Curry Function in Swift

Question

I want to make a function that return a curry function like below

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

addTwoNumbers(4)(b: 6) /         


        

Answer 1

I'm not sure this is actually going to be possible in the same way it is inside of languages like Python.

The core problem I see to having a single generic solution is the strong typing of the closures/funcs you want to accept.

You could fairly easily create a curry function that worked on a specific or common function signature, but as far as a general purpose curry I don't see a way for it to work. The issue is more than about the types of the arguments (as mentioned in comments) but also with the number of them.

I've written up a simple example of how you could implement a curry function. It works, but I don't see a sane way to have a truly generic one like you can in more loosely typed languages.

func add(a1: Int, a2: Int) -> Int {
    return a1 + a2
}

func curry(argument: Int, block: (Int, Int) -> Int) -> Int -> Int{
    func curried(arg: Int) -> Int {
        return block(argument, arg)
    }

    return curried
}

curry(5, add)(6)