import io

fn add (int a, int b) -> int {
    a + b
}

// return type is void by default
fn main () {
    // explicit types, or
    int val = add(2, 2)

    // type inferred from the functions' return value
    val := add(2, 2)

    // variables are immutable, however, you can update them with
    // the value of the old one.
    val = val + 1

    // a shorthand is val++, same for val--.

    // string interpolation is implicit
    io.puts("2 plus 2 = {val}")
}