Comment by slibhb | Hacker News Reader

Comment by slibhb | Hacker News Reader

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Async/await is clearly a feature in JS, though not for the reason the previous poster mentions. Async/await wasn't part of the language until 2017. If you don't like it, you can just use Promises. If you do that, there are no "colored function" (functions of color?).

As far as the article goes, I think the pattern in Ruby is great. I prefer it to JS. But the JS approach works fine and the whole controversy about colored functions is a little silly.

I would be interested in understanding why JS can't enable await from inside non-async functions. I (maybe naively) wonder if the compiler couldn't just figure out which functions to treat as async rather than making the programmer do it.

Using promises is basically no different than using async functions, and definitely doesn't "uncolor" your functions.

Any function that calls another that returns a Promise will have to return a Promise to represent completion correctly. That's the color.

> Any function that calls another that returns a Promise will have to return a Promise to represent completion correctly

No, it doesn't, closures let you update values in the wcope of the parent in .then() callbacks and then you can loop in the function and wait for completion and return a non-Promise value.

This is not true. If your sync function loops until the value is set, then the Promise will never resolve, since it never yields to the event loop.

With a well-configured dev env with typescript, prettier, eslint and the appropriate config, async/await does feel like a feature. The IDE adds the async keyword for you if you forget it. If you enable errors in the whole project, it will tell you of any file/function that has an inconsistency in that regard.

So yes the compiler can figure it out, but only with Typescript. For javascript, a promise it a promise, but it doesn't know that a function will return a promise until it does. You can try compiling some async/await codebase to an old ES5 version and see the mess.

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