Hey! Have you ever stumbled upon an idea which requires usage of <ServiceLoader> in Kotlin Multiplat...

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[Oleg Yukhnevich]

Hey!
Have you ever stumbled upon an idea which requires usage of ServiceLoader in Kotlin Multiplatform?
Me too, twice already.
That's why for the last several evenings I was working on something.
Introducing sweet-spi: Simple SPI (Service Provider Interface) for Kotlin Multiplatform (equivalent of JVM's Service Loader)
https://x.com/why_oleg/status/1822639475736129992
Feel free to check the README for all the details on how to use it and how it works!

[Edoardo Luppi]

For K/JS, have you considered the possibility of allowing JS consumers to contribute services?

For example, I've been working on an internal logging library that allows a VS Code extension consumer to plug-in its own logging implementation.

[Oleg Yukhnevich]

Theoretically it's possible, but not convenient. Even Java interoperability is out of scope for now.
I see it as a Kotlin-only solution for libraries.
Still, all declarations required to implement this on your side are public and marked with InternalSweetSpiApi annotation - but, they will probably stay forever due compatibility, as they are used by KSP plugin 🙃
Probably you can call registerInternalServiceModule (source) somewhere. But you need to be sure, that it's called before any calls to ServiceLoader.load
Reloading/Unloading of existing instances is not supported now

[Edoardo Luppi]

Thanks! Looks good btw.

Related, I hope EagerInitialization gets stabilized at some point, because it's pretty useful.

[Oleg Yukhnevich]

Just in case: do you have any other use-case except for ServiceLoader-like mechanism?

[Edoardo Luppi]

For EagerInitialization you mean?
I have quite a lot of top-level properties, and EagerInitialization (or globally setting -Xir-property-lazy-initialization=false) avoids the lazy initialization checks (x === VOID). If the properties are accessed in loops, the check adds unnecessary overhead.