How to call a interactive function with prompt from a lambda?

Question

I have this little LaTeX helper function:

(defun my--insert-chord (chord)
  "Prompt for a CHORD and insert it at point. TODO: make it agnostic to the package used."
  (interactive "MChord: ")
  (insert (concat "\\[" chord "]")))

that works like a breeze.

Now, I want to integrate with isearch. I have this other helper function (taken from this question and in turn from Endless Parentheses):

(defun isearch-exit-other-end ()
  "Exit isearch, at the opposite end of the string."
  (interactive)
  (goto-char isearch-other-end)
  (isearch-exit))

Now, I want to combine the two and bind themto a key. Since it's a one-off use, IIUC it makes sense to use a lambda:

(define-key isearch-mode-map (kbd "C-M-c")
          (lambda () (interactive) (isearch-exit-other-end) (call-interactively (my--insert-chord))))

But Emacs complains:

Debugger entered--Lisp error: (wrong-number-of-arguments (lambda (chord) "Prompt for a CHORD and insert it at point. TODO: m..." (interactive "MChord: ") (insert (concat "\\[" chord "]"))) 0)
  my--insert-chord()
  (call-interactively (my--insert-chord))
  (lambda nil (interactive) (isearch-exit-other-end) (call-interactively (my--insert-chord)))()
  funcall-interactively((lambda nil (interactive) (isearch-exit-other-end) (call-interactively (my--insert-chord))))
  command-execute((lambda nil (interactive) (isearch-exit-other-end) (call-interactively (my--insert-chord))))

Now, of course I haven't provided the correct number of arguments, that's because my--insert-chord should prompt for one. How can I achieve this? Of course, I can duplicate the interactive string in the lambda, but I suspect there's a clever way, since this would lead to code duplication. My Google-fu only provided examples to pass arguments via code, but that's not what I want. If this is a dup I apologize, and I will gratefully taken redirection.

Thanks!

Answer 1

Instead of providing a function to `call-interactively, you are calling the function (to pass the return value from that call).

Try (call-interactively 'my--insert-chord).