> I think it’s basically impossible to safely live-patch part of a compilation unit in most programming languages
There's no argument there; you're right. That's why V and Nim, for example, put reloadable things in a separate compilation unit and handle some things (global state at least) specially upon reload (if I understand what they do correctly.)
My point was that you can get quite close (sometimes with a massive pile of hacks and/or developer inconvenience), not that you can get the full experience (as in Smalltalk or Lisp) everywhere. Especially since the reloading being convenient is a large part of the experience, I think.
There's no argument there; you're right. That's why V and Nim, for example, put reloadable things in a separate compilation unit and handle some things (global state at least) specially upon reload (if I understand what they do correctly.)
My point was that you can get quite close (sometimes with a massive pile of hacks and/or developer inconvenience), not that you can get the full experience (as in Smalltalk or Lisp) everywhere. Especially since the reloading being convenient is a large part of the experience, I think.