Scala：语法糖 [英] Scala : Syntactic Sugar

问题描述

我一直在努力了解如何阅读此功能：

I have been scratching my head to understand how to read this function:

private def greeterBehavior(currentGreeting: String): Behavior[Command] =
    Actor.immutable[Command] { (ctx, msg) =>
      msg match {
        case WhoToGreet(who) =>
          greeterBehavior(s"hello, $who")
        case Greet =>
          println(currentGreeting)
          Actor.same
      }
    }

问题：

1）函数获取字符串并返回 Behavior [Command] 。 （理解）
但是.. Actor.immutable [Command] 是什么？
这是类型转换吗？还是物体？

1 ) function takes string and returns Behavior[Command] . ( understood) But .. what is Actor.immutable[Command] ? Is this a type casting ? or is it an object ?

2）如果我必须理解这样的语法，我可以参考的最佳地方或书是什么？

2) if I have to understand such syntax what is the best place or book I can refer?

推荐答案

不可变是 Actor 的一种方法，该方法具有通用类型参数，在这种情况下，类型为 Command 。

immutable is a method on Actor, which takes in a generic type parameter, in this case that type is Command.

任何值得阅读的Scala入门资料都应涵盖泛型。 在Scala中编程和不耐烦的Scala都很受欢迎。

Any intro to Scala material worth reading should cover generics. "Programming in Scala" and "Scala for the Impatient" are both popular.

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