Scala 多繼承 & 依賴注入

依賴注入：

trait Config {
  load
  val text: String
  def load: Unit
}

trait InMemoryConfig extends Config {
  lazy val text = "Hello"
  def load = println("load: " + text)
}

trait Context

trait MyContext extends Context {
  this: Config =>
  def welcome = this.text
}

object Env extends MyContext with InMemoryConfig

println(Env.text)

結果：
load: Hello
Hello

多繼承：
class Person
trait TTeacher extends Person {

  def teach = {println(" TTeacher")}

}
trait TPianoPlayer extends Person {

  def playPiano = {println("I’m playing piano. ")} //實方法，已實現

}
object PianoplayingTeacher extends Person with TTeacher with TPianoPlayer

PianoplayingTeacher.teach
PianoplayingTeacher.playPiano
結果：
 TTeacher
I’m playing piano.