Playing with cats

package.scala

package object types {
  type Or[+A, +B] = Either[A, B]

  object Or {
    import cats.syntax.either._
    import cats.Traverse

    def left[A, B](a: A): A Or B = Either.left(a)
    def right[A, B](b: B): A Or B = Either.right(b)

    def traverse[F[_] : Traverse, A, B](f: F[A Or B]): A Or F[B] = {
      Traverse[F]
        .find(f)(o => o.isLeft)
        .map(o => Or.left(o.left.get))
        .getOrElse(Or.right(Traverse[F].map(f)(o => o.right.get)))
    }
  }
}