Scala web series Pt. 1 authorization predicate combinators

authorization_predicate_combinators.scala

trait AuthorizationPredicate { self =>
  def evaluate(token: Token): Boolean
   
  def &&(predicate: AuthorizationPredicate): AuthorizationPredicate = new AuthorizationPredicate {
    override def evaluate(token: Token): Boolean = self.evaluate(token) && predicate.evaluate(token)
  }

  def ||(predicate: AuthorizationPredicate): AuthorizationPredicate = new AuthorizationPredicate {
    override def evaluate(token: token): Boolean = self.evaluate(token) || predicate.evaluate(token)
  }
}