Scala de Design Pattern: Builder

　Builderパターン。

package designpattern.builder
import scala.Enumeration
sealed trait Animal { val value: String }

object Lion extends Animal {val value = "Lion"}

object Eagle extends Animal {val value = "Eagle"}

object Human extends Animal {val value = "Human"}
class CompositAnimal(var element1: Animal, var element2: Animal) {

    override def toString = element1.value + " + " + element2.value

}
trait Composer {

    val result = new CompositAnimal(null, null)

    def setElement1: Unit

    def setElement2: Unit

}
class GrifonComposer extends Composer {

    def setElement1 = result.element1 = Lion

    def setElement2 = result.element2 = Eagle

}
class SphinxComposer extends Composer {

    def setElement1 = result.element1 = Lion

    def setElement2 = result.element2 = Human

}
class EaglemanComposer extends Composer {

    def setElement1 = result.element1 = Eagle

    def setElement2 = result.element2 = Human

}
class Director(var composer: Composer) {    

    def getCompositAnimal = composer.result

    def compose = { 

        composer.setElement1

        composer.setElement2

    }

}
object Main {

    def main(args: Array[String]) = {  

        val director1 = new Director(new GrifonComposer)

        director1.compose

        val grifon = director1.getCompositAnimal

        println(grifon)
        val director2 = new Director(new SphinxComposer)

        director2.compose

        val sphinx = director2.getCompositAnimal

        println(sphinx)

    }

}