BigCatAccount

case class M[+A](in: (A => Any) => Any);

def unit[A](x: A) = M { k: (A => Any) => k(x) }

def bind[A, B](m: M[A], f: A => M[B]): M[B] =
  M { k: (B => Any) =>
    m.in { x: A =>
      f(x).in(k)
    }
  }

BigCatAccount

object Main extends App {

  trait Functor[F[_]] {
    def map[A, B](fa: F[A])(f: A => B): F[B]
  }

  sealed trait Nat[A]
  final case class Z[A]() extends Nat[A]
  final case class S[A](a: A) extends Nat[A]

BigCatAccount

import cats.Functor
import cats.implicits._

import scala.language.higherKinds

sealed trait StackR
final case class DoneR(result: Int = 1) extends StackR
final case class MoreR(acc: StackR, next: Int) extends StackR

sealed trait Stack[A]

BigCatAccount

package fpmax

import scala.util.Try
import scala.io.StdIn.readLine

object App0 {
  def main: Unit = {
    println("What is your name?")

    val name = readLine()

BigCatAccount

object MyIteratee{
  sealed trait Input[+E] {
  }

  object Input {
    case class El[+E](e: E) extends Input[E]
    case object EOF extends Input[Nothing]
  }

  trait Iteratee[E, A] {