A cute little application exit status value class

ExitStatus.scala

import scala.language.implicitConversions

/** A process exit status. */
sealed abstract class ExitStatus(val code: Int) extends Product with Serializable

/** Exit statuses used conventionally across components. */
object ExitStatus {
  case object Success  extends ExitStatus(0)
  case object Error    extends ExitStatus(1)
  case object BadUsage extends ExitStatus(2) // 2 is conventional, e.g. bash builtins, grep
  case object NoOp     extends ExitStatus(3) // Nothing done, e.g. could not get ZooKeeper lock

  /** An innocent little conversion to give you the pleasing syntax of
    * {{{
    *   sys.exit(ExitStatus.Success)
    * }}}
    */
  implicit def exitStatus2int(status: ExitStatus): Int = status.code
}