This gets us a bit into the definition of "sugar", I think. Specifically, all the constructs you mention are syntactic shorthands for the same underlying concepts, and the original syntax also remains available - which is to say, those constructs actually are syntactic sugar. Ruby having three ways, in two cases, to do one thing, is not.

I'm glad you mentioned "The Good Parts"! Crockford published in 2008 and the state of the art in JS has so evolved as to make further such work mostly unnecessary, or so I infer from its more-or-less absence over the last decade or so at least. That Ruby still requires such explainers be published in 2023 seems more an argument to my point than to yours.

You're also very anxious to make the perfect the enemy of the good here, which is a surprise after the explicit disclaimer in my prior comment. Why are you asking me to defend an argument I've been at such pains to make clear I'm not advancing?

> the state of the art in JS has so evolved as to make further such work mostly unnecessary, or so I infer from its more-or-less absence over the last decade or so at least. That Ruby still requires such explainers be published in 2023

async/await was introduced in 2017. If you're suggesting that this required fewer "explainers" than a set of gradual changes to Ruby method call syntax, I'm afraid we're not operating under a common understanding of reality.

Kind of funny -- if I understand this correctly -- that Javascript was descended from Scheme which has delimited continuations and yet Javascript has async/await and function coloring nonsense, while ruby has continuations and fibers and doesn't need to worry about "function coloring" or "callback hell".

(Which I don't understand very well because I was a ruby programmer for 12 years, so missed all the async/await/callback-hell nonsense entirely that everyone is so obsessive about these days)

I don't believe Scheme as standardized has delimited continuations, only call/cc; it's just that Scheme implementations have often been the laboratories in which experiments on delimited control have been performed.