trait中super调用动态绑定

axman

于 2012-08-27 15:54:54 发布

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分类专栏： scala手记文章标签： class 扩展

本文链接：https://blog.csdn.net/axman/article/details/7912538

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class Root{
  def hello(){
    println("Hello,Root!")
  }
}

class SubA extends Root{
  override def hello() {
    println("Hello,SubA!")
  }
}


trait D extends Root{
  def traitHello(){
    super.hello();
  }
}

对于trait D而言，虽然其扩展了class Root,但是super.hello()并不是指Root的hello方法，而是在D被混入后的目标类的hello.

SCALA编译原文描述不严格：

The Doubling trait has two funny things going on. The first is that it declaresa superclass, IntQueue. This declaration means that the trait can only bemixed into a class that also extends IntQueue. Thus, you can mix Doublinginto BasicIntQueue, but not into Rational.