> `if (file_exists(f))` is misuse of the interface, a lesson in interface design, and a faulty pattern that's easy to repeat with async-await.

It's even easier to repeat without async-await, where you don't need to tag the function call with `await`!

> Think about it, you can't `await` on part of the state only once and then know it's available in other parts of code to avoid async pollution. When you solve this problem, you realize `await` was just in the way and is completely useless and code looks exactly like a callback or any other more primitive mechanism.

I don't understand why you can't do this by just bypassing the async/await mechanism when you're sure that the data is already loaded

```

data = null

async function getDataOrWait() { await data_is_non_null(); // however you do this return data }

function getData() { if (data == null) { throw new Error('data not available yet'); } return data; }

```

You aren't forced into using async/await everywhere all the time. this sounds like 'a misuse of the interface, a lesson in interface design', etc

> I think "how to express concurrency" is a question I'm not even trying to answer

You can't criticise async/await, which is explicitly a way to express concurrency, if you don't even care to answer the question - you're just complaining about a solution that solves a problem that you clearly don't have (if you don't need to express concurrency, then you don't need async/await, correct!)

> point to approaches that completely eliminate pollution and force you to write code in that "unrolled" way from start, something like Rx or FRP where time is exactly the unit they're dealing with.

So they don't 'eliminate pollution', they just pollute everything by default all the time (???)