Jelly-RDF · Ostrzyciel · Sep 4, 2026 · Sep 4, 2026 · Sep 4, 2026 · Sep 4, 2026
diff --git a/.scalafix.conf b/.scalafix.conf
@@ -4,4 +4,6 @@ rules = [
   ProcedureSyntax
   RedundantSyntax
 ]
-ExplicitResultTypes.memberVisibility = [Public]
+ExplicitResultTypes.memberVisibility = [Public]
+# Needed for Scalafix 0.14.7 and Scala 3.9. Remove after upgrading Scalafix.
+ExplicitResultTypes.fetchScala3CompilerArtifactsOnVersionMismatch = true
diff --git a/build.sbt b/build.sbt
@@ -2,7 +2,7 @@ import scala.language.postfixOps
 import scala.language.implicitConversions
 import scala.sys.process.*
 
-ThisBuild / scalaVersion := "3.3.8"
+ThisBuild / scalaVersion := "3.9.0"
 ThisBuild / organization := "eu.neverblink.jelly"
 ThisBuild / homepage := Some(uri("https://w3id.org/jelly/jelly-jvm"))
 ThisBuild / licenses := List("Apache-2.0" -> uri("https://www.apache.org/licenses/LICENSE-2.0"))

diff --git a/crunchy-protoc-plugin/src/main/scala/eu/neverblink/protoc/java/gen/EnumGenerator.scala b/crunchy-protoc-plugin/src/main/scala/eu/neverblink/protoc/java/gen/EnumGenerator.scala
@@ -229,7 +229,7 @@ class EnumGenerator(val info: EnumInfo):
       .sorted
       .toArray
     val createCaseIfs = (len: Int) => {
-      info.values.stream.filter(value => value.getName.length eq len).forEach(value => {
+      info.values.stream.filter(value => value.getName.length == len).forEach(value => {
         forName
           .beginControlFlow("if ($S == value)", value.getName)
           .addStatement("return $N", NamingUtil.filterKeyword(value.getName))

diff --git a/crunchy-protoc-plugin/src/main/scala/eu/neverblink/protoc/java/gen/RequestInfo.scala b/crunchy-protoc-plugin/src/main/scala/eu/neverblink/protoc/java/gen/RequestInfo.scala
@@ -350,10 +350,10 @@ object RequestInfo:
     // Used for the return type in the method, e.g., Optional<String>
     private def getOptionalReturnType: TypeName =
       if (isRepeated)
-        return ParameterizedTypeName.get(ClassName.get(classOf[Optional[_]]), getRepeatedStoreType)
+        return ParameterizedTypeName.get(ClassName.get(classOf[Optional[?]]), getRepeatedStoreType)
       val typeName = getTypeName
       if (!isPrimitive || (typeName eq TypeName.BOOLEAN))
-        return ParameterizedTypeName.get(ClassName.get(classOf[Optional[_]]), typeName.box)
+        return ParameterizedTypeName.get(ClassName.get(classOf[Optional[?]]), typeName.box)
       if (typeName eq TypeName.INT) return TypeName.get(classOf[OptionalInt])
       if (typeName eq TypeName.LONG) return TypeName.get(classOf[OptionalLong])
       if (typeName eq TypeName.FLOAT) return TypeName.get(classOf[OptionalDouble])
@@ -453,6 +453,6 @@ object RequestInfo:
 
     def getFields: Seq[RequestInfo.FieldInfo] = parentTypeInfo.fields
       .filter(field => field.descriptor.hasOneofIndex)
-      .filter(field => field.descriptor.getOneofIndex eq oneOfIndex)
+      .filter(field => field.descriptor.getOneofIndex == oneOfIndex)
       .toSeq
   }
diff --git a/docs/docs/index.md b/docs/docs/index.md
@@ -75,13 +75,13 @@ The following table shows the compatibility of the Jelly-JVM implementation with
 {: .jelly-table-tight }
 
