fn factorial : n {
    if n <= 1 {
        return 1;
    }
    return n * factorial(n - 1);
}

let result = factorial(5);  // 120
println(f"5! = {result}");

struct Point {
    fn new : x, y {
        return {"x": x, "y": y};
    }

    fn distance : p1, p2 {
        let dx = p1["x"] - p2["x"];
        let dy = p1["y"] - p2["y"];
        return (dx * dx + dy * dy) ** 0.5;
    }
}

let p1 = Point.new(3, 4);
let p2 = Point.new(0, 0);
let dist = Point.distance(p1, p2);  // 5.0

let name = "Alice";
let age = 30;
let items = [1, 2, 3];

println(f"Hello, {name}!");
println(f"Next year you'll be {age + 1}");
println(f"List has {len(items)} items: {items}");