/*
 * Copyright (C) 2014, United States Government, as represented by the
 * Administrator of the National Aeronautics and Space Administration.
 * All rights reserved.
 *
 * The Java Pathfinder core (jpf-core) platform is licensed 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 gov.nasa.jpf.vm;

/**
 * data encapsulation for backtracking. It's actually a Stream (offset being
 * incremented by get()) so it probably should be renamed
 */
public final class ArrayOffset {
  public int[] data;
  int          offset;

  public ArrayOffset (int[] d) {
    data = d;
    offset = 0;
  }

  public void advance(int n) {
    offset += n;
  }
  
  public int get () {
    return data[offset++];
  }

  public int peek () {
    return data[offset];
  }
}