xstate/es/interpreter.js

Finite State Machines and Statecharts for the Modern Web.

import { __values, __spreadArray, __read, __assign } from './_virtual/_tslib.js';
import { SpecialTargets, ActionTypes } from './types.js';
import { isStateConfig, State, bindActionToState } from './State.js';
import { errorPlatform, update, error as error$1, log, stop, start, cancel, send, raise } from './actionTypes.js';
import { initEvent, doneInvoke, toActionObjects, resolveActions, error, getActionFunction } from './actions.js';
import { IS_PRODUCTION } from './environment.js';
import { warn, mapContext, toObserver, isFunction, toSCXMLEvent, flatten, isRaisableAction, isPromiseLike, isObservable, isMachine, isBehavior, reportUnhandledExceptionOnInvocation, symbolObservable, isArray, toEventObject, isString, isActor, toInvokeSource, uniqueId } from './utils.js';
import { Scheduler } from './scheduler.js';
import { createDeferredActor, isSpawnedActor } from './Actor.js';
import { registry } from './registry.js';
import { getGlobal, registerService } from './devTools.js';
import { provide, consume } from './serviceScope.js';
import { spawnBehavior } from './behaviors.js';

var DEFAULT_SPAWN_OPTIONS = {
  sync: false,
  autoForward: false
};
var InterpreterStatus;

(function (InterpreterStatus) {
  InterpreterStatus[InterpreterStatus["NotStarted"] = 0] = "NotStarted";
  InterpreterStatus[InterpreterStatus["Running"] = 1] = "Running";
  InterpreterStatus[InterpreterStatus["Stopped"] = 2] = "Stopped";
})(InterpreterStatus || (InterpreterStatus = {}));

var Interpreter =
/*#__PURE__*/

/** @class */
function () {
  /**
   * Creates a new Interpreter instance (i.e., service) for the given machine with the provided options, if any.
   *
   * @param machine The machine to be interpreted
   * @param options Interpreter options
   */
  function Interpreter(machine, options) {
    if (options === void 0) {
      options = Interpreter.defaultOptions;
    }

    var _this = this;

    this.machine = machine;
    this.delayedEventsMap = {};
    this.listeners = new Set();
    this.contextListeners = new Set();
    this.stopListeners = new Set();
    this.doneListeners = new Set();
    this.eventListeners = new Set();
    this.sendListeners = new Set();
    /**
     * Whether the service is started.
     */

    this.initialized = false;
    this.status = InterpreterStatus.NotStarted;
    this.children = new Map();
    this.forwardTo = new Set();
    this._outgoingQueue = [];
    /**
     * Alias for Interpreter.prototype.start
     */

    this.init = this.start;
    /**
     * Sends an event to the running interpreter to trigger a transition.
     *
     * An array of events (batched) can be sent as well, which will send all
     * batched events to the running interpreter. The listeners will be
     * notified only **once** when all events are processed.
     *
     * @param event The event(s) to send
     */

    this.send = function (event, payload) {
      if (isArray(event)) {
        _this.batch(event);

        return _this.state;
      }

      var _event = toSCXMLEvent(toEventObject(event, payload));

      if (_this.status === InterpreterStatus.Stopped) {
        // do nothing
        if (!IS_PRODUCTION) {
          warn(false, "Event \"".concat(_event.name, "\" was sent to stopped service \"").concat(_this.machine.id, "\". This service has already reached its final state, and will not transition.\nEvent: ").concat(JSON.stringify(_event.data)));
        }

        return _this.state;
      }

      if (_this.status !== InterpreterStatus.Running && !_this.options.deferEvents) {
        throw new Error("Event \"".concat(_event.name, "\" was sent to uninitialized service \"").concat(_this.machine.id // tslint:disable-next-line:max-line-length
        , "\". Make sure .start() is called for this service, or set { deferEvents: true } in the service options.\nEvent: ").concat(JSON.stringify(_event.data)));
      }

      _this.scheduler.schedule(function () {
        // Forward copy of event to child actors
        _this.forward(_event);

        var nextState = _this._nextState(_event);

        _this.update(nextState, _event);
      });

      return _this._state; // TODO: deprecate (should return void)
      // tslint:disable-next-line:semicolon
    };

    this.sendTo = function (event, to, immediate) {
      var isParent = _this.parent && (to === SpecialTargets.Parent || _this.parent.id === to);
      var target = isParent ? _this.parent : isString(to) ? to === SpecialTargets.Internal ? _this : _this.children.get(to) || registry.get(to) : isActor(to) ? to : undefined;

      if (!target) {
        if (!isParent) {
          throw new Error("Unable to send event to child '".concat(to, "' from service '").concat(_this.id, "'."));
        } // tslint:disable-next-line:no-console


        if (!IS_PRODUCTION) {
          warn(false, "Service '".concat(_this.id, "' has no parent: unable to send event ").concat(event.type));
        }

