
public interface Navigate<T> {

    /**
     * Next group of outputs
     * <p/>
     * Important only invoke this once, as this method do not carry state, and is not intended to be used in a while
     * loop, but used by a if statement instead.
     *
     * @return next group or <tt>null</tt> if no more outputs
     */
    List<T> next();

    /**
     * Are there more outputs?
     * <p/>
     * Important only invoke this once, as this method do not carry state, and is not intended to be used in a while
     * loop, but used by a if statement instead.
     *
     * @return <tt>true</tt> if more outputs
     */
    boolean hasNext();

}
