How to have different implementations for Linux and Windows?

[mahozad]

How to provide an expect and separate actuals for Linux and Windows?

Because something should be implemented differently depending on the OS.

[ryanmitchener]

@mahozad I would recommend reading through https://kotlinlang.org/docs/multiplatform-hierarchy.html#default-hierarchy-template. You can set up your folder structure to have some target specific code via expect/actual. For windows and linux you would need to use the mingw and linux directories

[mahozad]

Are you sure? I think it's for native targets not jvm targets. Is there any compose multiplatform example?

[m-sasha]

There are no separate source sets for JVM on Windows/Linux/macOS; you just switch (at runtime) on the OS. You can use org.jetbrains.skiko.hostOs, or any 3rd-party OS-detecting library in Java.

[ryanmitchener]

@mahozad Sorry, I didn't realize you were trying to do this on the JVM. In that case what m-sasha said is true. There are no separate source sets for JVM targets. Instead, use the org.jetbrains.skiko.hostOs and either perform the OS check in-line or use it in your DI to inject the appropriate implementation based on OS.

[igordmn]

Yes, checking it in runtime is the default way.

If you need different binaries with different code, you can separate your project by different source sets, and include different sources depending on hostOs inside build.gradle.kts in build-time.

If your project is kotlin("multiplatform"), you can define an additional sourceset this way:

kotlin {
  sourcSets {
    if (...) { // check if it is Windows
        val windowsDesktopMain by creating {
            dependsOn(desktopMain)
        }
    }
    ...
  }
  ...

[mahozad]

The above solution by igordmn does not work even though I provided actual declaration in windowsDektopMain source set (with and without applyDefaultHierarchyTemplate() ):

Expected property 'myVariable' has no actual declaration in module <MyApp> for JVM

[okushnikov]

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.