Question

我有一个功能：

sigma(x: Int, y: Int, z: Int, a: Int)(f: (Int, Int, Int, Int) => Double): Double

我需要将其设置为另一个函数的参数：

bigPi(x: Int, y: Int, z: Int, a: Int)('Here should be sigma'):Double

如何正确定义sigma类型并将其用作bigPi的参数？

Answer 1

def sigma(x:Int, y:Int, z:Int, a:Int)(f:(Int,Int,Int,Int) => Double):Double = 1.1

def bigPi(x: Int, y: Int, z: Int, a: Int)(
             f: (Int,Int,Int,Int) => ((Int,Int,Int,Int) => Double) => Double
         ):Double = 2.2

bigPi(1,2,3,4)(sigma)

IntelliJ IDE表示没有多余的括号，但编译器则另有说明。

Answer 2

尝试一下：

def bigPi(x: Int, y: Int, z: Int, a: Int)(s: (Int, Int, Int, Int) => ((Int, Int, Int, Int) => Double) => Double) = whatever

Scala：如何使用函数作为参数？

2 个答案: