> LISP also got a type system retrofit decades ago, with "flavors" and the Common LISP Object System, and that was ugly, too. The lesson here is that retrofitti

> LISP also got a type system retrofit decades ago, with "flavors" and the Common LISP Object System, and that was ugly, too. The lesson here is that retrofitting a type system creates a mess. Flavors and CLOS are not "type systems". They are "object systems" and there is nothing "ugly" about them. Flavors was introduced into a Lisp which did not have a type system. Later CLOS was added to a Lisp which already had a type system: Common Lisp.