题
我正在尝试设计几个继承部分功能的课程,但是我似乎无法完全正确地获得语法。我的超类看起来像这样:
abstract class Controller {
val react:PartialFunction[Event,Unit]
}
子类看起来像:
class BoardRendererController(val renderer:BoardRenderer, val board:Board) extends Controller {
override val react {
case PieceMovedEvent(piece, origin, destination) => println("Moving now")
}
}
但这无法通过此错误编译
[ERROR] /workspace/pacman/src/main/scala/net/ceilingfish/pacman/BoardRendererController.scala:14: error: '=' expected but '{' found.
[INFO] override val react {
[INFO] ^
[ERROR] /workspace/pacman/src/main/scala/net/ceilingfish/pacman/BoardRendererController.scala:17: error: illegal start of simple expression
[INFO] }
[INFO] ^
我已经尝试了很多变化,有人知道正确的语法是什么?
解决方案
除了ABHIN4V的TERSE建议外,您仍然必须在定义中提供类型的注释,因此我建议您在您的基类中添加此添加:
type PFEU = PartialFunction[Event, Unit]
那么您的子类看起来像这样:
class BoardRendererController(val renderer:BoardRenderer, val board:Board)
extends Controller
{
override val react: PFEU = {
case PieceMovedEvent(piece, origin, destination) => println("Moving now")
}
}
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