Scala Enumeration alternative

ADTEnum.scala

import play.api.libs.json.{JsValue => PJsValue, JsString => PJsString, _}
import spray.json
import spray.json.{DeserializationException, JsString, JsValue, JsonFormat}

/**
 * Enum alternative with Json marshallers for free (Play and Spray)
 *
 * credit: https://gist.github.com/atamborrino/1d992ebb942cd5518ca2
 *
 * Use:
 *   sealed trait Dsp
 * object Dsp extends ADTEnum[Dsp] {
 *   case object AppNexus extends Dsp
 *   case object MediaMath extends Dsp
 *   val list = Seq(AppNexus, MediaMath)
 * }
 *
 * def foo(dsp: Dsp) = dsp match {
 *   case Dsp.AppNexus => "foo"
 *   case Dsp.MediaMath => "bar"
 * }
 * @tparam A
 */
trait ADTEnum[A] {

  val list: Seq[A]

  def withName(name: String): Option[A] = {
    list.find(_.toString.toLowerCase == name.toLowerCase)
  }

  implicit val sprayJsonReads: JsonFormat[A] = new JsonFormat[A] {
    def read(json: JsValue): A = json match {
      case JsString(raw) =>
        withName(raw)
          .getOrElse(throw new DeserializationException("error.ADTEnumUnknown"))
      case _ => throw new DeserializationException("error.ADTEnumMustBeAString")
    }
    def write(obj: A): JsValue = JsString(obj.toString)
  }

  implicit val playJsonFormat: Format[A] = new Format[A] {
    override def writes(o: A): PJsValue =
      PJsString(o.toString)
    override def reads(json: PJsValue): JsResult[A] =
      json match {
        case PJsString(raw) =>
          withName(raw) match {
            case Some(a) => JsSuccess(a)
            case None => JsError(__, "error.ADTEnumUnknown")
          }
        case _ => JsError(__, "error.ADTEnumMustBeAString")
      }
  }

}

Choose your preferred json library over spray-json or play-json here.
Based on the atamborrino original Gist but without the dependency to jto / validation.