Scala example source code file (mixins.scala)

This example Scala source code file (mixins.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

a, a, b, c, c, host, m1, m1, m2, m2::f, m3, test2, unit, unit

The Scala mixins.scala source code

// Test 1: "super" coming from mixins

import Console._;

object Test1 {
  class A {
    def f = "A::f";
  }

  class B extends A {
    override def f = "B::f";
  }

  trait M1 extends A {
    override def f = "M1::" + super.f;
  }

  class C extends B with M1 {
    override def f = super[M1].f;
  }

  def test(): Unit = {
    val c = new C;
    Console.println(c.f);
  }
}

// Test 2: qualified "super" inside of the host class

object Test2 {
  class M1 {
    def f = "M1::f";
  }

  trait M2 {
    def f = "M2::f";
  }

  trait M3 {
    def f = "M3::f";
  }

  class Host extends M1 with M2 with M3 {
    override def f = super[M1].f + " " + super[M2].f + " " + super[M3].f
  }

  def test(): Unit = {
    val h = new Host;
    Console.println(h.f)
  }
}

// Test 3: mixin evaluation order (bug 120)

object Test3 {

  class A(x: Unit, y: Unit) {
    Console.println("A");
  }

  trait B {
    println("B");
  }

  class C extends A({ println("one"); }, { println("two"); })
          with B {
    println("C");
  }

  def test() = {
    val c = new C();
  }
}

// Main testing function

object Test {
  def main(args: Array[String]): Unit = {
    Test1.test();
    Test2.test();
    Test3.test();
  }
}