(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
        typeof define === 'function' && define.amd ? define(['exports'], factory) :
            (factory((global.Redux = global.Redux || {})));
}(this, (function (exports) {
    'use strict';

    /** Detect free variable `global` from Node.js. */
    var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;

    /** Detect free variable `self`. */
    var freeSelf = typeof self == 'object' && self && self.Object === Object && self;

    /** Used as a reference to the global object. */
    var root = freeGlobal || freeSelf || Function('return this')();

    /** Built-in value references. */
    var Symbol = root.Symbol;

    /** Used for built-in method references. */
    var objectProto$1 = Object.prototype;

    /** Used to check objects for own properties. */
    var hasOwnProperty$1 = objectProto$1.hasOwnProperty;

    /**
     * Used to resolve the
     * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
     * of values.
     */
    var nativeObjectToString = objectProto$1.toString;

    /** Built-in value references. */
    var symToStringTag$1 = Symbol ? Symbol.toStringTag : undefined;

    /**
     * A specialized version of `baseGetTag` which ignores `Symbol.toStringTag` values.
     *
     * @private
     * @param {*} value The value to query.
     * @returns {string} Returns the raw `toStringTag`.
     */
    function getRawTag(value) {
        var isOwn = hasOwnProperty$1.call(value, symToStringTag$1),
            tag = value[symToStringTag$1];

        try {
            value[symToStringTag$1] = undefined;
            var unmasked = true;
        } catch (e) { }

        var result = nativeObjectToString.call(value);
        if (unmasked) {
            if (isOwn) {
                value[symToStringTag$1] = tag;
            } else {
                delete value[symToStringTag$1];
            }
        }
        return result;
    }

    /** Used for built-in method references. */
    var objectProto$2 = Object.prototype;

    /**
     * Used to resolve the
     * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
     * of values.
     */
    var nativeObjectToString$1 = objectProto$2.toString;

    /**
     * Converts `value` to a string using `Object.prototype.toString`.
     *
     * @private
     * @param {*} value The value to convert.
     * @returns {string} Returns the converted string.
     */
    function objectToString(value) {
        return nativeObjectToString$1.call(value);
    }

    /** `Object#toString` result references. */
    var nullTag = '[object Null]';
    var undefinedTag = '[object Undefined]';

    /** Built-in value references. */
    var symToStringTag = Symbol ? Symbol.toStringTag : undefined;

    /**
     * The base implementation of `getTag` without fallbacks for buggy environments.
     *
     * @private
     * @param {*} value The value to query.
     * @returns {string} Returns the `toStringTag`.
     */
    function baseGetTag(value) {
        if (value == null) {
            return value === undefined ? undefinedTag : nullTag;
        }
        return (symToStringTag && symToStringTag in Object(value))
            ? getRawTag(value)
            : objectToString(value);
    }

    /**
     * Creates a unary function that invokes `func` with its argument transformed.
     *
     * @private
     * @param {Function} func The function to wrap.
     * @param {Function} transform The argument transform.
     * @returns {Function} Returns the new function.
     */
    function overArg(func, transform) {
        return function (arg) {
            return func(transform(arg));
        };
    }

    /** Built-in value references. */
    var getPrototype = overArg(Object.getPrototypeOf, Object);

    /**
     * Checks if `value` is object-like. A value is object-like if it's not `null`
     * and has a `typeof` result of "object".
     *
     * @static
     * @memberOf _
     * @since 4.0.0
     * @category Lang
     * @param {*} value The value to check.
     * @returns {boolean} Returns `true` if `value` is object-like, else `false`.
     * @example
     *
     * _.isObjectLike({});
     * // => true
     *
     * _.isObjectLike([1, 2, 3]);
     * // => true
     *
     * _.isObjectLike(_.noop);
     * // => false
     *
     * _.isObjectLike(null);
     * // => false
     */
    function isObjectLike(value) {
        return value != null && typeof value == 'object';
    }

    /** `Object#toString` result references. */
    var objectTag = '[object Object]';

    /** Used for built-in method references. */
    var funcProto = Function.prototype;
    var objectProto = Object.prototype;

    /** Used to resolve the decompiled source of functions. */
    var funcToString = funcProto.toString;

    /** Used to check objects for own properties. */
    var hasOwnProperty = objectProto.hasOwnProperty;

    /** Used to infer the `Object` constructor. */
    var objectCtorString = funcToString.call(Object);

 
    function isPlainObject(value) {
        if (!isObjectLike(value) || baseGetTag(value) != objectTag) {
            return false;
        }
        var proto = getPrototype(value);
        if (proto === null) {
            return true;
        }
        var Ctor = hasOwnProperty.call(proto, 'constructor') && proto.constructor;
        return typeof Ctor == 'function' && Ctor instanceof Ctor &&
            funcToString.call(Ctor) == objectCtorString;
    }

    function symbolObservablePonyfill(root) {
        var result;
        var Symbol = root.Symbol;

        if (typeof Symbol === 'function') {
            if (Symbol.observable) {
                result = Symbol.observable;
            } else {
                result = Symbol('observable');
                Symbol.observable = result;
            }
        } else {
            result = '@@observable';
        }

        return result;
    }

    /* global window */
    var root$2;

    if (typeof self !== 'undefined') {
        root$2 = self;
    } else if (typeof window !== 'undefined') {
        root$2 = window;
    } else if (typeof global !== 'undefined') {
        root$2 = global;
    } else if (typeof module !== 'undefined') {
        root$2 = module;
    } else {
        root$2 = Function('return this')();
    }

    var result = symbolObservablePonyfill(root$2);

