<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2015 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_Shared
 * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    ##VERSION##, ##DATE##
 */


/**
 * PHPExcel_Shared_String
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Shared_String
{
    /**    Constants                */
    /**    Regular Expressions        */
    //    Fraction
    const STRING_REGEXP_FRACTION    = '(-?)(\d+)\s+(\d+\/\d+)';


    /**
     * Control characters array
     *
     * @var string[]
     */
    private static $_controlCharacters = array();

    /**
     * SYLK Characters array
     *
     * $var array
     */
    private static $_SYLKCharacters = array();

    /**
     * Decimal separator
     *
     * @var string
     */
    private static $_decimalSeparator;

    /**
     * Thousands separator
     *
     * @var string
     */
    private static $_thousandsSeparator;

    /**
     * Currency code
     *
     * @var string
     */
    private static $_currencyCode;

    /**
     * Is mbstring extension avalable?
     *
     * @var boolean
     */
    private static $_isMbstringEnabled;

    /**
     * Is iconv extension avalable?
     *
     * @var boolean
     */
    private static $_isIconvEnabled;

    /**
     * Build control characters array
     */
    private static function _buildControlCharacters()
    {
        for ($i = 0; $i <= 31; ++$i) {
            if ($i != 9 && $i != 10 && $i != 13) {
                $find = '_x' . sprintf('%04s', strtoupper(dechex($i))) . '_';
                $replace = chr($i);
                self::$_controlCharacters[$find] = $replace;
            }
        }
    }

