nodelist.js

这个weblogging 设计得比较精巧

/*
 * NodeList.js
 * A list of nodes nested at the same level in an XML document
 *
 * Copyright (C) 2001 David A. Lindquist ([e-mail])
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 * 
 * This library 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

function NodeList() {
  this.length = 0;
}

NodeList.prototype.getLength =
function() {
  return this.length;
}

NodeList.prototype.item =
function( index ) {
  var item;
  item = ( index < 0 ) ? this[ this.length + index ]
                       : this[ index ];
  return ( item || null );
}

NodeList.prototype.add =
function( node ) {
  this[ this.length++ ] = node;
}