S-expression comments in Common Lisp

Question

I have written a Common Lisp implementation of Scheme's s-expression comments (SRFI 62):

(eval-when (:compile-toplevel
 :load-toplevel
 :execute)
 (defun handle-s-expression-comment (stream char n)
 (declare (ignore char))
 (when n
 (error "Infix parameter not allowed in s-expression comment."))
 (read stream) ; Discard the next s-expression.
 (values))
 (set-dispatch-macro-character #\# #\; #'handle-s-expression-comment))

With s-expression comments:

• (+ 1 #;(* 2 3) 4) returns 5
• (list 'x #;'y 'z) returns (x z)
• (* 3 4 #;(+ 5 6)) returns 12
• (#;sqrt abs -123) returns 123

Is my implementation correct? What improvements can I make?

• Flux: (read stream) should be (read stream t nil t) instead. Refer to: read's recursive-p argument when used inside a reader macro.