更好的将地图[K，选项[V]]转换为地图[K，V] [英] Better way of converting a Map[K, Option[V]] to a Map[K,V]

问题描述

我有一些代码生成 Map ，其中值是 Option 类型，我当然想要一个仅包含真实值的地图。

I have some code that is producing a Map where the values are Option types, and I really of course want a map containing only the real values.

所以我需要转换这个，我在代码中提出的是

So I need to convert this, and what I've come up with in code is

  def toMap[K,V](input: Map[K, Option[V]]): Map[K, V] = {
    var result: Map[K, V] = Map()
    input.foreach({
      s: Tuple2[K, Option[V]] => {
        s match {
          case (key, Some(value)) => {
            result += ((key, value))
          }
          case _ => {
            // Don't add the None values
          }
        }
      }
    })
    result
  }

这是工作，但似乎不起眼。我怀疑这里有一些内置于我缺少的集合库。

which works, but seems inelegant. I suspect there's something for this built into the collections library that I'm missing.

有什么内置的，或者更成熟的方式来完成这个？ >

Is there something built in, or a more idiomatic way to accomplish this?

推荐答案

input.collect{case (k, Some(v)) => (k,v)}

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