text: /*
   * The Original Code is Mozilla Universal charset detector code.
   *
   * The Initial Developer of the Original Code is
   * Netscape Communications Corporation.
   * Portions created by the Initial Developer are Copyright (C) 2001
   * the Initial Developer. All Rights Reserved.
   *
   * Contributor(s):
   *   António Afonso (antonio.afonso gmail.com) - port to JavaScript
   *   Mark Pilgrim - port to Python
   *   Shy Shalom - original C code
   *
   * 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., 51 Franklin St, Fifth Floor, Boston, MA
   * 02110-1301  USA
   */
  
  !function(jschardet) {
  
  // This prober doesn't actually recognize a language or a charset.
  // It is a helper prober for the use of the Hebrew model probers
  
  ////// General ideas of the Hebrew charset recognition //////
  //
  // Four main charsets exist in Hebrew:
  // "ISO-8859-8" - Visual Hebrew
  // "windows-1255" - Logical Hebrew
  // "ISO-8859-8-I" - Logical Hebrew
  // "x-mac-hebrew" - ?? Logical Hebrew ??
  //
  // Both "ISO" charsets use a completely identical set of code points, whereas
  // "windows-1255" and "x-mac-hebrew" are two different proper supersets of
  // these code points. windows-1255 defines additional characters in the range
  // 0x80-0x9F as some misc punctuation marks as well as some Hebrew-specific
  // diacritics and additional 'Yiddish' ligature letters in the range 0xc0-0xd6.
  // x-mac-hebrew defines similar additional code points but with a different
  // mapping.
  //
  // As far as an average Hebrew text with no diacritics is concerned, all four
  // charsets are identical with respect to code points. Meaning that for the
  // main Hebrew alphabet, all four map the same values to all 27 Hebrew letters
  // (including final letters).
  //
  // The dominant difference between these charsets is their directionality.
  // "Visual" directionality means that the text is ordered as if the renderer is
  // not aware of a BIDI rendering algorithm. The renderer sees the text and
  // draws it from left to right. The text itself when ordered naturally is read
  // backwards. A buffer of Visual Hebrew generally looks like so:
  // "[last word of first line spelled backwards] [whole line ordered backwards
  // and spelled backwards] [first word of first line spelled backwards]
  // [end of line] [last word of second line] ... etc' "
  // adding punctuation marks, numbers and English text to visual text is
  // naturally also "visual" and from left to right.
  //
  // "Logical" directionality means the text is ordered "naturally" according to
  // the order it is read. It is the responsibility of the renderer to display
  // the text from right to left. A BIDI algorithm is used to place general
  // punctuation marks, numbers and English text in the text.
  //
  // Texts in x-mac-hebrew are almost impossible to find on the Internet. From
  // what little evidence I could find, it seems that its general directionality
  // is Logical.
  //
  // To sum up all of the above, the Hebrew probing mechanism knows about two
  // charsets:
  // Visual Hebrew - "ISO-8859-8" - backwards text - Words and sentences are
  //    backwards while line order is natural. For charset recognition purposes
  //    the line order is unimportant (In fact, for this implementation, even
  //    word order is unimportant).
  // Logical Hebrew - "windows-1255" - normal, naturally ordered text.
  //
  // "ISO-8859-8-I" is a subset of windows-1255 and doesn't need to be
  //    specifically identified.
  // "x-mac-hebrew" is also identified as windows-1255. A text in x-mac-hebrew
  //    that contain special punctuation marks or diacritics is displayed with
  //    some unconverted characters showing as question marks. This problem might
  //    be corrected using another model prober for x-mac-hebrew. Due to the fact
  //    that x-mac-hebrew texts are so rare, writing another model prober isn't
  //    worth the effort and performance hit.
  //
  //////// The Prober ////////
  //
  // The prober is divided between two SBCharSetProbers and a HebrewProber,
  // all of which are managed, created, fed data, inquired and deleted by the
  // SBCSGroupProber. The two SBCharSetProbers identify that the text is in
  // fact some kind of Hebrew, Logical or Visual. The final decision about which
  // one is it is made by the HebrewProber by combining final-letter scores
  // with the scores of the two SBCharSetProbers to produce a final answer.
  //
  // The SBCSGroupProber is responsible for stripping the original text of HTML
  // tags, English characters, numbers, low-ASCII punctuation characters, spaces
  // and new lines. It reduces any sequence of such characters to a single space.
  // The buffer fed to each prober in the SBCS group prober is pure text in
  // high-ASCII.
  // The two SBCharSetProbers (model probers) share the same language model:
  // Win1255Model.
  // The first SBCharSetProber uses the model normally as any other
  // SBCharSetProber does, to recognize windows-1255, upon which this model was
  // built. The second SBCharSetProber is told to make the pair-of-letter
  // lookup in the language model backwards. This in practice exactly simulates
  // a visual Hebrew model using the windows-1255 logical Hebrew model.
  //
  // The HebrewProber is not using any language model. All it does is look for
  // final-letter evidence suggesting the text is either logical Hebrew or visual
  // Hebrew. Disjointed from the model probers, the results of the HebrewProber
  // alone are meaningless. HebrewProber always returns 0.00 as confidence
  // since it never identifies a charset by itself. Instead, the pointer to the
  // HebrewProber is passed to the model probers as a helper "Name Prober".
  // When the Group prober receives a positive identification from any prober,
  // it asks for the name of the charset identified. If the prober queried is a
  // Hebrew model prober, the model prober forwards the call to the
  // HebrewProber to make the final decision. In the HebrewProber, the
  // decision is made according to the final-letters scores maintained and Both
  // model probers scores. The answer is returned in the form of the name of the
  // charset identified, either "windows-1255" or "ISO-8859-8".
  
