windjammer 0.48.0

// Example 4: Traits and Interfaces

// Define a trait (Windjammer traits need default implementations)
trait Drawable {
    fn draw(&self) -> string {
        "drawable"
    }
    fn area(&self) -> int {
        0
    }
}

// Define another trait
trait Movable {
    fn move_by(&mut self, dx: int, dy: int) {
        // Default: do nothing
    }
}

@auto
struct Circle {
    x: int,
    y: int,
    radius: int,
}

@auto
struct Square {
    x: int,
    y: int,
    side: int,
}

// Implement Drawable for Circle
impl Drawable for Circle {
    fn draw(&self) -> string {
        "Circle at (${self.x}, ${self.y}) with radius ${self.radius}"
    }
    
    fn area(&self) -> int {
        3 * self.radius * self.radius  // π ≈ 3
    }
}

// Implement Movable for Circle
impl Movable for Circle {
    fn move_by(&mut self, dx: int, dy: int) {
        self.x = self.x + dx
        self.y = self.y + dy
    }
}

// Implement Drawable for Square
impl Drawable for Square {
    fn draw(&self) -> string {
        "Square at (${self.x}, ${self.y}) with side ${self.side}"
    }
    
    fn area(&self) -> int {
        self.side * self.side
    }
}

// Implement Movable for Square
impl Movable for Square {
    fn move_by(&mut self, dx: int, dy: int) {
        self.x = self.x + dx
        self.y = self.y + dy
    }
}

fn main() {
    // Create shapes
    let mut circle = Circle {
        x: 0,
        y: 0,
        radius: 5,
    }
    
    let mut square = Square {
        x: 10,
        y: 10,
        side: 4,
    }
    
    // Use Drawable trait
    println!("${circle.draw()}")
    println!("Circle area: ${circle.area()}")
    
    println!("${square.draw()}")
    println!("Square area: ${square.area()}")
    
    // Use Movable trait
    circle.move_by(3, 4)
    println!("After moving: ${circle.draw()}")
    
    square.move_by(-5, -5)
    println!("After moving: ${square.draw()}")
}