anchor.diff:                      (return-from read-token (values (car result) t)))))
               (progn (vector-push-extend char token)
                      (setf collecting-token t)))
  -     finally (return token)))
  +     finally (if collecting-token
  +                 (return token)
  +                 nil)))
   
   (defun parse-token (token)
     (or (parse-integer-token token)
  
positive.code:      do (if (char= end-char char)
              (progn (read-char stream nil nil)
                     (return-from clutter-read-delimited-list (nreverse list)))
              (progn #+nil(read-char stream nil nil)
                     (push (clutter-read stream) list)))))
  
  (set-clutter-reader-macro-function #\( (lambda (stream char)
                                           (declare (ignore char))
  
negative.code:       (read-token stream)
      (if donep
          token
          (when token
            (parse-token token)))))
  