think\Template::parseBlock PHP Method

    private function parseBlock(&$content, $sort = false)
    {
        $regex = $this->getRegex('block');
        $result = [];
        if (preg_match_all($regex, $content, $matches, PREG_SET_ORDER | PREG_OFFSET_CAPTURE)) {
            $right = $keys = [];
            foreach ($matches as $match) {
                if (empty($match['name'][0])) {
                    if (count($right) > 0) {
                        $tag = array_pop($right);
                        $start = $tag['offset'] + strlen($tag['tag']);
                        $length = $match[0][1] - $start;
                        $result[$tag['name']] = ['begin' => $tag['tag'], 'content' => substr($content, $start, $length), 'end' => $match[0][0], 'parent' => count($right) ? end($right)['name'] : ''];
                        $keys[$tag['name']] = $match[0][1];
                    }
                } else {
                    // 标签头压入栈
                    $right[] = ['name' => $match[2][0], 'offset' => $match[0][1], 'tag' => $match[0][0]];
                }
            }
            unset($right, $matches);
            if ($sort) {
                // 按block标签结束符在模板中的位置排序
                array_multisort($keys, $result);
            }
        }
        return $result;
    }