struct AppState {
  var appName = "Demo App"
  var age = 6
  var names = ["hank", "cloe", "spike", "joffrey", "fido", "kahlil", "malik"]

  static let initialValue = AppState()
}

enum AppAction: Action {
  case growup
}

typealias AppStore = Store<AppReducer>

func appReducer(state: inout AppState, action: Action) {
  guard let action = action as? AppAction else { return }
  switch action {
  case .growup:
    state.age += 1
  }
}

// Create a store with the publisher middleware
// this middleware allows us to use `PublisherAction`
// later to dispatch an async action.
let store = AppStore(
  reducer: appReducer,
  state: .initialValue,
  middlewares: [createPublisherMiddleware()])

// Inject the store with `.environmentObject()`.
// Alternatively we could inject it with `.environment()`
let contentView = ContentView().environmentObject(store)

// later...
    window.rootViewController = UIHostingController(rootView: contentView)

extension Store {
  func dispatch(_ action: AppAction) {
    dispatch(action as Action)
  }

  subscript(_ action: AppAction) -> (() -> Void) {
    { [weak self] in self?.dispatch(action as Action) }
  }
}

struct MyView: View {
  var index: Int

  // Define your derived state
  struct MyDerivedState: Equatable {
    var age: Int
    var name: String
  }

  // Inject your store
  @EnvironmentObject var store: AppStore

  // Connect to the store
  var body: some View {
    Connect(store: store, selector: selector, content: body)
  }

  // Render something using the selected state
  private func body(_ state: MyDerivedState) -> some View {
    Text("Hello \(state.name)!")
  }
  
  // Setup a state selector
  private func selector(_ state: AppState) -> MyDerivedState {
    .init(age: state.age, name: state.names[index])
  }
}

    Button("Grow up") { self.store.dispatch(AppAction.growup) }
    
    // ... or ...
    
    Button("Grow up", action: store[AppAction.growup])

    Button("Grow up") { self.store.dispatch(.growup) }

    // ...or...

    Button("Grow up", action: store[.growup])

    Button("Grow up") { self.store.dispatch(self.delayedGrowup) }
    
  //...

  private let delayedGrowup = PublisherAction<AppState> { dispatch, getState, cancellables in
    Just(())
      .delay(for: 2, scheduler: RunLoop.main)
      .sink { _ in
        dispatch(AppAction.growup)
      }
      .store(in: &cancellables)
  }

@ObservedObject var store: AppStore