  jschardet.HebrewProber = function() {
      jschardet.CharSetProber.apply(this);
  
      // windows-1255 / ISO-8859-8 code points of interest
      var FINAL_KAF = '\xea'
      var NORMAL_KAF = '\xeb'
      var FINAL_MEM = '\xed'
      var NORMAL_MEM = '\xee'
      var FINAL_NUN = '\xef'
      var NORMAL_NUN = '\xf0'
      var FINAL_PE = '\xf3'
      var NORMAL_PE = '\xf4'
      var FINAL_TSADI = '\xf5'
      var NORMAL_TSADI = '\xf6'
  
      // Minimum Visual vs Logical final letter score difference.
      // If the difference is below this, don't rely solely on the final letter score distance.
      var MIN_FINAL_CHAR_DISTANCE = 5
  
      // Minimum Visual vs Logical model score difference.
      // If the difference is below this, don't rely at all on the model score distance.
      var MIN_MODEL_DISTANCE = 0.01
  
      var VISUAL_HEBREW_NAME = "ISO-8859-8"
      var LOGICAL_HEBREW_NAME = "windows-1255"
      var self = this;
  
      function init() {
          self._mLogicalProber = null;
          self._mVisualProber = null;
          self.reset();
      }
  
      this.reset = function() {
          this._mFinalCharLogicalScore = 0;
          this._mFinalCharVisualScore = 0;
          // The two last characters seen in the previous buffer,
          // mPrev and mBeforePrev are initialized to space in order to simulate a word
          // delimiter at the beginning of the data
          this._mPrev = " ";
          this._mBeforePrev = " ";
          // These probers are owned by the group prober.
      }
  
      this.setModelProbers = function(logicalProber, visualProber) {
          this._mLogicalProber = logicalProber;
          this._mVisualProber = visualProber;
      }
  
      this.isFinal = function(c) {
          return [FINAL_KAF, FINAL_MEM, FINAL_NUN, FINAL_PE, FINAL_TSADI].indexOf(c) != -1;
      }
  
      this.isNonFinal = function(c) {
          // The normal Tsadi is not a good Non-Final letter due to words like
          // 'lechotet' (to chat) containing an apostrophe after the tsadi. This
          // apostrophe is converted to a space in FilterWithoutEnglishLetters causing
          // the Non-Final tsadi to appear at an end of a word even though this is not
          // the case in the original text.
          // The letters Pe and Kaf rarely display a related behavior of not being a
          // good Non-Final letter. Words like 'Pop', 'Winamp' and 'Mubarak' for
          // example legally end with a Non-Final Pe or Kaf. However, the benefit of
          // these letters as Non-Final letters outweighs the damage since these words
          // are quite rare.
          return [NORMAL_KAF, NORMAL_MEM, NORMAL_NUN, NORMAL_PE].indexOf(c) != -1;
      }
  
