+ ((and (byte-code-function-p def) (integerp (aref def 0)))
+ (let* ((args-desc (aref def 0))
+ (max (lsh args-desc -8))
+ (min (logand args-desc 127))
+ (rest (logand args-desc 128))
+ (arglist ()))
+ (dotimes (i min)
+ (push (intern (concat "arg" (number-to-string (1+ i)))) arglist))
+ (when (> max min)
+ (push '&optional arglist)
+ (dotimes (i (- max min))
+ (push (intern (concat "arg" (number-to-string (+ 1 i min))))
+ arglist)))
+ (unless (zerop rest) (push '&rest arglist) (push 'rest arglist))
+ (nreverse arglist)))