Fabric language module for Kotlin. Adds support for Kotlin exclusive entrypoints and bundles the Kotlin Stdlib as well as common kotlinx libraries.

Add it as a dependency to your Gradle project:

dependencies {
    modImplementation("net.fabricmc:fabric-language-kotlin:1.12.3+kotlin.2.0.21")
}

Use the kotlin adapter for your mod by setting the adapter property in the fabric.mod.json file. Remember to the add a dependency entry to your fabric.mod.json file:

{
    "schemaVersion":  1, 
    "entrypoints": {
        "main": [
            {
                "adapter": "kotlin",
                "value": "package.ClassName"
            }
        ]
    },
    "depends": {
        "fabric-language-kotlin": ">=1.12.3+kotlin.2.0.21"
    }
}

For more info reference the fabric.mod.json documentation.

Do not forget to set the schemaVersion to 1 or it will fall back to schema 0 and will not attempt to load entrypoints.

{
    "adapter": "kotlin",
    "value": "mymod.MyMod"
}

package mymod
class MyMod : ModInitializer {
    override fun onInitialize() {
        TODO()
    }
}

{
    "adapter": "kotlin",
    "value": "mymod.MyMod"
}

package mymod
object MyMod : ModInitializer {
    override fun onInitialize() {
        TODO()
    }
}

{
    "adapter": "kotlin",
    "value": "mymod.MyMod::init"
}

package mymod
object MyMod  {
    fun init() {
        TODO()
    }
}

{
    "adapter": "kotlin",
    "value": "mymod.MyMod::initializer"
}

package mymod
object MyMod  {
    val initializer = ModInitializer {
        TODO()
    }
}

{
    "adapter": "kotlin",
    "value": "mymod.MyMod$Companion"
}

package mymod
class MyMod {
    companion object : ModInitializer {
        override fun onInitialize() {
            TODO()
        }
    }
}

{
    "adapter": "kotlin",
    "value": "mymod.MyMod$Companion::init"
}

package mymod
class MyMod  {
    companion object {
        fun init() {
            TODO()
        }
    }
}

{
    "adapter": "kotlin",
    "value": "mymod.MyMod$Companion::initializer"
}

package mymod
class MyMod  {
    companion object {
        val initializer = ModInitializer {
            TODO()
        }
    }
}

{
    "adapter": "kotlin",
    "value": "mymod.MyModKt::init"
}

package mymod

fun init() {
    TODO()
}

Companion objects can be used by appending $Companion to the class. Take care of processResources there, it might try to expand it, in that case escape it.

org.jetbrains.kotlin namespace:

• kotlin-stdlib 2.0.21 Docs, API docs, GitHub
• kotlin-reflect 2.0.21 Docs, API docs

org.jetbrains.kotlinx namespace:

• kotlinx-coroutines-core 1.9.0 Guide, API docs, GitHub
• kotlinx-coroutines-jdk8 1.9.0 API docs
• kotlinx-serialization-core 1.7.3 Guide, API docs, GitHub
• kotlinx-serialization-json 1.7.3 API docs
• kotlinx-serialization-cbor 1.7.3 API docs
• atomicfu 0.25.0 GitHub
• kotlinx-datetime 0.6.1 GitHub
• kotlinx-io-core 0.5.4 API docs, GitHub
• kotlinx-io-bytestring 0.5.4 API docs

https://maven.fabricmc.net/net/fabricmc/fabric-language-kotlin/

• Update the readme in templates/README.template.md.
• Run ./gradlew processMDTemplates.