Comment by kerkeslager

> JavaScript wanted to add the synthetic sugar for async/await, so the language had to be redesigned with that in mind. In a lisp, async/await could be implemented by a library instead, keeping the core still small and nimble.

Sure, but try hacking in infix notation or more complex notations like list[index] access, and you'll quickly see why hacking that stuff in is a bad idea. Lisp severely punishes adding syntactic sugar if it diverges at all from prefix s-expressions. Look at Clojure's member variable access for a real life example of how this plays out.

And if we're willing to make concessions that our syntactic sugar can only be as sweet as the overall design of the language allows, I think it makes sense to concede the same to Javascript and admit that Promises existed as libraries for years before async/await, and worked just fine in lots of production code.