Scala强调最小功能 [英] Scala underscore minimal function

问题描述

为了这个问题，让我们创建一个值:

Let's create a value for the sake of this question:

val a = 1 :: Nil

现在，我可以证明匿名函数可以这样写成速记形式:

now, I can demonstrate that the anonymous functions can be written in shorthand form like this:

a.map(_*2)

是否可以编写此函数的缩写?:

is it possible to write a shorthand of this function?:

a.map((x) => x)

我的解决方案不起作用:

my solution doesn't work:

a.map(_)

推荐答案

您的第一个速记形式也可以无点书写

Your first shorthand form can also be written point-free

a map (2*)

由于乘法是可交换的.

对于(x) => x，您需要identity功能.这是在Predef中定义的并且是通用的，因此可以确保它是类型安全的.

As for (x) => x, you want the identity function. This is defined in Predef and is generic, so you can be sure that it's type-safe.

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