        return;
      }

      if ('machine' in target) {
        // perhaps those events should be rejected in the parent
        // but atm it doesn't have easy access to all of the information that is required to do it reliably
        if (_this.status !== InterpreterStatus.Stopped || _this.parent !== target || // we need to send events to the parent from exit handlers of a machine that reached its final state
        _this.state.done) {
          // Send SCXML events to machines
          var scxmlEvent = __assign(__assign({}, event), {
            name: event.name === error$1 ? "".concat(error(_this.id)) : event.name,
            origin: _this.sessionId
          });

          if (!immediate && _this.machine.config.predictableActionArguments) {
            _this._outgoingQueue.push([target, scxmlEvent]);
          } else {
            target.send(scxmlEvent);
          }
        }
      } else {
        // Send normal events to other targets
        if (!immediate && _this.machine.config.predictableActionArguments) {
          _this._outgoingQueue.push([target, event.data]);
        } else {
          target.send(event.data);
        }
      }
    };

    this._exec = function (action, context, _event, actionFunctionMap) {
      if (actionFunctionMap === void 0) {
        actionFunctionMap = _this.machine.options.actions;
      }

      var actionOrExec = action.exec || getActionFunction(action.type, actionFunctionMap);
      var exec = isFunction(actionOrExec) ? actionOrExec : actionOrExec ? actionOrExec.exec : action.exec;

      if (exec) {
        try {
          return exec(context, _event.data, !_this.machine.config.predictableActionArguments ? {
            action: action,
            state: _this.state,
            _event: _event
          } : {
            action: action,
            _event: _event
          });
        } catch (err) {
          if (_this.parent) {
            _this.parent.send({
              type: 'xstate.error',
              data: err
            });
          }

          throw err;
        }
      }

      switch (action.type) {
        case raise:
          {
            // if raise action reached the interpreter then it's a delayed one
            var sendAction_1 = action;

            _this.defer(sendAction_1);

            break;
          }

        case send:
          var sendAction = action;

          if (typeof sendAction.delay === 'number') {
            _this.defer(sendAction);

            return;
          } else {
            if (sendAction.to) {
              _this.sendTo(sendAction._event, sendAction.to, _event === initEvent);
            } else {
              _this.send(sendAction._event);
            }
          }

          break;

        case cancel:
          _this.cancel(action.sendId);

          break;

        case start:
          {
            if (_this.status !== InterpreterStatus.Running) {
              return;
            }

            var activity = action.activity; // If the activity will be stopped right after it's started
            // (such as in transient states)
            // don't bother starting the activity.

            if ( // in v4 with `predictableActionArguments` invokes are called eagerly when the `this.state` still points to the previous state
            !_this.machine.config.predictableActionArguments && !_this.state.activities[activity.id || activity.type]) {
              break;
            } // Invoked services


            if (activity.type === ActionTypes.Invoke) {
              var invokeSource = toInvokeSource(activity.src);
              var serviceCreator = _this.machine.options.services ? _this.machine.options.services[invokeSource.type] : undefined;
              var id = activity.id,
                  data = activity.data;

              if (!IS_PRODUCTION) {
                warn(!('forward' in activity), // tslint:disable-next-line:max-line-length
                "`forward` property is deprecated (found in invocation of '".concat(activity.src, "' in in machine '").concat(_this.machine.id, "'). ") + "Please use `autoForward` instead.");
              }

              var autoForward = 'autoForward' in activity ? activity.autoForward : !!activity.forward;

              if (!serviceCreator) {
                // tslint:disable-next-line:no-console
                if (!IS_PRODUCTION) {
                  warn(false, "No service found for invocation '".concat(activity.src, "' in machine '").concat(_this.machine.id, "'."));
                }

                return;
              }

              var resolvedData = data ? mapContext(data, context, _event) : undefined;

              if (typeof serviceCreator === 'string') {
                // TODO: warn
                return;
              }

              var source = isFunction(serviceCreator) ? serviceCreator(context, _event.data, {
                data: resolvedData,
                src: invokeSource,
                meta: activity.meta
              }) : serviceCreator;

              if (!source) {
                // TODO: warn?
                return;
              }

              var options = void 0;

              if (isMachine(source)) {
                source = resolvedData ? source.withContext(resolvedData) : source;
                options = {
                  autoForward: autoForward
                };
              }

              _this.spawn(source, id, options);
            } else {
              _this.spawnActivity(activity);
            }

            break;
          }

        case stop:
          {
            _this.stopChild(action.activity.id);

            break;
          }

        case log:
          var _a = action,
              label = _a.label,
              value = _a.value;

          if (label) {
            _this.logger(label, value);
          } else {
            _this.logger(value);
          }

          break;

        default:
          if (!IS_PRODUCTION) {
            warn(false, "No implementation found for action type '".concat(action.type, "'"));
          }

          break;
      }
    };

    var resolvedOptions = __assign(__assign({}, Interpreter.defaultOptions), options);

    var clock = resolvedOptions.clock,
        logger = resolvedOptions.logger,
        parent = resolvedOptions.parent,
        id = resolvedOptions.id;
    var resolvedId = id !== undefined ? id : machine.id;
    this.id = resolvedId;
    this.logger = logger;
    this.clock = clock;
    this.parent = parent;
    this.options = resolvedOptions;
    this.scheduler = new Scheduler({
      deferEvents: this.options.deferEvents
    });
    this.sessionId = registry.bookId();
  }

