Subversion Repositories eFlore/Applications.cel

Rev

Blame | Last modification | View Log | RSS feed

<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2013 PHPExcel
 *
 * 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 Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_Writer_Excel5
 * @copyright  Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    ##VERSION##, ##DATE##
 */

// Original file header of PEAR::Spreadsheet_Excel_Writer_Parser (used as the base for this class):
// -----------------------------------------------------------------------------------------
// *  Class for parsing Excel formulas
// *
// *  License Information:
// *
// *    Spreadsheet_Excel_Writer:  A library for generating Excel Spreadsheets
// *    Copyright (c) 2002-2003 Xavier Noguer xnoguer@rezebra.com
// *
// *    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
// */


/**
 * PHPExcel_Writer_Excel5_Parser
 *
 * @category   PHPExcel
 * @package    PHPExcel_Writer_Excel5
 * @copyright  Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Writer_Excel5_Parser
{
        /**     Constants                               */
        // Sheet title in unquoted form
        // Invalid sheet title characters cannot occur in the sheet title:
        //              *:/\?[]
        // Moreover, there are valid sheet title characters that cannot occur in unquoted form (there may be more?)
        // +-% '^&<>=,;#()"{}
        const REGEX_SHEET_TITLE_UNQUOTED = '[^\*\:\/\\\\\?\[\]\+\-\% \\\'\^\&\<\>\=\,\;\#\(\)\"\{\}]+';

        // Sheet title in quoted form (without surrounding quotes)
        // Invalid sheet title characters cannot occur in the sheet title:
        // *:/\?[]                                      (usual invalid sheet title characters)
        // Single quote is represented as a pair ''
        const REGEX_SHEET_TITLE_QUOTED = '(([^\*\:\/\\\\\?\[\]\\\'])+|(\\\'\\\')+)+';

        /**
         * The index of the character we are currently looking at
         * @var integer
         */
        public $_current_char;

        /**
         * The token we are working on.
         * @var string
         */
        public $_current_token;

        /**
         * The formula to parse
         * @var string
         */
        public $_formula;

        /**
         * The character ahead of the current char
         * @var string
         */
        public $_lookahead;

        /**
         * The parse tree to be generated
         * @var string
         */
        public $_parse_tree;

        /**
         * Array of external sheets
         * @var array
         */
        public $_ext_sheets;

        /**
         * Array of sheet references in the form of REF structures
         * @var array
         */
        public $_references;

        /**
         * The class constructor
         *
         */
        public function __construct()
        {
                $this->_current_char  = 0;
                $this->_current_token = '';       // The token we are working on.
                $this->_formula       = '';       // The formula to parse.
                $this->_lookahead     = '';       // The character ahead of the current char.
                $this->_parse_tree    = '';       // The parse tree to be generated.
                $this->_initializeHashes();      // Initialize the hashes: ptg's and function's ptg's
                $this->_ext_sheets = array();
                $this->_references = array();
        }

        /**
         * Initialize the ptg and function hashes.
         *
         * @access private
         */
        function _initializeHashes()
        {
                // The Excel ptg indices
                $this->ptg = array(
                        'ptgExp'       => 0x01,
                        'ptgTbl'       => 0x02,
                        'ptgAdd'       => 0x03,
                        'ptgSub'       => 0x04,
                        'ptgMul'       => 0x05,
                        'ptgDiv'       => 0x06,
                        'ptgPower'     => 0x07,
                        'ptgConcat'    => 0x08,
                        'ptgLT'        => 0x09,
                        'ptgLE'        => 0x0A,
                        'ptgEQ'        => 0x0B,
                        'ptgGE'        => 0x0C,
                        'ptgGT'        => 0x0D,
                        'ptgNE'        => 0x0E,
                        'ptgIsect'     => 0x0F,
                        'ptgUnion'     => 0x10,
                        'ptgRange'     => 0x11,
                        'ptgUplus'     => 0x12,
                        'ptgUminus'    => 0x13,
                        'ptgPercent'   => 0x14,
                        'ptgParen'     => 0x15,
                        'ptgMissArg'   => 0x16,
                        'ptgStr'       => 0x17,
                        'ptgAttr'      => 0x19,
                        'ptgSheet'     => 0x1A,
                        'ptgEndSheet'  => 0x1B,
                        'ptgErr'       => 0x1C,
                        'ptgBool'      => 0x1D,
                        'ptgInt'       => 0x1E,
                        'ptgNum'       => 0x1F,
                        'ptgArray'     => 0x20,
                        'ptgFunc'      => 0x21,
                        'ptgFuncVar'   => 0x22,
                        'ptgName'      => 0x23,
                        'ptgRef'       => 0x24,
                        'ptgArea'      => 0x25,
                        'ptgMemArea'   => 0x26,
                        'ptgMemErr'    => 0x27,
                        'ptgMemNoMem'  => 0x28,
                        'ptgMemFunc'   => 0x29,
                        'ptgRefErr'    => 0x2A,
                        'ptgAreaErr'   => 0x2B,
                        'ptgRefN'      => 0x2C,
                        'ptgAreaN'     => 0x2D,
                        'ptgMemAreaN'  => 0x2E,
                        'ptgMemNoMemN' => 0x2F,
                        'ptgNameX'     => 0x39,
                        'ptgRef3d'     => 0x3A,
                        'ptgArea3d'    => 0x3B,
                        'ptgRefErr3d'  => 0x3C,
                        'ptgAreaErr3d' => 0x3D,
                        'ptgArrayV'    => 0x40,
                        'ptgFuncV'     => 0x41,
                        'ptgFuncVarV'  => 0x42,
                        'ptgNameV'     => 0x43,
                        'ptgRefV'      => 0x44,
                        'ptgAreaV'     => 0x45,
                        'ptgMemAreaV'  => 0x46,
                        'ptgMemErrV'   => 0x47,
                        'ptgMemNoMemV' => 0x48,
                        'ptgMemFuncV'  => 0x49,
                        'ptgRefErrV'   => 0x4A,
                        'ptgAreaErrV'  => 0x4B,
                        'ptgRefNV'     => 0x4C,
                        'ptgAreaNV'    => 0x4D,
                        'ptgMemAreaNV' => 0x4E,
                        'ptgMemNoMemN' => 0x4F,
                        'ptgFuncCEV'   => 0x58,
                        'ptgNameXV'    => 0x59,
                        'ptgRef3dV'    => 0x5A,
                        'ptgArea3dV'   => 0x5B,
                        'ptgRefErr3dV' => 0x5C,
                        'ptgAreaErr3d' => 0x5D,
                        'ptgArrayA'    => 0x60,
                        'ptgFuncA'     => 0x61,
                        'ptgFuncVarA'  => 0x62,
                        'ptgNameA'     => 0x63,
                        'ptgRefA'      => 0x64,
                        'ptgAreaA'     => 0x65,
                        'ptgMemAreaA'  => 0x66,
                        'ptgMemErrA'   => 0x67,
                        'ptgMemNoMemA' => 0x68,
                        'ptgMemFuncA'  => 0x69,
                        'ptgRefErrA'   => 0x6A,
                        'ptgAreaErrA'  => 0x6B,
                        'ptgRefNA'     => 0x6C,
                        'ptgAreaNA'    => 0x6D,
                        'ptgMemAreaNA' => 0x6E,
                        'ptgMemNoMemN' => 0x6F,
                        'ptgFuncCEA'   => 0x78,
                        'ptgNameXA'    => 0x79,
                        'ptgRef3dA'    => 0x7A,
                        'ptgArea3dA'   => 0x7B,
                        'ptgRefErr3dA' => 0x7C,
                        'ptgAreaErr3d' => 0x7D
                        );

