public class GetNth implements FLVisitor_I {
  private final int index;

  public GetNth(int i) {
    index = i;
  }

  public Object forEmpty (Empty list) {
    throw new java.util.NoSuchElementException ("Empty has no data.");
  }

  public Object forCons(Cons list) {
    if (0 == index) {
      return list.first();
    }
    else return list.rest().execute(new GetNth(index-1));
  }
}