PipeForward.swift

// pipe-forward operator
precedencegroup ForwardApplication {
    associativity: left
}

infix operator |>: ForwardApplication

func |> <A, B>(a: A, f: (A) -> B) -> B {
    return f(a)
}

// non-curried add
func add(a: Int, b: Int) -> Int {
    return a + b
}

// curried version of add
func addCurry(a: Int) -> (Int) -> Int {
    return { b in
        return a + b
    }
}

// partial application
let addOne = addCurry(a: 1)

// both of these return 2
1 |> addOne
1 |> addCurry(a: 1)

// returns 3
1 |> addCurry(a: 1) |> addOne