> migrating obsolete state Do you mean like in Lisp with update-instance-with-different-class for example? https://www.lispworks.com/documentation/HyperSpec/B

> migrating obsolete state Do you mean like in Lisp with update-instance-with-different-class for example? https://www.lispworks.com/documentation/HyperSpec/Body/f_update.htm https://www.lispworks.com/documentation/HyperSpec/Body/f_upd...