Shapes Sample
 ```""" Shapes.cobra for http://onestepback.org/articles/poly/ whose purpose is to "see this small problem written in several different OO languages" http://cobra-language.com/ by CsabaU@Hotmail.com & Charles Esterbrook """ class Shape is abstract """ The root class for all 2D shapes which are anchored to an (x, y) point in space, but can be moved. """ cue init(x as number, y as number) base.init _x, _y = x, y pro x from var as number pro y from var as number def moveTo(newX as number, newY as number) """ Move to the given absolute position. """ _x, _y = newX, newY def relativeMove(deltaX as number, deltaY as number) """ Move position by the given delta. """ _x += deltaX _y += deltaY def draw """ Subclasses should override, invoke base and print the rest of their properties. """ print 'Draw [.typeOf.name] at ([_x], [_y]), ' stop class Rectangle inherits Shape cue init(x as number, y as number, width as number, height as number) base.init(x, y) _width, _height = width, height pro width from var as number pro height from var as number def draw base.draw print 'height [_height], width [_width]' class Circle inherits Shape cue init(x as number, y as number, radius as number) base.init(x, y) _radius = radius pro radius from var as number def draw base.draw print 'radius [_radius]' class Program def main shapes = [Rectangle(10, 20, 5, 6), Circle(15, 25, 8)] # using shapes polymorphically for shape in shapes shape.draw shape.relativeMove(100, 100) shape.draw # access rectangle specific features rect = Rectangle(0, 0, 15, 15) rect.width = 30 rect.draw ```