你如何编写了Scala的模式匹配代码块？

Question

你如何编写一个函数中的代码块花费为包含case语句的参数？举例来说，在我的代码块，我不想做一个匹配或默认情况下明确。我期待这样的事情

myApi {
    case Whatever() => // code for case 1
    case SomethingElse() => // code for case 2
}

和我myApi（）内，它会实际执行的代码块，做匹配。

Answer 1

您必须使用PartialFunction这一点。

scala> def patternMatchWithPartialFunction(x: Any)(f: PartialFunction[Any, Unit]) = f(x)
patternMatchWithPartialFunction: (x: Any)(f: PartialFunction[Any,Unit])Unit

scala> patternMatchWithPartialFunction("hello") {
     |   case s: String => println("Found a string with value: " + s)
     |   case _ => println("Found something else")
     | }
Found a string with value: hello

scala> patternMatchWithPartialFunction(42) {
     |   case s: String => println("Found a string with value: " + s)
     |   case _ => println("Found something else")
     | }
Found something else

Answer 2

此应该足以解释： Scala中的游：模式匹配