Scala adapter pattern - maxondev.com

java-adapter-general.java

    public interface Adaptee {
        void doAdaptee();
    }

    public interface Adaptor {
        void doAdaptor();
    }

    class Client{
        private final Adaptor adaptor;
        
        public Client(Adaptor adaptor) {
            this.adaptor = adaptor;
        }
        public void foo() {
            this.adaptor.doAdaptor();
        }
    }
    
    public class AdapteeAdapter implements Adaptor{
        private final Adaptee adaptee;

        public AdapteeAdapter(Adaptee adaptee) {
            this.adaptee = adaptee;
        }

        @Override
        public void doAdaptor() {
            this.adaptee.doAdaptee();
        }
    }
    
    Adaptee adaptee = null;
    Adaptor adaptor = new AdapteeAdapter(adaptee);
    Client client = new Client(adaptor);

scala-adapter-aircon-typeclass.scala

  case class Celsius(degrees: Double)

  case class Fahrenheit(degrees: Double)

  trait ToCelsius[From] {
    def convert(source: From): Celsius
  }

  class FahrenheitConverter extends ToCelsius[Fahrenheit] {
    override def convert(source: Fahrenheit): Celsius = new Celsius((source.degrees - 32) * 5 / 9)
  }

  class CelsiusIdentityConverter extends ToCelsius[Celsius] {
    override def convert(source: Celsius): Celsius = source
  }

  class AirConditioner {
    def setTemperature[T](degrees: T)(implicit ev: ToCelsius[T]): Unit = {
      val converter = implicitly[ToCelsius[T]]
      val asCelsius = converter.convert(degrees)
      println(s"Set to $asCelsius")
    }
  }

  implicit val fahrenheitToCelsius = new FahrenheitConverter
  implicit val celsiusIdentity = new CelsiusIdentityConverter

  val airConditioner = new AirConditioner()
  airConditioner.setTemperature(new Fahrenheit(75))
  airConditioner.setTemperature(new Celsius(23))

scala-adapter-airconditioner.scala

case class Celsius(degrees: Double)
case class Fahrenheit(degrees: Double)

class AirConditioner{
  def setTemperature(celsius: Celsius) = println(s"Set to ${celsius.degrees}")
}

implicit def fahrenheit2Celsius(fahrenheit: Fahrenheit): Celsius = new Celsius((fahrenheit.degrees - 32) * 5/9)

new AirConditioner().setTemperature(new Fahrenheit(75))

scala-adapter-general.scala

trait Adaptor {
  def doAdaptor
}

class Client(adaptor: Adaptor){
  def foo = adaptor.doAdaptor
}

trait Adaptee {
  def doAdaptee
}

implicit def adaptee2Adaptor(adaptee: Adaptee): Adaptor = {
  new Adaptor {
    override def doAdaptor: Unit = adaptee.doAdaptee
  }
}

val adaptee: Adaptee = ???

val client = new Client(adaptee)