                // Thanks to Michael Meeks and Gnumeric for the initial arg values.
                //
                // The following hash was generated by "function_locale.pl" in the distro.
                // Refer to function_locale.pl for non-English function names.
                //
                // The array elements are as follow:
                // ptg:   The Excel function ptg code.
                // args:  The number of arguments that the function takes:
                //           >=0 is a fixed number of arguments.
                //           -1  is a variable  number of arguments.
                // class: The reference, value or array class of the function args.
                // vol:   The function is volatile.
                //
                $this->_functions = array(
                          // function                  ptg  args  class  vol
                          'COUNT'           => array(   0,   -1,    0,    0 ),
                          'IF'              => array(   1,   -1,    1,    0 ),
                          'ISNA'            => array(   2,    1,    1,    0 ),
                          'ISERROR'         => array(   3,    1,    1,    0 ),
                          'SUM'             => array(   4,   -1,    0,    0 ),
                          'AVERAGE'         => array(   5,   -1,    0,    0 ),
                          'MIN'             => array(   6,   -1,    0,    0 ),
                          'MAX'             => array(   7,   -1,    0,    0 ),
                          'ROW'             => array(   8,   -1,    0,    0 ),
                          'COLUMN'          => array(   9,   -1,    0,    0 ),
                          'NA'              => array(  10,    0,    0,    0 ),
                          'NPV'             => array(  11,   -1,    1,    0 ),
                          'STDEV'           => array(  12,   -1,    0,    0 ),
                          'DOLLAR'          => array(  13,   -1,    1,    0 ),
                          'FIXED'           => array(  14,   -1,    1,    0 ),
                          'SIN'             => array(  15,    1,    1,    0 ),
                          'COS'             => array(  16,    1,    1,    0 ),
                          'TAN'             => array(  17,    1,    1,    0 ),
                          'ATAN'            => array(  18,    1,    1,    0 ),
                          'PI'              => array(  19,    0,    1,    0 ),
                          'SQRT'            => array(  20,    1,    1,    0 ),
                          'EXP'             => array(  21,    1,    1,    0 ),
                          'LN'              => array(  22,    1,    1,    0 ),
                          'LOG10'           => array(  23,    1,    1,    0 ),
                          'ABS'             => array(  24,    1,    1,    0 ),
                          'INT'             => array(  25,    1,    1,    0 ),
                          'SIGN'            => array(  26,    1,    1,    0 ),
                          'ROUND'           => array(  27,    2,    1,    0 ),
                          'LOOKUP'          => array(  28,   -1,    0,    0 ),
                          'INDEX'           => array(  29,   -1,    0,    1 ),
                          'REPT'            => array(  30,    2,    1,    0 ),
                          'MID'             => array(  31,    3,    1,    0 ),
                          'LEN'             => array(  32,    1,    1,    0 ),
                          'VALUE'           => array(  33,    1,    1,    0 ),
                          'TRUE'            => array(  34,    0,    1,    0 ),
                          'FALSE'           => array(  35,    0,    1,    0 ),
                          'AND'             => array(  36,   -1,    0,    0 ),
                          'OR'              => array(  37,   -1,    0,    0 ),
                          'NOT'             => array(  38,    1,    1,    0 ),
                          'MOD'             => array(  39,    2,    1,    0 ),
                          'DCOUNT'          => array(  40,    3,    0,    0 ),
                          'DSUM'            => array(  41,    3,    0,    0 ),
                          'DAVERAGE'        => array(  42,    3,    0,    0 ),
                          'DMIN'            => array(  43,    3,    0,    0 ),
                          'DMAX'            => array(  44,    3,    0,    0 ),
                          'DSTDEV'          => array(  45,    3,    0,    0 ),
                          'VAR'             => array(  46,   -1,    0,    0 ),
                          'DVAR'            => array(  47,    3,    0,    0 ),
                          'TEXT'            => array(  48,    2,    1,    0 ),
                          'LINEST'          => array(  49,   -1,    0,    0 ),
                          'TREND'           => array(  50,   -1,    0,    0 ),
                          'LOGEST'          => array(  51,   -1,    0,    0 ),
                          'GROWTH'          => array(  52,   -1,    0,    0 ),
                          'PV'              => array(  56,   -1,    1,    0 ),
                          'FV'              => array(  57,   -1,    1,    0 ),
                          'NPER'            => array(  58,   -1,    1,    0 ),
                          'PMT'             => array(  59,   -1,    1,    0 ),
                          'RATE'            => array(  60,   -1,    1,    0 ),
                          'MIRR'            => array(  61,    3,    0,    0 ),
                          'IRR'             => array(  62,   -1,    0,    0 ),
                          'RAND'            => array(  63,    0,    1,    1 ),
                          'MATCH'           => array(  64,   -1,    0,    0 ),
                          'DATE'            => array(  65,    3,    1,    0 ),
                          'TIME'            => array(  66,    3,    1,    0 ),
                          'DAY'             => array(  67,    1,    1,    0 ),
                          'MONTH'           => array(  68,    1,    1,    0 ),
                          'YEAR'            => array(  69,    1,    1,    0 ),
                          'WEEKDAY'         => array(  70,   -1,    1,    0 ),
                          'HOUR'            => array(  71,    1,    1,    0 ),
                          'MINUTE'          => array(  72,    1,    1,    0 ),
                          'SECOND'          => array(  73,    1,    1,    0 ),
                          'NOW'             => array(  74,    0,    1,    1 ),
                          'AREAS'           => array(  75,    1,    0,    1 ),
                          'ROWS'            => array(  76,    1,    0,    1 ),
                          'COLUMNS'         => array(  77,    1,    0,    1 ),
                          'OFFSET'          => array(  78,   -1,    0,    1 ),
                          'SEARCH'          => array(  82,   -1,    1,    0 ),
                          'TRANSPOSE'       => array(  83,    1,    1,    0 ),
                          'TYPE'            => array(  86,    1,    1,    0 ),
                          'ATAN2'           => array(  97,    2,    1,    0 ),
                          'ASIN'            => array(  98,    1,    1,    0 ),
                          'ACOS'            => array(  99,    1,    1,    0 ),
                          'CHOOSE'          => array( 100,   -1,    1,    0 ),
                          'HLOOKUP'         => array( 101,   -1,    0,    0 ),
                          'VLOOKUP'         => array( 102,   -1,    0,    0 ),
                          'ISREF'           => array( 105,    1,    0,    0 ),
                          'LOG'             => array( 109,   -1,    1,    0 ),
                          'CHAR'            => array( 111,    1,    1,    0 ),
                          'LOWER'           => array( 112,    1,    1,    0 ),
                          'UPPER'           => array( 113,    1,    1,    0 ),
                          'PROPER'          => array( 114,    1,    1,    0 ),
                          'LEFT'            => array( 115,   -1,    1,    0 ),
                          'RIGHT'           => array( 116,   -1,    1,    0 ),
                          'EXACT'           => array( 117,    2,    1,    0 ),
                          'TRIM'            => array( 118,    1,    1,    0 ),
                          'REPLACE'         => array( 119,    4,    1,    0 ),
                          'SUBSTITUTE'      => array( 120,   -1,    1,    0 ),
                          'CODE'            => array( 121,    1,    1,    0 ),
                          'FIND'            => array( 124,   -1,    1,    0 ),
                          'CELL'            => array( 125,   -1,    0,    1 ),
                          'ISERR'           => array( 126,    1,    1,    0 ),
                          'ISTEXT'          => array( 127,    1,    1,    0 ),
                          'ISNUMBER'        => array( 128,    1,    1,    0 ),
                          'ISBLANK'         => array( 129,    1,    1,    0 ),
                          'T'               => array( 130,    1,    0,    0 ),
                          'N'               => array( 131,    1,    0,    0 ),
                          'DATEVALUE'       => array( 140,    1,    1,    0 ),
                          'TIMEVALUE'       => array( 141,    1,    1,    0 ),
                          'SLN'             => array( 142,    3,    1,    0 ),
                          'SYD'             => array( 143,    4,    1,    0 ),
                          'DDB'             => array( 144,   -1,    1,    0 ),
                          'INDIRECT'        => array( 148,   -1,    1,    1 ),
                          'CALL'            => array( 150,   -1,    1,    0 ),
                          'CLEAN'           => array( 162,    1,    1,    0 ),
                          'MDETERM'         => array( 163,    1,    2,    0 ),
                          'MINVERSE'        => array( 164,    1,    2,    0 ),
                          'MMULT'           => array( 165,    2,    2,    0 ),
                          'IPMT'            => array( 167,   -1,    1,    0 ),
                          'PPMT'            => array( 168,   -1,    1,    0 ),
                          'COUNTA'          => array( 169,   -1,    0,    0 ),
