Scala Rules

scala_rules.scala

// They’re an idiomatic way of representing data using “ands” and “ors”. For example:

// a shape is a rectangle or a circle
// a rectangle has a width and a height
// a circle has a radius

// In ADT (Algebraic Data Types (ADTs))terminology, “and” types such as rectangle and circle are products,
// whereas the “or” types such as shape are coproducts. 
// In Scala, we typically represent products using case classes and coproducts using sealed traits:

sealed trait Shape
final case class Rectangle(width: Double, height: Double) extends Shape
final case class Circle(radius: Double) extends Shape