ivy/doc/sample/Vehicle.im

package net.doorstuck.vehicles

protocol Vehicle
    - startup
    - shutdown
    - nr-wheels
    - nr-doors
    - turn(direction:dir)
    - accelerate(direction:dir)
    - velocity
end

class Car <Vehicle>
    - startup
        self.engine-running = true
    end

    - shutdown
        self.engine-running = false
    end

    - nr-wheels
        ^4
    end

    - nr-doors
        ^4
    end

    - turn(direction:dir)
        self.current-direction = dir
    end

    - accelerate(direction:dir)
        match dir
            $forward => self.current-velocity += 1,
            $backward => self.current-velocity -= 1,
        end
    end

    - velocity
        ^self.current-velocity
    end
end