Hi again! So, I'm using a library that expects me ...

# javascript

[bod]

Hi again! So, I'm using a library that expects me to return an AsyncIterator. For instance here's something in JS :

myAsyncIterator = async function* () {
        for await (const word of ["one", "two", "three"]) {
          yield { count: word };
        }
      }

Any idea how to write an equivalent in Kotlin?

[turansky]

You can check AsyncIterator contract in lib.dom.d.ts to write effective addapter

[bod]

Thanks! I can't seem to find it there 🤔

[bod]

but I'm especially wondering how one can write the equivalent of an "function*" (a generator function) in Kotlin

[bod]

and an "async" one at that

[turansky]

I can’t seem to find it there 🤔

Do you use IDEA?

[turansky]

And which compiler do you use?

[bod]

Yes IDEA, and the IR one

[turansky]

Screenshot 2022-04-23 at 23.00.37.png

[turansky]

It’s from IDEA typings

[bod]

Very interesting! I wonder why I can't see this but I'll investigate. Thanks a lot!

[turansky]

https://github.com/JetBrains/kotlin-wrappers/pull/1456

[turansky]

Very interesting! I wonder why I can’t see this but I’ll investigate

1. Create JS file
2. Write Symbol.asyncIterator
3. Cmd + click on asyncIterator
4. PROFIT

[turansky]

https://github.com/JetBrains/kotlin-wrappers/pull/1457

[bod]

wow! Very cool. Let me see if I can make this work in my case

[bod]

well, that helped me a lot! I finally managed to make this work. Huge thanks! 🙏

[turansky]

Do you have analog of initial code?

[bod]

(sorry for the late reply) You can see how I did it here.

[bod]

I use a bunch of dynamic so it's weakly typed, but that's ok for my use-case

[turansky]

You can use wrappers for strict typings

[Sergei Grishchenko]

Idiomatically JS generators (function*) relates to suspend in Kotlin but I think we (wrappers developers) need some invent some wrappers and strategies to make integration to generators more seamless, example of such integration is

public suspend fun <T> kotlin.js.Promise<T>.await(): T { /* compiled code */ }

from kotlinx.coroutines

[bod]

yeah it kinds of makes sense in the end when you know where to look at 😅 But I think I wouldn't have made it alone without the pointers from Victor. Maybe it's easier if you're a more experienced JS developer than myself.