10
があります：エラー：それは、私はこのエラーが発生した以下のコードでは5人の未実装のメンバー
class Animal needs to be abstract, since: it has 5 unimplemented members. /** As seen from class Animal, the
missing signatures are as follows. * For convenience, these are usable as stub implementations. */ def
favFood_=(x$1: Double): Unit = ??? def flyingType_=(x$1: scala.designpatterns.Strategy.Flys): Unit = ??? def
name_=(x$1: String): Unit = ??? def sound_=(x$1: String): Unit = ??? def speed_=(x$1: Double): Unit = ???
私は、コード_にクラスの動物のインスタンス変数のすべてを初期化する場合ので、クラスの動物は、抽象的である必要があります正しくコンパイルします。これらのエラーはどういう意味ですか？
package scala.designpatterns
/**
*
* Decoupling
* Encapsulating the concept or behaviour that varies, in this case the ability to fly
*
* Composition
* Instead of inheriting an ability through inheritence the class is composed with objects with the right abilit built in
* Composition allows to change the capabilites of objects at runtime
*/
object Strategy {
def main(args: Array[String]) {
var sparky = new Dog
var tweety = new Bird
println("Dog : " + sparky.tryToFly)
println("Bird : " + tweety.tryToFly)
}
trait Flys {
def fly: String
}
class ItFlys extends Flys {
def fly: String = {
"Flying High"
}
}
class CantFly extends Flys {
def fly: String = {
"I can't fly"
}
}
class Animal {
var name: String
var sound: String
var speed: Double
var favFood: Double
var flyingType: Flys
def tryToFly: String = {
this.flyingType.fly
}
def setFlyingAbility(newFlyType: Flys) = {
flyingType = newFlyType
}
def setSound(newSound: String) = {
sound = newSound
}
def setSpeed(newSpeed: Double) = {
speed = newSpeed
}
}
class Dog extends Animal {
def digHole = {
println("Dug a hole!")
}
setSound("Bark")
//Sets the fly trait polymorphically
flyingType = new CantFly
}
class Bird extends Animal {
setSound("Tweet")
//Sets the fly trait polymorphically
flyingType = new ItFlys
}
}