    /**
     * Build SYLK characters array
     */
    private static function _buildSYLKCharacters()
    {
        self::$_SYLKCharacters = array(
            "\x1B 0"  => chr(0),
            "\x1B 1"  => chr(1),
            "\x1B 2"  => chr(2),
            "\x1B 3"  => chr(3),
            "\x1B 4"  => chr(4),
            "\x1B 5"  => chr(5),
            "\x1B 6"  => chr(6),
            "\x1B 7"  => chr(7),
            "\x1B 8"  => chr(8),
            "\x1B 9"  => chr(9),
            "\x1B :"  => chr(10),
            "\x1B ;"  => chr(11),
            "\x1B <"  => chr(12),
            "\x1B :"  => chr(13),
            "\x1B >"  => chr(14),
            "\x1B ?"  => chr(15),
            "\x1B!0"  => chr(16),
            "\x1B!1"  => chr(17),
            "\x1B!2"  => chr(18),
            "\x1B!3"  => chr(19),
            "\x1B!4"  => chr(20),
            "\x1B!5"  => chr(21),
            "\x1B!6"  => chr(22),
            "\x1B!7"  => chr(23),
            "\x1B!8"  => chr(24),
            "\x1B!9"  => chr(25),
            "\x1B!:"  => chr(26),
            "\x1B!;"  => chr(27),
            "\x1B!<"  => chr(28),
            "\x1B!="  => chr(29),
            "\x1B!>"  => chr(30),
            "\x1B!?"  => chr(31),
            "\x1B'?"  => chr(127),
            "\x1B(0"  => '€', // 128 in CP1252
            "\x1B(2"  => '‚', // 130 in CP1252
            "\x1B(3"  => 'ƒ', // 131 in CP1252
            "\x1B(4"  => '„', // 132 in CP1252
            "\x1B(5"  => '…', // 133 in CP1252
            "\x1B(6"  => '†', // 134 in CP1252
            "\x1B(7"  => '‡', // 135 in CP1252
            "\x1B(8"  => 'ˆ', // 136 in CP1252
            "\x1B(9"  => '‰', // 137 in CP1252
            "\x1B(:"  => 'Š', // 138 in CP1252
            "\x1B(;"  => '‹', // 139 in CP1252
            "\x1BNj"  => 'Œ', // 140 in CP1252
            "\x1B(>"  => 'Ž', // 142 in CP1252
            "\x1B)1"  => '‘', // 145 in CP1252
            "\x1B)2"  => '’', // 146 in CP1252
            "\x1B)3"  => '“', // 147 in CP1252
            "\x1B)4"  => '”', // 148 in CP1252
            "\x1B)5"  => '•', // 149 in CP1252
            "\x1B)6"  => '–', // 150 in CP1252
            "\x1B)7"  => '—', // 151 in CP1252
            "\x1B)8"  => '˜', // 152 in CP1252
            "\x1B)9"  => '™', // 153 in CP1252
            "\x1B):"  => 'š', // 154 in CP1252
            "\x1B);"  => '›', // 155 in CP1252
            "\x1BNz"  => 'œ', // 156 in CP1252
            "\x1B)>"  => 'ž', // 158 in CP1252
            "\x1B)?"  => 'Ÿ', // 159 in CP1252
            "\x1B*0"  => ' ', // 160 in CP1252
            "\x1BN!"  => '¡', // 161 in CP1252
            "\x1BN\"" => '¢', // 162 in CP1252
            "\x1BN#"  => '£', // 163 in CP1252
            "\x1BN("  => '¤', // 164 in CP1252
            "\x1BN%"  => '¥', // 165 in CP1252
            "\x1B*6"  => '¦', // 166 in CP1252
            "\x1BN'"  => '§', // 167 in CP1252
            "\x1BNH " => '¨', // 168 in CP1252
            "\x1BNS"  => '©', // 169 in CP1252
            "\x1BNc"  => 'ª', // 170 in CP1252
            "\x1BN+"  => '«', // 171 in CP1252
            "\x1B*<"  => '¬', // 172 in CP1252
            "\x1B*="  => '­', // 173 in CP1252
            "\x1BNR"  => '®', // 174 in CP1252
            "\x1B*?"  => '¯', // 175 in CP1252
            "\x1BN0"  => '°', // 176 in CP1252
            "\x1BN1"  => '±', // 177 in CP1252
            "\x1BN2"  => '²', // 178 in CP1252
            "\x1BN3"  => '³', // 179 in CP1252
            "\x1BNB " => '´', // 180 in CP1252
