alt Hacker NewsI answered the quiz and it said "you must be a Javascript developer", which is true enough - that's probably my second-most-proficient language. In fact, I'm a Ruby developer partially because I hate the idea of async/await and I'm feeling very smug about my choice after reading this.
Some of these design decisions seem indefensible to me. For example, what the authors call "Suspension":
-> Static: Await points guaranteed to suspend -- JavaScript
-> Dynamic: No guarantees on awaiting tasks -- C# · Swift · Tokio · Smol · Asyncio · Trio
What is "await" if not a synonym for "suspend"?!?
async/await is one product of a long line of thought that says "threads are too hard for programmers to get right". Threads (really, shared memory) have real usability issues for developers, but once you grok the semantics (which largely map to the physical execution model in a CPU) that knowledge is transferrable across virtually all languages and runtimes.
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> async/await is one product of a long line of thought that says "threads are too hard for programmers to get right".
Having used both threads and async/await and using them both in the same program, I don't see how async/await is supposed to make it easier to get right.
In my experience, async/await seems to be a solution to avoid running too many threads. In Javascript, because you could only have one thread in browsers; in other languages because thread per X is too many threads and queuing to a thread pool might not be desirable either.
Async/await always feels terrible to use though. Some other way to get thread like semantics without having to have OS threads for everything seems better (to me). Erlang processes, Java Loom Virtual Threads (which I haven't used), etc. If it avoids having all memory shared, even better.
> What is "await" if not a synonym for "suspend"?!?
There are scenarios where something might need to await and might not. Why take the hit if you are able to do something synchronously? Edit: this is especially important given the “viral” nature of colored functions.
It does make it hard to reason about, but this kind of problem is all over the place - e.g. very similar-looking code can have very different semantics depending on your framework if you’re using jsx or a particular decorator means one thing in one project and something else in another. That’s just part of the game at this point.
> What is "await" if not a synonym for "suspend"?!?
it's a question of whether the runtime is guaranteed to suspend at an await point or if it may choose not to
> async/await is one product of a long line of thought that says "threads are too hard for programmers to get right".
what? no! concurrency vs parallelism etc etc
I'm teaching async calls in makearcade to my 10yo son, to bypass a platform bug. He said he doesn't get it. My answer was: Don't worry, adults don't get it either.
> What is "await" if not a synonym for "suspend"?!?
The `await` keyword in most languages is not a synonym for suspending thread execution so much as it is an effectual attempt to replicate the functionality of `coreturn`[0]. To wit, if an underlying `Future`/`Promise` has completed before the `await` instruction is evaluated, the thread executing same will not be suspended.
0 - https://www.euclideanspace.com/maths/discrete/category/highe...