text: /* ***** BEGIN LICENSE BLOCK *****
   * Distributed under the BSD license:
   *
   * Copyright (c) 2010, Ajax.org B.V.
   * All rights reserved.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of Ajax.org B.V. nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * ***** END LICENSE BLOCK ***** */
  
  define(function (require, exports, module) {
      "use strict";
  
      /**
       *
       *
       * This class provides an essay way to treat the document as a stream of tokens, and provides methods to iterate over these tokens.
       * @class TokenIterator
       **/
  
      /**
       * Creates a new token iterator object. The inital token index is set to the provided row and column coordinates.
       * @param {EditSession} session The session to associate with
       * @param {Number} initialRow The row to start the tokenizing at
       * @param {Number} initialColumn The column to start the tokenizing at
       *
       * @constructor
       **/
      var TokenIterator = function (session, initialRow, initialColumn) {
          this.$session = session;
          this.$row = initialRow;
          this.$rowTokens = session.getTokens(initialRow);
  
          var token = session.getTokenAt(initialRow, initialColumn);
          this.$tokenIndex = token ? token.index : -1;
      };
  
      (function () {
  
          /**
           * Tokenizes all the items from the current point to the row prior in the document.
           * @returns {[String]} If the current point is not at the top of the file, this function returns `null`. Otherwise, it returns an array of the tokenized strings.
           **/
          this.stepBackward = function () {
              this.$tokenIndex -= 1;
  
              while (this.$tokenIndex < 0) {
                  this.$row -= 1;
                  if (this.$row < 0) {
                      this.$row = 0;
                      return null;
                  }
  
                  this.$rowTokens = this.$session.getTokens(this.$row);
                  this.$tokenIndex = this.$rowTokens.length - 1;
              }
  
              return this.$rowTokens[this.$tokenIndex];
          };
  
          /**
           * Tokenizes all the items from the current point until the next row in the document. If the current point is at the end of the file, this function returns `null`. Otherwise, it returns the tokenized string.
           * @returns {String}
           **/
          this.stepForward = function () {
              this.$tokenIndex += 1;
              var rowCount;
              while (this.$tokenIndex >= this.$rowTokens.length) {
                  this.$row += 1;
                  if (!rowCount)
                      rowCount = this.$session.getLength();
                  if (this.$row >= rowCount) {
                      this.$row = rowCount - 1;
                      return null;
                  }
  
                  this.$rowTokens = this.$session.getTokens(this.$row);
                  this.$tokenIndex = 0;
              }
  
              return this.$rowTokens[this.$tokenIndex];
          };
  
          /**
           *
           * Returns the current tokenized string.
           * @returns {String}
           **/
          this.getCurrentToken = function () {
              return this.$rowTokens[this.$tokenIndex];
          };
  
          /**
           *
           * Returns the current row.
           * @returns {Number}
           **/
          this.getCurrentTokenRow = function () {
              return this.$row;
          };
  
          /**
           *
           * Returns the current column.
           * @returns {Number}
           **/
          this.getCurrentTokenColumn = function () {
              var rowTokens = this.$rowTokens;
              var tokenIndex = this.$tokenIndex;
  
              // If a column was cached by EditSession.getTokenAt, then use it
              var column = rowTokens[tokenIndex].start;
              if (column !== undefined)
                  return column;
  
              column = 0;
              while (tokenIndex > 0) {
                  tokenIndex -= 1;
                  column += rowTokens[tokenIndex].value.length;
              }
  
              return column;
          };
  
          /**
           * Return the current token position.
           * @returns {Position}
           */
          this.getCurrentTokenPosition = function () {
              return {row: this.$row, column: this.getCurrentTokenColumn()};
          };
  
      }).call(TokenIterator.prototype);
  
      exports.TokenIterator = TokenIterator;
  });
  