SAM-with-receiver compiler plugin

Edit pageLast modified: 19 March 2024

The sam-with-receiver compiler plugin makes the first parameter of the annotated Java "single abstract method" (SAM) interface method a receiver in Kotlin. This conversion only works when the SAM interface is passed as a Kotlin lambda, both for SAM adapters and SAM constructors (see the SAM conversions documentation for more details).

Here is an example:

public @interface SamWithReceiver {}

@SamWithReceiver
public interface TaskRunner {
    void run(Task task);
}
fun test(context: TaskContext) {
    val runner = TaskRunner {
        // Here 'this' is an instance of 'Task'

        println("$name is started")
        context.executeTask(this)
        println("$name is finished")
    }
}

Gradle

The usage is the same to all-open and no-arg, except the fact that sam-with-receiver does not have any built-in presets, and you need to specify your own list of special-treated annotations.

plugins {
    kotlin("plugin.sam.with.receiver") version "2.1.20"
}

Then specify the list of SAM-with-receiver annotations:

samWithReceiver {
    annotation("com.my.SamWithReceiver")
}

Maven

<plugin>
    <artifactId>kotlin-maven-plugin</artifactId>
    <groupId>org.jetbrains.kotlin</groupId>
    <version>${kotlin.version}</version>

    <configuration>
        <compilerPlugins>
            <plugin>sam-with-receiver</plugin>
        </compilerPlugins>

        <pluginOptions>
            <option>
                sam-with-receiver:annotation=com.my.SamWithReceiver
            </option>
        </pluginOptions>
    </configuration>

    <dependencies>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-maven-sam-with-receiver</artifactId>
            <version>${kotlin.version}</version>
        </dependency>
    </dependencies>
</plugin>

Command-line compiler

Add the plugin JAR file to the compiler plugin classpath and specify the list of sam-with-receiver annotations:

-Xplugin=$KOTLIN_HOME/lib/sam-with-receiver-compiler-plugin.jar
-P plugin:org.jetbrains.kotlin.samWithReceiver:annotation=com.my.SamWithReceiver