Internals of Async / Await in JavaScript

Re:Internals of Async / Await in JavaScript by littlestymaar on Saturday September 02, 2023 @04:45AM (#37359616)

I think seeing generators as special functions makes them feel more magic than what they really are: generators are nothing more than a syntactic sugar for objects with a “call” method that will change the values of the private fields in this object, that's why you can call it repeatedly with different results.

Some patterns become easier to write with the generator syntax, but it's not really adding expressive power. (Unlike futures for instance)

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Re:Internals of Async / Await in JavaScript by heavenlyblue on Saturday September 02, 2023 @05:58AM (#37360041)

You could also have an object with on_success, on_failure attributes so Futures are the same syntax sugar

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Re:Internals of Async / Await in JavaScript by littlestymaar on Saturday September 02, 2023 @10:15AM (#37361724)

In JavaScript, where you have first class functions and an event loop built-in, yes. But for languages that lack one of those, then no.

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Re:Internals of Async / Await in JavaScript by btown on Saturday September 02, 2023 @06:31AM (#37360199)

IMO this is like saying a high-level language is syntactic sugar for assembly.

Generators allow you to write a state machine as a procedural function whose local variables are automatically suspended when you yield and restored when the caller returns control to the generator. They compile this down to, as you said, an object with a call method. But that transformation is as nontrivial as any compilation/transpilation project.

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