import java.util.Stack;

aspect Caching {
  interface CacheRoot {
    void propagate();
    int getLastFlushed();
    void invalidate();
    void flushCaches();
    boolean incremental(boolean flag);
  }

  public boolean CacheRoot.flushing = false;
  boolean CacheRoot.incremental = true;

  public CacheRoot ASTNode.getCacheRoot() {
    ASTNode n = this;
    while(/*n != null &&*/ !(n instanceof CacheRoot))
      n = n.parent;
    return (CacheRoot)n;
  }

  private Stack<Caching.CacheRoot> ASTNode$State.cachestack = new Stack<Caching.CacheRoot>();
  private Caching.CacheRoot ASTNode$State.curroot = null;

  public void ASTNode$State.pushCacheRoot(Caching.CacheRoot root) {
    cachestack.push(curroot=root);
  }

  public void ASTNode$State.popCacheRoot() {
    cachestack.pop();
    curroot = cachestack.isEmpty()? null : cachestack.peek();
  }

  public Caching.CacheRoot ASTNode$State.getCurrentCacheRoot() {
    assert(curroot != null);
    return curroot;
  }

}