 |                                                                    Jelly-JVM                                                                    | Java | <abbr title="Scala is used only in tests and jelly-pekko-* modules. Other modules are 100% in Java">Scala</abbr> | <abbr title="Eclipse RDF4J">RDF4J</abbr> | <abbr title="Apache Jena">Jena</abbr> | <abbr title="Apache Pekko, used in jelly-pekko-* modules.">Pekko</abbr> |                         Neo4j                         |
-|:-----------------------------------------------------------------------------------------------------------------------------------------------:|:----:|:-------------------------:|:-----------:|:-------------------------------------:|:-----------------------------------------------------------------------:|:-----------------------------------------------------:|
-| [4.0.x](https://w3id.org/jelly/jelly-jvm/4.0.x)–[**{{ jvm_package_version() }}**](https://w3id.org/jelly/jelly-jvm/{{ jvm_package_version() }}) | 21+[^3]  |      3.3.x (LTS)[^2]      |    6.x.x    |              5.4.x–6.x.x              |                               1.1.x–1.2.x                               | {{ neo4j_version('min') }}–{{ neo4j_version('max') }} |
-|                                                 [3.7.x](https://w3id.org/jelly/jelly-jvm/3.7.x)                                                 | 17+  |      3.3.x (LTS)[^2]      | 4.3.x–5.x.x |              5.x.x–6.x.x              |                               1.1.x–1.2.x                               |                     5.1.0–5.26.0                      |
-|                         [3.5.x](https://w3id.org/jelly/jelly-jvm/3.5.x)–[3.6.x](https://w3id.org/jelly/jelly-jvm/3.6.x)                         | 17+  |      3.3.x (LTS)[^2]      | 4.3.x–5.x.x |                 5.x.x                 |                               1.1.x–1.2.x                               |                     5.1.0–5.26.0                      |
-|                         [3.0.x](https://w3id.org/jelly/jelly-jvm/3.0.x)–[3.4.x](https://w3id.org/jelly/jelly-jvm/3.4.x)                         | 17+  |      3.3.x (LTS)[^2]      |    5.x.x    |                 5.x.x                 |                                  1.1.x                                  |                           –                           |
-|                        [2.0.x](https://w3id.org/jelly/jelly-jvm/2.0.x)–[2.10.x](https://w3id.org/jelly/jelly-jvm/2.10.x)                        | 17+  |        3.3.x (LTS)        |    5.x.x    |                 5.x.x                 |                                  1.1.x                                  |                           –                           |
-|                                                 [1.0.x](https://w3id.org/jelly/jelly-jvm/1.0.x)                                                 | 11+  | 3.3.x (LTS)<br>2.13.x[^1] |    4.x.x    |                 4.x.x                 |                                  1.0.x                                  |                           –                           |
+|:-----------------------------------------------------------------------------------------------------------------------------------------------:|:----:|:----------------------------------------------------------------------------------------------------------------:|:-----------:|:-------------------------------------:|:-----------------------------------------------------------------------:|:-----------------------------------------------------:|
+| [4.0.x](https://w3id.org/jelly/jelly-jvm/4.0.x)–[**{{ jvm_package_version() }}**](https://w3id.org/jelly/jelly-jvm/{{ jvm_package_version() }}) | 21+[^3]  |                                                 3.9.x (LTS)[^2]                                                  |    6.x.x    |              5.4.x–6.x.x              |                               1.1.x–1.2.x                               | {{ neo4j_version('min') }}–{{ neo4j_version('max') }} |
+|                                                 [3.7.x](https://w3id.org/jelly/jelly-jvm/3.7.x)                                                 | 17+  |                                                 3.3.x (LTS)[^2]                                                  | 4.3.x–5.x.x |              5.x.x–6.x.x              |                               1.1.x–1.2.x                               |                     5.1.0–5.26.0                      |
+|                         [3.5.x](https://w3id.org/jelly/jelly-jvm/3.5.x)–[3.6.x](https://w3id.org/jelly/jelly-jvm/3.6.x)                         | 17+  |                                                 3.3.x (LTS)[^2]                                                  | 4.3.x–5.x.x |                 5.x.x                 |                               1.1.x–1.2.x                               |                     5.1.0–5.26.0                      |
+|                         [3.0.x](https://w3id.org/jelly/jelly-jvm/3.0.x)–[3.4.x](https://w3id.org/jelly/jelly-jvm/3.4.x)                         | 17+  |                                                 3.3.x (LTS)[^2]                                                  |    5.x.x    |                 5.x.x                 |                                  1.1.x                                  |                           –                           |
+|                        [2.0.x](https://w3id.org/jelly/jelly-jvm/2.0.x)–[2.10.x](https://w3id.org/jelly/jelly-jvm/2.10.x)                        | 17+  |                                                   3.3.x (LTS)                                                    |    5.x.x    |                 5.x.x                 |                                  1.1.x                                  |                           –                           |
+|                                                 [1.0.x](https://w3id.org/jelly/jelly-jvm/1.0.x)                                                 | 11+  |                                            3.3.x (LTS)<br>2.13.x[^1]                                             |    4.x.x    |                 4.x.x                 |                                  1.0.x                                  |                           –                           |
 
 See the **[compatibility policy](user/compatibility.md)** for more details and the **[release notes on GitHub](https://github.com/Jelly-RDF/jelly-jvm/releases)**.
 
