CssSelector::tokenize_selectors PHP Метод

    protected function tokenize_selectors($selector)
    {
        // split tokens by , except in an attribute selector
        $tokens = array();
        $quoted = false;
        $token = '';
        for ($i = 0, $max = strlen($selector); $i < $max; $i++) {
            if (',' == $selector[$i] && !$quoted) {
                $tokens[] = trim($token);
                $token = '';
            } elseif ('"' == $selector[$i]) {
                $token .= $selector[$i];
                $quoted = $quoted ? false : true;
            } else {
                $token .= $selector[$i];
            }
        }
        if ($token) {
            $tokens[] = trim($token);
        }
        return $tokens;
    }