scala as scripting language [duplicate]

Answer 1

See my answer here: "eval" in Scala

(I assume you are already aware of scala interactive mode, and how to write executable scripts with a Scala-compatible shebang #! line.)

Answer 2

somehow I already found out how to use scala as scripting language but I still have a problem with the classLoader

object O{
  def foo = println("Hello World in object O")
}

trait T{
  def foo:String
}

object MyInterpreter extends App{
  val srcA = 
  """ 
  println("Hello World from srcA") 
  """

  val srcB = """ O.foo """

  val srcC = """ 
  class A extends T{ 
    def foo = "Hello World from srcC"
    override def toString = "this is A in a src"
  }
  """


  val out = System.out
  val flusher = new java.io.PrintWriter(out)

  val interpreter = {
  val settings = new import scala.tools.nsc.GenericRunnerSettings( println _ )
  new scala.tools.nsc.interpreter.IMain(settings, flusher)
  }

  interpreter.interpret(srcA)
  interpreter.interpret(srcB)
  interpreter.compileString(srcC)

  val classA = interpreter.classLoader.findClass("A")

  println(classA)

  val constructors = classA.getDeclaredConstructors
  val myinstance = constructors(0).newInstance()

  println(myinstance)

  //this still throws an classCastException
  myinstance.asInstanceOf[T].foo 
  //but everything else works
}