  Object.defineProperty(Interpreter.prototype, "initialState", {
    get: function () {
      var _this = this;

      if (this._initialState) {
        return this._initialState;
      }

      return provide(this, function () {
        _this._initialState = _this.machine.initialState;
        return _this._initialState;
      });
    },
    enumerable: false,
    configurable: true
  });
  Object.defineProperty(Interpreter.prototype, "state", {
    /**
     * @deprecated Use `.getSnapshot()` instead.
     */
    get: function () {
      if (!IS_PRODUCTION) {
        warn(this.status !== InterpreterStatus.NotStarted, "Attempted to read state from uninitialized service '".concat(this.id, "'. Make sure the service is started first."));
      }

      return this._state;
    },
    enumerable: false,
    configurable: true
  });
  /**
   * Executes the actions of the given state, with that state's `context` and `event`.
   *
   * @param state The state whose actions will be executed
   * @param actionsConfig The action implementations to use
   */

  Interpreter.prototype.execute = function (state, actionsConfig) {
    var e_1, _a;

    try {
      for (var _b = __values(state.actions), _c = _b.next(); !_c.done; _c = _b.next()) {
        var action = _c.value;
        this.exec(action, state, actionsConfig);
      }
    } catch (e_1_1) {
      e_1 = {
        error: e_1_1
      };
    } finally {
      try {
        if (_c && !_c.done && (_a = _b.return)) _a.call(_b);
      } finally {
        if (e_1) throw e_1.error;
      }
    }
  };

  Interpreter.prototype.update = function (state, _event) {
    var e_2, _a, e_3, _b, e_4, _c, e_5, _d;

    var _this = this; // Attach session ID to state


    state._sessionid = this.sessionId; // Update state

    this._state = state; // Execute actions

    if ((!this.machine.config.predictableActionArguments || // this is currently required to execute initial actions as the `initialState` gets cached
    // we can't just recompute it (and execute actions while doing so) because we try to preserve identity of actors created within initial assigns
    _event === initEvent) && this.options.execute) {
      this.execute(this.state);
    } else {
      var item = void 0;

      while (item = this._outgoingQueue.shift()) {
        item[0].send(item[1]);
      }
    } // Update children


    this.children.forEach(function (child) {
      _this.state.children[child.id] = child;
    }); // Dev tools

    if (this.devTools) {
      this.devTools.send(_event.data, state);
    } // Execute listeners


    if (state.event) {
      try {
        for (var _e = __values(this.eventListeners), _f = _e.next(); !_f.done; _f = _e.next()) {
          var listener = _f.value;
          listener(state.event);
        }
      } catch (e_2_1) {
        e_2 = {
          error: e_2_1
        };
      } finally {
        try {
          if (_f && !_f.done && (_a = _e.return)) _a.call(_e);
        } finally {
          if (e_2) throw e_2.error;
        }
      }
    }

    try {
      for (var _g = __values(this.listeners), _h = _g.next(); !_h.done; _h = _g.next()) {
        var listener = _h.value;
        listener(state, state.event);
      }
    } catch (e_3_1) {
      e_3 = {
        error: e_3_1
      };
    } finally {
      try {
        if (_h && !_h.done && (_b = _g.return)) _b.call(_g);
      } finally {
        if (e_3) throw e_3.error;
      }
    }

    try {
      for (var _j = __values(this.contextListeners), _k = _j.next(); !_k.done; _k = _j.next()) {
        var contextListener = _k.value;
        contextListener(this.state.context, this.state.history ? this.state.history.context : undefined);
      }
    } catch (e_4_1) {
      e_4 = {
        error: e_4_1
      };
    } finally {
      try {
        if (_k && !_k.done && (_c = _j.return)) _c.call(_j);
      } finally {
        if (e_4) throw e_4.error;
      }
    }

    if (this.state.done) {
      // get final child state node
      var finalChildStateNode = state.configuration.find(function (sn) {
        return sn.type === 'final' && sn.parent === _this.machine;
      });
      var doneData = finalChildStateNode && finalChildStateNode.doneData ? mapContext(finalChildStateNode.doneData, state.context, _event) : undefined;
      this._doneEvent = doneInvoke(this.id, doneData);

      try {
        for (var _l = __values(this.doneListeners), _m = _l.next(); !_m.done; _m = _l.next()) {
          var listener = _m.value;
          listener(this._doneEvent);
        }
      } catch (e_5_1) {
        e_5 = {
          error: e_5_1
        };
      } finally {
        try {
          if (_m && !_m.done && (_d = _l.return)) _d.call(_l);
        } finally {
          if (e_5) throw e_5.error;
        }
      }

      this._stop();

      this._stopChildren();

      registry.free(this.sessionId);
    }
  };
  /*
   * Adds a listener that is notified whenever a state transition happens. The listener is called with
   * the next state and the event object that caused the state transition.
   *
   * @param listener The state listener
   */


