Identity Monad

gistfile1.txt

trait Monad[M[_]] {
  def pure[A](a: A): M[A]
  def flatMap[A, B](f: A => M[B]): M[A] => M[B]
  def map[A, B](f: A => B): M[A] => M[B] = flatMap(a => pure(f(a)))
}
 
object Id {
  type Id[X] = X

  implicit val M: Monad[Id] = sys.error("todo")
}