@@ -121,5 +121,5 @@ The development of the Jelly protocol, its implementations, and supporting tooli
 ![European Funds for Smart Economy, Republic of Poland, Co-funded by the European Union](assets/featured/feng_rp_eu.png)
 
 [^1]: Scala 2.13-compatible builds of Jelly-JVM are available for Jelly-JVM 1.0.x. Scala 2 support was removed in subsequent versions. [See more details](https://w3id.org/jelly/jelly-jvm/1.0.x/user/scala2).
-[^2]: Scala version applies **only** to the `jelly-pekko-*` modules. The other modules **do not depend** on Scala and are compatible with any version of Java 21+.
+[^2]: Scala version applies **only** to the `jelly-pekko-*` modules. The other modules **do not depend** on Scala.
 [^3]: The `jelly-rdf4j-*` modules require **Java 25+**, because RDF4J 6 does. All other modules run on Java 21+. Building Jelly-JVM from source requires JDK 25+ in all cases.
diff --git a/examples/src/main/scala/eu/neverblink/jelly/examples/PekkoGrpc.scala b/examples/src/main/scala/eu/neverblink/jelly/examples/PekkoGrpc.scala
@@ -63,8 +63,8 @@ object PekkoGrpc extends shared.ScalaExample:
     .withFallback(ConfigFactory.defaultApplication())
 
   // We will need two Pekko actor systems to run the streams – one for the server and one for the client
-  val serverActorSystem: ActorSystem[_] = ActorSystem(Behaviors.empty, "ServerSystem")
-  val clientActorSystem: ActorSystem[_] = ActorSystem(Behaviors.empty, "ClientSystem", config)
+  val serverActorSystem: ActorSystem[?] = ActorSystem(Behaviors.empty, "ServerSystem")
+  val clientActorSystem: ActorSystem[?] = ActorSystem(Behaviors.empty, "ClientSystem", config)
 
   // Our mock dataset that we will send around in the streams
   val dataset: Dataset =
@@ -73,7 +73,7 @@ object PekkoGrpc extends shared.ScalaExample:
   /** Main method that starts the server and the client.
     */
   def main(args: Array[String]): Unit =
-    given system: ActorSystem[_] = serverActorSystem
+    given system: ActorSystem[?] = serverActorSystem
     given ExecutionContext = system.executionContext
 
     // Start the server
@@ -95,7 +95,7 @@ object PekkoGrpc extends shared.ScalaExample:
   /** The client part of the example.
     */
   private def runClient(): Unit =
-    given system: ActorSystem[_] = clientActorSystem
+    given system: ActorSystem[?] = clientActorSystem
     given ExecutionContext = system.executionContext
 
     // Create a gRPC client
@@ -192,7 +192,7 @@ object PekkoGrpc extends shared.ScalaExample:
     * You will also need to implement this trait in your own service. It defines the logic with
     * which the server will handle incoming streams and subscriptions.
     */
-  class ExampleJellyService(using system: ActorSystem[_]) extends RdfStreamService:
+  class ExampleJellyService(using system: ActorSystem[?]) extends RdfStreamService:
     given ExecutionContext = system.executionContext
 
     /** Handler for clients publishing RDF streams to the server.

diff --git a/jmh/src/main/scala/eu/neverblink/jelly/jmh/RdfStreamFrameDecodeBench.scala b/jmh/src/main/scala/eu/neverblink/jelly/jmh/RdfStreamFrameDecodeBench.scala
@@ -11,7 +11,7 @@ import org.openjdk.jmh.infra.Blackhole
 object RdfStreamFrameDecodeBench:
   @State(Scope.Benchmark)
   class BenchInput:
-    var toDecode: Array[RdfStreamFrame] = _
+    var toDecode: Array[RdfStreamFrame] = scala.compiletime.uninitialized
 