  Interpreter.prototype.onTransition = function (listener) {
    this.listeners.add(listener); // Send current state to listener

    if (this.status === InterpreterStatus.Running) {
      listener(this.state, this.state.event);
    }

    return this;
  };

  Interpreter.prototype.subscribe = function (nextListenerOrObserver, _, // TODO: error listener
  completeListener) {
    var _this = this;

    var observer = toObserver(nextListenerOrObserver, _, completeListener);
    this.listeners.add(observer.next); // Send current state to listener

    if (this.status !== InterpreterStatus.NotStarted) {
      observer.next(this.state);
    }

    var completeOnce = function () {
      _this.doneListeners.delete(completeOnce);

      _this.stopListeners.delete(completeOnce);

      observer.complete();
    };

    if (this.status === InterpreterStatus.Stopped) {
      observer.complete();
    } else {
      this.onDone(completeOnce);
      this.onStop(completeOnce);
    }

    return {
      unsubscribe: function () {
        _this.listeners.delete(observer.next);

        _this.doneListeners.delete(completeOnce);

        _this.stopListeners.delete(completeOnce);
      }
    };
  };
  /**
   * Adds an event listener that is notified whenever an event is sent to the running interpreter.
   * @param listener The event listener
   */


  Interpreter.prototype.onEvent = function (listener) {
    this.eventListeners.add(listener);
    return this;
  };
  /**
   * Adds an event listener that is notified whenever a `send` event occurs.
   * @param listener The event listener
   */


  Interpreter.prototype.onSend = function (listener) {
    this.sendListeners.add(listener);
    return this;
  };
  /**
   * Adds a context listener that is notified whenever the state context changes.
   * @param listener The context listener
   */


  Interpreter.prototype.onChange = function (listener) {
    this.contextListeners.add(listener);
    return this;
  };
  /**
   * Adds a listener that is notified when the machine is stopped.
   * @param listener The listener
   */


  Interpreter.prototype.onStop = function (listener) {
    this.stopListeners.add(listener);
    return this;
  };
  /**
   * Adds a state listener that is notified when the statechart has reached its final state.
   * @param listener The state listener
   */


  Interpreter.prototype.onDone = function (listener) {
    if (this.status === InterpreterStatus.Stopped && this._doneEvent) {
      listener(this._doneEvent);
    } else {
      this.doneListeners.add(listener);
    }

    return this;
  };
  /**
   * Removes a listener.
   * @param listener The listener to remove
   */


  Interpreter.prototype.off = function (listener) {
    this.listeners.delete(listener);
    this.eventListeners.delete(listener);
    this.sendListeners.delete(listener);
    this.stopListeners.delete(listener);
    this.doneListeners.delete(listener);
    this.contextListeners.delete(listener);
    return this;
  };
  /**
   * Starts the interpreter from the given state, or the initial state.
   * @param initialState The state to start the statechart from
   */


  Interpreter.prototype.start = function (initialState) {
    var _this = this;

    if (this.status === InterpreterStatus.Running) {
      // Do not restart the service if it is already started
      return this;
    } // yes, it's a hack but we need the related cache to be populated for some things to work (like delayed transitions)
    // this is usually called by `machine.getInitialState` but if we rehydrate from a state we might bypass this call
    // we also don't want to call this method here as it resolves the full initial state which might involve calling assign actions
    // and that could potentially lead to some unwanted side-effects (even such as creating some rogue actors)


    this.machine._init();

    registry.register(this.sessionId, this);
    this.initialized = true;
    this.status = InterpreterStatus.Running;
    var resolvedState = initialState === undefined ? this.initialState : provide(this, function () {
      return isStateConfig(initialState) ? _this.machine.resolveState(initialState) : _this.machine.resolveState(State.from(initialState, _this.machine.context));
    });

    if (this.options.devTools) {
      this.attachDev();
    }

    this.scheduler.initialize(function () {
      _this.update(resolvedState, initEvent);
    });
    return this;
  };

  Interpreter.prototype._stopChildren = function () {
    // TODO: think about converting those to actions
    this.children.forEach(function (child) {
      if (isFunction(child.stop)) {
        child.stop();
      }
    });
    this.children.clear();
  };

  Interpreter.prototype._stop = function () {
    var e_6, _a, e_7, _b, e_8, _c, e_9, _d, e_10, _e;

    try {
      for (var _f = __values(this.listeners), _g = _f.next(); !_g.done; _g = _f.next()) {
        var listener = _g.value;
        this.listeners.delete(listener);
      }
    } catch (e_6_1) {
      e_6 = {
        error: e_6_1
      };
    } finally {
      try {
        if (_g && !_g.done && (_a = _f.return)) _a.call(_f);
      } finally {
        if (e_6) throw e_6.error;
      }
    }

    try {
      for (var _h = __values(this.stopListeners), _j = _h.next(); !_j.done; _j = _h.next()) {
        var listener = _j.value; // call listener, then remove

        listener();
        this.stopListeners.delete(listener);
      }
    } catch (e_7_1) {
      e_7 = {
        error: e_7_1
      };
    } finally {
      try {
        if (_j && !_j.done && (_b = _h.return)) _b.call(_h);
      } finally {
        if (e_7) throw e_7.error;
      }
    }