            "\x1BN5"  => 'µ', // 181 in CP1252
            "\x1BN6"  => '¶', // 182 in CP1252
            "\x1BN7"  => '·', // 183 in CP1252
            "\x1B+8"  => '¸', // 184 in CP1252
            "\x1BNQ"  => '¹', // 185 in CP1252
            "\x1BNk"  => 'º', // 186 in CP1252
            "\x1BN;"  => '»', // 187 in CP1252
            "\x1BN<"  => '¼', // 188 in CP1252
            "\x1BN="  => '½', // 189 in CP1252
            "\x1BN>"  => '¾', // 190 in CP1252
            "\x1BN?"  => '¿', // 191 in CP1252
            "\x1BNAA" => 'À', // 192 in CP1252
            "\x1BNBA" => 'Á', // 193 in CP1252
            "\x1BNCA" => 'Â', // 194 in CP1252
            "\x1BNDA" => 'Ã', // 195 in CP1252
            "\x1BNHA" => 'Ä', // 196 in CP1252
            "\x1BNJA" => 'Å', // 197 in CP1252
            "\x1BNa"  => 'Æ', // 198 in CP1252
            "\x1BNKC" => 'Ç', // 199 in CP1252
            "\x1BNAE" => 'È', // 200 in CP1252
            "\x1BNBE" => 'É', // 201 in CP1252
            "\x1BNCE" => 'Ê', // 202 in CP1252
            "\x1BNHE" => 'Ë', // 203 in CP1252
            "\x1BNAI" => 'Ì', // 204 in CP1252
            "\x1BNBI" => 'Í', // 205 in CP1252
            "\x1BNCI" => 'Î', // 206 in CP1252
            "\x1BNHI" => 'Ï', // 207 in CP1252
            "\x1BNb"  => 'Ð', // 208 in CP1252
            "\x1BNDN" => 'Ñ', // 209 in CP1252
            "\x1BNAO" => 'Ò', // 210 in CP1252
            "\x1BNBO" => 'Ó', // 211 in CP1252
            "\x1BNCO" => 'Ô', // 212 in CP1252
            "\x1BNDO" => 'Õ', // 213 in CP1252
            "\x1BNHO" => 'Ö', // 214 in CP1252
            "\x1B-7"  => '×', // 215 in CP1252
            "\x1BNi"  => 'Ø', // 216 in CP1252
            "\x1BNAU" => 'Ù', // 217 in CP1252
            "\x1BNBU" => 'Ú', // 218 in CP1252
            "\x1BNCU" => 'Û', // 219 in CP1252
            "\x1BNHU" => 'Ü', // 220 in CP1252
            "\x1B-="  => 'Ý', // 221 in CP1252
            "\x1BNl"  => 'Þ', // 222 in CP1252
            "\x1BN{"  => 'ß', // 223 in CP1252
            "\x1BNAa" => 'à', // 224 in CP1252
            "\x1BNBa" => 'á', // 225 in CP1252
            "\x1BNCa" => 'â', // 226 in CP1252
            "\x1BNDa" => 'ã', // 227 in CP1252
            "\x1BNHa" => 'ä', // 228 in CP1252
            "\x1BNJa" => 'å', // 229 in CP1252
            "\x1BNq"  => 'æ', // 230 in CP1252
            "\x1BNKc" => 'ç', // 231 in CP1252
            "\x1BNAe" => 'è', // 232 in CP1252
            "\x1BNBe" => 'é', // 233 in CP1252
            "\x1BNCe" => 'ê', // 234 in CP1252
            "\x1BNHe" => 'ë', // 235 in CP1252
            "\x1BNAi" => 'ì', // 236 in CP1252
            "\x1BNBi" => 'í', // 237 in CP1252
            "\x1BNCi" => 'î', // 238 in CP1252
            "\x1BNHi" => 'ï', // 239 in CP1252
            "\x1BNs"  => 'ð', // 240 in CP1252
            "\x1BNDn" => 'ñ', // 241 in CP1252
            "\x1BNAo" => 'ò', // 242 in CP1252
            "\x1BNBo" => 'ó', // 243 in CP1252
            "\x1BNCo" => 'ô', // 244 in CP1252
            "\x1BNDo" => 'õ', // 245 in CP1252
            "\x1BNHo" => 'ö', // 246 in CP1252
            "\x1B/7"  => '÷', // 247 in CP1252
            "\x1BNy"  => 'ø', // 248 in CP1252
            "\x1BNAu" => 'ù', // 249 in CP1252
            "\x1BNBu" => 'ú', // 250 in CP1252
            "\x1BNCu" => 'û', // 251 in CP1252
            "\x1BNHu" => 'ü', // 252 in CP1252
            "\x1B/="  => 'ý', // 253 in CP1252
            "\x1BN|"  => 'þ', // 254 in CP1252
            "\x1BNHy" => 'ÿ', // 255 in CP1252
        );
    }

