[Emacs] Implement setq-like customize-set-variable macro

This commit is contained in:
Lucien Cartier-Tilet 2022-06-15 21:38:51 +02:00
parent 9215d8dd1e
commit 1550d6c3e9
Signed by: phundrak
GPG Key ID: BD7789E705CB8DCA

View File

@ -510,6 +510,50 @@ This is a wrapper around `eval-after-load' that:
(car body))))))
#+end_src
** A better custom variable setter
:PROPERTIES:
:CUSTOM_ID: Basic-Configuration-A-better-custom-variable-setter-56z4ni61lhj0
:END:
Something people often forget about custom variables in Elisp is they
can have a custom setter that will run some code if we set the
variable properly with ~customize-set-variable~, so ~setq~ shouldnt be
the users choice by default. But repeatedly writing
~customize-set-variable~ can get tiring and boring. So why not take the
best of both world and create ~csetq~, a ~setq~ that uses
~customize-set-variable~ under the hood while it keeps a syntax similar
to the one ~setq~ uses?
#+begin_src emacs-lisp
(defmacro csetq (&rest forms)
"Bind each custom variable FORM to the value of its VAL.
FORMS is a list of pairs of values [FORM VAL].
If FORM has a custom setter, use it to set FORM to VAL.
Otherwise, use `set-default'.
\(fn [FORM VAL]...)"
(declare (debug (&rest sexp form))
(indent 1))
;; Check if we have an even number of arguments
(when (= (mod (length forms) 2) 1)
(signal 'wrong-number-of-arguments (list 'csetq (1+ (length forms)))))
(let (sexps)
;; Transform FORMS into a list of pairs (FORM . VALUE)
`(progn ,@(progn
(while forms
(let ((form (pop forms))
(value (pop forms)))
(push `(customize-set-variable ',form ,value)
sexps)))
(reverse sexps)))))
#+end_src
I first got inspired by [[https://oremacs.com/2015/01/17/setting-up-ediff/][this blog article]] (archived article, just in
case) but it seems the code snippet no longer works properly, so not
only did I have to modify it to make it work with an arbitrary amount
of arguments (as long as its pairs of variables and their value), but
I also had to make the code simply work.
* Custom Elisp
:PROPERTIES:
:CUSTOM_ID: Custom-Elispksvjel6184j0