001    /*
002     *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003     *
004     *  This file is licensed to You under the Eclipse Public License (EPL);
005     *  You may not use this file except in compliance with the License. You
006     *  may obtain a copy of the License at
007     *
008     *      http://www.opensource.org/licenses/eclipse-1.0.php
009     *
010     *  See the COPYRIGHT.txt file distributed with this work for information
011     *  regarding copyright ownership.
012     */
013    package org.jikesrvm.compilers.opt.util;
014    
015    import java.util.Enumeration;
016    
017    /**
018     */
019    public class CompoundEnumerator<T> implements Enumeration<T> {
020      private final Enumeration<T> first;
021      private final Enumeration<T> second;
022    
023      public CompoundEnumerator(Enumeration<T> first, Enumeration<T> second) {
024        this.first = first;
025        this.second = second;
026      }
027    
028      public boolean hasMoreElements() {
029        return first.hasMoreElements() || second.hasMoreElements();
030      }
031    
032      public T nextElement() {
033        if (first.hasMoreElements()) {
034          return first.nextElement();
035        } else {
036          return second.nextElement();
037        }
038      }
039    }