fn main() unit = {
    run(print-answer)
    do-add(add, 1, 2)
    println("map: {map(1, int-to-uint)}")
}

fn run(f: fn() unit) unit = f()

fn print-answer() unit =
    println("The answer is {42}")

fn add(a: int, b: int) int = {
    a + b
}

fn do-add(f: fn(int, int) int, a: int, b: int) unit =
    println("a + b = {f(a, b)}")

fn map[A, B](val: A, f: fn(A) B) B = {
    f(val)
}

fn int-to-uint(val: int) uint = uint(val)