Scala：Functional Objects

先上代码

class FunctionalObjects(var _x: Int, var _y: Int) {
  require(_x > 0)
  require(_y > 0)

  def this(value: Int) = this(value, value)

  def x = _x

  def x_=(value: Int) { _x = value }

  def y = _y

  def y_=(value: Int) { _y = value }

  def +(value: Int): FunctionalObjects = { 
    _x += value
    _y += value

    this
  }

  def +(value: FunctionalObjects): FunctionalObjects = { 
    _x += value.x
    _y += value.y

    this
  }


  override def toString(): String = {
    "("+ _x +", "+ _y +")"
  }
}

object FunctionalObjects {
  implicit def intToFunctionalObjectsTest(value: Int) = new FunctionalObjects(value)

  def main(args: Array[String]) {
    var test = new FunctionalObjects(5)
    test.y = 6
    println(test)
    println(test + 4)
    println(4 + test)
  }
}

隐式类型转换、运算符方法、属性语法，这些都不必多说，大家一看就明白，scala的构造方法得简单的解释一下，类型名称后面跟随的参数列表就是“主要构造函数”的签名，类型定义中出现的可执行语句，都是其方法体。def this 定义的构造方法为“次要构造方法”。