MyPersonalHell.scala

class IndexProcess private (config: Config) {
  
  // e.g.
  // index {
  //  entities {
  //    slide {
  //      products: {to: many, is: product}
  //      sites: {to: many, is: site}
  //    }
  //    site: {
  //      architects: {to: many, is: architect}
  //      engineers: {to: many, is: engineer}
  //    }
  //    product: {}
  //    architect: {}
  //    engineer: {}
  //  }
  // }
  
  val entities: Config = config.getConfig("entities")

  // Flatten a configuration, extracting child objects.
  // Config(...) => Seq(child1, child2, ...original - (child1..child2))
  def normalize(config: Config, as: String): List[Config] = {
    config.root.keySet.asScala filter { key =>
      entities.hasPath(joinPath(as, key))
    } match {
      case Map.empty => List.apply(config)
      case relKeys => {
        val parent: Config = relKeys.foldRight(config) {
          (key, config) => config.withoutPath(key)
        }

        val children: List[Config] = relKeys.flatMap {
          (key) => normalize(
            config.getConfig(key), 
            entities.getString(joinPath(as, key, "is"))
          )
        }.toList

        children :+ parent
      }
    }
  }
}