Scala:如何使用可变参数列表定义匿名函数? [英] Scala: How do I define an anonymous function with a variable argument list?

问题描述

在 Scala 中，我如何定义一个接受可变数量参数的匿名函数?

In Scala, how do I define an anonymous function which takes a variable number of arguments?

scala> def foo = (blah:Int*) => 3
<console>:1: error: ')' expected but identifier found.
       def foo = (blah:Int*) => 3
                          ^

推荐答案

看起来这是不可能的.在第 6.23 章的语言规范中匿名函数 语法不允许在类型后使用 *.在第 4.6 章 函数声明和定义中，类型后面可以有一个 *.

It looks like this is not possible. In the language specification in chapter 6.23 Anonymous functions the syntax does not allow an * after a type. In chapter 4.6 Function Declarations and Definitions after the type there can be an *.

你可以做的是:

scala> def foo(ss: String*) = println(ss.length)
foo: (ss: String*)Unit

scala> val bar = foo _
bar: (String*) => Unit = <function1>

scala> bar("a", "b", "c")
3

scala> bar()
0

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