Question

我有称为“run1”和“run2”的scala函数，它接受3个参数。当我应用它们时，我想提供一个带隐式参数的匿名函数。它在下面的示例代码中不适用于这两种情况。我想知道是否

这甚至可能吗？
如果有可能，语法是什么？




       object Main extends App {
          type fType = (Object, String, Long) => Object

          def run1( f: fType ) {
            f( new Object, "Second Param", 3)
          }

          run1 { implicit (p1, p2, p3) => // fails
            println(p1)
            println(p2)
            println(p3)
            new Object()
          }

          def run2( f: fType ) {
            val fC = f.curried
            fC(new Object)("Second Param")(3)
          }

          run2 { implicit p1 => implicit p2 => implicit p3 => // fails
            println(p1)
            println(p2)
            println(p3)
            new Object()
          }
        }

Answer 1

你正在讨论run2内的函数，所以run2仍然需要一个非curried函数。请参阅以下代码，了解适用的版本：

object Main extends App {
  type fType = (Object, String, Long) => Object
  type fType2 = Object => String => Long => Object //curried

  def run1( f: fType ) {
    f( new Object, "Second Param", 3)
  }

  // Won't work, language spec doesn't allow it
  run1 { implicit (p1, p2, p3) => 
    println(p1)
    println(p2)
    println(p3)
    new Object()
  }

  def run2( f: fType2 ) {
    f(new Object)("Second Param")(3)
  }

  run2 { implicit p1 => implicit p2 => implicit p3 =>
    println(p1)
    println(p2)
    println(p3)
    new Object()
  }
}

如何使用多个隐式参数创建scala匿名函数

1 个答案: