Scala 封裝可break和continue的foreach循環

發現scala里沒有break和continue, 有時候實在是需要的話就要自己try catch異常,代碼看起來有點蛋疼, 所以封裝了一個可break和continue的foreach.

import scala.collection.TraversableLike

case class Breakable() {

  def break: Unit = throw BreakException

  def continue: Unit = throw ContinueException

  def foreach(t: TraversableLike[_, _], op: Any => Unit): Unit = {
    try {
      t.foreach(i => {
        try {
          op(i)
        } catch {
          case ex: Exception =>
            if (ex != ContinueException) throw ex
        }
      })
    } catch {
      case ex: Exception =>
        if (ex != BreakException) throw ex
    }
  }

  object BreakException extends Exception

  object ContinueException extends Exception

}

　　

 

 

使用

 

import com.myTest.util.Breakable

/**
 * Created by Administrator on 2017/2/25 0025.
 */
object TestCode {
  def main(args: Array[String]) {
    val b = Breakable()
    val a = List(1,2,3,4,5,6,7,8,9)
    b.foreach(a, i => {
      if(i == 5) b.continue
      if(i == 7) b.break
      println(i)
    })
  }

}

　　輸出

 

1
2
3
4
6