Given a 100% Kotlin Android project, does moving all code from `src/main/java` to `src/main/kotlin` ...

# android

[tseisel]

Given a 100% Kotlin Android project, does moving all code from src/main/java to src/main/kotlin has any positive impact on build speed ?
I'd expect to avoid at least a java compiler pass.

[Dominaezzz]

I think you can still have java source code in src/main/kotlin, so it won't make a difference.

[wasyl]

I don’t think it makes a difference where you keep the code. If you want to avoid java compiler pass, you actually need to only have .kt classes in the entire Gradle module.

[wasyl]

Consider that classes from src/main/java see classes from src/main/kotlin and vice versa, so Kotlin folks can’t really make any optimizations based on where the files are

[wasyl]

But with separate modules, the Gradle plugin can see that only kt files are present, so it doesn’t need to engage javac. But it’s also quite difficult, for example if you use annotation processor that generates java code, you’ll end up with mixed .kt and .java files anyway

[wasyl]

Also I’m not an expert here, so I may be wrong — it’s just something I recall from a talk from some conference

[tseisel]

Thanks @Dominaezzz and @wasyl.
Since I'm using a lot of annotation processors that generate Java code, I don't think that would have any impact then.
I guess I'd better split my project into multiple gradle modules.