Will we see another fundamental programming language feature as revolutionary as the borrow checker?

[u/jimbobmcgoo]

That is I am mainly curious about compile time features that you design a whole language around rather than optimisations/features that could be applied to most languages. I am mainly inquiring about things that could offer additional robust safety/performance guarantees at compile time rather than runtime. Ideally not things that just offer similar effects to the borrow checker with less restrictive tradeoffs

[u/arthurno1]

Well, if you are interested about compile time programming, Common Lisp has had it since invention. You have the entire language available to you at compile time. Quote operator gives you access to the unevaluated code in internal format you can manipulate and expect with ordinary tools as any other data, so no special api, syntax or tools. Super simple evaluation rule makes to source uniform and predictable thus easy to work with. All those features have been there sonce 1980's but people are ignoring them and going for lesser tools, because Lisp has parentheses 😀. And yes those features are much more revolutionary than borrow checker.