Great discussion of the perils of self-modifying elisp code:
miniblog.
Related Posts
Incredibly impressive: reverse-engineering and modifying SNES games so they run on the faster CPU in the cartridge, not the console CPU: https://www.retrorgb.com/vitor-vilelas-race-drivin-sa-1-hack-released.html
Golang's "named return" is a pretty wild feature I haven't seen elsewhere. (The closest I know is &aux in Common Lisp.)
Implicit `return` example: https://tour.golang.org/basics/7 or even modifying results before returning:
Medic is a really interesting tool in Racket for adding debug statement to a program without modifying it! This saves you littering your code with print statements. https://docs.racket-lang.org/medic/Demo_1__border-expr_and_at-expr.html
I suspect a s-expression syntax really helps for an approach like this.