    try {
      for (var _k = __values(this.contextListeners), _l = _k.next(); !_l.done; _l = _k.next()) {
        var listener = _l.value;
        this.contextListeners.delete(listener);
      }
    } catch (e_8_1) {
      e_8 = {
        error: e_8_1
      };
    } finally {
      try {
        if (_l && !_l.done && (_c = _k.return)) _c.call(_k);
      } finally {
        if (e_8) throw e_8.error;
      }
    }

    try {
      for (var _m = __values(this.doneListeners), _o = _m.next(); !_o.done; _o = _m.next()) {
        var listener = _o.value;
        this.doneListeners.delete(listener);
      }
    } catch (e_9_1) {
      e_9 = {
        error: e_9_1
      };
    } finally {
      try {
        if (_o && !_o.done && (_d = _m.return)) _d.call(_m);
      } finally {
        if (e_9) throw e_9.error;
      }
    }

    if (!this.initialized) {
      // Interpreter already stopped; do nothing
      return this;
    }

    this.initialized = false;
    this.status = InterpreterStatus.Stopped;
    this._initialState = undefined;

    try {
      // we are going to stop within the current sync frame
      // so we can safely just cancel this here as nothing async should be fired anyway
      for (var _p = __values(Object.keys(this.delayedEventsMap)), _q = _p.next(); !_q.done; _q = _p.next()) {
        var key = _q.value;
        this.clock.clearTimeout(this.delayedEventsMap[key]);
      }
    } catch (e_10_1) {
      e_10 = {
        error: e_10_1
      };
    } finally {
      try {
        if (_q && !_q.done && (_e = _p.return)) _e.call(_p);
      } finally {
        if (e_10) throw e_10.error;
      }
    } // clear everything that might be enqueued


    this.scheduler.clear();
    this.scheduler = new Scheduler({
      deferEvents: this.options.deferEvents
    });
  };
  /**
   * Stops the interpreter and unsubscribe all listeners.
   *
   * This will also notify the `onStop` listeners.
   */


  Interpreter.prototype.stop = function () {
    // TODO: add warning for stopping non-root interpreters
    var _this = this; // grab the current scheduler as it will be replaced in _stop


    var scheduler = this.scheduler;

    this._stop(); // let what is currently processed to be finished


    scheduler.schedule(function () {
      // it feels weird to handle this here but we need to handle this even slightly "out of band"
      var _event = toSCXMLEvent({
        type: 'xstate.stop'
      });

      var nextState = provide(_this, function () {
        var exitActions = flatten(__spreadArray([], __read(_this.state.configuration), false).sort(function (a, b) {
          return b.order - a.order;
        }).map(function (stateNode) {
          return toActionObjects(stateNode.onExit, _this.machine.options.actions);
        }));

        var _a = __read(resolveActions(_this.machine, _this.state, _this.state.context, _event, [{
          type: 'exit',
          actions: exitActions
        }], _this.machine.config.predictableActionArguments ? _this._exec : undefined, _this.machine.config.predictableActionArguments || _this.machine.config.preserveActionOrder), 2),
            resolvedActions = _a[0],
            updatedContext = _a[1];

        var newState = new State({
          value: _this.state.value,
          context: updatedContext,
          _event: _event,
          _sessionid: _this.sessionId,
          historyValue: undefined,
          history: _this.state,
          actions: resolvedActions.filter(function (action) {
            return !isRaisableAction(action);
          }),
          activities: {},
          events: [],
          configuration: [],
          transitions: [],
          children: {},
          done: _this.state.done,
          tags: _this.state.tags,
          machine: _this.machine
        });
        newState.changed = true;
        return newState;
      });

      _this.update(nextState, _event);

      _this._stopChildren();

      registry.free(_this.sessionId);
    });
    return this;
  };

  Interpreter.prototype.batch = function (events) {
    var _this = this;

    if (this.status === InterpreterStatus.NotStarted && this.options.deferEvents) {
      // tslint:disable-next-line:no-console
      if (!IS_PRODUCTION) {
        warn(false, "".concat(events.length, " event(s) were sent to uninitialized service \"").concat(this.machine.id, "\" and are deferred. Make sure .start() is called for this service.\nEvent: ").concat(JSON.stringify(event)));
      }
    } else if (this.status !== InterpreterStatus.Running) {
      throw new Error( // tslint:disable-next-line:max-line-length
      "".concat(events.length, " event(s) were sent to uninitialized service \"").concat(this.machine.id, "\". Make sure .start() is called for this service, or set { deferEvents: true } in the service options."));
    }

    if (!events.length) {
      return;
    }

    var exec = !!this.machine.config.predictableActionArguments && this._exec;
    this.scheduler.schedule(function () {
      var e_11, _a;

      var nextState = _this.state;
      var batchChanged = false;
      var batchedActions = [];

      var _loop_1 = function (event_1) {
        var _event = toSCXMLEvent(event_1);

