TCBox.scala

package com.emg.slidedeck.agent.safeindex

import scala.language.{higherKinds, implicitConversions}
import scalaz.Alpha.{F, G, T}

sealed trait TCBox[TC[_]] {
  type T
  val value: T
  val evidence: TC[T]
}

object TCBox {

  def apply[T, TC[_]](value: T)(implicit ev: TC[T]): TCBox[TC] =
    MkTCBox(value)

  def unapply[TC[_]](box: TCBox[TC]): Option[(box.T, TC[box.T])] =
    Some(box.value -> box.evidence)

  implicit def anyToBox[TC[_], A: TC](value: A): TCBox[TC] = TCBox(value)
}

private case class MkTCBox[A, TC[_]](value: A)(implicit val evidence: TC[A])
  extends TCBox[TC] {
  type T = A
}

sealed trait TCBoxF[TC[_[_], _]] {
  type T
  type F[_]
  val value: T
  val evidence: TC[F, T]
}

object TCBoxF {

  type Aux[TC[_[_], _], F0[_]] = TCBoxF[TC] {type F[A] = F0[A]}

  def apply[TC[_[_], _], F[_], T](value: T)(implicit ev: TC[F, T]): TCBoxF[TC] =
    MkTCBoxF(value)

  def unapply[TC[_[_], _]](box: TCBoxF[TC]): Option[(box.T, TC[box.F, box.T])] =
    Some(box.value -> box.evidence)

  implicit def anyToBoxF[TC[_[_],_], F[_], A](value: A)(implicit ev: TC[F, A]): TCBoxF[TC] = TCBoxF(value)
}

private case class MkTCBoxF[F0[_], A, TC[_[_], _]](value: A)(implicit val evidence: TC[F0, A])
  extends TCBoxF[TC] {

  type T = A
  type F[X] = F0[X]
}