@ramin_hal9001 @rml
> you might be referring to Lisp's "image based programming" model. This is where Lisp basically freezes itself when an exception is thrown, then you can make changes to the code and resume execution

Image-based, yes. Condition system has nothing to do with this. Functions can be recompiled without dealing with it.

Erlang is famous, yes. One active member of our local Emacs community uses Elixir and seems to enjoy it, and claims they even use macros fairly often. Maybe it would be possible and beneficial to have such concurrency in a Common Lisp implementation (or in Emacs) but I have enough life goals already. 🙂