    /**
     * Get whether mbstring extension is available
     *
     * @return boolean
     */
    public static function getIsMbstringEnabled()
    {
        if (isset(self::$_isMbstringEnabled)) {
            return self::$_isMbstringEnabled;
        }

        self::$_isMbstringEnabled = function_exists('mb_convert_encoding') ?
            true : false;

        return self::$_isMbstringEnabled;
    }

    /**
     * Get whether iconv extension is available
     *
     * @return boolean
     */
    public static function getIsIconvEnabled()
    {
        if (isset(self::$_isIconvEnabled)) {
            return self::$_isIconvEnabled;
        }

        // Fail if iconv doesn't exist
        if (!function_exists('iconv')) {
            self::$_isIconvEnabled = false;
            return false;
        }

        // Sometimes iconv is not working, and e.g. iconv('UTF-8', 'UTF-16LE', 'x') just returns false,
        if (!@iconv('UTF-8', 'UTF-16LE', 'x')) {
            self::$_isIconvEnabled = false;
            return false;
        }

        // Sometimes iconv_substr('A', 0, 1, 'UTF-8') just returns false in PHP 5.2.0
        // we cannot use iconv in that case either (http://bugs.php.net/bug.php?id=37773)
        if (!@iconv_substr('A', 0, 1, 'UTF-8')) {
            self::$_isIconvEnabled = false;
            return false;
        }

        // CUSTOM: IBM AIX iconv() does not work
        if (defined('PHP_OS') && @stristr(PHP_OS, 'AIX') && defined('ICONV_IMPL') && (@strcasecmp(ICONV_IMPL, 'unknown') == 0) && defined('ICONV_VERSION') && (@strcasecmp(ICONV_VERSION, 'unknown') == 0)) {
            self::$_isIconvEnabled = false;
            return false;
        }

        // If we reach here no problems were detected with iconv
        self::$_isIconvEnabled = true;
        return true;
    }

    public static function buildCharacterSets()
    {
        if (empty(self::$_controlCharacters)) {
            self::_buildControlCharacters();
        }
        if (empty(self::$_SYLKCharacters)) {
            self::_buildSYLKCharacters();
        }
    }

    /**
     * Convert from OpenXML escaped control character to PHP control character
     *
     * Excel 2007 team:
     * ----------------
     * That's correct, control characters are stored directly in the shared-strings table.
     * We do encode characters that cannot be represented in XML using the following escape sequence:
     * _xHHHH_ where H represents a hexadecimal character in the character's value...
     * So you could end up with something like _x0008_ in a string (either in a cell value (<v>)
     * element or in the shared string <t> element.
     *
     * @param     string    $value    Value to unescape
     * @return     string
     */
    public static function ControlCharacterOOXML2PHP($value = '')
    {
        return str_replace(array_keys(self::$_controlCharacters), array_values(self::$_controlCharacters), $value);
    }

    /**
     * Convert from PHP control character to OpenXML escaped control character
     *
     * Excel 2007 team:
     * ----------------
     * That's correct, control characters are stored directly in the shared-strings table.
     * We do encode characters that cannot be represented in XML using the following escape sequence:
     * _xHHHH_ where H represents a hexadecimal character in the character's value...
     * So you could end up with something like _x0008_ in a string (either in a cell value (<v>)
     * element or in the shared string <t> element.
     *
     * @param     string    $value    Value to escape
     * @return     string
     */
    public static function ControlCharacterPHP2OOXML($value = '')
    {
        return str_replace(array_values(self::$_controlCharacters), array_keys(self::$_controlCharacters), $value);
    }

    /**
     * Try to sanitize UTF8, stripping invalid byte sequences. Not perfect. Does not surrogate characters.
     *
     * @param string $value
     * @return string
     */
    public static function SanitizeUTF8($value)
    {
        if (self::getIsIconvEnabled()) {
            $value = @iconv('UTF-8', 'UTF-8', $value);
            return $value;
        }

        if (self::getIsMbstringEnabled()) {
            $value = mb_convert_encoding($value, 'UTF-8', 'UTF-8');
            return $value;
        }

        // else, no conversion
        return $value;
    }

    /**
     * Check if a string contains UTF8 data
     *
     * @param string $value
     * @return boolean
     */
    public static function IsUTF8($value = '')
    {
        return $value === '' || preg_match('/^./su', $value) === 1;
    }

    /**
     * Formats a numeric value as a string for output in various output writers forcing
     * point as decimal separator in case locale is other than English.
     *
     * @param mixed $value
     * @return string
     */
    public static function FormatNumber($value)
    {
        if (is_float($value)) {
            return str_replace(',', '.', $value);
        }
        return (string) $value;
    }

