取消选择选项 [英] Un-optioning an optioned Option

问题描述

说我有一个val s: Option[Option[String]].因此，它可以具有以下值:

Say I have a val s: Option[Option[String]]. It can thus have the following values:

Some(Some("foo")) Some(None) None

我想减少它，以便第一个变成Some("foo")，而另两个变成None.显然，有很多方法可以完成此操作，但是我正在寻找一种简单的，也许内置的，少于一个内衬的纸.

I want to reduce it so that the first becomes Some("foo") while the two others become None. Obviously there are many ways to accomplish this, but I'm looking for a simple, perhaps built-in, less-than-one-liner.

推荐答案

flatten不存在是一个遗憾.应该.

It's a shame that flatten doesn't exist. It should.

现在平底版确实存在.

和以前一样，

s getOrElse None

(除了其他答案)也将做同样的事情.

(in addition to the other answers) will also do the same thing.

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