        _this.forward(_event);

        nextState = provide(_this, function () {
          return _this.machine.transition(nextState, _event, undefined, exec || undefined);
        });
        batchedActions.push.apply(batchedActions, __spreadArray([], __read(_this.machine.config.predictableActionArguments ? nextState.actions : nextState.actions.map(function (a) {
          return bindActionToState(a, nextState);
        })), false));
        batchChanged = batchChanged || !!nextState.changed;
      };

      try {
        for (var events_1 = __values(events), events_1_1 = events_1.next(); !events_1_1.done; events_1_1 = events_1.next()) {
          var event_1 = events_1_1.value;

          _loop_1(event_1);
        }
      } catch (e_11_1) {
        e_11 = {
          error: e_11_1
        };
      } finally {
        try {
          if (events_1_1 && !events_1_1.done && (_a = events_1.return)) _a.call(events_1);
        } finally {
          if (e_11) throw e_11.error;
        }
      }

      nextState.changed = batchChanged;
      nextState.actions = batchedActions;

      _this.update(nextState, toSCXMLEvent(events[events.length - 1]));
    });
  };
  /**
   * Returns a send function bound to this interpreter instance.
   *
   * @param event The event to be sent by the sender.
   */


  Interpreter.prototype.sender = function (event) {
    return this.send.bind(this, event);
  };

  Interpreter.prototype._nextState = function (event, exec) {
    var _this = this;

    if (exec === void 0) {
      exec = !!this.machine.config.predictableActionArguments && this._exec;
    }

    var _event = toSCXMLEvent(event);

    if (_event.name.indexOf(errorPlatform) === 0 && !this.state.nextEvents.some(function (nextEvent) {
      return nextEvent.indexOf(errorPlatform) === 0;
    })) {
      throw _event.data.data;
    }

    var nextState = provide(this, function () {
      return _this.machine.transition(_this.state, _event, undefined, exec || undefined);
    });
    return nextState;
  };
  /**
   * Returns the next state given the interpreter's current state and the event.
   *
   * This is a pure method that does _not_ update the interpreter's state.
   *
   * @param event The event to determine the next state
   */


  Interpreter.prototype.nextState = function (event) {
    return this._nextState(event, false);
  };

  Interpreter.prototype.forward = function (event) {
    var e_12, _a;

    try {
      for (var _b = __values(this.forwardTo), _c = _b.next(); !_c.done; _c = _b.next()) {
        var id = _c.value;
        var child = this.children.get(id);

        if (!child) {
          throw new Error("Unable to forward event '".concat(event, "' from interpreter '").concat(this.id, "' to nonexistant child '").concat(id, "'."));
        }

        child.send(event);
      }
    } catch (e_12_1) {
      e_12 = {
        error: e_12_1
      };
    } finally {
      try {
        if (_c && !_c.done && (_a = _b.return)) _a.call(_b);
      } finally {
        if (e_12) throw e_12.error;
      }
    }
  };

  Interpreter.prototype.defer = function (sendAction) {
    var _this = this;

    var timerId = this.clock.setTimeout(function () {
      if ('to' in sendAction && sendAction.to) {
        _this.sendTo(sendAction._event, sendAction.to, true);
      } else {
        _this.send(sendAction._event);
      }
    }, sendAction.delay);

    if (sendAction.id) {
      this.delayedEventsMap[sendAction.id] = timerId;
    }
  };

  Interpreter.prototype.cancel = function (sendId) {
    this.clock.clearTimeout(this.delayedEventsMap[sendId]);
    delete this.delayedEventsMap[sendId];
  };

  Interpreter.prototype.exec = function (action, state, actionFunctionMap) {
    if (actionFunctionMap === void 0) {
      actionFunctionMap = this.machine.options.actions;
    }

    this._exec(action, state.context, state._event, actionFunctionMap);
  };

  Interpreter.prototype.removeChild = function (childId) {
    var _a;

    this.children.delete(childId);
    this.forwardTo.delete(childId); // this.state might not exist at the time this is called,
    // such as when a child is added then removed while initializing the state

    (_a = this.state) === null || _a === void 0 ? true : delete _a.children[childId];
  };

  Interpreter.prototype.stopChild = function (childId) {
    var child = this.children.get(childId);

    if (!child) {
      return;
    }

    this.removeChild(childId);

    if (isFunction(child.stop)) {
      child.stop();
    }
  };

  Interpreter.prototype.spawn = function (entity, name, options) {
    if (this.status !== InterpreterStatus.Running) {
      return createDeferredActor(entity, name);
    }

    if (isPromiseLike(entity)) {
      return this.spawnPromise(Promise.resolve(entity), name);
    } else if (isFunction(entity)) {
      return this.spawnCallback(entity, name);
    } else if (isSpawnedActor(entity)) {
      return this.spawnActor(entity, name);
    } else if (isObservable(entity)) {
      return this.spawnObservable(entity, name);
    } else if (isMachine(entity)) {
      return this.spawnMachine(entity, __assign(__assign({}, options), {
        id: name
      }));
    } else if (isBehavior(entity)) {
      return this.spawnBehavior(entity, name);
    } else {
      throw new Error("Unable to spawn entity \"".concat(name, "\" of type \"").concat(typeof entity, "\"."));
    }
  };

