cond clause for optional arguments

Question

Am using an optional argument and want to use cond to execute (do-this) if actm is present and matches 'regexp, and (do-that) otherwise. Is the following the correct way to do it, or am I missing something?

(defun kmsec (&optional actm)
  "Identify comment category ';; [Category]'."
  
(cond

   ((eq actm 'regexp)
       (do-this))

   (t
       (do-that)) ))

Answer 1

That is one way to do it. Given that there are only two alternatives, another way to do it is:

(defun kmsec (&optional actm)
  "Identify comment category ';; [Category]'."
  
  (if (eq actm 'regexp)
      (do-this)
    (do-that)))