Hi Robert

I just tried using key-description, for example

(define-minor-mode math-typing-mode
"A minor mode for typing maths characters"
:init-value nil
:lighter " Math"
(let ((map (make-sparse-keymap)))
(if math-typing-mode
(progn

(define-key map (kbd "C-3") (key-description "\u00B3"))

(use-local-map map))
(use-local-map nil))))

but this produces the same result as

(define-key map (kbd "C-3") "\u00B3")

while

(define-key map (kbd "C-3") [?\u00B3]) or my original lambda works (inserts the unicode character when you press C-3)

Probably I misunderstand what you are suggesting though?

On Mon, 9 Jun 2025 at 15:40, Eli Zaretskii <eliz@gnu.org> wrote:

> Cc: 78714@debbugs.gnu.org, Andreas Schwab <schwab@linux-m68k.org>
> From: Robert Pluim <rpluim@gmail.com>
> Date: Mon, 09 Jun 2025 13:48:31 +0200
>
> >>>>> On Mon, 9 Jun 2025 11:05:40 +0100, John Holman <john.g.holman@gmail.com> said:
>
> John> Many thanks Andreas - that's certainly more concise than using a lambda.
> John> I do think this is a trap for users who may expect that a key definition
> John> that a single character string simply specifies the character to be
> John> inserted when that key is pressed rather than a macro. Treating a string
> John> with a single character as a character to insert rather than a
> John> one-character macro might avoid that, or if that is awkward to implement or
> John> otherwise undesirable an explicit warning in the documentation might help.
> John> The documentation for define-key does say that a string is treated as a
> John> keyboard macro, but the significance of that is easy to miss.
>
> (info "(emacs) Init Rebinding") describes how to do this. The
> docstring for `keymap-global-set' also mentions `key-description',
> which avoids the need to manually write in vector notation, which I
> guess we could add to `keymap-set' as well.

Feel free to add that.