README.md

[TODO]

Test.scala

import java.io.ObjectOutputStream
import java.io.ObjectInputStream
import java.io.FileOutputStream
import java.io.FileInputStream


class OuterScopeThatDefinesFunction extends Serializable {
  // This method returns a function whose $outer scope is this class.
  // Note that the function does not reference any variables in this scope,
  // so the generated class won't contain any fields.
  def func = (a: Int) => a
}

// This class is a simple wrapper that holds a function:
class UsesFunction(val func: Int => Int) extends Serializable { }

object Main {
  def main(args: Array[String]) {
    if (args.size == 0) {
      println("Serializing object to test.bin")
      // Define a function in an outer scope
      val functionDefinitionScope = new OuterScopeThatDefinesFunction()
      // Put that function into an object
      val c = new UsesFunction(functionDefinitionScope.func)
      // Serialize that object
      val fs = new FileOutputStream("test.bin")
      val os = new ObjectOutputStream(fs)
      os.writeObject(c)
      os.close()
      fs.close()
    }

    else {
      println("Deserializing object from test.bin")
      // Read the object serialized in the previous step
      val fs = new FileInputStream("test.bin")
      val os = new ObjectInputStream(fs)
      val c = os.readObject().asInstanceOf[UsesFunction]
    }
  }
}

test.sh

#!/usr/bin/env bash

if [ -z $1 ]; then
    echo "Usage: $0 scalaVersion"
    exit -1
fi

SCALA_VERSION=$1
echo "Testing with Scala $1"

set -x

rm test.bin
sbt "++ $SCALA_VERSION" clean compile
scala -cp target/scala-*/classes/ Main
scala -cp target/scala-*/classes/ Main read
rm target/scala-*/classes/OuterScopeThatDefinesFunction.class
scala -cp target/scala-*/classes/ Main read