     @Setup(Level.Trial)
     def setup(): Unit =

diff --git a/jmh/src/main/scala/eu/neverblink/jelly/jmh/RdfTripleRecursiveBench.scala b/jmh/src/main/scala/eu/neverblink/jelly/jmh/RdfTripleRecursiveBench.scala
@@ -10,7 +10,7 @@ object RdfTripleRecursiveBench:
   class BenchInput:
     val random = new scala.util.Random(123)
 
-    var toParse: Array[Byte] = _
+    var toParse: Array[Byte] = scala.compiletime.uninitialized
 
     val size = 1000
 

diff --git a/jmh/src/main/scala/eu/neverblink/jelly/jmh/ReadStringBench.scala b/jmh/src/main/scala/eu/neverblink/jelly/jmh/ReadStringBench.scala
@@ -6,11 +6,11 @@ import org.openjdk.jmh.annotations.*
 object ReadStringBench:
   @State(Scope.Benchmark)
   class BenchInput:
-    var toParse: Array[Byte] = _
+    var toParse: Array[Byte] = scala.compiletime.uninitialized
 
     val size = 1000
 
-    var inputStream: CodedInputStream = _
+    var inputStream: CodedInputStream = scala.compiletime.uninitialized
 
     @Setup(Level.Trial)
     def setup(): Unit =

diff --git a/jmh/src/main/scala/eu/neverblink/jelly/jmh/sparql/SparqlDecodeBench.scala b/jmh/src/main/scala/eu/neverblink/jelly/jmh/sparql/SparqlDecodeBench.scala
@@ -45,13 +45,13 @@ object SparqlDecodeBench:
         "realistic-mixed",
       ),
     )
-    var preset: String = _
+    var preset: String = scala.compiletime.uninitialized
 
     @Param(Array("4096"))
-    var valuesPerFrame: Int = _
+    var valuesPerFrame: Int = scala.compiletime.uninitialized
 
-    var bytes: Array[Byte] = _
-    var frames: Array[SparqlResultsFrame] = _
+    var bytes: Array[Byte] = scala.compiletime.uninitialized
+    var frames: Array[SparqlResultsFrame] = scala.compiletime.uninitialized
 
     @Setup(Level.Trial)
     def setup(): Unit =

diff --git a/jmh/src/main/scala/eu/neverblink/jelly/jmh/sparql/SparqlEncodeBench.scala b/jmh/src/main/scala/eu/neverblink/jelly/jmh/sparql/SparqlEncodeBench.scala
@@ -37,12 +37,12 @@ object SparqlEncodeBench:
         "realistic-mixed",
       ),
     )
-    var preset: String = _
+    var preset: String = scala.compiletime.uninitialized
 
     @Param(Array("4096"))
-    var valuesPerFrame: Int = _
+    var valuesPerFrame: Int = scala.compiletime.uninitialized
 
-    var data: SparqlBenchData.Data = _
+    var data: SparqlBenchData.Data = scala.compiletime.uninitialized
 
     @Setup(Level.Trial)
     def setup(): Unit =

diff --git a/jmh/src/main/scala/eu/neverblink/jelly/jmh/sparql/SparqlSizeReport.scala b/jmh/src/main/scala/eu/neverblink/jelly/jmh/sparql/SparqlSizeReport.scala
@@ -114,7 +114,8 @@ object SparqlSizeReport:
 
   private def run(config: Config): Unit =
     JenaSystem.init()
-    val names = if config.presets.nonEmpty then config.presets else SparqlDataGen.presetNames
+    val names = if config.presets.nonEmpty then config.presets
+    else SparqlDataGen.presetNames :+ "weather"
 
     config.dumpDir.foreach { dir =>
       Files.createDirectories(dir)
@@ -131,7 +132,8 @@ object SparqlSizeReport:
 
     var filesWritten = 0
     for name <- names do
-      val data = SparqlBenchData.load(name)
+      val data = if name == "weather" then SparqlBenchData.loadWeather(throughputRows)
+      else SparqlBenchData.load(name)
       val outputs = serialize(data, config.maxValuesPerFrame)
 
       config.dumpDir.foreach { dir =>

diff --git a/pekko-grpc/src/main/scala/eu/neverblink/jelly/grpc/RdfStreamServer.scala b/pekko-grpc/src/main/scala/eu/neverblink/jelly/grpc/RdfStreamServer.scala
@@ -50,12 +50,12 @@ object RdfStreamServer:
   *   actor system
   */
 final class RdfStreamServer(options: RdfStreamServer.Options, streamService: RdfStreamService)(using
-    system: ActorSystem[_],
+    system: ActorSystem[?],
 ):
   given ExecutionContext = system.executionContext
 
   private val logger = LoggerFactory.getLogger(getClass)
-  private var binding: Option[ServerBinding] = _
+  private var binding: Option[ServerBinding] = scala.compiletime.uninitialized
 
