Java / Kotlin (JVM)

The JVM binding io.github.goplasmatic:datalogic reaches the shared C ABI directly through the Java FFM API (java.lang.foreign), with no JNA or JNI glue. It requires JDK 22 or newer (the FFM API is final since 22) and works from Java, Kotlin, and Scala.

Installation

Add the dependency to your project:

Maven (pom.xml)

<dependency>
    <groupId>io.github.goplasmatic</groupId>
    <artifactId>datalogic</artifactId>
    <version>5.0.1</version>
</dependency>

Gradle (build.gradle)

implementation 'io.github.goplasmatic:datalogic:5.0.1'

Note: The Maven groupId is io.github.goplasmatic, but the Java package path is com.goplasmatic.datalogic.

Quick Start

One-Shot Evaluation

import com.goplasmatic.datalogic.Engine;

public class Main {
    public static void main(String[] args) {
        try (Engine engine = new Engine()) {
            String result = engine.apply("{\"+\": [1, 2, 3]}", "{}");
            System.out.println(result); // "6"
        }
    }
}

Reusable Compiled Rules

Always compile rules when executing them repeatedly. Use Java’s try-with-resources statement to ensure native resources are disposed of correctly:

import com.goplasmatic.datalogic.Engine;
import com.goplasmatic.datalogic.Rule;

public class Main {
    public static void main(String[] args) {
        try (Engine engine = new Engine();
             Rule rule = engine.compile("{\"if\": [{ \">\": [{\"var\": \"score\"}, 50] }, \"pass\", \"fail\"]}")) {
            
            System.out.println(rule.evaluate("{\"score\": 75}")); // "pass"
            System.out.println(rule.evaluate("{\"score\": 30}")); // "fail"
        }
    }
}

Arena Recycling with Session

To recycle memory allocations in hot loops, open a Session:

import com.goplasmatic.datalogic.Engine;
import com.goplasmatic.datalogic.Rule;
import com.goplasmatic.datalogic.Session;

public class Main {
    public static void main(String[] args) {
        try (Engine engine = new Engine();
             Rule rule = engine.compile("{\"var\": \"user.name\"}")) {
            
            try (Session session = engine.openSession()) {
                for (String input : dataset) {
                    // Reuses the internal arena; does not allocate fresh memory
                    String name = session.evaluate(rule, input);
                    System.out.println(name);
                }
            }
        }
    }
}

Concurrency

• Engine and Rule instances are fully thread-safe and can be shared globally.
• Session instances are not thread-safe and must be kept local to individual threads.

Going deeper

• C ABI internals: memory management & thread safety — the native-heap ownership rules every FFI binding shares
• Engine configuration semantics
• JVM binding README — full API surface, error types, and platform table