Let's imagine that we have an application that takes data about people from a database. The reading operation is something that is expensive, and it is a good candidate for lazy evaluation. For this example, we will simply simulate reading from the database. First of all, our model will be as simple as the following:
case class Person(name: String, age: Int)
Now, let's create a companion object that will have a method that simulates getting the data about people from a database:
object Person { def getFromDatabase(): List[Person] = { // simulate we're getting people from database by sleeping System.out.println("Retrieving people...") Thread.sleep(3000) List( Person("Ivan", 26), Person("Maria", 26)
