Use Hook to alter global variables but only for current buffer
reddit / emacs

----------------------------------------------------------------------
Top_Bird1552 · 2022-08-18 07:16

Hi emacs friends,

 your expertise and wisdom is required.

Please let me first describe my use case.

I'm using electric pair ([https://www.emacswiki.org/emacs/ElectricPair
](https://www.emacswiki.org/emacs/ElectricPair)) and my humble init
for this is like

    (electric-pair-mode 1)
    (setq electric-pair-pairs '((?\{ . ?\})
                            (?\( . ?\))
                            (?\[ . ?\])
                            (?\" . ?\")))

Which is sufficient for coding and simple text. For org-mode however I
also want to use the "electric pairing" for "\*" (and maybe other
markup features in org-mode like "\~" for example).

So I added

    (add-hook 'org-mode-hook (lambda ()
                                (setq electric-pair-pairs
                                 (append electric-pair-pairs '((?\* .
?\*))))))

Problem here is that is now set for all the other modes as well which
I don't want.

I only want this to be appended for org-mode buffers nothing else.

Due to a lack of fantasy I don't even know how to approach this.

​

Any help is highly appreciated. Thanks for your time guys!

----------------------------------------------------------------------
flexibeast · 2022-08-18 08:07

Use the `make-local-variable` function, i.e.:

    (make-local-variable 'electric-pair-pairs)

----------------------------------------------------------------------
Top_Bird1552 · 2022-08-18 08:40

Thanks u/flexibeast your solution is exactly what I was looking for.

My solution:

`(add-hook 'org-mode-hook (lambda () (progn (make-local-variable
'electric-pair-pairs) (setq electric-pair-pairs (append electric-pair-
pairs '((?\* . ?\*)))))))`

​

So actually one creates a local variable that simply shadows the
global one.

----------------------------------------------------------------------
dakra · 2022-08-18 09:09

You can also use `setq-local` which is like `make-local-variable` plus
`setq`.

----------------------------------------------------------------------
Top_Bird1552 · 2022-08-18 09:33

This indeed makes even easier and cleaner.

Thank you u/dakra

----------------------------------------------------------------------
ppvvaa · 2022-08-18 10:49

Could anyone explain why what OP tried doesn't work?
Edit: oh, I get it: if they open an org file, the code gets executed,
but of course it does not get "de-executed" if he visits another non
org buffer