Scala 大小写匹配默认值

Question

如何在匹配案例中获得默认值？

//Just an example, this value is usually not known
val something: String = "value"

something match {
    case "val" => "default"
    case _ => smth(_) //need to reference the value here - doesn't work
}

更新:我发现我的问题没有被真正理解，这就是为什么我要展示一个更接近我正在研究的真实事物的例子:

val db =    current.configuration.getList("instance").get.unwrapped()
            .map(f => f.asInstanceOf[java.util.HashMap[String, String]].toMap)
            .find(el => el("url").contains(referer))
            .getOrElse(Map("config" -> ""))
            .get("config").get match {
                case "" => current.configuration.getString("database").getOrElse("defaultDatabase")
                case _  => doSomethingWithDefault(_)
            }

Answer 1

something match {
    case "val" => "default"
    case default => smth(default)
}

它不是关键字，只是别名，因此这也可以:

something match {
    case "val" => "default"
    case everythingElse => smth(everythingElse)
}