Protocols

The following protocols are available globally.

  • The “state” part of our finite state machine.

    Instances of the conforming type model the states of our system. Their implementations of shouldTrasition(to:) determine what transitions between states are allowed.

    Note

    In theory, this could be any type capable of calculating whether a transition between two instances of itself are legal. In practice, it’s almost always best to use an enum. For example:

    enum TrafficLight: Transitionable {
  case red, yellow, green

  func shouldTransition(to: Self) -> Bool {
    switch (self, to) {
    case (.red, green),
         (.green, .yellow),
         (.yellow, red):
      return true
    default:
      return false
    }
  }
}
    See more

    Declaration

    Swift

    public protocol Transitionable