package hackery for moving classes between packages

rehome-class.lisp

(defgeneric rehome-class (class new-home)
  (:method ((class symbol) new-home)
    (rehome-class (find-class class) (find-package new-home)))
  (:method ((class class) (new-home package))
    (let ((old-home (symbol-package (class-name class)))
          (symbols (list* (class-name class)
                          (mapcar 'sb-mop:slot-definition-name
                                  (sb-mop:class-direct-slots class)))))
      (mapc (lambda (symbol) (unintern symbol old-home)) symbols)
      (import symbols new-home)
      (import symbols old-home))))

rehome-symbol.lisp

(defun rehome-symbol (symbol new-home &aux (old-home (symbol-package symbol)))
  (unintern symbol old-home)
  (import (list symbol) new-home)
  (import (list symbol) old-home))

https://gist.github.com/adlai/eb29616be321f351d72a?permalink_comment_id=1305993#gistcomment-1305993