Use add-hook instead of add to list about poly-markdown

[czipperz]

Example code:

(add-hook 'markdown-mode-hook #'poly-markdown-mode)

[vspinu]

It's not needed in all markdown files. The canonical way is to extend the markdown mode and assoc into auto-mode alist.

https://github.com/polymode/poly-R/blob/master/poly-R.el#L92

You can add hook locally if you want but that will mess child modes and also modes which use markdown as host or (especially) innermode.

[czipperz]

Really we shouldn't be adding the hook at all, instead let the user enable it manually. That's what I've seen

[czipperz]

The canonical way is to extend the markdown mode and assoc into auto-mode alist.

That's definitely not something I've seen. magit-filenotify recommends add-hook. racer uses the same. The wiki recommends add-hook for paredit.

Where did you get this idea?

[vspinu]

That's definitely not something I've seen

You haven't seen enough. Those functionality enhancers designed as to be used in hooks. Polymodes are proper emacs modes. Emacs modes are installed in auto-mode alist. End of story.

If a polymode is intended to be used as a minor-mode then yes, it should be placed in a hook, but poly-markdown is generally not.

The technical reason that I have given above is a very severe one. If I load it in markdown hook then child modes like poly-markdown+r-mode will trigger poly-markdown-mode, if markdown-mode is used as a innermode it will trigger the poly-markdown-mode etc.