SBT 0.13.8 SettingKey.~= 方法有什么作用 [英] SBT 0.13.8 what does the SettingKey.~= method do

问题描述

SettingKey.~= 方法用于从 libraryDependencies 中排除依赖项(参见 播放 2.3.8 sbt，不包括 logback)，但试图找出它的作用是很困难的:

The SettingKey.~= method is used to exclude dependencies from libraryDependencies (see play 2.3.8 sbt excluding logback), but trying to find out what it does is hard as:

1. http 上没有关于此功能的文档://www.scala-sbt.org/0.13.12/api/index.html#sbt.SettingKey、
2. 无法使用 Google 进行搜索，因为它在方法名称中使用了符号
3. 检查 SBT 源代码(https://github.com/sbt/sbt/blob/0.13/main/settings/src/main/scala/sbt/Structure.scala#L47) 没有提供明显的答案.

1. There is no documentation about this function at http://www.scala-sbt.org/0.13.12/api/index.html#sbt.SettingKey,
2. It cannot be searched using Google as it uses symbols in the method name and
3. Examination of the SBT source code (https://github.com/sbt/sbt/blob/0.13/main/settings/src/main/scala/sbt/Structure.scala#L47) does not provide an obvious answer.

谁能解释一下这是做什么的?

Can anyone shed light on what this does?

推荐答案

someScopedKey ~= f

相当于

someScopedKey := f(someScopedKey.value)

换句话说，它使用给定的函数转换设置/任务的先前值.这就是关于它的全部信息.

In other words, it transforms the previous value of the setting/task with a given function. That's literally all there is to know about it.

这篇关于SBT 0.13.8 SettingKey.~= 方法有什么作用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！