  Interpreter.prototype.spawnMachine = function (machine, options) {
    var _this = this;

    if (options === void 0) {
      options = {};
    }

    var childService = new Interpreter(machine, __assign(__assign({}, this.options), {
      parent: this,
      id: options.id || machine.id
    }));

    var resolvedOptions = __assign(__assign({}, DEFAULT_SPAWN_OPTIONS), options);

    if (resolvedOptions.sync) {
      childService.onTransition(function (state) {
        _this.send(update, {
          state: state,
          id: childService.id
        });
      });
    }

    var actor = childService;
    this.children.set(childService.id, actor);

    if (resolvedOptions.autoForward) {
      this.forwardTo.add(childService.id);
    }

    childService.onDone(function (doneEvent) {
      _this.removeChild(childService.id);

      _this.send(toSCXMLEvent(doneEvent, {
        origin: childService.id
      }));
    }).start();
    return actor;
  };

  Interpreter.prototype.spawnBehavior = function (behavior, id) {
    var actorRef = spawnBehavior(behavior, {
      id: id,
      parent: this
    });
    this.children.set(id, actorRef);
    return actorRef;
  };

  Interpreter.prototype.spawnPromise = function (promise, id) {
    var _a;

    var _this = this;

    var canceled = false;
    var resolvedData;
    promise.then(function (response) {
      if (!canceled) {
        resolvedData = response;

        _this.removeChild(id);

        _this.send(toSCXMLEvent(doneInvoke(id, response), {
          origin: id
        }));
      }
    }, function (errorData) {
      if (!canceled) {
        _this.removeChild(id);

        var errorEvent = error(id, errorData);

        try {
          // Send "error.platform.id" to this (parent).
          _this.send(toSCXMLEvent(errorEvent, {
            origin: id
          }));
        } catch (error) {
          reportUnhandledExceptionOnInvocation(errorData, error, id);

          if (_this.devTools) {
            _this.devTools.send(errorEvent, _this.state);
          }

          if (_this.machine.strict) {
            // it would be better to always stop the state machine if unhandled
            // exception/promise rejection happens but because we don't want to
            // break existing code so enforce it on strict mode only especially so
            // because documentation says that onError is optional
            _this.stop();
          }
        }
      }
    });
    var actor = (_a = {
      id: id,
      send: function () {
        return void 0;
      },
      subscribe: function (next, handleError, complete) {
        var observer = toObserver(next, handleError, complete);
        var unsubscribed = false;
        promise.then(function (response) {
          if (unsubscribed) {
            return;
          }

          observer.next(response);

          if (unsubscribed) {
            return;
          }

          observer.complete();
        }, function (err) {
          if (unsubscribed) {
            return;
          }

          observer.error(err);
        });
        return {
          unsubscribe: function () {
            return unsubscribed = true;
          }
        };
      },
      stop: function () {
        canceled = true;
      },
      toJSON: function () {
        return {
          id: id
        };
      },
      getSnapshot: function () {
        return resolvedData;
      }
    }, _a[symbolObservable] = function () {
      return this;
    }, _a);
    this.children.set(id, actor);
    return actor;
  };

  Interpreter.prototype.spawnCallback = function (callback, id) {
    var _a;

    var _this = this;

    var canceled = false;
    var receivers = new Set();
    var listeners = new Set();
    var emitted;

    var receive = function (e) {
      emitted = e;
      listeners.forEach(function (listener) {
        return listener(e);
      });

      if (canceled) {
        return;
      }

      _this.send(toSCXMLEvent(e, {
        origin: id
      }));
    };

    var callbackStop;

    try {
      callbackStop = callback(receive, function (newListener) {
        receivers.add(newListener);
      });
    } catch (err) {
      this.send(error(id, err));
    }

    if (isPromiseLike(callbackStop)) {
      // it turned out to be an async function, can't reliably check this before calling `callback`
      // because transpiled async functions are not recognizable
      return this.spawnPromise(callbackStop, id);
    }

    var actor = (_a = {
      id: id,
      send: function (event) {
        return receivers.forEach(function (receiver) {
          return receiver(event);
        });
      },
      subscribe: function (next) {
        var observer = toObserver(next);
        listeners.add(observer.next);
        return {
          unsubscribe: function () {
            listeners.delete(observer.next);
          }
        };
      },
      stop: function () {
        canceled = true;

        if (isFunction(callbackStop)) {
          callbackStop();
        }
      },
      toJSON: function () {
        return {
          id: id
        };
      },
      getSnapshot: function () {
        return emitted;
      }
    }, _a[symbolObservable] = function () {
      return this;
    }, _a);
    this.children.set(id, actor);
    return actor;
  };

  Interpreter.prototype.spawnObservable = function (source, id) {
    var _a;

    var _this = this;

    var emitted;
    var subscription = source.subscribe(function (value) {
      emitted = value;

      _this.send(toSCXMLEvent(value, {
        origin: id
      }));
    }, function (err) {
      _this.removeChild(id);

