scala命名參數在函數作爲參數？

Question

我挺有用的打字稿的功能與-PARAM-名稱作爲功能PARAMS：

function doHello(
    helloFunc: (lastName: string, firstName: string) => void, 
    ... 
) { ... } 

這裏，helloFunc描述了 '命名爲' PARAMS（姓氏，名字）

功能-AS-PARAM

但我只能找到不PARAM-名的例子，比如：

case class HelloWoot(
    helloFunc: (String, String) => Unit, 
    ... 
) 

其省略了約helloFunc簽名的一些信息。

那麼，我如何獲得以下代碼在Scala中編譯？

case class HelloWoot(
    helloFunc: (lastName: String, firstName: String) => Unit, 
    // Error 
) 

Answer 1

無法在高階函數中提供命名參數。如果你擔心人們混淆了字符串參數，你可以引入這樣的新類型：

// New object with firstName and lastName 
case class NamesObject(firstName: String, lastName: String) 

// Higher order function now takes the new type as input 
case class HelloWoot(helloFunc: (NamesObject) => Unit) 

// You can now safely access the correct variable without having to rely on their order in the Tuple2 
HelloWoot(a => println(a.firstName, a.lastName))