knightpop

trait Printable {
  def print: String
}

case class PrintableClass(value: String) extends Printable {
  override def print: String = s"value: ${value.toString}"
}

case class ValueCaseClass(value: String)

knightpop

val userId: Long = 12
val deviceUuid: Long = 1234
val carSerialId: Long = 12345

def getHashCode(
 userId: Long,
 deviceUuid: Long,
 carSerialId: Long
): String = {
  val userIdPlus: Long = userId + 1

knightpop

import shapeless.{Coproduct, CNil, :+:, Inl, Inr}
type Id = UserId :+: DeviceUuid :+: CarSerialId :+: CNil

def getId(id: Id): Long = id match {
  case Inl(userId) => userId + 1
  case Inr(Inl(deviceUuid)) => deviceUuid + 2
  case Inr(Inr(Inl(carSerialId))) => carSerialId + 3
  case Inr(Inr(Inr(cNil))) => 0
}

knightpop

def getUserIdOrDeviceIdOrCarSerialId(
 id: Either[UserId, Either[DeviceUuid, CarSerialId]]
): Long = id match {
  case Left(userId) => userId + 1
  case Right(Left(deviceUuid)) => deviceUuid + 2
  case Right(Right(carSerialId)) => carSerialId + 3
}

getUserIdOrDeviceIdOrCarSerialId(Left(taggedUserId))
getUserIdOrDeviceIdOrCarSerialId(Right(Left(taggedDeviceUuid)))

knightpop

def getId(userId: UserId): Long = userId + 1
def getId(deviceUuid: DeviceUuid): Long = deviceUuid + 2      // Not Compiled because tagged type erased after compile
def getId(carSerialId: CarSerialId): Long = carSerialId + 3   // Not Compiled because tagged type erased after compile

knightpop

import shapeless.tag
import shapeless.tag.@@

trait UserIdTag
trait DeviceUuidTag
trait CarSerialIdTag

type UserId = Long @@ UserIdTag
type DeviceUuid = Long @@ DeviceUuidTag
type CarSerialId = Long @@ CarSerialIdTag

knightpop

case class UserIdCaseClass(userId: Long)
case class DeviceUuidCaseClass(deviceUuid: Long)
case class CarSerialIdCaseClass(carSerialId: Long)

def getHashCodeCaseClass(
  userIdCaseClass: UserIdCaseClass, 
  deviceUuidCaseClass: DeviceUuidCaseClass, 
  carSerialIdCaseClass: CarSerialIdCaseClass
): String = {
  val userIdPlus: Long = userIdCaseClass.userId + 1

knightpop

val userId: Long = 12
val deviceUuid: Long = 1234
val carSerialId: Long = 12345

def getHashCode(
 userId: Long,
 deviceUuid: Long,
 carSerialId: Long
): String = {
  val userIdPlus: Long = userId + 1

knightpop

implicit val string: String = "Hello"
implicit val boolean: Boolean = true
implicit val int: Int = 0

def getImplicitT[T](implicit t: T): T = t

getImplicitT[Int]
getImplicitT[String]
getImplicitT[Boolean]

knightpop

implicit val optionInt: Option[Int] = Some(1)
implicit val optionBoolean: Option[Boolean] = Some(true)

def getImplicitOptionInt(implicit oInt: Option[Int]): Int = oInt.get
def getImplicitOptionBoolean(implicit oBoolean: Option[Boolean]): Boolean = oBoolean.get

getImplicitOptionInt
getImplicitOptionBoolean

def getImplicitlyOptionA[A: Option]: A = implicitly[Option[A]].get