[remexre]

How would algebraic types work with SLIME? If I remove a constructor from my algebraic type, what happens to values of that type that are built with that constructor that're stored in globals?

In the same way that non-hygienic macros in a Lisp-2 with a CL-style package system are a local optimum, many non-obvious design choices in the Common Lisp type system and CLOS make SLIME "just work" in almost every case.

[kscarlet]

I guess this case is workable similar to struct redefintion. There can be a condition and a CONTINUE restart, which makes instances of the removed constructor obsolete.