code: function TokenStreamBase(input, tokenData){
  
      /**
       * The string reader for easy access to the text.
       * @type StringReader
       * @property _reader
       * @private
       */
      this._reader = input ? new StringReader(input.toString()) : null;
  
      /**
       * Token object for the last consumed token.
       * @type Token
       * @property _token
       * @private
       */
      this._token = null;
  
      /**
       * The array of token information.
       * @type Array
       * @property _tokenData
       * @private
       */
      this._tokenData = tokenData;
  
      /**
       * Lookahead token buffer.
       * @type Array
       * @property _lt
       * @private
       */
      this._lt = [];
  
      /**
       * Lookahead token buffer index.
       * @type int
       * @property _ltIndex
       * @private
       */
      this._ltIndex = 0;
  
      this._ltIndexCache = [];
  }
docs: Generic TokenStream providing base functionality.
  @class TokenStreamBase
  @namespace parserlib.util
  @constructor
  @param {String|StringReader} input The text to tokenize or a reader from
  which to read the input.