                          'PRODUCT'         => array( 183,   -1,    0,    0 ),
                          'FACT'            => array( 184,    1,    1,    0 ),
                          'DPRODUCT'        => array( 189,    3,    0,    0 ),
                          'ISNONTEXT'       => array( 190,    1,    1,    0 ),
                          'STDEVP'          => array( 193,   -1,    0,    0 ),
                          'VARP'            => array( 194,   -1,    0,    0 ),
                          'DSTDEVP'         => array( 195,    3,    0,    0 ),
                          'DVARP'           => array( 196,    3,    0,    0 ),
                          'TRUNC'           => array( 197,   -1,    1,    0 ),
                          'ISLOGICAL'       => array( 198,    1,    1,    0 ),
                          'DCOUNTA'         => array( 199,    3,    0,    0 ),
                          'USDOLLAR'        => array( 204,   -1,    1,    0 ),
                          'FINDB'           => array( 205,   -1,    1,    0 ),
                          'SEARCHB'         => array( 206,   -1,    1,    0 ),
                          'REPLACEB'        => array( 207,    4,    1,    0 ),
                          'LEFTB'           => array( 208,   -1,    1,    0 ),
                          'RIGHTB'          => array( 209,   -1,    1,    0 ),
                          'MIDB'            => array( 210,    3,    1,    0 ),
                          'LENB'            => array( 211,    1,    1,    0 ),
                          'ROUNDUP'         => array( 212,    2,    1,    0 ),
                          'ROUNDDOWN'       => array( 213,    2,    1,    0 ),
                          'ASC'             => array( 214,    1,    1,    0 ),
                          'DBCS'            => array( 215,    1,    1,    0 ),
                          'RANK'            => array( 216,   -1,    0,    0 ),
                          'ADDRESS'         => array( 219,   -1,    1,    0 ),
                          'DAYS360'         => array( 220,   -1,    1,    0 ),
                          'TODAY'           => array( 221,    0,    1,    1 ),
                          'VDB'             => array( 222,   -1,    1,    0 ),
                          'MEDIAN'          => array( 227,   -1,    0,    0 ),
                          'SUMPRODUCT'      => array( 228,   -1,    2,    0 ),
                          'SINH'            => array( 229,    1,    1,    0 ),
                          'COSH'            => array( 230,    1,    1,    0 ),
                          'TANH'            => array( 231,    1,    1,    0 ),
                          'ASINH'           => array( 232,    1,    1,    0 ),
                          'ACOSH'           => array( 233,    1,    1,    0 ),
                          'ATANH'           => array( 234,    1,    1,    0 ),
                          'DGET'            => array( 235,    3,    0,    0 ),
                          'INFO'            => array( 244,    1,    1,    1 ),
                          'DB'              => array( 247,   -1,    1,    0 ),
                          'FREQUENCY'       => array( 252,    2,    0,    0 ),
                          'ERROR.TYPE'      => array( 261,    1,    1,    0 ),
                          'REGISTER.ID'     => array( 267,   -1,    1,    0 ),
                          'AVEDEV'          => array( 269,   -1,    0,    0 ),
                          'BETADIST'        => array( 270,   -1,    1,    0 ),
                          'GAMMALN'         => array( 271,    1,    1,    0 ),
                          'BETAINV'         => array( 272,   -1,    1,    0 ),
                          'BINOMDIST'       => array( 273,    4,    1,    0 ),
                          'CHIDIST'         => array( 274,    2,    1,    0 ),
                          'CHIINV'          => array( 275,    2,    1,    0 ),
                          'COMBIN'          => array( 276,    2,    1,    0 ),
                          'CONFIDENCE'      => array( 277,    3,    1,    0 ),
                          'CRITBINOM'       => array( 278,    3,    1,    0 ),
                          'EVEN'            => array( 279,    1,    1,    0 ),
                          'EXPONDIST'       => array( 280,    3,    1,    0 ),
                          'FDIST'           => array( 281,    3,    1,    0 ),
                          'FINV'            => array( 282,    3,    1,    0 ),
                          'FISHER'          => array( 283,    1,    1,    0 ),
                          'FISHERINV'       => array( 284,    1,    1,    0 ),
                          'FLOOR'           => array( 285,    2,    1,    0 ),
                          'GAMMADIST'       => array( 286,    4,    1,    0 ),
                          'GAMMAINV'        => array( 287,    3,    1,    0 ),
                          'CEILING'         => array( 288,    2,    1,    0 ),
                          'HYPGEOMDIST'     => array( 289,    4,    1,    0 ),
                          'LOGNORMDIST'     => array( 290,    3,    1,    0 ),
                          'LOGINV'          => array( 291,    3,    1,    0 ),
                          'NEGBINOMDIST'    => array( 292,    3,    1,    0 ),
                          'NORMDIST'        => array( 293,    4,    1,    0 ),
                          'NORMSDIST'       => array( 294,    1,    1,    0 ),
                          'NORMINV'         => array( 295,    3,    1,    0 ),
                          'NORMSINV'        => array( 296,    1,    1,    0 ),
                          'STANDARDIZE'     => array( 297,    3,    1,    0 ),
                          'ODD'             => array( 298,    1,    1,    0 ),
                          'PERMUT'          => array( 299,    2,    1,    0 ),
                          'POISSON'         => array( 300,    3,    1,    0 ),
                          'TDIST'           => array( 301,    3,    1,    0 ),
                          'WEIBULL'         => array( 302,    4,    1,    0 ),
                          'SUMXMY2'         => array( 303,    2,    2,    0 ),
                          'SUMX2MY2'        => array( 304,    2,    2,    0 ),
                          'SUMX2PY2'        => array( 305,    2,    2,    0 ),
                          'CHITEST'         => array( 306,    2,    2,    0 ),
                          'CORREL'          => array( 307,    2,    2,    0 ),
                          'COVAR'           => array( 308,    2,    2,    0 ),
                          'FORECAST'        => array( 309,    3,    2,    0 ),
                          'FTEST'           => array( 310,    2,    2,    0 ),
                          'INTERCEPT'       => array( 311,    2,    2,    0 ),
                          'PEARSON'         => array( 312,    2,    2,    0 ),
                          'RSQ'             => array( 313,    2,    2,    0 ),
                          'STEYX'           => array( 314,    2,    2,    0 ),
                          'SLOPE'           => array( 315,    2,    2,    0 ),
                          'TTEST'           => array( 316,    4,    2,    0 ),
                          'PROB'            => array( 317,   -1,    2,    0 ),
                          'DEVSQ'           => array( 318,   -1,    0,    0 ),
                          'GEOMEAN'         => array( 319,   -1,    0,    0 ),
                          'HARMEAN'         => array( 320,   -1,    0,    0 ),
                          'SUMSQ'           => array( 321,   -1,    0,    0 ),
                          'KURT'            => array( 322,   -1,    0,    0 ),
                          'SKEW'            => array( 323,   -1,    0,    0 ),
                          'ZTEST'           => array( 324,   -1,    0,    0 ),
                          'LARGE'           => array( 325,    2,    0,    0 ),
                          'SMALL'           => array( 326,    2,    0,    0 ),
                          'QUARTILE'        => array( 327,    2,    0,    0 ),
                          'PERCENTILE'      => array( 328,    2,    0,    0 ),
                          'PERCENTRANK'     => array( 329,   -1,    0,    0 ),
                          'MODE'            => array( 330,   -1,    2,    0 ),
                          'TRIMMEAN'        => array( 331,    2,    0,    0 ),
                          'TINV'            => array( 332,    2,    1,    0 ),
                          'CONCATENATE'     => array( 336,   -1,    1,    0 ),
                          'POWER'           => array( 337,    2,    1,    0 ),
                          'RADIANS'         => array( 342,    1,    1,    0 ),
                          'DEGREES'         => array( 343,    1,    1,    0 ),
                          'SUBTOTAL'        => array( 344,   -1,    0,    0 ),
                          'SUMIF'           => array( 345,   -1,    0,    0 ),
                          'COUNTIF'         => array( 346,    2,    0,    0 ),
                          'COUNTBLANK'      => array( 347,    1,    0,    0 ),
                          'ISPMT'           => array( 350,    4,    1,    0 ),
                          'DATEDIF'         => array( 351,    3,    1,    0 ),
                          'DATESTRING'      => array( 352,    1,    1,    0 ),
                          'NUMBERSTRING'    => array( 353,    2,    1,    0 ),
                          'ROMAN'           => array( 354,   -1,    1,    0 ),
                          'GETPIVOTDATA'    => array( 358,   -1,    0,    0 ),
                          'HYPERLINK'       => array( 359,   -1,    1,    0 ),
                          'PHONETIC'        => array( 360,    1,    0,    0 ),
                          'AVERAGEA'        => array( 361,   -1,    0,    0 ),
                          'MAXA'            => array( 362,   -1,    0,    0 ),
                          'MINA'            => array( 363,   -1,    0,    0 ),
                          'STDEVPA'         => array( 364,   -1,    0,    0 ),
                          'VARPA'           => array( 365,   -1,    0,    0 ),
                          'STDEVA'          => array( 366,   -1,    0,    0 ),
                          'VARA'            => array( 367,   -1,    0,    0 ),
                          'BAHTTEXT'        => array( 368,    1,    0,    0 ),
                          );
        }

