Reliable way of finding if we are in RST or Markdown mode?

[LecrisUT]

I am trying to write an sphinx autodoc module with support for both rst and markdown, but I am hitting a wall w.r.t. finding out what is the current node's parser. Specifically we have 3 scenarios where the directive is being executed:

.. domain:autodoc:: path

```{domain:autodoc} path
```

```{eval-rst}
.. domain:autodoc:: path
```

Using env.parser.supports() it could work for the first 2 cases (not sure if the env is adjusted for each document?), but it fails for the 3rd because it is still a MystParser there. Another option would be to check state.state_machine, which seems more reliable, but it would be nice to have a method that does not rely on isinstance().

Anyone got some development tips here?