Re: Wrong comment character when adding file local variables?

[Nick Dokos <ndokos@gmail.com>]

Rainer M Krug <r.m.krug@gmail.com> writes:

> On Friday, June 7, 2013, Vitalie Spinu wrote:
>
>     All your examples are placed in fundamental mode. The comments are
>     treated by org and thus are correct, local variables are inserted
>     according to the major mode.
>
> The question is why - all .R files are automatically in r mode when I
> open them and all other R files tangle fine. 
>
That's because the auto-mode-alist tells emacs that .R files should be
in R-mode, so after emacs opens the file, it calls the R-mode function.

>     I don't how this could be easily fixed on org side, but you can
>     solve it straightforwardly with:
>    
>     (add-to-list 'auto-mode-alist (cons "NAME\\|DESC" 'R-mode))
>
> Ok - I'check it out on Monday.
>

That's one way: it's got its downside in that the names have to match,
so you have to remember to modify the auto-mode-alist when you use
different names when tangling.

Another way is to modify the function below:

>     > I use the following in my .emacs file to set the
>     > post-tangle-hook to add the local file variables:
>    
>     > ,----
>     > |  (defvar org-babel-tangled-file nil
>     > |    "If non-nill, current file was tangled with org-babel-tangle")
>     > |  (put 'org-babel-tangled-file 'safe-local-variable 'booleanp)
>     > |
>     > |  (defun org-babel-mark-file-as-tangled ()
              (R-mode)  ; <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
>     > |     (add-file-local-variable 'org-babel-tangled-file t)
>     > |     (add-file-local-variable 'buffer-read-only t)
>     > |     ;; (add-file-local-variable 'eval: (auto-revert-mode))
>     > |     (basic-save-buffer))
>     > |
>     > |  (add-hook 'org-babel-post-tangle-hook
>     > |            'org-babel-mark-file-as-tangled)
>     > `----
>    
>    

to call R-mode explicitly. That's got its own downside: all your
tangled files are going to be in R-mode.

The point is that you have to tell emacs somehow what you are doing:
it can't guess that you are producing R-mode files without some help.

-- 
Nick