如何建模类型安全的枚举类型？ [英] How to model type-safe enum types?

问题描述

Scala没有像Java一样的类型安全枚举。给定一组相关的常量，Scala中代表这些常量的最好方法是什么？

Scala doesn't have type-safe enums like Java has. Given a set of related constants, what would be the best way in Scala to represent those constants?

推荐答案

http://www.scala-lang.org/docu/files/api/scala/ Enumeration.html

示例使用

  object Main extends App {

    object WeekDay extends Enumeration {
      type WeekDay = Value
      val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value
    }
    import WeekDay._

    def isWorkingDay(d: WeekDay) = ! (d == Sat || d == Sun)

    WeekDay.values filter isWorkingDay foreach println
  }

这篇关于如何建模类型安全的枚举类型？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！