scala 特质

package com.jason.qianfeng

trait Iterator[A] {
  val name = "Iterator"

  def hasNext: Boolean

  def next: A
}

trait Log {
  def log(msg: String): Unit = {
    println(msg)
  }
}

class IntIterator(to: Int) extends Iterator[Int] with Log {
  var current = 0

  override def hasNext = current < to

  override def next = {
    if (current < to) {
      log("has next")
      val r = current
      current += 1
      r
    } else {
      0
    }
  }

}

object IteratorTest{
  def main(args: Array[String]): Unit = {
    val it = new IntIterator(10)
    println(it.next)
    println(it.next)
    println(it.next)
  }
}