Best way to detect font-lock mode is on?

[Tim X]

Just wanting to know what people would suggest as the best way to detect
if font-lock mode is enabled. 

I have two functions I use in a mode to determine if the point is
currently within a comment or a string. If font-lock mode is enabled,
this is quite a fast operation as I can just test the text property.
However, if font-lock is not enabled, I need to do some parsing to try
and determine whether point is on a comment or string. I have defined
two functions i.e. 

(defun pde-in-comment-p ()
  "Returns t if point is within a comment, nil otherwise."
  (if font-lock-defaults
      (eq (get-text-property (point) 'face) 'font-lock-comment-face)
    (nth 4 (parse-partial-sexp (point-min) (point)))))

(defun pde-in-string-p ()
  "Return t if point within a string, nil otherwise."
  (if font-lock-defaults
      (eq (get-text-property (point) 'face) 'font-lock-string-face)
    (nth 3 (parse-partial-sexp (point-min) (point)))))

As you can see, I'm using font-lock-defaults to test whether font-lock
is enabled. Is this the best way to go or is there a more
reliable/better test to use?

Tim

-- 
tcross (at) rapttech dot com dot au