does not bind AnyVal properly...

[shengc]

This throws java.lang.reflect.MalformedParameterizedTypeException. I think the problem is Guice depends on Java reflection which cannot properly interpret AnyVal, as I cannot assign null to the initial value of Foo in BarProvider, since Foo is not bounded by Null

class Foo(val foo: String) extends AnyVal {}
object Foo {
  def apply(foo: String): Foo = new Foo(foo)

  def empty: Foo = new Foo("")
}

import com.google.inject._
import net.codingwell.scalaguice._

class BarProvider extends Provider[String] {
  @Inject val foo: Foo = Foo.empty

  def get() = foo.toString()
}

class Module extends AbstractModule with ScalaModule {
  def configure() {
    bind[Foo].toInstance(Foo("abc"))
    bind[String].toProvider[BarProvider]
  }
}

import net.codingwell.scalaguice.InjectorExtensions._

val injector = Guice.createInjector(new Module)
Console.println(injector.instance[String])

[nbauernfeind]

By the way, I think you want this implementation of get (which injects the wrapped string foo and not Foo.toString()):

class BarProvider extends Provider[String] {
  @Inject val foo: Foo = Foo.empty

  def get() = foo.foo
}

If you're looking to allow your Foo.empty to be Foo(null) then you need to mark the injection as null-safe. In that case try this:

import javax.annotation.Nullable

class BarProvider extends Provider[String] {
  @Inject @Nullable val foo: Foo = Foo.empty

  def get() = foo.foo
}

[nbauernfeind]

Or possibly you wanted to do this?

@Inject @Nullable val foo: Foo = null.asInstanceOf[Foo]

I can't seem to reproduce the specific error that you're getting. Is there a specific version of guice/jvm/scala that you're using?

[nbauernfeind]

Actually, I can't seem to get guice to inject the Foo inside of the BarProvider. So yeah, it doesn't seem like I can inject an AnyVal at all.

[shengc]

@nbauernfeind that is really weird ! It does not throw exception now. However as I change BarProvider to spit out Foo.foo instead, the program always prints empty string instead of abc. Is that what happens at your end ?

[shengc]

Unless this is an sbt bug, this snippet has a totally messed up error ...

case class A()
case class B()

class Foo[A, B](val foo: String) extends AnyVal {}
object Foo {
  def apply(foo: String): Foo[A, B] = {
    Console.println("h")
   new Foo(foo) 
  }

  def empty: Foo[A, B] = new Foo("")
}

import com.google.inject._
import com.google.inject.name._
import net.codingwell.scalaguice._

class BarProvider extends Provider[String] {
  @Inject @Named("f") val foo: Foo[A, B] = Foo.empty

  def get() = foo.foo
}

class M extends AbstractModule with ScalaModule {
  def configure() {
    bind[Foo[A, B]].annotatedWithName("f").toInstance(Foo("abc"))
    bind[String].toProvider[BarProvider]
  }
}

import net.codingwell.scalaguice.InjectorExtensions._

val injector = Guice.createInjector(new M)
Console.println(injector.instance[String]

error:

1) No implementation for java.lang.String annotated with     @com.google.inject.name.Named(value=f) was bound.
  while locating java.lang.String annotated with @com.google.inject.name.Named(value=f)
    for field at BarProvider.foo(<console>:25)
 at M.bind(<console>:30)

[shengc]

A minimized example showing the problem.

  import com.google.inject._
  import com.google.inject.name._
  import net.codingwell.scalaguice._

  class Foo(val foo: String) extends AnyVal

  class Bar @Inject() (foo: Foo) {
    override def toString() = foo.foo
  }

  object TestModule extends AbstractModule with ScalaModule {
    def configure() {
      bind[Foo].toInstance(new Foo("abc"))
      bind[Bar]
    }
  }

  import net.codingwell.scalaguice.InjectorExtensions._

  val injector = Guice.createInjector(TestModule)

  Console.println("bar = " + injector.instance[Bar].toString())
  Console.println("foo = " + injector.instance[Foo].foo

output:

[info] bar =
[info] foo = abc