        /**
         * Convert a token to the proper ptg value.
         *
         * @access private
         * @param mixed $token The token to convert.
         * @return mixed the converted token on success
         */
        function _convert($token)
        {
                if (preg_match("/\"([^\"]|\"\"){0,255}\"/", $token)) {
                        return $this->_convertString($token);

                } elseif (is_numeric($token)) {
                        return $this->_convertNumber($token);

                // match references like A1 or $A$1
                } elseif (preg_match('/^\$?([A-Ia-i]?[A-Za-z])\$?(\d+)$/',$token)) {
                        return $this->_convertRef2d($token);

                // match external references like Sheet1!A1 or Sheet1:Sheet2!A1 or Sheet1!$A$1 or Sheet1:Sheet2!$A$1
                } elseif (preg_match("/^" . self::REGEX_SHEET_TITLE_UNQUOTED . "(\:" . self::REGEX_SHEET_TITLE_UNQUOTED . ")?\!\\$?[A-Ia-i]?[A-Za-z]\\$?(\d+)$/u",$token)) {
                        return $this->_convertRef3d($token);

                // match external references like 'Sheet1'!A1 or 'Sheet1:Sheet2'!A1 or 'Sheet1'!$A$1 or 'Sheet1:Sheet2'!$A$1
                } elseif (preg_match("/^'" . self::REGEX_SHEET_TITLE_QUOTED . "(\:" . self::REGEX_SHEET_TITLE_QUOTED . ")?'\!\\$?[A-Ia-i]?[A-Za-z]\\$?(\d+)$/u",$token)) {
                        return $this->_convertRef3d($token);

                // match ranges like A1:B2 or $A$1:$B$2
                } elseif (preg_match('/^(\$)?[A-Ia-i]?[A-Za-z](\$)?(\d+)\:(\$)?[A-Ia-i]?[A-Za-z](\$)?(\d+)$/', $token)) {
                        return $this->_convertRange2d($token);

                // match external ranges like Sheet1!A1:B2 or Sheet1:Sheet2!A1:B2 or Sheet1!$A$1:$B$2 or Sheet1:Sheet2!$A$1:$B$2
                } elseif (preg_match("/^" . self::REGEX_SHEET_TITLE_UNQUOTED . "(\:" . self::REGEX_SHEET_TITLE_UNQUOTED . ")?\!\\$?([A-Ia-i]?[A-Za-z])?\\$?(\d+)\:\\$?([A-Ia-i]?[A-Za-z])?\\$?(\d+)$/u",$token)) {
                        return $this->_convertRange3d($token);

                // match external ranges like 'Sheet1'!A1:B2 or 'Sheet1:Sheet2'!A1:B2 or 'Sheet1'!$A$1:$B$2 or 'Sheet1:Sheet2'!$A$1:$B$2
                } elseif (preg_match("/^'" . self::REGEX_SHEET_TITLE_QUOTED . "(\:" . self::REGEX_SHEET_TITLE_QUOTED . ")?'\!\\$?([A-Ia-i]?[A-Za-z])?\\$?(\d+)\:\\$?([A-Ia-i]?[A-Za-z])?\\$?(\d+)$/u",$token)) {
                        return $this->_convertRange3d($token);

                // operators (including parentheses)
                } elseif (isset($this->ptg[$token])) {
                        return pack("C", $this->ptg[$token]);

        // match error codes
                } elseif (preg_match("/^#[A-Z0\/]{3,5}[!?]{1}$/", $token) or $token == '#N/A') {
                    return $this->_convertError($token);

                // commented so argument number can be processed correctly. See toReversePolish().
                /*elseif (preg_match("/[A-Z0-9\xc0-\xdc\.]+/",$token))
                {
                        return($this->_convertFunction($token,$this->_func_args));
                }*/

                // if it's an argument, ignore the token (the argument remains)
                } elseif ($token == 'arg') {
                        return '';
                }

                // TODO: use real error codes
                throw new PHPExcel_Writer_Exception("Unknown token $token");
        }

        /**
         * Convert a number token to ptgInt or ptgNum
         *
         * @access private
         * @param mixed $num an integer or double for conversion to its ptg value
         */
        function _convertNumber($num)
        {
                // Integer in the range 0..2**16-1
                if ((preg_match("/^\d+$/", $num)) and ($num <= 65535)) {
                        return pack("Cv", $this->ptg['ptgInt'], $num);
                } else { // A float
                        if (PHPExcel_Writer_Excel5_BIFFwriter::getByteOrder()) { // if it's Big Endian
                                $num = strrev($num);
                        }
                        return pack("Cd", $this->ptg['ptgNum'], $num);
                }
        }

        /**
         * Convert a string token to ptgStr
         *
         * @access private
         * @param string $string A string for conversion to its ptg value.
         * @return mixed the converted token on success
         */
        function _convertString($string)
        {
                // chop away beggining and ending quotes
                $string = substr($string, 1, strlen($string) - 2);
                if (strlen($string) > 255) {
                        throw new PHPExcel_Writer_Exception("String is too long");
                }

                return pack('C', $this->ptg['ptgStr']) . PHPExcel_Shared_String::UTF8toBIFF8UnicodeShort($string);
        }

        /**
         * Convert a function to a ptgFunc or ptgFuncVarV depending on the number of
         * args that it takes.
         *
         * @access private
         * @param string  $token    The name of the function for convertion to ptg value.
         * @param integer $num_args The number of arguments the function receives.
         * @return string The packed ptg for the function
         */
        function _convertFunction($token, $num_args)
        {
                $args     = $this->_functions[$token][1];
//              $volatile = $this->_functions[$token][3];

                // Fixed number of args eg. TIME($i,$j,$k).
                if ($args >= 0) {
                        return pack("Cv", $this->ptg['ptgFuncV'], $this->_functions[$token][0]);
                }
                // Variable number of args eg. SUM($i,$j,$k, ..).
                if ($args == -1) {
                        return pack("CCv", $this->ptg['ptgFuncVarV'], $num_args, $this->_functions[$token][0]);
                }
        }

        /**
         * Convert an Excel range such as A1:D4 to a ptgRefV.
         *
         * @access private
         * @param string        $range  An Excel range in the A1:A2
         * @param int           $class
         */
        function _convertRange2d($range, $class=0)
        {

                // TODO: possible class value 0,1,2 check Formula.pm
                // Split the range into 2 cell refs
                if (preg_match('/^(\$)?([A-Ia-i]?[A-Za-z])(\$)?(\d+)\:(\$)?([A-Ia-i]?[A-Za-z])(\$)?(\d+)$/', $range)) {
                        list($cell1, $cell2) = explode(':', $range);
                } else {
                        // TODO: use real error codes
                        throw new PHPExcel_Writer_Exception("Unknown range separator");
                }

                // Convert the cell references
                list($row1, $col1) = $this->_cellToPackedRowcol($cell1);
                list($row2, $col2) = $this->_cellToPackedRowcol($cell2);

                // The ptg value depends on the class of the ptg.
                if ($class == 0) {
                        $ptgArea = pack("C", $this->ptg['ptgArea']);
                } elseif ($class == 1) {
                        $ptgArea = pack("C", $this->ptg['ptgAreaV']);
                } elseif ($class == 2) {
                        $ptgArea = pack("C", $this->ptg['ptgAreaA']);
                } else {
                        // TODO: use real error codes
                        throw new PHPExcel_Writer_Exception("Unknown class $class");
                }
                return $ptgArea . $row1 . $row2 . $col1. $col2;
        }

