anchor.diff:                      (alex:rcurry #'closer-mop:subclassp class)
                       (modes buffer)
                       :key #'class-of)))
  -      (unless (sera:single results)
  +      (when (< 1 (length results))
           (log:warn "Found multiple matching modes."))
         (values (first results)
                 results))
  +    ;; CCL catches the error at compile time but not all implementations do,
  +    ;; hence the redundant error report here.
       (error "Mode ~a does not exist" mode-symbol)))
   
   (-> current-mode ((or keyword string) &optional buffer) (maybe mode))
  
positive.code:                    body))
           (direct-slots (first body))
           (options (rest body)))
      `(define-class ,name (,@(append direct-superclasses
                                      (unless (find 'mode direct-superclasses) '(mode))))
         ,direct-slots
         ,@(append options
                   (when docstring
                     `((:documentation ,docstring)))
                   `((:export-class-name-p t)
                     (:export-accessor-names-p t)
                     (:export-predicate-name-p t)
                     (:accessor-name-transformer (class*:make-name-transformer name))
                     (:metaclass mode-class))))))
  
  (hooks:define-hook-type mode (function (mode)))
  
  
negative.code:                              (:command (mapcar #'name (list-commands))))))
      (let ((results (delete designator symbols :key #'symbol-name :test #'string/=)))
        (unless (sera:single results)
          (log:warn "Multiple ~a modes found: ~a" designator results))
        (values (first results)
                results))))
  
  (deftype mode-symbol ()
    `(satisfies mode-class))
  
  (-> find-submode (mode-symbol &optional buffer) (maybe mode))
  (export-always 'find-submode)
  (defun find-submode (mode-symbol &optional (buffer (current-buffer)))
    "Return the first submode instance of MODE-SYMBOL in BUFFER.
  As a second value, return all matching submode instances.
  Return nil if mode is not found."
  