code: function(charCode)
  	{
  		var output = "";
  		if (charCode>255) {
  			output = "\\u"+(charCode<4096?"0":"")+charCode.toString(16);
  		} else if (charCode>127) {
  			output = "\\x"+charCode.toString(16);
  		} else {
  			output = (this.needsEscapingInCharClass(charCode)?"\\":"")+String.fromCharCode(charCode);
  		}
  		return output;
  	}
docs: Returns the character matching the provided unicode value
  as it should be displayed in a character class in a Regexp :
  -  ] needs escaping
  - characters above 256 are \u....
  - characters between 128 and 255 are \x..
  - others (even below 32) are raw