        /**
         * Convert an Excel 3d range such as "Sheet1!A1:D4" or "Sheet1:Sheet2!A1:D4" to
         * a ptgArea3d.
         *
         * @access private
         * @param string $token An Excel range in the Sheet1!A1:A2 format.
         * @return mixed The packed ptgArea3d token on success.
         */
        function _convertRange3d($token)
        {
//              $class = 0; // formulas like Sheet1!$A$1:$A$2 in list type data validation need this class (0x3B)

                // Split the ref at the ! symbol
                list($ext_ref, $range) = explode('!', $token);

                // Convert the external reference part (different for BIFF8)
                $ext_ref = $this->_getRefIndex($ext_ref);

                // Split the range into 2 cell refs
                list($cell1, $cell2) = explode(':', $range);

                // Convert the cell references
                if (preg_match("/^(\\$)?[A-Ia-i]?[A-Za-z](\\$)?(\d+)$/", $cell1)) {
                        list($row1, $col1) = $this->_cellToPackedRowcol($cell1);
                        list($row2, $col2) = $this->_cellToPackedRowcol($cell2);
                } else { // It's a rows range (like 26:27)
                         list($row1, $col1, $row2, $col2) = $this->_rangeToPackedRange($cell1.':'.$cell2);
                }

                // The ptg value depends on the class of the ptg.
//              if ($class == 0) {
                        $ptgArea = pack("C", $this->ptg['ptgArea3d']);
//              } elseif ($class == 1) {
//                      $ptgArea = pack("C", $this->ptg['ptgArea3dV']);
//              } elseif ($class == 2) {
//                      $ptgArea = pack("C", $this->ptg['ptgArea3dA']);
//              } else {
//                      throw new PHPExcel_Writer_Exception("Unknown class $class");
//              }

                return $ptgArea . $ext_ref . $row1 . $row2 . $col1. $col2;
        }

        /**
         * Convert an Excel reference such as A1, $B2, C$3 or $D$4 to a ptgRefV.
         *
         * @access private
         * @param string $cell An Excel cell reference
         * @return string The cell in packed() format with the corresponding ptg
         */
        function _convertRef2d($cell)
        {
//              $class = 2; // as far as I know, this is magick.

                // Convert the cell reference
                $cell_array = $this->_cellToPackedRowcol($cell);
                list($row, $col) = $cell_array;

                // The ptg value depends on the class of the ptg.
//              if ($class == 0) {
//                      $ptgRef = pack("C", $this->ptg['ptgRef']);
//              } elseif ($class == 1) {
//                      $ptgRef = pack("C", $this->ptg['ptgRefV']);
//              } elseif ($class == 2) {
                        $ptgRef = pack("C", $this->ptg['ptgRefA']);
//              } else {
//                      // TODO: use real error codes
//                      throw new PHPExcel_Writer_Exception("Unknown class $class");
//              }
                return $ptgRef.$row.$col;
        }

        /**
         * Convert an Excel 3d reference such as "Sheet1!A1" or "Sheet1:Sheet2!A1" to a
         * ptgRef3d.
         *
         * @access private
         * @param string $cell An Excel cell reference
         * @return mixed The packed ptgRef3d token on success.
         */
        function _convertRef3d($cell)
        {
//              $class = 2; // as far as I know, this is magick.

                // Split the ref at the ! symbol
                list($ext_ref, $cell) = explode('!', $cell);

                // Convert the external reference part (different for BIFF8)
                $ext_ref = $this->_getRefIndex($ext_ref);

                // Convert the cell reference part
                list($row, $col) = $this->_cellToPackedRowcol($cell);

                // The ptg value depends on the class of the ptg.
//              if ($class == 0) {
//                      $ptgRef = pack("C", $this->ptg['ptgRef3d']);
//              } elseif ($class == 1) {
//                      $ptgRef = pack("C", $this->ptg['ptgRef3dV']);
//              } elseif ($class == 2) {
                        $ptgRef = pack("C", $this->ptg['ptgRef3dA']);
//              } else {
//                      throw new PHPExcel_Writer_Exception("Unknown class $class");
//              }

                return $ptgRef . $ext_ref. $row . $col;
        }

    /**
     * Convert an error code to a ptgErr
     *
     * @access  private
         * @param       string  $errorCode      The error code for conversion to its ptg value
     * @return  string                          The error code ptgErr
     */
    function _convertError($errorCode)
    {
                switch ($errorCode) {
                        case '#NULL!':  return pack("C", 0x00);
                        case '#DIV/0!': return pack("C", 0x07);
                        case '#VALUE!': return pack("C", 0x0F);
                        case '#REF!':   return pack("C", 0x17);
                        case '#NAME?':  return pack("C", 0x1D);
                        case '#NUM!':   return pack("C", 0x24);
                        case '#N/A':    return pack("C", 0x2A);
                }
                return pack("C", 0xFF);
    }

        /**
         * Convert the sheet name part of an external reference, for example "Sheet1" or
         * "Sheet1:Sheet2", to a packed structure.
         *
         * @access      private
         * @param       string  $ext_ref        The name of the external reference
         * @return      string                          The reference index in packed() format
         */
        function _packExtRef($ext_ref)
        {
                $ext_ref = preg_replace("/^'/", '', $ext_ref); // Remove leading  ' if any.
                $ext_ref = preg_replace("/'$/", '', $ext_ref); // Remove trailing ' if any.

                // Check if there is a sheet range eg., Sheet1:Sheet2.
                if (preg_match("/:/", $ext_ref)) {
                        list($sheet_name1, $sheet_name2) = explode(':', $ext_ref);

                        $sheet1 = $this->_getSheetIndex($sheet_name1);
                        if ($sheet1 == -1) {
                                throw new PHPExcel_Writer_Exception("Unknown sheet name $sheet_name1 in formula");
                        }
                        $sheet2 = $this->_getSheetIndex($sheet_name2);
                        if ($sheet2 == -1) {
                                throw new PHPExcel_Writer_Exception("Unknown sheet name $sheet_name2 in formula");
                        }

                        // Reverse max and min sheet numbers if necessary
                        if ($sheet1 > $sheet2) {
                                list($sheet1, $sheet2) = array($sheet2, $sheet1);
                        }
                } else { // Single sheet name only.
                        $sheet1 = $this->_getSheetIndex($ext_ref);
                        if ($sheet1 == -1) {
                                throw new PHPExcel_Writer_Exception("Unknown sheet name $ext_ref in formula");
                        }
                        $sheet2 = $sheet1;
                }

                // References are stored relative to 0xFFFF.
                $offset = -1 - $sheet1;

                return pack('vdvv', $offset, 0x00, $sheet1, $sheet2);
        }

        /**
         * Look up the REF index that corresponds to an external sheet name
         * (or range). If it doesn't exist yet add it to the workbook's references
         * array. It assumes all sheet names given must exist.
         *
         * @access private
         * @param string $ext_ref The name of the external reference
         * @return mixed The reference index in packed() format on success
         */
        function _getRefIndex($ext_ref)
        {
                $ext_ref = preg_replace("/^'/", '', $ext_ref); // Remove leading  ' if any.
                $ext_ref = preg_replace("/'$/", '', $ext_ref); // Remove trailing ' if any.
                $ext_ref = str_replace('\'\'', '\'', $ext_ref); // Replace escaped '' with '

                // Check if there is a sheet range eg., Sheet1:Sheet2.
                if (preg_match("/:/", $ext_ref)) {
                        list($sheet_name1, $sheet_name2) = explode(':', $ext_ref);

                        $sheet1 = $this->_getSheetIndex($sheet_name1);
                        if ($sheet1 == -1) {
                                throw new PHPExcel_Writer_Exception("Unknown sheet name $sheet_name1 in formula");
                        }
                        $sheet2 = $this->_getSheetIndex($sheet_name2);
                        if ($sheet2 == -1) {
                                throw new PHPExcel_Writer_Exception("Unknown sheet name $sheet_name2 in formula");
                        }

                        // Reverse max and min sheet numbers if necessary
                        if ($sheet1 > $sheet2) {
                                list($sheet1, $sheet2) = array($sheet2, $sheet1);
                        }
                } else { // Single sheet name only.
                        $sheet1 = $this->_getSheetIndex($ext_ref);
                        if ($sheet1 == -1) {
                                throw new PHPExcel_Writer_Exception("Unknown sheet name $ext_ref in formula");
                        }
                        $sheet2 = $sheet1;
                }

