mixins.scala

来自「JAVA 语言的函数式编程扩展」· SCALA 代码 · 共 86 行

// $Id: mixins.scala 5359 2005-12-16 15:33:49Z dubochet $

// 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();
  }
}