与中缀运算符绑定的上下文

Question

对于给定的抽象类 Edge2D，我采用泛型类型 T 上下文绑定到某个接口 Point2DInterface。

abstract class Edge2D[T : Point2DInterface] {

  val p1: T
  val p2: T

  def length(): Double = {
    implicitly[Point2DInterface[T]].Sub(p1, p2)
  }
}

trait Point2DInterface[T] {
  def Sub(first: T, second: T): Double
}

通过以下实现，当 T=DoublePoint2D

object Implicits {

  implicit object DoublePoint2DInterface extends Point2DInterface[DoublePoint2D] {
    def Sub(first: DoublePoint2D, second: DoublePoint2D): Double = {
      first - second
    }
  }
}

如何为 T 创建中缀运算符？所以我可以写

  def length(): Double = {
    p1 - p2
  }

不管上一个问题，我想知道，有没有办法结合起来 隐式对象的实现？ 例如，结合 DoublePoint2DInterface 和 IntPoint2DInterface。

object Implicits {

  implicit object DoublePoint2DInterface extends Point2DInterface[DoublePoint2D] {
    def Sub(first: DoublePoint2D, second: DoublePoint2D): Double = {
      first - second
    }
  }

implicit object IntPoint2DInterface extends Point2DInterface[IntPoint2D] {
    def Sub(first: IntPoint2D, second: IntPoint2D): Double = {
      first - second
    }
    }

Answer 1

如何为 T 创建中缀运算符？

implicit class Point2DInterfaceOps[T](x: T)(implicit evidence: Point2DInterfaceOps[T]) {
  def -(y: T) = evidence.Sub(x, y)
  ...
}

不管前面的问题，不知道有没有办法结合隐式对象的实现？

使其通用，即将IntPoint2D 和DoublePoint2D 替换为Point2D[T: Numeric]，将两个隐式对象替换为implicit def numericPoint2D[T: Numeric]: Point2DInterface[Point2D[T]]