      this.feed = function(aBuf) {
          // Final letter analysis for logical-visual decision.
          // Look for evidence that the received buffer is either logical Hebrew or
          // visual Hebrew.
          // The following cases are checked:
          // 1) A word longer than 1 letter, ending with a final letter. This is an
          //    indication that the text is laid out "naturally" since the final letter
          //    really appears at the end. +1 for logical score.
          // 2) A word longer than 1 letter, ending with a Non-Final letter. In normal
          //    Hebrew, words ending with Kaf, Mem, Nun, Pe or Tsadi, should not end with
          //    the Non-Final form of that letter. Exceptions to this rule are mentioned
          //    above in isNonFinal(). This is an indication that the text is laid out
          //    backwards. +1 for visual score
          // 3) A word longer than 1 letter, starting with a final letter. Final letters
          //    should not appear at the beginning of a word. This is an indication that
          //    the text is laid out backwards. +1 for visual score.
          //
          // The visual score and logical score are accumulated throughout the text and
          // are finally checked against each other in GetCharSetName().
          // No checking for final letters in the middle of words is done since that case
          // is not an indication for either Logical or Visual text.
          //
          // We automatically filter out all 7-bit characters (replace them with spaces)
          // so the word boundary detection works properly. [MAP]
  
          if( this.getState() == jschardet.Constants.notMe ) {
              // Both model probers say it's not them. No reason to continue.
              return jschardet.Constants.notMe;
          }
  
          aBuf = this.filterHighBitOnly(aBuf);
  
          for( var i = 0, cur; i < aBuf.length; i++ ) {
              cur = aBuf[i];
              if( cur == " " ) {
                  // We stand on a space - a word just ended
                  if( this._mBeforePrev != " " ) {
                      // next-to-last char was not a space so self._mPrev is not a 1 letter word
                      if( this.isFinal(this._mPrev) ) {
                          // case (1) [-2:not space][-1:final letter][cur:space]
                          this._mFinalCharLogicalScore++;
                      } else if( this.isNonFinal(this._mPrev) ) {
                          // case (2) [-2:not space][-1:Non-Final letter][cur:space]
                          this._mFinalCharVisualScore++;
                      }
                  }
              } else {
                  // Not standing on a space
                  if( this._mBeforePrev == " " && this.isFinal(this._mPrev) && cur != " " ) {
                      // case (3) [-2:space][-1:final letter][cur:not space]
                      this._mFinalCharVisualScore++;
                  }
              }
              this._mBeforePrev = this._mPrev;
              this._mPrev = cur;
          }
          // Forever detecting, till the end or until both model probers return eNotMe (handled above)
          return jschardet.Constants.detecting;
      }
  
      this.getCharsetName = function() {
          // Make the decision: is it Logical or Visual?
          // If the final letter score distance is dominant enough, rely on it.
          var finalsub = this._mFinalCharLogicalScore - this._mFinalCharVisualScore;
          if( finalsub >= MIN_FINAL_CHAR_DISTANCE ) {
              return LOGICAL_HEBREW_NAME;
          }
          if( finalsub <= -MIN_FINAL_CHAR_DISTANCE ) {
              return VISUAL_HEBREW_NAME;
          }
  
          // It's not dominant enough, try to rely on the model scores instead.
          var modelsub = this._mLogicalProber.getConfidence() - this._mVisualProber.getConfidence();
          if( modelsub > MIN_MODEL_DISTANCE ) {
              return LOGICAL_HEBREW_NAME;
          }
          if( modelsub < -MIN_MODEL_DISTANCE ) {
              return VISUAL_HEBREW_NAME;
          }
  
          // Still no good, back to final letter distance, maybe it'll save the day.
          if( finalsub < 0 ) {
              return VISUAL_HEBREW_NAME;
          }
  
          // (finalsub > 0 - Logical) or (don't know what to do) default to Logical.
          return LOGICAL_HEBREW_NAME;
      }
  
      this.getState = function() {
          // Remain active as long as any of the model probers are active.
          if( this._mLogicalProber.getState() == jschardet.Constants.notMe &&
              this._mVisualProber.getState() == jschardet.Constants.notMe ) {
              return jschardet.Constants.notMe;
          }
          return jschardet.Constants.detecting;
      }
  
      init();
  }
  jschardet.HebrewProber.prototype = new jschardet.CharSetProber();
  
  // https://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Objects/Array/IndexOf
  if (!Array.prototype.indexOf)
  {
      Array.prototype.indexOf = function(elt /*, from*/)
      {
          var len = this.length >>> 0;
  
          var from = Number(arguments[1]) || 0;
          from = (from < 0)
               ? Math.ceil(from)
               : Math.floor(from);
          if (from < 0)
              from += len;
  
          for (; from < len; from++)
          {
              if (from in this &&
                  this[from] === elt)
                  return from;
          }
          return -1;
      };
  }
  
  }(require('./init'));
  