Scala language provider for Minecraft 26.1.x.

Branch 26.1

This mod adds a Scala library to Minecraft 26.1.2 with Forge and NeoForge. NO COMPATIBILITY WITH 1.x version of SLP.

Usage

• For Player – Download a Jar file from Curse Forge or Modrinth and move the file to your mods folder. This mod will not appear in the mod list.

• For Developer
  See the example directory.

  In your build.gradle, add below code in the top-level.

  repositories {
      maven {
          name = "kotori316"
          url = uri("https://maven.kotori316.com")
          content {
              // The artifact id differs by loader: "scalablecatsforce" for Forge,
              // "scalablecatsforce-neoforge" for NeoForge.
              includeModule("com.kotori316", "scalablecatsforce")
              includeModule("com.kotori316", "scalablecatsforce-neoforge")
          }
      }
  }
  
  dependencies {
      // Add Forge or NeoForge dependency as the platform requires
  
      // Scala, no need to add Scala2 dependency since 3.8.3
      implementation('org.scala-lang:scala3-library_3:3.8.4')
      // Add if you need this library.
      // the runtime copy is bundled in the SLP jar.
      implementation('org.typelevel:cats-kernel_3:2.13.0')
  
      // The language loader. You can put the jar to the mods dir instead of declaring in `build.gradle.kts`.
      // Pick the artifact for your loader (the version below is shared by both).
      // Forge:
      runtimeOnly("com.kotori316:scalablecatsforce:5.0.0-mc26.1.2-3.8.4:dev") {
          transitive(false)
      }
      // NeoForge:
      // runtimeOnly("com.kotori316:scalablecatsforce-neoforge:5.0.0-mc26.1.2-3.8.4:dev") {
      //     transitive(false)
      // }
  }

  • If the Minecraft client doesn't launch with an exception to modules, change scala dependency from "implementation" to "compileOnly" and add slp mod in the mods directory.
  • The published artifact id depends on the loader: com.kotori316:scalablecatsforce (Forge) and com.kotori316:scalablecatsforce-neoforge (NeoForge). Available versions are listed in their Maven metadata:
    • Forge: https://maven.kotori316.com/com/kotori316/scalablecatsforce/maven-metadata.xml
    • NeoForge: https://maven.kotori316.com/com/kotori316/scalablecatsforce-neoforge/maven-metadata.xml
  • Change the library version if needed.
    • See detail pages in CurseForge or Modrinth to get which library version is included in the Jar file.
  • From 26.1.2 version, SLP includes Scala 3.8.4

Limitations

In this section, I note some points you should care.

1. Avoid use of Mod.EventBusSubscriber in Java code. This will cause exception in "compileScala" task.

• Use in Scala code will not throw an exception.

2. If you got the compile error "ambiguous reference to overloaded definition", specify the return type.

• For example, val offsetPos = pos.relative(direction) will cause this error because relative is declared both in BlockPos and Vec3i, and the return types are different. So, the compiler can't determine which method to call. To resolve this issue, specify the return type as follows. val offsetPos: BlockPos = pos.relative(direction)

3. On Forge, do not import the per-primitive Cats convenience packages cats.kernel.instances.{byte, char, short, int, long, float, double, boolean} directly.

• These packages are named after Java reserved words, so the Forge jar drops them (see the API section). Code such as import cats.kernel.instances.int.* compiles against the official Cats but throws NoClassDefFoundError: cats/kernel/instances/int/package$ at runtime on Forge. The instances are still available via cats.implicits.*, cats.syntax.*, cats.kernel.instances.all.*, or cats.kernel.instances.<Type>Instances (e.g. cats.kernel.instances.IntInstances). NeoForge bundles the jars as-is and is unaffected.

API

• Scala - GitHub - is licenced under the Apache License, Version 2.0.
• Cats - GitHub - is licenced under the License.
  • SLP bundles the official Cats. NeoForge uses the jars as-is. The Forge jar removes the Java-reserved-word packages (e.g. cats.kernel.instances.byte) from cats-kernel, because Forge's module system rejects them while building the module layer at boot.