anchor.diff:             (let ((snippet (or snippet
                                 #++(format nil "(~s ~s ~s ~{~s~}" definer name lambda-list body))))
                `(                  ;,(format nil "(~s ~s)" definer name)
  -               ,@(if file
  +               ,@(if buffer
  +                     `((:buffer ,buffer))
                        `((:file ,file)
  -                       (:modified ,(file-write-date file)))
  -                     `((:buffer ,buffer)))
  +                       (:modified ,(file-write-date file))))
                    ,(or (assoc :position position)
                         (assoc :offset position)
                         (assoc :line position)
  
positive.code: (defparameter *ps-source-file* nil)
  (defparameter *ps-source-position* nil)
  (defparameter *ps-source-buffer* nil)
  (defparameter *ps-source-definer-name* nil)
  
  ;;; macros
  
negative.code:             (let* ((buffer (getf (sb-c:definition-source-location-plist sl)
                                   :emacs-buffer))
                     ;; use in prder of decreasing preference:
                     ;; :emacs-buffer
                     ;;   (use buffer first, since C-c C-c is probably
                     ;;    on stuff that hasn't been saved yet, file may
                     ;;    not even exist yet)
                     ;; :emacs-filename from source-location-plist
                     ;; source-location-namestring (which gets stuff like
                     ;; "/tmp/fileRBYgJc" from C-c C-c in *slime-scratch*)
                     (file (or (getf (sb-c:definition-source-location-plist sl)
                                     :emacs-filename)
                               (sb-c:definition-source-location-namestring
                                   sl)))
                     (position `((,@(if (sb-c:definition-source-location-plist
                                            sl)
                                        `(,@(if buffer '(:offset 0) '(:position))
                                            ,(or (getf (sb-c:definition-source-location-plist
                                                           sl)
                                                       :emacs-position)
  