bug: defcustom's :key-value should be :value-type

[shirakami-chigusa]

Is there an existing issue for this?

• I have searched the existing issues

Issue description

When I try to change custom values ​​using setopt in init.el, I get a warning.

setopt also checks whether the value is valid for the user option. For instance, using setopt to set a user option defined with a number type to a string will signal an error.

GNU Emacs Lisp Reference Manual - setopt

  (setopt
   meow-selection-command-fallback
   '((meow-change . meow-change-char)
     (meow-kill . meow-kill-whole-line)
     (meow-cancel-selection . keyboard-quit)
     (meow-pop-selection . meow-pop-grab)
     (meow-beacon-change . meow-beacon-change-char)))

⛔ Warning (emacs): Value '(((meow-change . meow-change-char) (meow-kill . meow-kill-whole-line) (meow-cancel-selection . keyboard-quit) (meow-pop-selection . meow-pop-grab) (meow-beacon-change . meow-beacon-change-char)))' for 'meow-selection-command-fallback' does not match type (alist :key-type (function :tag Command) :key-value (function :tag Fallback))

meow/meow-var.el

Lines 49 to 58 in bc05b04

	(defcustom meow-selection-command-fallback
	'((meow-change . meow-change-char)
	(meow-kill . meow-C-k)
	(meow-cancel-selection . keyboard-quit)
	(meow-pop-selection . meow-pop-grab)
	(meow-beacon-change . meow-beacon-change-char))
	"Fallback commands for selection commands when there is no available selection."
	:group 'meow
	:type '(alist :key-type (function :tag "Command")
	:key-value (function :tag "Fallback")))

I think :key-value is wrong and :value-type is correct.

Composite Types (GNU Emacs Lisp Reference Manual)

(alist :key-type key-type :value-type value-type)

All defcustom defined in meow-var.el have the same problem.

[eshrh]

I can't actually reproduce this exact error... i think it's because the value-type defaults to "sexp" if not specified. What version of emacs are you using?

Anyway, good catch, thanks!

[shirakami-chigusa]

I'm using Emacs 29.3 (setopt is a feature implemented in emacs 29.1, setopt does type checking).

https://github.com/emacs-mirror/emacs/blob/ae8f815613c2e072e92aa8fe7b4bcf2fdabc7408/lisp/cus-edit.el#L1051-L1078

defcustom values from all other packages can be used without warning.

I think There is no type called :key-value.
value-type is a expected type name. Is there the type :key-value?

Composite Types (GNU Emacs Lisp Reference Manual)

• Code search results :value-type emacs
  • You can find a lot of Emacs code that uses value-type.
• Code search results :key-value emacs
  • I could find the code only used by meow and helm.

[shirakami-chigusa]

i think it's because the value-type defaults to "sexp" if not specified.

Ah, I found out why the warning appeared.

The code that causes the warning is as follows:

 (setopt meow-selection-command-fallback
   '((meow-change . meow-change-char)
     (meow-kill . meow-kill-whole-line)
     (meow-cancel-selection . keyboard-quit)
     (meow-pop-selection . meow-pop-grab)
     (meow-beacon-change . meow-beacon-change-char)))
 (require 'meow)

The correct code is below.

 (require 'meow)
 (setopt meow-selection-command-fallback
   '((meow-change . meow-change-char)
     (meow-kill . meow-kill-whole-line)
     (meow-cancel-selection . keyboard-quit)
     (meow-pop-selection . meow-pop-grab)
     (meow-beacon-change . meow-beacon-change-char)))

Because I used setopt before require, the defcustom type definitions were not loaded yet.

Thanks!