                // assume all references belong to this document
                $supbook_index = 0x00;
                $ref = pack('vvv', $supbook_index, $sheet1, $sheet2);
                $total_references = count($this->_references);
                $index = -1;
                for ($i = 0; $i < $total_references; ++$i) {
                        if ($ref == $this->_references[$i]) {
                                $index = $i;
                                break;
                        }
                }
                // if REF was not found add it to references array
                if ($index == -1) {
                        $this->_references[$total_references] = $ref;
                        $index = $total_references;
                }

                return pack('v', $index);
        }

        /**
         * Look up the index that corresponds to an external sheet name. The hash of
         * sheet names is updated by the addworksheet() method of the
         * PHPExcel_Writer_Excel5_Workbook class.
         *
         * @access      private
         * @param       string  $sheet_name             Sheet name
         * @return      integer                                 The sheet index, -1 if the sheet was not found
         */
        function _getSheetIndex($sheet_name)
        {
                if (!isset($this->_ext_sheets[$sheet_name])) {
                        return -1;
                } else {
                        return $this->_ext_sheets[$sheet_name];
                }
        }

        /**
         * This method is used to update the array of sheet names. It is
         * called by the addWorksheet() method of the
         * PHPExcel_Writer_Excel5_Workbook class.
         *
         * @access public
         * @see PHPExcel_Writer_Excel5_Workbook::addWorksheet()
         * @param string  $name  The name of the worksheet being added
         * @param integer $index The index of the worksheet being added
         */
        function setExtSheet($name, $index)
        {
                $this->_ext_sheets[$name] = $index;
        }

        /**
         * pack() row and column into the required 3 or 4 byte format.
         *
         * @access private
         * @param string $cell The Excel cell reference to be packed
         * @return array Array containing the row and column in packed() format
         */
        function _cellToPackedRowcol($cell)
        {
                $cell = strtoupper($cell);
                list($row, $col, $row_rel, $col_rel) = $this->_cellToRowcol($cell);
                if ($col >= 256) {
                        throw new PHPExcel_Writer_Exception("Column in: $cell greater than 255");
                }
                if ($row >= 65536) {
                        throw new PHPExcel_Writer_Exception("Row in: $cell greater than 65536 ");
                }

                // Set the high bits to indicate if row or col are relative.
                $col |= $col_rel << 14;
                $col |= $row_rel << 15;
                $col = pack('v', $col);

                $row = pack('v', $row);

                return array($row, $col);
        }

        /**
         * pack() row range into the required 3 or 4 byte format.
         * Just using maximum col/rows, which is probably not the correct solution
         *
         * @access private
         * @param string $range The Excel range to be packed
         * @return array Array containing (row1,col1,row2,col2) in packed() format
         */
        function _rangeToPackedRange($range)
        {
                preg_match('/(\$)?(\d+)\:(\$)?(\d+)/', $range, $match);
                // return absolute rows if there is a $ in the ref
                $row1_rel = empty($match[1]) ? 1 : 0;
                $row1     = $match[2];
                $row2_rel = empty($match[3]) ? 1 : 0;
                $row2     = $match[4];
                // Convert 1-index to zero-index
                --$row1;
                --$row2;
                // Trick poor inocent Excel
                $col1 = 0;
                $col2 = 65535; // FIXME: maximum possible value for Excel 5 (change this!!!)

                // FIXME: this changes for BIFF8
                if (($row1 >= 65536) or ($row2 >= 65536)) {
                        throw new PHPExcel_Writer_Exception("Row in: $range greater than 65536 ");
                }

                // Set the high bits to indicate if rows are relative.
                $col1 |= $row1_rel << 15;
                $col2 |= $row2_rel << 15;
                $col1 = pack('v', $col1);
                $col2 = pack('v', $col2);

                $row1 = pack('v', $row1);
                $row2 = pack('v', $row2);

                return array($row1, $col1, $row2, $col2);
        }

        /**
         * Convert an Excel cell reference such as A1 or $B2 or C$3 or $D$4 to a zero
         * indexed row and column number. Also returns two (0,1) values to indicate
         * whether the row or column are relative references.
         *
         * @access private
         * @param string $cell The Excel cell reference in A1 format.
         * @return array
         */
        function _cellToRowcol($cell)
        {
                preg_match('/(\$)?([A-I]?[A-Z])(\$)?(\d+)/',$cell,$match);
                // return absolute column if there is a $ in the ref
                $col_rel = empty($match[1]) ? 1 : 0;
                $col_ref = $match[2];
                $row_rel = empty($match[3]) ? 1 : 0;
                $row     = $match[4];

                // Convert base26 column string to a number.
                $expn   = strlen($col_ref) - 1;
                $col    = 0;
                $col_ref_length = strlen($col_ref);
                for ($i = 0; $i < $col_ref_length; ++$i) {
                        $col += (ord($col_ref{$i}) - 64) * pow(26, $expn);
                        --$expn;
                }

                // Convert 1-index to zero-index
                --$row;
                --$col;

                return array($row, $col, $row_rel, $col_rel);
        }

        /**
         * Advance to the next valid token.
         *
         * @access private
         */
        function _advance()
        {
                $i = $this->_current_char;
                $formula_length = strlen($this->_formula);
                // eat up white spaces
                if ($i < $formula_length) {
                        while ($this->_formula{$i} == " ") {
                                ++$i;
                        }

                        if ($i < ($formula_length - 1)) {
                                $this->_lookahead = $this->_formula{$i+1};
                        }
                        $token = '';
                }

                while ($i < $formula_length) {
                        $token .= $this->_formula{$i};

                        if ($i < ($formula_length - 1)) {
                                $this->_lookahead = $this->_formula{$i+1};
                        } else {
                                $this->_lookahead = '';
                        }

                        if ($this->_match($token) != '') {
                                //if ($i < strlen($this->_formula) - 1) {
                                //    $this->_lookahead = $this->_formula{$i+1};
                                //}
                                $this->_current_char = $i + 1;
                                $this->_current_token = $token;
                                return 1;
                        }

                        if ($i < ($formula_length - 2)) {
                                $this->_lookahead = $this->_formula{$i+2};
                        } else { // if we run out of characters _lookahead becomes empty
                                $this->_lookahead = '';
                        }
                        ++$i;
                }
                //die("Lexical error ".$this->_current_char);
        }