      _this.send(toSCXMLEvent(error(id, err), {
        origin: id
      }));
    }, function () {
      _this.removeChild(id);

      _this.send(toSCXMLEvent(doneInvoke(id), {
        origin: id
      }));
    });
    var actor = (_a = {
      id: id,
      send: function () {
        return void 0;
      },
      subscribe: function (next, handleError, complete) {
        return source.subscribe(next, handleError, complete);
      },
      stop: function () {
        return subscription.unsubscribe();
      },
      getSnapshot: function () {
        return emitted;
      },
      toJSON: function () {
        return {
          id: id
        };
      }
    }, _a[symbolObservable] = function () {
      return this;
    }, _a);
    this.children.set(id, actor);
    return actor;
  };

  Interpreter.prototype.spawnActor = function (actor, name) {
    this.children.set(name, actor);
    return actor;
  };

  Interpreter.prototype.spawnActivity = function (activity) {
    var implementation = this.machine.options && this.machine.options.activities ? this.machine.options.activities[activity.type] : undefined;

    if (!implementation) {
      if (!IS_PRODUCTION) {
        warn(false, "No implementation found for activity '".concat(activity.type, "'"));
      } // tslint:disable-next-line:no-console


      return;
    } // Start implementation


    var dispose = implementation(this.state.context, activity);
    this.spawnEffect(activity.id, dispose);
  };

  Interpreter.prototype.spawnEffect = function (id, dispose) {
    var _a;

    this.children.set(id, (_a = {
      id: id,
      send: function () {
        return void 0;
      },
      subscribe: function () {
        return {
          unsubscribe: function () {
            return void 0;
          }
        };
      },
      stop: dispose || undefined,
      getSnapshot: function () {
        return undefined;
      },
      toJSON: function () {
        return {
          id: id
        };
      }
    }, _a[symbolObservable] = function () {
      return this;
    }, _a));
  };

  Interpreter.prototype.attachDev = function () {
    var global = getGlobal();

    if (this.options.devTools && global) {
      if (global.__REDUX_DEVTOOLS_EXTENSION__) {
        var devToolsOptions = typeof this.options.devTools === 'object' ? this.options.devTools : undefined;
        this.devTools = global.__REDUX_DEVTOOLS_EXTENSION__.connect(__assign(__assign({
          name: this.id,
          autoPause: true,
          stateSanitizer: function (state) {
            return {
              value: state.value,
              context: state.context,
              actions: state.actions
            };
          }
        }, devToolsOptions), {
          features: __assign({
            jump: false,
            skip: false
          }, devToolsOptions ? devToolsOptions.features : undefined)
        }), this.machine);
        this.devTools.init(this.state);
      } // add XState-specific dev tooling hook


      registerService(this);
    }
  };

  Interpreter.prototype.toJSON = function () {
    return {
      id: this.id
    };
  };

  Interpreter.prototype[symbolObservable] = function () {
    return this;
  };

  Interpreter.prototype.getSnapshot = function () {
    if (this.status === InterpreterStatus.NotStarted) {
      return this.initialState;
    }

    return this._state;
  };
  /**
   * The default interpreter options:
   *
   * - `clock` uses the global `setTimeout` and `clearTimeout` functions
   * - `logger` uses the global `console.log()` method
   */


  Interpreter.defaultOptions = {
    execute: true,
    deferEvents: true,
    clock: {
      setTimeout: function (fn, ms) {
        return setTimeout(fn, ms);
      },
      clearTimeout: function (id) {
        return clearTimeout(id);
      }
    },
    logger: /*#__PURE__*/console.log.bind(console),
    devTools: false
  };
  Interpreter.interpret = interpret;
  return Interpreter;
}();

var resolveSpawnOptions = function (nameOrOptions) {
  if (isString(nameOrOptions)) {
    return __assign(__assign({}, DEFAULT_SPAWN_OPTIONS), {
      name: nameOrOptions
    });
  }

  return __assign(__assign(__assign({}, DEFAULT_SPAWN_OPTIONS), {
    name: uniqueId()
  }), nameOrOptions);
};

function spawn(entity, nameOrOptions) {
  var resolvedOptions = resolveSpawnOptions(nameOrOptions);
  return consume(function (service) {
    if (!IS_PRODUCTION) {
      var isLazyEntity = isMachine(entity) || isFunction(entity);
      warn(!!service || isLazyEntity, "Attempted to spawn an Actor (ID: \"".concat(isMachine(entity) ? entity.id : 'undefined', "\") outside of a service. This will have no effect."));
    }

    if (service) {
      return service.spawn(entity, resolvedOptions.name, resolvedOptions);
    } else {
      return createDeferredActor(entity, resolvedOptions.name);
    }
  });
}
/**
 * Creates a new Interpreter instance for the given machine with the provided options, if any.
 *
 * @param machine The machine to interpret
 * @param options Interpreter options
 */

function interpret(machine, options) {
  var interpreter = new Interpreter(machine, options);
  return interpreter;
}

export { Interpreter, InterpreterStatus, interpret, spawn };