    /**
     * Converts a UTF-8 string into BIFF8 Unicode string data (8-bit string length)
     * Writes the string using uncompressed notation, no rich text, no Asian phonetics
     * If mbstring extension is not available, ASCII is assumed, and compressed notation is used
     * although this will give wrong results for non-ASCII strings
     * see OpenOffice.org's Documentation of the Microsoft Excel File Format, sect. 2.5.3
     *
     * @param string  $value    UTF-8 encoded string
     * @param mixed[] $arrcRuns Details of rich text runs in $value
     * @return string
     */
    public static function UTF8toBIFF8UnicodeShort($value, $arrcRuns = array())
    {
        // character count
        $ln = self::CountCharacters($value, 'UTF-8');
        // option flags
        if (empty($arrcRuns)) {
            $opt = (self::getIsIconvEnabled() || self::getIsMbstringEnabled()) ?
                0x0001 : 0x0000;
            $data = pack('CC', $ln, $opt);
            // characters
            $data .= self::ConvertEncoding($value, 'UTF-16LE', 'UTF-8');
        } else {
            $data = pack('vC', $ln, 0x09);
            $data .= pack('v', count($arrcRuns));
            // characters
            $data .= self::ConvertEncoding($value, 'UTF-16LE', 'UTF-8');
            foreach ($arrcRuns as $cRun) {
                $data .= pack('v', $cRun['strlen']);
                $data .= pack('v', $cRun['fontidx']);
            }
        }
        return $data;
    }

    /**
     * Converts a UTF-8 string into BIFF8 Unicode string data (16-bit string length)
     * Writes the string using uncompressed notation, no rich text, no Asian phonetics
     * If mbstring extension is not available, ASCII is assumed, and compressed notation is used
     * although this will give wrong results for non-ASCII strings
     * see OpenOffice.org's Documentation of the Microsoft Excel File Format, sect. 2.5.3
     *
     * @param string $value UTF-8 encoded string
     * @return string
     */
    public static function UTF8toBIFF8UnicodeLong($value)
    {
        // character count
        $ln = self::CountCharacters($value, 'UTF-8');

        // option flags
        $opt = (self::getIsIconvEnabled() || self::getIsMbstringEnabled()) ?
            0x0001 : 0x0000;

        // characters
        $chars = self::ConvertEncoding($value, 'UTF-16LE', 'UTF-8');

        $data = pack('vC', $ln, $opt) . $chars;
        return $data;
    }

    /**
     * Convert string from one encoding to another. First try mbstring, then iconv, finally strlen
     *
     * @param string $value
     * @param string $to Encoding to convert to, e.g. 'UTF-8'
     * @param string $from Encoding to convert from, e.g. 'UTF-16LE'
     * @return string
     */
    public static function ConvertEncoding($value, $to, $from)
    {
        if (self::getIsIconvEnabled()) {
            return iconv($from, $to, $value);
        }

        if (self::getIsMbstringEnabled()) {
            return mb_convert_encoding($value, $to, $from);
        }

        if ($from == 'UTF-16LE') {
            return self::utf16_decode($value, false);
        } else if ($from == 'UTF-16BE') {
            return self::utf16_decode($value);
        }
        // else, no conversion
        return $value;
    }

    /**
     * Decode UTF-16 encoded strings.
     *
     * Can handle both BOM'ed data and un-BOM'ed data.
     * Assumes Big-Endian byte order if no BOM is available.
     * This function was taken from http://php.net/manual/en/function.utf8-decode.php
     * and $bom_be parameter added.
     *
     * @param   string  $str  UTF-16 encoded data to decode.
     * @return  string  UTF-8 / ISO encoded data.
     * @access  public
     * @version 0.2 / 2010-05-13
     * @author  Rasmus Andersson {@link http://rasmusandersson.se/}
     * @author vadik56
     */
    public static function utf16_decode($str, $bom_be = TRUE) {
        if (strlen($str) < 2) {
            return $str;
        }
        $c0 = ord($str{0});
        $c1 = ord($str{1});
        if ($c0 == 0xfe && $c1 == 0xff) {
            $str = substr($str,2);
        } elseif ($c0 == 0xff && $c1 == 0xfe) {
            $str = substr($str,2);
            $bom_be = false;
        }
        $len = strlen($str);
        $newstr = '';
        for($i=0;$i<$len;$i+=2) {
            if ($bom_be) {
                $val = ord($str{$i})   << 4;
                $val += ord($str{$i+1});
            } else {
                $val = ord($str{$i+1}) << 4;
                $val += ord($str{$i});
            }
            $newstr .= ($val == 0x228) ? "\n" : chr($val);
        }
        return $newstr;
    }

