private function changeDelimiters($text, $index)
    {
        $startIndex = strpos($text, '=', $index) + 1;
        $close      = '=' . $this->ctag;
        $closeIndex = strpos($text, $close, $index);

        $this->setDelimiters(trim(substr($text, $startIndex, $closeIndex - $startIndex)));

        $this->tokens[] = array(
            self::TYPE => self::T_DELIM_CHANGE,
            self::LINE => $this->line,
        );

        return $closeIndex + strlen($close) - 1;
    }