support `JEP 476: Module Import Declarations` in `JavaParsers`

[xuwei-k]

Reproduction steps

https://openjdk.org/jeps/476

Scala version: 2.13.14

$ java --version
openjdk 23-ea 2024-09-17
OpenJDK Runtime Environment (build 23-ea+25-2094)
OpenJDK 64-Bit Server VM (build 23-ea+25-2094, mixed mode, sharing)

B.scala

class B

A.java

import module java.base;

public class A {
}

build.sbt

javacOptions ++= Seq("--enable-preview", "--release", scala.util.Properties.javaSpecVersion)

scalaVersion := "2.13.14"

project/build.properties

sbt.version=1.10.0

Problem

run sbt compile

[error] my-example-project-path/A.java:1:15: `;` expected but identifier found.
[error] import module java.base;
[error]               ^
[error] one error found
[error] (Compile / compileIncremental) Compilation failed

workaround

set compileOrder := CompileOrder.JavaThenScala or compileOrder := CompileOrder.ScalaThenJava in sbt

[som-snytt]

The Java feature is mostly about prototyping and JShell. It would be nice if -Yimports handled modules.

scala -Yimports:java.lang,scala,scala.Predef,scala.annotation,scala.util.chaining
becomes
scala -Yimports:java.base,scala,scala.Predef,scala.annotation,scala.util.chaining
where for conflicts between module and package names it could support
scala -Yimports:module java.base,etc
or someday just
scala -Yimports:java.base,scala.base

[SethTisue]

would it be useful for our parser to accept but ignore such imports? or does it need to actually take action in order for the change to be useful?

[xuwei-k]

finalized in JDK 25

• https://openjdk.org/jeps/511
• 8344708: Implement JEP 511: Module Import Declarations openjdk/jdk#23801