   /** Start this server.
     * @return

diff --git a/pekko-grpc/src/main/scala/eu/neverblink/jelly/grpc/RdfStreamServiceHandler.scala b/pekko-grpc/src/main/scala/eu/neverblink/jelly/grpc/RdfStreamServiceHandler.scala
@@ -117,26 +117,40 @@ object RdfStreamServiceHandler {
         (reader, writer) =>
           (method match {
             case "SubscribeRdf" =>
-              GrpcMarshalling.unmarshal(request.entity)(RdfStreamSubscribeSerializer, mat, reader)
+              GrpcMarshalling.unmarshal(request.entity)(using
+                RdfStreamSubscribeSerializer,
+                mat,
+                reader,
+              )
                 .map(implementation.subscribeRdf)
                 .map(e =>
-                  GrpcMarshalling.marshalStream(e, eHandler)(
+                  GrpcMarshalling.marshalStream(e, eHandler)(using
                     RdfStreamFrameSerializer,
                     writer,
                     system,
                   ),
                 )
 
             case "PublishRdf" =>
-              GrpcMarshalling.unmarshalStream(request.entity)(RdfStreamFrameSerializer, mat, reader)
+              GrpcMarshalling.unmarshalStream(request.entity)(using
+                RdfStreamFrameSerializer,
+                mat,
+                reader,
+              )
                 .flatMap(implementation.publishRdf)
                 .map(e =>
-                  GrpcMarshalling.marshal(e, eHandler)(RdfStreamReceivedSerializer, writer, system),
+                  GrpcMarshalling.marshal(e, eHandler)(using
+                    RdfStreamReceivedSerializer,
+                    writer,
+                    system,
+                  ),
                 )
 
             case m => Future.failed(new NotImplementedError(s"Not implemented: $m"))
           })
-            .recoverWith(GrpcExceptionHandler.from(eHandler(system.classicSystem))(system, writer)),
+            .recoverWith(
+              GrpcExceptionHandler.from(eHandler(system.classicSystem))(using system, writer),
+            ),
       ).getOrElse(unsupportedMediaType)
 
     Function.unlift((req: model.HttpRequest) =>

diff --git a/pekko-grpc/src/test/scala/eu/neverblink/jelly/grpc/GrpcSpec.scala b/pekko-grpc/src/test/scala/eu/neverblink/jelly/grpc/GrpcSpec.scala
@@ -48,10 +48,10 @@ class GrpcSpec extends AnyWordSpec, Matchers, ScalaFutures, BeforeAndAfterAll:
     .withFallback(ConfigFactory.defaultApplication())
 
   val testKit: ActorTestKit = ActorTestKit(conf)
-  val serverSystem: ActorSystem[_] = testKit.system
+  val serverSystem: ActorSystem[?] = testKit.system
 
   class TestService(storedData: Map[String, Seq[RdfStreamFrame]]) extends RdfStreamService:
-    given system: ActorSystem[_] = serverSystem
+    given system: ActorSystem[?] = serverSystem
     given ExecutionContext = system.executionContext
     var receivedData: mutable.Map[String, Seq[RdfStreamFrame]] = mutable.Map()
 
@@ -105,7 +105,7 @@ class GrpcSpec extends AnyWordSpec, Matchers, ScalaFutures, BeforeAndAfterAll:
     (name, confKey, service, bound)
   })
 
-  given clientSystem: ActorSystem[_] = ActorSystem(Behaviors.empty, "TestClient", conf)
+  given clientSystem: ActorSystem[?] = ActorSystem(Behaviors.empty, "TestClient", conf)
 
   override def afterAll(): Unit =
     ActorTestKit.shutdown(clientSystem)

diff --git a/project/plugins.sbt b/project/plugins.sbt
@@ -6,5 +6,3 @@ addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.4.4")
 addSbtPlugin("com.github.sbt" % "sbt-jacoco" % "3.6.0")
 addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.14.7")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.6.2")
-
-addDependencyTreePlugin