    /**
     * Get character count. First try mbstring, then iconv, finally strlen
     *
     * @param string $value
     * @param string $enc Encoding
     * @return int Character count
     */
    public static function CountCharacters($value, $enc = 'UTF-8')
    {
        if (self::getIsMbstringEnabled()) {
            return mb_strlen($value, $enc);
        }

        if (self::getIsIconvEnabled()) {
            return iconv_strlen($value, $enc);
        }

        // else strlen
        return strlen($value);
    }

    /**
     * Get a substring of a UTF-8 encoded string. First try mbstring, then iconv, finally strlen
     *
     * @param string $pValue UTF-8 encoded string
     * @param int $pStart Start offset
     * @param int $pLength Maximum number of characters in substring
     * @return string
     */
    public static function Substring($pValue = '', $pStart = 0, $pLength = 0)
    {
        if (self::getIsMbstringEnabled()) {
            return mb_substr($pValue, $pStart, $pLength, 'UTF-8');
        }

        if (self::getIsIconvEnabled()) {
            return iconv_substr($pValue, $pStart, $pLength, 'UTF-8');
        }

        // else substr
        return substr($pValue, $pStart, $pLength);
    }

    /**
     * Convert a UTF-8 encoded string to upper case
     *
     * @param string $pValue UTF-8 encoded string
     * @return string
     */
    public static function StrToUpper($pValue = '')
    {
        if (function_exists('mb_convert_case')) {
            return mb_convert_case($pValue, MB_CASE_UPPER, "UTF-8");
        }
        return strtoupper($pValue);
    }

    /**
     * Convert a UTF-8 encoded string to lower case
     *
     * @param string $pValue UTF-8 encoded string
     * @return string
     */
    public static function StrToLower($pValue = '')
    {
        if (function_exists('mb_convert_case')) {
            return mb_convert_case($pValue, MB_CASE_LOWER, "UTF-8");
        }
        return strtolower($pValue);
    }

    /**
     * Convert a UTF-8 encoded string to title/proper case
     *    (uppercase every first character in each word, lower case all other characters)
     *
     * @param string $pValue UTF-8 encoded string
     * @return string
     */
    public static function StrToTitle($pValue = '')
    {
        if (function_exists('mb_convert_case')) {
            return mb_convert_case($pValue, MB_CASE_TITLE, "UTF-8");
        }
        return ucwords($pValue);
    }

    public static function mb_is_upper($char)
    {
        return mb_strtolower($char, "UTF-8") != $char;
    }

    public static function mb_str_split($string)
    {
        # Split at all position not after the start: ^
        # and not before the end: $
        return preg_split('/(?<!^)(?!$)/u', $string);
    }

    /**
     * Reverse the case of a string, so that all uppercase characters become lowercase
     *    and all lowercase characters become uppercase
     *
     * @param string $pValue UTF-8 encoded string
     * @return string
     */
    public static function StrCaseReverse($pValue = '')
    {
        if (self::getIsMbstringEnabled()) {
            $characters = self::mb_str_split($pValue);
            foreach ($characters as &$character) {
                if (self::mb_is_upper($character)) {
                    $character = mb_strtolower($character, 'UTF-8');
                } else {
                    $character = mb_strtoupper($character, 'UTF-8');
                }
            }
            return implode('', $characters);
        }
        return strtolower($pValue) ^ strtoupper($pValue) ^ $pValue;
    }

    /**
     * Identify whether a string contains a fractional numeric value,
     *    and convert it to a numeric if it is
     *
     * @param string &$operand string value to test
     * @return boolean
     */
    public static function convertToNumberIfFraction(&$operand)
    {
        if (preg_match('/^'.self::STRING_REGEXP_FRACTION.'$/i', $operand, $match)) {
            $sign = ($match[1] == '-') ? '-' : '+';
            $fractionFormula = '='.$sign.$match[2].$sign.$match[3];
            $operand = PHPExcel_Calculation::getInstance()->_calculateFormulaValue($fractionFormula);
            return true;
        }
        return false;
    }    //    function convertToNumberIfFraction()

