Trying to get a basic Nested Set structure defined using not terrible code.

NestedSet.scala

package models

case class Channel(id:Int, title:String, hidden:Boolean, left:Int, children:Seq[Channel]) {

  def right = 2

  def ++(children:Seq[Channel]) = {
    copy(children = children.scanLeft(this) { (previous, channel) =>
      channel.copy(left = previous.right + 1)
    }.tail)
  }
}

object Channel {
  object root extends Channel(0, "root", true, 1, Nil)
}

// Channel.root ++ Seq(Channel(1, "child1", false, 0, Nil), Channel(2, "child2", false, 27, Nil), Channel(3, "child3", false, 10, Nil))

// Almost there, but the Channel++ needs to pass in the left of the first argument, and the right for every other.
// So a scanLeft that had *two* accumulators? One of them a List to map to, and the other a cumulative variable to express?
// Maybe I'm forced to use a foldLeft[Tuple2] instead?