Using both `event-apply-meta-modifier` and `event-apply-super-modifier` for the same shortcut

Question

I use the commands event-apply-meta-modifier and event-apply-super-modifier to have keys I can tap that apply the meta and super modifier to the next typed shortcut. But when I first apply the meta modifier, then tap the key that should apply the super modifier, Emacs doesn't stack the modifiers but instead says

M-` is undefined

(I have event-apply-super-modifier on the `-key). So I tried to define a command

(defun ahp/event-apply-meta-and-super-modifier ()
  "This function kills all lines in the buffer of a regexp-search using the all-package."
  (interactive)
  (call-interactively 'event-apply-meta-modifier)
  (call-interactively 'event-apply-super-modifier)
  )

But when I use this command Emacs says

ahp/event-apply-meta-and-super-modifier: Wrong type argument: commandp, event-apply-meta-modifier

How can I make this command work?

Answer 1

I simply concatenated the definitions of those two functions:

(defun MetaSuper-next-cmd ()
  (interactive)
  (execute-kbd-macro (vector (event-apply-modifier (event-apply-modifier (read-event) 'super 23 "s-") 'meta 27 "M-"))))

Test:

(keymap-global-set "M-s-<left>" #'beginning-of-defun)
(keymap-global-set "M-s-j" #'beginning-of-defun)

M-x MetaSuper-next-cmd <left> or M-x MetaSuper-next-cmd j.