import cats._, cats.data._, cats.implicits._
import cats.free.Free
import cats.arrow.FunctionK
import monix.eval.Coeval
object ParserForFreeMonad extends App {
  trait MyAlgebraF[A]
  final case class Append(cmd: String) extends MyAlgebraF[Int]
  final case class Upsert(cmd: String) extends MyAlgebraF[Unit]

  type MyAlgebra[A] = Free[MyAlgebraF, A]

  val nt = Lambda[FunctionK[MyAlgebraF, Coeval]] {
    case Append(cmd) => Coeval { println(cmd); 1 }
    case Upsert(cmd) => Coeval { println(cmd) }
  }

  val prog = for {
    a <- Free.liftF(Append("append"))
    u <- Free.liftF(Upsert("upsert"))
  } yield a

  println(prog.foldMap(nt).runTry)
}