TypeMember使って実装したGraph

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TypeMember使って実装したGraph

generics版 https://gist.github.com/seraphr/6858351

01Graph.scala

trait Graph {
  graph =>

  type _Node <: Node
  type _Edge <: Edge

  private val mNodeEdge: (Seq[_Node], Seq[_Edge]) = init
  def init: (Seq[_Node], Seq[_Edge])

  val (nodes, edges) = mNodeEdge

  trait Node {
    def edges: Seq[_Edge] = graph.edges.filter(e => e.node1 == this || e.node2 == this)
  }

  trait Edge {
    val nodes: (_Node, _Node)
    val node1 = nodes._1
    val node2 = nodes._2
  }
}

02DirectedGraph.scala

trait DirectedGraph extends Graph {
  type _Edge <: DirectedEdge


  trait DirectedEdge extends super.Edge {
    val from: _Node
    val to: _Node
  }
}

03WeightedDirectedGraph.scala

trait WeightedDirectedGraph extends WeightedGraph with DirectedGraph {
  type _Edge <: WeightedDirectedEdge

  trait WeightedDirectedEdge extends super.WeightedEdge with super.DirectedEdge
}

04WeightedGraph.scala

trait WeightedGraph extends Graph {
  type _Edge <: WeightedEdge


  trait WeightedEdge extends super.Edge {
    val weight: Int
  }
}

05Main.scala

object Main {
  object WeightedDirectedGraph extends WeightedDirectedGraph {
    type _Node = DefaultNode
    type _Edge = DefaultEdge

    override def init: (Seq[_Node], Seq[_Edge]) = {
      val tNode1 = new DefaultNode
      val tNode2 = new DefaultNode
      val tNode3 = new DefaultNode
      val tEdge1 = DefaultEdge(tNode1, tNode2, 10)
      val tEdge2 = DefaultEdge(tNode2, tNode3, 12)

      (Seq(tNode1, tNode2, tNode3), Seq(tEdge1, tEdge2))
    }

    class DefaultNode extends super.Node
    case class DefaultEdge(from: _Node, to: _Node, weight: Int) extends super.WeightedDirectedEdge {
      override val nodes = (from, to)
    }
  }
}