RxStore.swift

import Foundation
import RxSwift
import ReSwift

class RxStore<State>: Store<AppState>, StoreSubscriber where State : StateType {
  public typealias StoreSubscriberStateType = State
  
  private var stateObservable:Observable<State> {
    return subject.asObserver()
      .shareReplay(1)
  }
  
  private var subject = PublishSubject<State>()
  
  required init(reducer: @escaping (Action, State?) -> State, state: State?, middleware: [Middleware<State>] = []) {
    super.init(reducer: reducer, state: state, middleware: middleware)
    self.subscribe(self)
  }
  
  deinit {
    self.unsubscribe(self)
  }
  
  func newState(state newState: State) {
    subject.onNext(newState)
  }
  
  func observe<S>(mapState:@escaping (State) -> S) -> Observable<S> {
    return stateObservable
      .map(mapState)
  }
  
}

let mainStore = RxStore<AppState>(
  reducer: applicationReducer,
  state: nil
)

mainStore
  .observe { $0.navigationState }
  .subscribe(onNext: { navigationState in
    print("Route: \(navigationState.route)")
  })