serialization example (typeclass pattern)

gistfile1.scala

case class Person(name: String, age: Int)
case class Restaurant(name: String, servesBrunch: Boolean)

trait Serializable[T] {
  def ser(t: T): String
}
def serialize[T](t: T)(implicit s: Serializable[T]) =
  s.ser(t)

implicit object PersonIsSerializable
extends Serializable[Person] {
  def ser(p: Person) =
    "Person(" + p.name + "," + p.age + ")"
}

implicit object PersonIsJSONable
extends Serializable[Person] {
  def ser(p: Person) =
    "{ \"person\": { " +
    "\"name\": \"" + p.name +
    "\", \"age\": " + p.age + " } }"
}

case class Group(people: Person*)

implicit object GroupIsSerializable
extends Serializable[Group] {
  def ser(g: Group) =
    g.people.map(PersonIsSerializable.ser)
      .mkString("Group(", ",", ")")
}

// scala> serialize(Group(Person("Seth", 40), Person("Kaarin", 42)))
// res9: String = Group(Person(Seth,40),Person(Kaarin,42))

implicit def ListIsSerializable[T : Serializable] =
  new Serializable[List[T]] {
    def ser(xs: List[T]) =
      xs.map(serialize(_))
        .mkString("List(", ",", ")")
  }

// scala> serialize(List(Person("Seth", 40), Person("Kaarin", 42)))
// res1: String = List(Person(Seth,40),Person(Kaarin,42))