content: /*
   * InputStack.java July 2006
   *
   * Copyright (C) 2006, Niall Gallagher <niallg@users.sf.net>
   *
   * 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 com.aliyun.odps.simpleframework.xml.stream;
  
  /**
   * The <code>InputStack</code> is used to keep track of the nodes 
   * that have been read from the document. This ensures that when
   * nodes are read from the source document that the reader can tell
   * whether a child node for a given <code>InputNode</code> can be
   * created. Each created node is pushed, and popped when ended.
   *
   * @author Niall Gallagher
   *
   * @see InputNode
   */ 
  class InputStack extends Stack<InputNode> {
  
     /**
      * Constructor for the <code>InputStack</code> object. This is
      * used to create a stack that can be used to keep track of the
      * elements that have been read from the source XML document.
      */         
     public InputStack() {
        super(6);
     }
     
     /**
      * This is used to determine if the specified node is relevant
      * with respect to the state of the input stack. This returns
      * true if there are no elements in the stack, which accounts
      * for a new root node. Also this returns true if the specified
      * node exists within the stack and is thus an active node.
      * 
      * @param value this is the input node value to be checked
      * 
      * @return returns true if the node is relevant in the stack
      */
     public boolean isRelevant(InputNode value) {
        return contains(value) || isEmpty();
     }
  }