How do I auto-fill lines in brackets in emacs (markdown-mode)?

Question

I'm relatively new to Emacs, but have been experimenting with it to see if it would be worth switching. I write in Markdown and use pandoc to convert to whatever I need. In case it matters, I'm running Emacs 23.3.1 on Ubuntu 12.04.

I'm a graduate student in the humanities, so my writing is heavy on the footnotes. Footnotes, in pandoc, are formatted within square brackets. The problem I'm having is that auto-fill mode seems to ignore text within brackets, so my footnotes end up snaking their way across the page--and the only fix I've been able to find is to manually break the lines myself, every time I edit the paragraph. That's obviously less than ideal. (I could also give up on inline footnotes, and leave them all separate references, but I'd prefer not to, and it doesn't seem like that should be necessary.)

So my question is, is there a way to make auto-fill mode operate on text within brackets, too? Is there a reason it doesn't by default?

Many thanks,

-- Brian

Answer 1

Brian,

Add the following to your init file† to allow auto-fill in markdown-mode to break lines inside square brackets:

(require 'markdown-mode)
(defun markdown-nobreak-p () nil)

What we did is redefine the function "markdown-nobreak-p" (originally defined here: http://jblevins.org/git/markdown-mode.git/commit/?id=66566a55 ) to always return "nil" which means "yes you are allowed to break at this point". The original version of this function would return non-nil for points inside square brackets.

† http://www.gnu.org/software/emacs/manual/html_node/emacs/Find-Init.html

Answer 2

It turns out that markdown-mode, as of v. 1.7, deliberately avoids breaking lines in square brackets in order to avoid breaking links--which is the most common use of brackets for Markdown. See http://jblevins.org/projects/markdown-mode/rev-1-7.

Answer 3

Auto-fill by itself does not prevent filling inside brackets. It can be told to do so by the major-mode, tho, so I guess the problem depends on your major mode. If you're using mardown-mode, then please report this problem to its maintainer. In any case, you may want to try and use M-q to explicitly fill the paragraph, since it does not always follow the same conventions as auto-filling: it's more explicit than auto-fill, but still more automatic than placing the newlines by hand.