anchor.diff:            syntax-preceding-property
             syntax-forward-search-property-end
             syntax-backward-search-property-start
  +          skip-whitespace-forward
  +          skip-whitespace-backward
             skip-space-and-comment-forward
             skip-space-and-comment-backward))
   
  
positive.code:     (unless (shift-position -1)
        (return nil))))
  
  (defun skip-space-and-comment-forward ()
    (loop
      (skip-chars-forward #'syntax-space-char-p)
      (unless (and (not (eq *syntax-comment-attribute* (syntax-preceding-property :attribute)))
                   (eq *syntax-comment-attribute* (syntax-following-property :attribute)))
        (return t))
  
negative.code: 
  (defun skip-space-and-comment-backward ()
    (loop
      (skip-whitespace-backward)
      (unless (and (not (eq *syntax-comment-attribute* (syntax-following-property :attribute)))
                   (eq *syntax-comment-attribute* (syntax-preceding-property :attribute)))
        (return t))
  