Moving to Kotlin 2 (once 2.0.20 is released)

[ftomassetti]

Kotlin 2 is coming, bringing benefits to the multi-platform projects.

Current versions of Kotlin 2 (Kotlin 2.0.0-Beta3 as of now) cannot be used in production, but we may start running experiments to see if there are issues with the Kotlin 2 compiler. In my experience with other projects the migration was rather smooth, but this is a project supporting many platforms and perhaps there could be more suprises.

[lppedd]

Probably in 3/4 months?
Left is Beta4, and a couple of RCs at least.

We can already try out K2 tho.

[lppedd]

Just compiled/tested with K2, all good!

[ftomassetti]

Just compiled/tested with K2, all good!

Great!

[ftomassetti]

I guess with Kotlin 2, the K2 compiler is enabled by default, right?

[lppedd]

Yes, exactly.

K1 will be available for some minor versions IIRC (e.g., 2.2), so there is no rush in case of issues (which we don't have anyway).

[sschuberth]

Will the generated code improve with K2? This comment seems to hint at it.

[lppedd]

@sschuberth in this specific case we might benefit of future language capabilities, but the main improvement is a bit of speed up when building.

No changes for generated code, but in case you can be more specific and I can try to answer.

[lppedd]

I've tested Beta4 today with the K2 IDE.
Still not ready imo, especially the IDE plugin (you can't work in non-JVM or non-Common source sets). We can definitely update to Kotlin 2.0, but we will need to keep the API version at the 1.9 level, as that's where most users will be at for quite some time.

[ftomassetti]

Now Kotlin 2.0.0 has been released, so we could check the situation and decide if we want to move to K2 using API 1.9

[lppedd]

I've been observing the situation since beta versions. My advice is to wait until 2.0.20. That's what most issues, and they are a lot, are targeting.

[ftomassetti]

Noted, thank you

[lppedd]

Like, stuff like KT-68538 needs to be fixed before considering an update to 2.0+.
It's too risky.

[lppedd]

2.0.20-Beta1 should be out mid next week.