Emacs ESS Mode - Tabbing for Comment Region

Question

I am using the Emacs-Speaks-Statistics (ESS) mode for Emacs. When editing R code, any comment lines (those starting with #) automatically get tabbed to the far right when I create a new line above it. How should I change my .emacs.el file to fix this?

For example, I have:

# Comment

Now, after putting my cursor at the beginning of the line and pressing Enter, I get:

                                # Comment

Thanks for any hints.

Brosy

Answer 1

Use '###' if you don't want the comments indented. According to the manual,

By default, comments beginning with ‘###’ are aligned to the beginning of the line. Comments beginning with ‘##’ are aligned to the current level of indentation for the block containing the comment. Finally, comments beginning with ‘#’ are aligned to a column on the right (the 40th column by default, but this value is controlled by the variable comment-column,) or just after the expression on the line containing the comment if it extends beyond the indentation column.

Diddle

I am glad I looked before asking this exact same question. I marked up this answer because I think it is really a better solution than the answer above. I have long thought this was a bug / problem with ESS mode, but after tweaking my syntax, my problems have all gone away. – Fabrienne

This convention may seem odd if you do not use Emacs much. However, this convention comes from lisp and emacs-lisp, where the number of semi-colons denotes the type of comment, and hence how it should be indented. – Kvass

Answer 2

Either

(setq ess-fancy-comments nil)

if you never want to indent single-# comments, or

(add-hook 'ess-mode-hook 
          (lambda () 
            (local-set-key (kbd "RET") 'newline)))

if you want to change the behavior of Enter so it doesn't indent.

Latticework

Rather I think you should use "#" for end-of-line comments, and these are nicely indented to the same column on purpose --> nice code "listing". For the other comments, really do get in to the habit of using "##" (much more than "###"): These indent as other "statements" within that block of code – Hulda

I'm still in favour of deciding how many #s I should use. One is generally sufficient so this answer is greatly appreciated as my comment is not moved to a location I don't want it to be... – Chlorenchyma

Answer 3

Setting ess-indent-with-fancy-comments to nil will remove the weird single-# indentation, but it must be set either buffer-locally in a hook (as in Rob's answer), OR before ESS is loaded:

(setq ess-indent-with-fancy-comments nil)
(require 'ess)

Other ways to make sure it is set before ESS is loaded, is to set it in M-x configure, or to set it in the :init section of use-package.

What's going on is that ESS defines styles at initialization in ess-style-alist, and then applies the default style in every buffer. So to make sure these styles respect ess-indent-with-fancy-comment, you must make sure to set it before the styles are defined.

Heatstroke

After my upgrading to ESS 18.10.3, the hooking method does not work for me anymore. setq before require ess works. – Milano

Answer 4

Jouni's answer didn't work for me. But I found an approach here that does: https://stat.ethz.ch/pipermail/ess-help/2016-May/010970.html

   (defun my-ess-settings ()
     (setq ess-indent-with-fancy-comments nil))
   (add-hook 'ess-mode-hook #'my-ess-settings)

Bondholder

Yes I had to do this too for it to work, otherwise it would get overriden locally. – Kreplach