content: /*
   * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package openjdk.tools.sjavac.options;
  
  import java.util.Iterator;
  
  /**
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  public class ArgumentIterator implements Iterator<String> {
  
      /** The underlying argument iterator */
      private Iterator<String> iter;
  
      /** Extra state used to implement peek and current */
      private String current;
      private String buffered;
  
      public ArgumentIterator(Iterable<String> iter) {
          this.iter = iter.iterator();
      }
  
      @Override
      public boolean hasNext() {
          return buffered != null || iter.hasNext();
      }
  
      @Override
      public String next() {
          fillBuffer();
          current = buffered;
          buffered = null;
          return current;
      }
  
      /**
       * @return the last element returned by next() (or {@code null} if next has
       * never been invoked on this iterator).
       */
      public String current() {
          return current;
      }
  
      /** Can't remove current element, since we may have buffered it. */
      @Override
      public void remove() {
          throw new UnsupportedOperationException();
      }
  
      /**
       * @return Returns the next element without advancing the iterator
       */
      public String peek() {
          fillBuffer();
          return buffered;
      }
  
      private void fillBuffer() {
          if (buffered == null && iter.hasNext())
              buffered = iter.next();
      }
  
  }
  