    /**
     * Get the decimal separator. If it has not yet been set explicitly, try to obtain number
     * formatting information from locale.
     *
     * @return string
     */
    public static function getDecimalSeparator()
    {
        if (!isset(self::$_decimalSeparator)) {
            $localeconv = localeconv();
            self::$_decimalSeparator = ($localeconv['decimal_point'] != '')
                ? $localeconv['decimal_point'] : $localeconv['mon_decimal_point'];

            if (self::$_decimalSeparator == '') {
                // Default to .
                self::$_decimalSeparator = '.';
            }
        }
        return self::$_decimalSeparator;
    }

    /**
     * Set the decimal separator. Only used by PHPExcel_Style_NumberFormat::toFormattedString()
     * to format output by PHPExcel_Writer_HTML and PHPExcel_Writer_PDF
     *
     * @param string $pValue Character for decimal separator
     */
    public static function setDecimalSeparator($pValue = '.')
    {
        self::$_decimalSeparator = $pValue;
    }

    /**
     * Get the thousands separator. If it has not yet been set explicitly, try to obtain number
     * formatting information from locale.
     *
     * @return string
     */
    public static function getThousandsSeparator()
    {
        if (!isset(self::$_thousandsSeparator)) {
            $localeconv = localeconv();
            self::$_thousandsSeparator = ($localeconv['thousands_sep'] != '')
                ? $localeconv['thousands_sep'] : $localeconv['mon_thousands_sep'];

            if (self::$_thousandsSeparator == '') {
                // Default to .
                self::$_thousandsSeparator = ',';
            }
        }
        return self::$_thousandsSeparator;
    }

    /**
     * Set the thousands separator. Only used by PHPExcel_Style_NumberFormat::toFormattedString()
     * to format output by PHPExcel_Writer_HTML and PHPExcel_Writer_PDF
     *
     * @param string $pValue Character for thousands separator
     */
    public static function setThousandsSeparator($pValue = ',')
    {
        self::$_thousandsSeparator = $pValue;
    }

    /**
     *    Get the currency code. If it has not yet been set explicitly, try to obtain the
     *        symbol information from locale.
     *
     * @return string
     */
    public static function getCurrencyCode()
    {
        if (!isset(self::$_currencyCode)) {
            $localeconv = localeconv();
            self::$_currencyCode = ($localeconv['currency_symbol'] != '')
                ? $localeconv['currency_symbol'] : $localeconv['int_curr_symbol'];

            if (self::$_currencyCode == '') {
                // Default to $
                self::$_currencyCode = '$';
            }
        }
        return self::$_currencyCode;
    }

    /**
     * Set the currency code. Only used by PHPExcel_Style_NumberFormat::toFormattedString()
     *        to format output by PHPExcel_Writer_HTML and PHPExcel_Writer_PDF
     *
     * @param string $pValue Character for currency code
     */
    public static function setCurrencyCode($pValue = '$')
    {
        self::$_currencyCode = $pValue;
    }

    /**
     * Convert SYLK encoded string to UTF-8
     *
     * @param string $pValue
     * @return string UTF-8 encoded string
     */
    public static function SYLKtoUTF8($pValue = '')
    {
        // If there is no escape character in the string there is nothing to do
        if (strpos($pValue, '') === false) {
            return $pValue;
        }

        foreach (self::$_SYLKCharacters as $k => $v) {
            $pValue = str_replace($k, $v, $pValue);
        }

        return $pValue;
    }

    /**
     * Retrieve any leading numeric part of a string, or return the full string if no leading numeric
     *    (handles basic integer or float, but not exponent or non decimal)
     *
     * @param    string    $value
     * @return    mixed    string or only the leading numeric part of the string
     */
    public static function testStringAsNumeric($value)
    {
        if (is_numeric($value)) {
            return $value;
        }
        $v = floatval($value);
        return (is_numeric(substr($value, 0, strlen($v)))) ? $v : $value;
    }
}