“使用"功能 [英] "using" function

问题描述

我已将使用"函数定义如下:

I've defined 'using' function as following:

def using[A, B <: {def close(): Unit}] (closeable: B) (f: B => A): A =
  try { f(closeable) } finally { closeable.close() }

我可以这样使用它:

using(new PrintWriter("sample.txt")){ out =>
  out.println("hellow world!")
}

现在我很好奇如何定义使用"函数来接受任意数量的参数，并且能够分别访问它们:

now I'm curious how to define 'using' function to take any number of parameters, and be able to access them separately:

using(new BufferedReader(new FileReader("in.txt")), new PrintWriter("out.txt")){ (in, out) =>
  out.println(in.readLIne)
}

推荐答案

已经有人这样做了—它叫做 Scala ARM.

Someone has already done this—it's called Scala ARM.

来自自述文件:

import resource._
for(input <- managed(new FileInputStream("test.txt")) {
  // Code that uses the input as a FileInputStream
}

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