kotlinc-lein

A Leiningen plugin for compiling Kotlin source files. It behaves similarly with the Leiningen javac plugin.

####Latest version:

Requirements

The kotlinc-lein plugin works with Leiningen version 2.0.0 or higher.

Installation

You can install the plugin by adding kotlinc-lein to your project.clj file in the :plugins section:

(defproject megacorp/superservice "1.0.0-SNAPSHOT"
  :min-lein-version "2.0.0"
  :plugins          [[kotlinc-lein "0.1.0"]])
  :dependencies     [[org.jetbrains.kotlin/kotlin-runtime "1.0.2"]]

In addition, notice that you should also add the Kotlin Runtime dependency explicitly.

Source Layout

By default, Leiningen assumes your project only has Clojure source code under src. When using both Clojure and Kotlin in the same codebase, however, it is necessary to tell Leiningen where to find Kotlin sources.

To do so, use :source-paths and :kotlin-source-paths options in the project definition:

(defproject megacorp/superservice "1.0.0-SNAPSHOT"
  :source-paths        ["src/clojure"]
  :kotlin-source-paths ["src/kotlin"])

Having one source root contain another (e.g. src and src/kotlin) can cause obscure problems.

Kotlin Source Compilation

To compile Kotlin sources, you can run

$ lein kotlinc

To automatically compile Kotlin sources add "kotlinc" to the :prep-tasks vector

Setting Kotlin Compiler Options With Leiningen

When compiling Kotlin sources, it may be necessary to pass extra arguments to the compiler. For example, it is very important to target the version of the generated JVM bytecodes. This can be done via the :kotlinc-options which takes a vector of arguments as you would pass them to kotlinc on the command line. In this case we want to generate JVM bytecode 1.6 and to use Kotlin language version 1.0:

(defproject megacorp/superservice "1.0.0-SNAPSHOT"
  :kotlinc-options ["-jvm-target" "1.6" "-language-version" "1.0"])

Equivalently through the command line:

$ lein kotlinc -jvm-target 1.6 -language-version 1.0

Take note that the example options above are only available when using the snapshot of the Kotlin compiler version 1.1

Changing the Default Kotlin Compiler Version (Currently 1.0.2)

To use different version of the Kotlin compiler, do it like this:

(defproject megacorp/superservice "1.0.0-SNAPSHOT"
  ;; add desired version here
  :kotlin-compiler-version "1.1-SNAPSHOT"
  ;; get snaphot version from repository
  :repositories            [["snapshots" "http://oss.sonatype.org/content/repositories/snapshots"]]
  ;; match runtime version of the compiler
  :dependencies            [[org.jetbrains.kotlin/kotlin-runtime "1.1-SNAPSHOT"]])

License

Copyright © 2016 Clyde Tan

Distributed under the Eclipse Public License either version - v 1.0.