        /**
         * Checks if it's a valid token.
         *
         * @access private
         * @param mixed $token The token to check.
         * @return mixed       The checked token or false on failure
         */
        function _match($token)
        {
                switch($token) {
                        case "+":
                        case "-":
                        case "*":
                        case "/":
                        case "(":
                        case ")":
                        case ",":
                        case ";":
                        case ">=":
                        case "<=":
                        case "=":
                        case "<>":
                        case "^":
                        case "&":
                        case "%":
                                return $token;
                                break;
                        case ">":
                                if ($this->_lookahead == '=') { // it's a GE token
                                        break;
                                }
                                return $token;
                                break;
                        case "<":
                                // it's a LE or a NE token
                                if (($this->_lookahead == '=') or ($this->_lookahead == '>')) {
                                        break;
                                }
                                return $token;
                                break;
                        default:
                                // if it's a reference A1 or $A$1 or $A1 or A$1
                                if (preg_match('/^\$?[A-Ia-i]?[A-Za-z]\$?[0-9]+$/',$token) and
                                   !preg_match("/[0-9]/",$this->_lookahead) and
                                   ($this->_lookahead != ':') and ($this->_lookahead != '.') and
                                   ($this->_lookahead != '!'))
                                {
                                        return $token;
                                }
                                // If it's an external reference (Sheet1!A1 or Sheet1:Sheet2!A1 or Sheet1!$A$1 or Sheet1:Sheet2!$A$1)
                                elseif (preg_match("/^" . self::REGEX_SHEET_TITLE_UNQUOTED . "(\:" . self::REGEX_SHEET_TITLE_UNQUOTED . ")?\!\\$?[A-Ia-i]?[A-Za-z]\\$?[0-9]+$/u",$token) and
                                           !preg_match("/[0-9]/",$this->_lookahead) and
                                           ($this->_lookahead != ':') and ($this->_lookahead != '.'))
                                {
                                        return $token;
                                }
                                // If it's an external reference ('Sheet1'!A1 or 'Sheet1:Sheet2'!A1 or 'Sheet1'!$A$1 or 'Sheet1:Sheet2'!$A$1)
                                elseif (preg_match("/^'" . self::REGEX_SHEET_TITLE_QUOTED . "(\:" . self::REGEX_SHEET_TITLE_QUOTED . ")?'\!\\$?[A-Ia-i]?[A-Za-z]\\$?[0-9]+$/u",$token) and
                                           !preg_match("/[0-9]/",$this->_lookahead) and
                                           ($this->_lookahead != ':') and ($this->_lookahead != '.'))
                                {
                                        return $token;
                                }
                                // if it's a range A1:A2 or $A$1:$A$2
                                elseif (preg_match('/^(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+:(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+$/', $token) and
                                           !preg_match("/[0-9]/",$this->_lookahead))
                                {
                                        return $token;
                                }
                                // If it's an external range like Sheet1!A1:B2 or Sheet1:Sheet2!A1:B2 or Sheet1!$A$1:$B$2 or Sheet1:Sheet2!$A$1:$B$2
                                elseif (preg_match("/^" . self::REGEX_SHEET_TITLE_UNQUOTED . "(\:" . self::REGEX_SHEET_TITLE_UNQUOTED . ")?\!\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+:\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+$/u",$token) and
                                           !preg_match("/[0-9]/",$this->_lookahead))
                                {
                                        return $token;
                                }
                                // If it's an external range like 'Sheet1'!A1:B2 or 'Sheet1:Sheet2'!A1:B2 or 'Sheet1'!$A$1:$B$2 or 'Sheet1:Sheet2'!$A$1:$B$2
                                elseif (preg_match("/^'" . self::REGEX_SHEET_TITLE_QUOTED . "(\:" . self::REGEX_SHEET_TITLE_QUOTED . ")?'\!\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+:\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+$/u",$token) and
                                           !preg_match("/[0-9]/",$this->_lookahead))
                                {
                                        return $token;
                                }
                                // If it's a number (check that it's not a sheet name or range)
                                elseif (is_numeric($token) and
                                                (!is_numeric($token.$this->_lookahead) or ($this->_lookahead == '')) and
                                                ($this->_lookahead != '!') and ($this->_lookahead != ':'))
                                {
                                        return $token;
                                }
                                // If it's a string (of maximum 255 characters)
                                elseif (preg_match("/\"([^\"]|\"\"){0,255}\"/",$token) and $this->_lookahead != '"' and (substr_count($token, '"')%2 == 0))
                                {
                                        return $token;
                                }
                            // If it's an error code
                            elseif (preg_match("/^#[A-Z0\/]{3,5}[!?]{1}$/", $token) or $token == '#N/A')
                            {
                                return $token;
                            }
                                // if it's a function call
                                elseif (preg_match("/^[A-Z0-9\xc0-\xdc\.]+$/i",$token) and ($this->_lookahead == "("))
                                {
                                        return $token;
                                }
                                //      It's an argument of some description (e.g. a named range),
                                //              precise nature yet to be determined
                                elseif(substr($token,-1) == ')') {
                                        return $token;
                                }
                                return '';
                }
        }

        /**
         * The parsing method. It parses a formula.
         *
         * @access public
         * @param string $formula The formula to parse, without the initial equal
         *                        sign (=).
         * @return mixed true on success
         */
        function parse($formula)
        {
                $this->_current_char = 0;
                $this->_formula      = $formula;
                $this->_lookahead    = isset($formula{1}) ? $formula{1} : '';
                $this->_advance();
                $this->_parse_tree   = $this->_condition();
                return true;
        }

        /**
         * It parses a condition. It assumes the following rule:
         * Cond -> Expr [(">" | "<") Expr]
         *
         * @access private
         * @return mixed The parsed ptg'd tree on success
         */
        function _condition()
        {
                $result = $this->_expression();
                if ($this->_current_token == "<") {
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgLT', $result, $result2);
                } elseif ($this->_current_token == ">") {
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgGT', $result, $result2);
                } elseif ($this->_current_token == "<=") {
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgLE', $result, $result2);
                } elseif ($this->_current_token == ">=") {
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgGE', $result, $result2);
                } elseif ($this->_current_token == "=") {
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgEQ', $result, $result2);
                } elseif ($this->_current_token == "<>") {
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgNE', $result, $result2);
                } elseif ($this->_current_token == "&") {
                    $this->_advance();
                    $result2 = $this->_expression();
                    $result = $this->_createTree('ptgConcat', $result, $result2);
                }
                return $result;
        }

        /**
         * It parses a expression. It assumes the following rule:
         * Expr -> Term [("+" | "-") Term]
         *      -> "string"
         *      -> "-" Term : Negative value
         *      -> "+" Term : Positive value
         *      -> Error code
         *
         * @access private
         * @return mixed The parsed ptg'd tree on success
         */
        function _expression()
        {
                // If it's a string return a string node
                if (preg_match("/\"([^\"]|\"\"){0,255}\"/", $this->_current_token)) {
                        $tmp = str_replace('""', '"', $this->_current_token);
                        if (($tmp == '"') || ($tmp == '')) $tmp = '""'; //      Trap for "" that has been used for an empty string
                        $result = $this->_createTree($tmp, '', '');
                        $this->_advance();
                        return $result;
        // If it's an error code
        } elseif (preg_match("/^#[A-Z0\/]{3,5}[!?]{1}$/", $this->_current_token) or $this->_current_token == '#N/A'){
                    $result = $this->_createTree($this->_current_token, 'ptgErr', '');
                    $this->_advance();
                    return $result;
                // If it's a negative value
        } elseif ($this->_current_token == "-") {
                        // catch "-" Term
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgUminus', $result2, '');
                        return $result;
        // If it's a positive value
                } elseif ($this->_current_token == "+") {
                        // catch "+" Term
                        $this->_advance();
                        $result2 = $this->_expression();
                        $result = $this->_createTree('ptgUplus', $result2, '');
                        return $result;
                }
                $result = $this->_term();
                while (($this->_current_token == "+") or
                           ($this->_current_token == "-") or
                           ($this->_current_token == "^")) {
                /**/
                        if ($this->_current_token == "+") {
                                $this->_advance();
                                $result2 = $this->_term();
                                $result = $this->_createTree('ptgAdd', $result, $result2);
                        } elseif ($this->_current_token == "-") {
                                $this->_advance();
                                $result2 = $this->_term();
                                $result = $this->_createTree('ptgSub', $result, $result2);
                        } else {
                                $this->_advance();
                                $result2 = $this->_term();
                                $result = $this->_createTree('ptgPower', $result, $result2);
                        }
                }
                return $result;
        }

        /**
         * This function just introduces a ptgParen element in the tree, so that Excel
         * doesn't get confused when working with a parenthesized formula afterwards.
         *
         * @access private
         * @see _fact()
         * @return array The parsed ptg'd tree
         */
        function _parenthesizedExpression()
        {
                $result = $this->_createTree('ptgParen', $this->_expression(), '');
                return $result;
        }

        /**
         * It parses a term. It assumes the following rule:
         * Term -> Fact [("*" | "/") Fact]
         *
         * @access private
         * @return mixed The parsed ptg'd tree on success
         */
        function _term()
        {
                $result = $this->_fact();
                while (($this->_current_token == "*") or
                           ($this->_current_token == "/")) {
                /**/
                        if ($this->_current_token == "*") {
                                $this->_advance();
                                $result2 = $this->_fact();
                                $result = $this->_createTree('ptgMul', $result, $result2);
                        } else {
                                $this->_advance();
                                $result2 = $this->_fact();
                                $result = $this->_createTree('ptgDiv', $result, $result2);
                        }
                }
                return $result;
        }

