You-Dont-Know-JS | 📗📒 JS Book Series | Media library

Why is impl applied to itself (plus the deps object)? I used w3schools/apply() for looking at how apply() works. There is in the 1st example just an object applied to a function, and not the function itself plus an object.

Check out Function#apply() on MDN. Usually MDN is has more information, so it's worth using it for reference.

When you call apply() the first argument is the this value for the executed function. In a lot of cases, it doesn't matter what that value is - you can also pass null if you don't care about it.

Raw JSON Path doesn't do this, but depending on the implementation you're using, it might be supported.

We're currently in progress writing a formal specification. One of the open issues is the breadth of expression support we want. Feel free to add a comment. Once the spec is defined and published, I imagine most implementations will update to adhere.

I am not exactly sure what is the desired output but have a look at this.

You can see the outer level are genres, followed by nested publishers with nested books within.

1. Firstly, I got all the genres.
2. Then I got the books and publishers with $lookup.
3. I used $unwind to separate publishers.
4. I added books with $addFields to each publisher for filtering it later.
5. I used $group to get relevant elements and $addToSet to make an array of publishers.
6. Finally, I used $project with $map and $filter to get relevant books for each publisher.

I think your looking for $lookup with a pipeline like this:

https://mongoplayground.net/p/H_OsKvN_npf

The exports object is created for your module before your module runs, and if there are circular dependencies, other modules may have access to that default object before your module can fill it in. If you replace it, they may have the old, original object, and not (eventually) see your exports. If you add to it, then even though the object didn't have your exports initially, eventually it will have it, even if the other module got access to the object before those exports existed.

More in the Cycles section of the CJS module documentation.

We can adapt the cycle example in that section to demonstrate it:

a.js (note changes):

No. The scope that contains name and b are not created until the function foo() is called.

In order to find one book you can use:

For your original question, you want to see them run in parallel. You can use Promise.all to run multiple async tasks, it will waits for all async tasks resolved and return an output array.

Promise.all executes async tasks by iterating them(in series), not technically executes them in parallel, but they are running in parallel. It will give you a result when all async tasks resolved or rejected if any one of them failed.

Or you can just run them 1 by 1 without Promise.all. they won't block each other, so still in parallel, but you Promise.all just help you handle callback results in one place.

The output will be either 12 or 20, depends on random timeout you set for bar and foo functions.

For race condition, only the setTimeout functions are asynchronous, but all operations in callbacks are synchronous and non-blocking, so the thread won't jump from operations in one callback to another callback unless all operations in that callback are finished.

But in JS, you can still have data race when using SharedArrayBuffer which needs Atomics object to prevent data race.