Implicit scoping implementation of privacy layer

ImpPrivacy.scala

package com.sumologic.metplay

object ImplicitPrivacy {

  sealed trait PrivacyLevel
  case object High extends PrivacyLevel
  case object Low extends PrivacyLevel
  type High = High.type
  type Low = Low.type

  sealed trait HasLevel[L]
  object Permissions {
    implicit object HasLow extends HasLevel[Low]
    implicit object HasHigh extends HasLevel[High]
  }

  def high[T](data: T): ImpSec[High, T] = new ImpSec(data)
  def low[T](data: T): ImpSec[Low, T] = new ImpSec(data)

  class ImpSec[PL <: PrivacyLevel, T](data: T) {
    protected val _data = data

    def fmap[S](f: T => S): ImpSec[PL, S] = new ImpSec(f(_data))

    def reveal(implicit has: HasLevel[PL]): T = _data
  }
}