        /**
         * It parses a factor. It assumes the following rule:
         * Fact -> ( Expr )
         *       | CellRef
         *       | CellRange
         *       | Number
         *       | Function
         *
         * @access private
         * @return mixed The parsed ptg'd tree on success
         */
        function _fact()
        {
                if ($this->_current_token == "(") {
                        $this->_advance();         // eat the "("
                        $result = $this->_parenthesizedExpression();
                        if ($this->_current_token != ")") {
                                throw new PHPExcel_Writer_Exception("')' token expected.");
                        }
                        $this->_advance();         // eat the ")"
                        return $result;
                }
                // if it's a reference
                if (preg_match('/^\$?[A-Ia-i]?[A-Za-z]\$?[0-9]+$/',$this->_current_token))
                {
                        $result = $this->_createTree($this->_current_token, '', '');
                        $this->_advance();
                        return $result;
                }
                // If it's an external reference (Sheet1!A1 or Sheet1:Sheet2!A1 or Sheet1!$A$1 or Sheet1:Sheet2!$A$1)
                elseif (preg_match("/^" . self::REGEX_SHEET_TITLE_UNQUOTED . "(\:" . self::REGEX_SHEET_TITLE_UNQUOTED . ")?\!\\$?[A-Ia-i]?[A-Za-z]\\$?[0-9]+$/u",$this->_current_token))
                {
                        $result = $this->_createTree($this->_current_token, '', '');
                        $this->_advance();
                        return $result;
                }
                // If it's an external reference ('Sheet1'!A1 or 'Sheet1:Sheet2'!A1 or 'Sheet1'!$A$1 or 'Sheet1:Sheet2'!$A$1)
                elseif (preg_match("/^'" . self::REGEX_SHEET_TITLE_QUOTED . "(\:" . self::REGEX_SHEET_TITLE_QUOTED . ")?'\!\\$?[A-Ia-i]?[A-Za-z]\\$?[0-9]+$/u",$this->_current_token))
                {
                        $result = $this->_createTree($this->_current_token, '', '');
                        $this->_advance();
                        return $result;
                }
                // if it's a range A1:B2 or $A$1:$B$2
                elseif (preg_match('/^(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+:(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+$/',$this->_current_token) or
                                preg_match('/^(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+\.\.(\$)?[A-Ia-i]?[A-Za-z](\$)?[0-9]+$/',$this->_current_token))
                {
                        // must be an error?
                        $result = $this->_createTree($this->_current_token, '', '');
                        $this->_advance();
                        return $result;
                }
                // If it's an external range (Sheet1!A1:B2 or Sheet1:Sheet2!A1:B2 or Sheet1!$A$1:$B$2 or Sheet1:Sheet2!$A$1:$B$2)
                elseif (preg_match("/^" . self::REGEX_SHEET_TITLE_UNQUOTED . "(\:" . self::REGEX_SHEET_TITLE_UNQUOTED . ")?\!\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+:\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+$/u",$this->_current_token))
                {
                        // must be an error?
                        //$result = $this->_current_token;
                        $result = $this->_createTree($this->_current_token, '', '');
                        $this->_advance();
                        return $result;
                }
                // If it's an external range ('Sheet1'!A1:B2 or 'Sheet1'!A1:B2 or 'Sheet1'!$A$1:$B$2 or 'Sheet1'!$A$1:$B$2)
                elseif (preg_match("/^'" . self::REGEX_SHEET_TITLE_QUOTED . "(\:" . self::REGEX_SHEET_TITLE_QUOTED . ")?'\!\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+:\\$?([A-Ia-i]?[A-Za-z])?\\$?[0-9]+$/u",$this->_current_token))
                {
                        // must be an error?
                        //$result = $this->_current_token;
                        $result = $this->_createTree($this->_current_token, '', '');
                        $this->_advance();
                        return $result;
                }
                // If it's a number or a percent
                elseif (is_numeric($this->_current_token))
                {
                    if($this->_lookahead == '%'){
                        $result = $this->_createTree('ptgPercent', $this->_current_token, '');
                    } else {
                        $result = $this->_createTree($this->_current_token, '', '');
                    }
                    $this->_advance();
                    return $result;
                }
                // if it's a function call
                elseif (preg_match("/^[A-Z0-9\xc0-\xdc\.]+$/i",$this->_current_token))
                {
                        $result = $this->_func();
                        return $result;
                }
                throw new PHPExcel_Writer_Exception("Syntax error: ".$this->_current_token.
                                                                 ", lookahead: ".$this->_lookahead.
                                                                 ", current char: ".$this->_current_char);
        }

        /**
         * It parses a function call. It assumes the following rule:
         * Func -> ( Expr [,Expr]* )
         *
         * @access private
         * @return mixed The parsed ptg'd tree on success
         */
        function _func()
        {
                $num_args = 0; // number of arguments received
                $function = strtoupper($this->_current_token);
                $result   = ''; // initialize result
                $this->_advance();
                $this->_advance();         // eat the "("
                while ($this->_current_token != ')') {
                /**/
                        if ($num_args > 0) {
                                if ($this->_current_token == "," or
                                        $this->_current_token == ";")
                                {
                                        $this->_advance();  // eat the "," or ";"
                                } else {
                                        throw new PHPExcel_Writer_Exception("Syntax error: comma expected in ".
                                                                          "function $function, arg #{$num_args}");
                                }
                                $result2 = $this->_condition();
                                $result = $this->_createTree('arg', $result, $result2);
                        } else { // first argument
                                $result2 = $this->_condition();
                                $result = $this->_createTree('arg', '', $result2);
                        }
                        ++$num_args;
                }
                if (!isset($this->_functions[$function])) {
                        throw new PHPExcel_Writer_Exception("Function $function() doesn't exist");
                }
                $args = $this->_functions[$function][1];
                // If fixed number of args eg. TIME($i,$j,$k). Check that the number of args is valid.
                if (($args >= 0) and ($args != $num_args)) {
                        throw new PHPExcel_Writer_Exception("Incorrect number of arguments in function $function() ");
                }

                $result = $this->_createTree($function, $result, $num_args);
                $this->_advance();         // eat the ")"
                return $result;
        }

        /**
         * Creates a tree. In fact an array which may have one or two arrays (sub-trees)
         * as elements.
         *
         * @access private
         * @param mixed $value The value of this node.
         * @param mixed $left  The left array (sub-tree) or a final node.
         * @param mixed $right The right array (sub-tree) or a final node.
         * @return array A tree
         */
        function _createTree($value, $left, $right)
        {
                return array('value' => $value, 'left' => $left, 'right' => $right);
        }

        /**
         * Builds a string containing the tree in reverse polish notation (What you
         * would use in a HP calculator stack).
         * The following tree:
         *
         *    +
         *   / \
         *  2   3
         *
         * produces: "23+"
         *
         * The following tree:
         *
         *    +
         *   / \
         *  3   *
         *     / \
         *    6   A1
         *
         * produces: "36A1*+"
         *
         * In fact all operands, functions, references, etc... are written as ptg's
         *
         * @access public
         * @param array $tree The optional tree to convert.
         * @return string The tree in reverse polish notation
         */
        function toReversePolish($tree = array())
        {
                $polish = ""; // the string we are going to return
                if (empty($tree)) { // If it's the first call use _parse_tree
                        $tree = $this->_parse_tree;
                }

                if (is_array($tree['left'])) {
                        $converted_tree = $this->toReversePolish($tree['left']);
                        $polish .= $converted_tree;
                } elseif ($tree['left'] != '') { // It's a final node
                        $converted_tree = $this->_convert($tree['left']);
                        $polish .= $converted_tree;
                }
                if (is_array($tree['right'])) {
                        $converted_tree = $this->toReversePolish($tree['right']);
                        $polish .= $converted_tree;
                } elseif ($tree['right'] != '') { // It's a final node
                        $converted_tree = $this->_convert($tree['right']);
                        $polish .= $converted_tree;
                }
                // if it's a function convert it here (so we can set it's arguments)
                if (preg_match("/^[A-Z0-9\xc0-\xdc\.]+$/",$tree['value']) and
                        !preg_match('/^([A-Ia-i]?[A-Za-z])(\d+)$/',$tree['value']) and
                        !preg_match("/^[A-Ia-i]?[A-Za-z](\d+)\.\.[A-Ia-i]?[A-Za-z](\d+)$/",$tree['value']) and
                        !is_numeric($tree['value']) and
                        !isset($this->ptg[$tree['value']]))
                {
                        // left subtree for a function is always an array.
                        if ($tree['left'] != '') {
                                $left_tree = $this->toReversePolish($tree['left']);
                        } else {
                                $left_tree = '';
                        }
                        // add it's left subtree and return.
                        return $left_tree.$this->_convertFunction($tree['value'], $tree['right']);
                } else {
                        $converted_tree = $this->_convert($tree['value']);
                }
                $polish .= $converted_tree;
                return $polish;
        }

}