NOTE: This repository has been discontinued in favor ofActomaton.

ReactiveAutomaton

Example

// 1. Define `State`s and `Input`s.enumState{case loggedOut, loggingIn, loggedIn, loggingOut}enumInput{case login, loginOK, logout, logoutOKcase forceLogout}// Additional effects (`SignalProducer`s) while state-transitioning.// (NOTE: Use `SignalProducer.empty` for no effect)letloginOKProducer= /* show UI, setup DB, request APIs, ..., and send `Input.loginOK` */let logoutOKProducer= /* show UI, clear cache, cancel APIs, ..., and send `Input.logoutOK` */let forceLogoutOKProducer= /* do something more special, ..., and send `Input.logoutOK` */let canForceLogout:(State)-> Bool=[.loggingIn,.loggedIn].contains// 2. Setup state-transition mappings.letmappings:[Automaton<State,Input>.EffectMapping]=[  /*  Input   |   fromState => toState     |      Effect       */  /* ----------------------------------------------------------*/.login    |.loggedOut=>.loggingIn  | loginOKProducer,.loginOK  |.loggingIn=>.loggedIn   |.empty,.logout   |.loggedIn=>.loggingOut | logoutOKProducer,.logoutOK |.loggingOut=>.loggedOut  |.empty,.forceLogout | canForceLogout=>.loggingOut | forceLogoutOKProducer]// 3. Prepare input pipe for sending `Input` to `Automaton`.let(inputSignal, inputObserver)=Signal<Input,NoError>.pipe()// 4. Setup `Automaton`.letautomaton=Automaton(    state:.loggedOut,    input: inputSignal,    mapping:reduce(mappings),  // combine mappings using `reduce` helper    strategy:.latest   // NOTE: `.latest` cancels previous running effect)// Observe state-transition replies (`.success` or `.failure`).automaton.replies.observeNext{ replyinprint("received reply =\(reply)")}// Observe current state changes.automaton.state.producer.startWithValues{ stateinprint("current state =\(state)")}

letsend= inputObserver.send(value:)expect(automaton.state.value)==.loggedIn    // already logged insend(Input.logout)expect(automaton.state.value)==.loggingOut  // logging out...// `logoutOKProducer` will automatically send `Input.logoutOK` later// and transit to `State.loggedOut`.expect(automaton.state.value)==.loggedOut   // already logged outsend(Input.login)expect(automaton.state.value)==.loggingIn   // logging in...// `loginOKProducer` will automatically send `Input.loginOK` later// and transit to `State.loggedIn`.// 👨🏽 < But wait, there's more!// Let's send `Input.forceLogout` immediately after `State.loggingIn`.send(Input.forceLogout)                       // 💥💣💥expect(automaton.state.value)==.loggingOut  // logging out...// `forceLogoutOKProducer` will automatically send `Input.logoutOK` later// and transit to `State.loggedOut`.

References

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