enum Shape {
    Circle(float)
    Rect(float, float)
    Named(str, []int)
    Point
}

fn Shape.area() -> float {
    return match self {
        Circle(r) -> 3.0 * r * r
        Rect(w, h) -> w * h
        Named(_, sizes) -> float(sizes.len)
        Point -> 0.0
    }
}

fn describe(Shape s) -> str {
    match s {
        Shape.Circle(r) -> return "circle " + str(r)
        Shape.Named(name, _) -> return "named " + name
        else -> return "other"
    }
}

fn main() {
    shapes := [Shape.Circle(2.0), Shape.Rect(2.0, 3.5), Shape.Named("tri", [1, 2, 3]), Shape.Point]
    for s in shapes {
        print(s, s.area(), describe(s))
    }
    copy := shapes[2]
    shapes.clear()
    print(copy)
    p := Shape.Point
    match p {
        Point -> print("a point")
        else -> print("no")
    }
}