public static double AreaSwitch(this TagShape s)
{
switch (s.Tag)
{
case ShapeCase.Circle:
return(Math.PI * s.Radius * s.Radius);
case ShapeCase.Rectangle:
return(s.Height * s.Width);
default:
throw new ArgumentOutOfRangeException();
}
}
public static TagShape ToTagShape(this Shape s) =>
s.Match(
circle => TagShape.Circle(circle.Radius),
rectangle => TagShape.Rectangle(rectangle.Height, rectangle.Width));
public static double AreaMatch(this TagShape s) =>
s.Match(
radius => Math.PI * radius * radius,
(height, width) => height * width);
