Comments in Function Definitions

Inside functions defined with defun LFE permits optional comment strings in the Common Lisp style after the argument list. So we can have:

(defun max (x y)
  "The max function."
  (if (>= x y) x y))

Optional comments are also allowed in match style functions after the function name and before the clauses:

(defun max
  "The max function."
  ((x y) (when (>= x y)) x)
  ((x y) y))

This is also possible in a similar style in local functions defined by flet and fletrec:

(defun foo (x y)
  "The max function."
  (flet ((m (a b) "Local comment."
            (if (>= a b) a b)))
    (m x y)))