Implement Console of FP in Scala using Scalaz v7.2.0-M3

Console.scala

import scalaz._
import scalaz.Free._
import scalaz.std.function._
import scalaz.{ Free, ~> }

sealed trait Console[A]
case object ReadLine extends Console[Option[String]]
case class PrintLine(line: String) extends Console[Unit]

object Console {
  type ConsoleIO[A] = Free[Console, A]
  def readLn: ConsoleIO[Option[String]] = liftF(ReadLine)
  def printLn(line: String): ConsoleIO[Unit] = liftF(PrintLine(line))
}

object ConsoleApp extends App {
  import Console._
  val console2Function0 = new (Console ~> Function0) {
    override def apply[A](fa: Console[A]): () => A = fa match {
      case ReadLine => () => Some(io.StdIn.readLine())
      case PrintLine(line) => () => println(line)
    }
  }

  val msg = "I can only interact with the console."
  val f = for {
    _ <- printLn(msg)
    line <- readLn
  } yield line

  val r1: Free[Function0,Option[String]] = f.mapSuspension(console2Function0)
  println(r1.run)

  val r2: () => Option[String] = f.foldMap(console2Function0)
  println(r2())
}