> It seems like the idea of the macro, and more generally of expressing code succinctly, is the closest to obsolete in my memory?

Seems more important than ever? Every model degrades the more context you use, programs that can be described more succinctly will be better made, at least when using LLMs to create these, as it's much easier to fit more "meat" per token.

I'm on the same "S-Expressions taking over is inevitable" but to be fair, I've been on this train for the last decade so maybe I'm slightly biased.

Token efficiency is good, but in practice, model familiarity is more important.

Look at what happened with TOON. They came up with a format meant to replace JSON for agents, but despite being way more succinct, its novelty meant that LLMs spent just as many tokens correcting mistakes while using it.

TBF, that was several months ago, an eternity in LLM time. Someone should rerun those language studies, it's possible the SOTA has changed.

That’s a plausible story, but doesn’t seem to bear out in terms of models being amazing at Lisp. Like, Sonnet 4.5 was writing me emacs Lisp with unbalanced parentheses.

I don’t really have faith that I could write macros of such incredible brilliance that it would outweigh the models’ facility with Python.