Semigroups8.scala

object Example4Semigroup extends App with Data {

  implicit val moneySemigroup = new Semigroup[Money] {
    override def combine(x: Money, y: Money): Money = {
      Money(x.dollars + y.dollars + ((x.cents + y.cents) / 100),
        (x.cents + y.cents) % 100)
    }
  }

  import cats.instances.int._
  import cats.instances.map._

  def add[A: Semigroup](a: A, b: A)(implicit semigroup: Semigroup[A]): A = semigroup.combine(a, b)

  println(s"Salary credit in you account xxxxxxx ${add(balance, salary)}")
  println(s"Salary transfer to all employees ${add(balances, salaries)}")

  // another way to call combine method with beautiful syntax using cats
  import cats.syntax.semigroup._

  println(s"Salary transfer to all employees ${balances |+| salaries}")
  println(s"Your game marbles balance is: ${marbles |+| won}")
}

// output
// Salary credit in you account xxxxxxx Money(422,44)
// Salary transfer to all employees Map(James -> Money(713,96), Jimmy -> Money(543,88))
// Salary transfer to all employees Map(James -> Money(713,96), Jimmy -> Money(543,88))
// Your game marbles balance is: Map(James -> 6, Jimmy -> 6)