ruurtjan

object MoreOrthogonal {
  def flatMap[A, B](l: List[A], f: A => List[B]): List[B] =
    MoreOrthogonal.flatten(MoreOrthogonal.map(l, f))

  def flatten[A](l: List[List[A]]): List[A] = ???

  def map[A, B](l: List[A], f: A => B): List[B] = ???
}

ruurtjan

object initial_encoded_email_filter {
  final case class Address(emailAddress: String)
  final case class Email(sender: Address, to: List[Address], subject: String, body: String)

  sealed trait EmailFilter { self =>
    def &&(that: EmailFilter): EmailFilter = EmailFilter.And(self, that)

    def ||(that: EmailFilter): EmailFilter = (self.negate && that.negate).negate

    def negate : EmailFilter = EmailFilter.Not(self)

ruurtjan

object final_encoded_email_filter {
  final case class Address(emailAddress: String)
  final case class Email(sender: Address, to: List[Address], subject: String, body: String)

  case class EmailFilter(run: Email => Boolean) { self =>
    def &&(that: EmailFilter): EmailFilter = EmailFilter(email => self.run(email) && that.run(email))

    def ||(that: EmailFilter): EmailFilter =  EmailFilter(email => self.run(email) || that.run(email))

    def negate : EmailFilter = EmailFilter(email => !self.run(email))

ruurtjan

  case class EmailFilter(run: Email => Boolean) { self =>
    def &&(that: EmailFilter): EmailFilter =
      EmailFilter(email => self.run(email) && that.run(email))
    def ||(that: EmailFilter): EmailFilter =
      EmailFilter(email => self.run(email) || that.run(email))
    def negate : EmailFilter =
      EmailFilter(email => !self.run(email))
  }

  object EmailFilter {

ruurtjan

  sealed trait EmailFilter { self =>
    def &&(that: EmailFilter): EmailFilter = EmailFilter.And(self, that)
    def ||(that: EmailFilter): EmailFilter = (self.negate && that.negate).negate
    def negate : EmailFilter = EmailFilter.Not(self)

    import EmailFilter._
    def run(email: Email): Boolean = self match {
      case Always => true
      case Not(filter: EmailFilter) => !filter.run(email)
      case And(left: EmailFilter, right: EmailFilter) =>