指定多态函数的类型以将其作为参数传递 [英] Specify type of polymorphic function to pass it as argument

问题描述

我有一个函数curry，该函数将函数(A, B) -> C作为参数，并返回A -> B -> C.它在功能g(a: Int, b: Int) -> Int上正常工作.另外，我有一个函数f，它是多态的，所以它的类型是模棱两可的.这是代码:

I have function curry that takes a function (A, B) -> C as an argument, and returns A -> B -> C. It works fine on function g(a: Int, b: Int) -> Int. Also, I have function f, that is polymorphic, so its type is ambigous. Here is the code:

func g(a: Int, b: Int) -> Int { return a + b }

func f(a: Int, b: Int) -> Int { return a + b }
func f(a: Float, b: Float) -> Float { return a + b }

func curry<A, B, C>(f: (A, B) -> C) -> A -> B -> C {
  return { a in { b in f(a, b) } }
}

let curriedG = curry(g) //curriedG type Int -> Int -> Int

let curriedF = curry(f) //Error, Ambigous use of 'f(_:b:)'

很明显，我不能执行curry(f)，但是有什么办法，所以我可以指定要使用特定的f()实现?

It is obvious, that I can't do curry(f), but, is there any way, so I could specify, that I want to use specific f() implementation?

我为什么需要这个. 由于初始化器.我想咖喱特定的初始化程序，假设struct A有两个初始化程序:init(t: T, y: Y)和init(u: U, h: H)，我想咖喱其中之一.

Why I need this. Because of initialisers. I want to curry specific initialiser, lets say struct A has two initialisers: init(t: T, y: Y) and init(u: U, h: H), I want to curry one of them.

谢谢！

推荐答案

由于f超载，您必须指定要使用的f:

Since f is overloaded, you have to specify which f you want:

let curriedF = curry(f as (Float, Float) -> Float)

或结果应该是什么:

let curriedF = curry(f) as Float -> Float -> Float

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