Swift 柯里化(currying)和反柯里化(uncurrying)

// Demo of currying

func addTwoNums(a: Int)(num: Int) -> Int {

    return a + num

}

let addToFour = addTwoNums(4)

let result = addToFour(num: 6)

print("result: \(result)")

func greaterThan(comparor: Int)(input: Int) -> Bool {

    return input > comparor

}

let greaterThan10 = greaterThan(10)

let b1 = greaterThan10(input: 10)

let b2 = greaterThan10(input: 4)

print("b1: \(b1)")

print("b2: \(b2)")

// Demo of uncurrying

let foo = {(a: Int) -> (Int) ->Int in

    return {(b: Int) ->Int in

        return a * a + b * b

    }

}

let interesting = foo(3)(4)

print("interesting: \(interesting)")

let interestingAgain = (foo(3))(4)

print("interestingAgain: \(interestingAgain)")