anchor.diff:    ;; TODO: Report if mode is not found.
     (let* ((buffers (if buffers
                         (uiop:ensure-list buffers)
  -                      (prompt
  -                       :prompt "Enable mode(s) for buffer(s)"
  -                       :sources (make-instance 'buffer-source
  -                                               :multi-selection-p t
  -                                               :return-actions '()))))
  +                      (unless explicit-buffers-p
  +                        (prompt
  +                         :prompt "Enable mode(s) for buffer(s)"
  +                         :sources (make-instance 'buffer-source
  +                                                 :multi-selection-p t
  +                                                 :return-actions '())))))
            (modes (if modes
                       (uiop:ensure-list modes)
  -                    (prompt
  -                     :prompt "Enable mode(s)"
  -                     :sources (make-instance 'inactive-mode-source
  -                                             :buffers buffers)))))
  +                    (unless explicit-modes-p
  +                      (prompt
  +                       :prompt "Enable mode(s)"
  +                       :sources (make-instance 'inactive-mode-source
  +                                               :buffers buffers))))))
       (mapcar (lambda (buffer)
                 (mapcar (lambda (mode-sym)
                           (apply #'enable (or (find mode-sym (modes buffer) :key #'name)
  
positive.code:   (:export-class-name-p t)
    (:metaclass user-class))
  
  (define-command enable-modes (&optional modes buffers args)
    "Enable MODES for BUFFERS.
  MODES should be a list of mode symbols.
  BUFFERS and MODES are automatically coerced into a list.
  
negative.code:   ;; TODO: Report if mode is not found.
    (let* ((buffers (if buffers
                        (uiop:ensure-list buffers)
                        (unless explicit-buffers-p
                          (prompt
                           :prompt "Enable mode(s) for buffer(s)"
                           :sources (make-instance 'buffer-source
                                                   :multi-selection-p t
                                                   :return-actions '())))))
           (modes (if modes
                      (uiop:ensure-list modes)
                      (unless explicit-modes-p
                        (prompt
                         :prompt "Enable mode(s)"
                         :sources (make-instance 'inactive-mode-source
                                                 :buffers buffers))))))
      (mapcar (lambda (buffer)
                (mapcar #'disable (delete nil (mapcar (lambda (mode) (find mode (modes buffer) :key #'name))
                                                      (uiop:ensure-list modes)))))
  