在不命名中间值的情况下对值进行链接操作

问题描述

有时我会执行一系列计算，逐渐转换一些值，例如:

Sometimes I perform a sequence of computations gradually transforming some value, like:

def complexComputation(input: String): String = {
  val first = input.reverse
  val second = first + first
  val third = second * 3
  third
}

命名变量有时很麻烦，我想避免这种情况.我为此使用的一种模式是使用Option.map链接值:

Naming variables is sometimes cumbersome and I would like to avoid it. One pattern I am using for this is chaining the values using Option.map:

def complexComputation(input: String): String = {
  Option(input)
    .map(_.reverse)
    .map(s => s + s)
    .map(_ * 3)
    .get
}

使用Option/get对我来说并不自然.还有其他通常的方法吗?

Using Option / get however does not feel quite natural to me. Is there some other way this is commonly done?

推荐答案

实际上，使用 Scala 2.13 .它将介绍管道:

Actually, it will be possible with Scala 2.13. It will introduce pipe:

import scala.util.chaining._

input //"str"
 .pipe(s => s.reverse) //"rts"
 .pipe(s => s + s) //"rtsrts"
 .pipe(s => s * 3) //"rtsrtsrtsrtsrtsrts"

版本 2.13.0-M1 已发布.如果您不想使用里程碑版本，则可以考虑使用向后移植?

Version 2.13.0-M1 is already released. If you don't want to use the milestone version, maybe consider using backport?

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