I can haz no package-private class in Scala?

Question

Sorry for the catchy title. ;-)

I want to create a package-private class with a package-private method in Scala, so my class looks somewhat like this:

package net.java.truevfs.ext.pace

import ...

private[pace] abstract class AspectController(controller: FsController)
extends FsDecoratingController(controller) {

  private[pace] def apply[V](operation: => V): V

  ... // lots of other stuff
}

However, if I use javap to check what the Scala compiler effectively creates, I get something like this:

$ javap -classpath target/classes net.java.truevfs.ext.pace.AspectController
Compiled from "AspectController.scala"
public abstract class net.java.truevfs.ext.pace.AspectController extends net.java.truevfs.kernel.spec.FsDecoratingController implements scala.ScalaObject{
    public abstract java.lang.Object apply(scala.Function0);
    ...
}

This means that although the Scala compiler might respect the access restrictions, I could still call this class from any Java code, which is a clear encapsulation violation.

Am I missing something? Is there a way to make this work as intended?

Answer 1

In addition to @Régis' answer, the reason Scala compiler doesn't make the class package-private is because by Scala rules it can be accessed from other packages: namely, subpackages of net.java.truevfs.ext.pace. E.g.

package net.java.truevfs.ext.pace.subpackage
import net.java.truevfs.ext.pace.AspectController

class Subclass extends AspectController { ... }

is legal in Scala, but in Java classes from net.java.truevfs.ext.pace.subpackage can't access package-private classes from net.java.truevfs.ext.pace.