private def bind()

in finagle-core/src/main/scala/com/twitter/finagle/Namer.scala [218:266]
44 lines of code
20 McCabe index (conditional complexity)

  private def bind(
    lookup: Path => Activity[NameTree[Name]],
    depth: Int,
    weight: Option[Double]
  )(
    tree: NameTree[Name]
  ): Activity[NameTree[Name.Bound]] =
    if (depth > namerMaxDepth())
      Activity.exception(
        new NamerExceededMaxDepthException(
          s"Max recursion level: ${namerMaxDepth()} reached in Namer lookup"))
    else
      tree match {
        case Leaf(Name.Path(path)) => lookup(path).flatMap(bind(lookup, depth + 1, weight))
        case Leaf(bound @ Name.Bound(addr)) =>
          // Add the weight of the parent to the addr's metadata
          // Note: this assumes a single level of tree weights
          val addrWithWeight = addr.map { addr =>
            (addr, weight) match {
              case (Addr.Bound(addrs, metadata), Some(weight)) =>
                Addr.Bound(addrs, metadata + ((AddrWeightKey, weight)))
              case _ => addr
            }
          }
          Activity.value(Leaf(Name.Bound(addrWithWeight, bound.id, bound.path)))

        case Fail => Activity.value(Fail)
        case Neg => Activity.value(Neg)
        case Empty => Activity.value(Empty)

        case Union() => Activity.value(Neg)
        case Union(Weighted(weight, tree)) => bind(lookup, depth, Some(weight))(tree)
        case Union(trees @ _*) => bindUnion(lookup, depth, trees)

        case Alt() => Activity.value(Neg)
        case Alt(tree) => bind(lookup, depth, weight)(tree)
        case Alt(trees @ _*) =>
          def loop(trees: Seq[NameTree[Name]]): Activity[NameTree[Name.Bound]] =
            trees match {
              case Nil => Activity.value(Neg)
              case Seq(head, tail @ _*) =>
                bind(lookup, depth, weight)(head).flatMap {
                  case Fail => Activity.value(Fail)
                  case Neg => loop(tail)
                  case head => Activity.value(head)
                }
            }
          loop(trees)
      }