public function __construct($encoding = null)
{
if (self::$utfMode === null) {
self::$utfMode = defined('BX_UTF');
}
if (self::$punycodePrefix === null) {
self::$punycodePrefix = "xn--";
self::$punycodePrefixLength = self::ByteLength(self::$punycodePrefix);
self::$punycodePrefixUcs4 = $this->Utf8ToUcs4(self::$punycodePrefix);
}
if (self::$prefixUcs4 === null) {
self::$prefixUcs4 = $this->Utf8ToUcs4(self::PREFIX);
}
if (self::$hyphenUcs4 === null) {
self::$hyphenUcs4 = $this->Utf8ToUcs4("-");
}
if (!is_null($encoding)) {
$this->encoding = $encoding;
} elseif (self::$utfMode) {
$this->encoding = "utf-8";
} elseif (defined("SITE_CHARSET") && strlen(SITE_CHARSET) > 0) {
$this->encoding = SITE_CHARSET;
} elseif (defined("LANG_CHARSET") && strlen(LANG_CHARSET) > 0) {
$this->encoding = LANG_CHARSET;
} else {
$this->encoding = "utf-8";
}
}