    /**
     * These are private action types reserved by Redux.
     * For any unknown actions, you must return the current state.
     * If the current state is undefined, you must return the initial state.
     * Do not reference these action types directly in your code.
     */
    var ActionTypes = {
        INIT: '@@redux/INIT'

    }

    function createStore(reducer, preloadedState, enhancer) {
        var _ref2;

        if (typeof preloadedState === 'function' && typeof enhancer === 'undefined') {
            enhancer = preloadedState;
            preloadedState = undefined;
        }

        if (typeof enhancer !== 'undefined') {
            if (typeof enhancer !== 'function') {
                throw new Error('Expected the enhancer to be a function.');
            }

            return enhancer(createStore)(reducer, preloadedState);
        }

        if (typeof reducer !== 'function') {
            throw new Error('Expected the reducer to be a function.');
        }

        var currentReducer = reducer;
        var currentState = preloadedState;
        var currentListeners = [];
        var nextListeners = currentListeners;
        var isDispatching = false;

        function ensureCanMutateNextListeners() {
            // 将原来的复制一份
            if (nextListeners === currentListeners) {
                nextListeners = currentListeners.slice();
            }
        }

     
        function getState() {
            return currentState;
        }

      
        function subscribe(listener) {
            if (typeof listener !== 'function') {
                throw new Error('Expected listener to be a function.');
            }

            var isSubscribed = true;

            ensureCanMutateNextListeners();
            nextListeners.push(listener);

            return function unsubscribe() {
                if (!isSubscribed) {
                    return;
                }

                isSubscribed = false;

                ensureCanMutateNextListeners();
                var index = nextListeners.indexOf(listener);
                nextListeners.splice(index, 1);
            };
        }

        /**
         * Dispatches an action. It is the only way to trigger a state change.
         *
         * The `reducer` function, used to create the store, will be called with the
         * current state tree and the given `action`. Its return value will
         * be considered the **next** state of the tree, and the change listeners
         * will be notified.
         *
         * The base implementation only supports plain object actions. If you want to
         * dispatch a Promise, an Observable, a thunk, or something else, you need to
         * wrap your store creating function into the corresponding middleware. For
         * example, see the documentation for the `redux-thunk` package. Even the
         * middleware will eventually dispatch plain object actions using this method.
         *
         * @param {Object} action A plain object representing 鈥渨hat changed鈥�. It is
         * a good idea to keep actions serializable so you can record and replay user
         * sessions, or use the time travelling `redux-devtools`. An action must have
         * a `type` property which may not be `undefined`. It is a good idea to use
         * string constants for action types.
         *
         * @returns {Object} For convenience, the same action object you dispatched.
         *
         * Note that, if you use a custom middleware, it may wrap `dispatch()` to
         * return something else (for example, a Promise you can await).
         */
        function dispatch(action) {
            var ok
            try {
                ok = action.type.toUpperCase() == action.type
            } catch (e) {
                ok = false
            }
            if (!ok) {
                throw new Error('action必须是一个纯对象，并且其type属性是一个字符串，所有字母应该大写')
            }
            if (isDispatching) {
                throw new Error('Reducers may not dispatch actions.');
            }

            try {
                isDispatching = true;
                currentState = currentReducer(currentState, action);
            } finally {
                isDispatching = false;
            }

            var listeners = currentListeners = nextListeners;
            for (var i = 0; i < listeners.length; i++) {
                var listener = listeners[i];
                listener();
            }

            return action;
        }

        /**
         * Replaces the reducer currently used by the store to calculate the state.
         *
         * You might need this if your app implements code splitting and you want to
         * load some of the reducers dynamically. You might also need this if you
         * implement a hot reloading mechanism for Redux.
         *
         * @param {Function} nextReducer The reducer for the store to use instead.
         * @returns {void}
         */
        function replaceReducer(nextReducer) {
            if (typeof nextReducer !== 'function') {
                throw new Error('Expected the nextReducer to be a function.');
            }

            currentReducer = nextReducer;
            dispatch({ type: ActionTypes.INIT });
        }

        /**
         * Interoperability point for observable/reactive libraries.
         * @returns {observable} A minimal observable of state changes.
         * For more information, see the observable proposal:
         * https://github.com/tc39/proposal-observable
         */
        function observable() {
            var _ref;

            var outerSubscribe = subscribe;
            return _ref = {
                /**
                 * The minimal observable subscription method.
                 * @param {Object} observer Any object that can be used as an observer.
                 * The observer object should have a `next` method.
                 * @returns {subscription} An object with an `unsubscribe` method that can
                 * be used to unsubscribe the observable from the store, and prevent further
                 * emission of values from the observable.
                 */
                subscribe: function subscribe(observer) {
                    if (typeof observer !== 'object') {
                        throw new TypeError('Expected the observer to be an object.');
                    }

                    function observeState() {
                        if (observer.next) {
                            observer.next(getState());
                        }
                    }

                    observeState();
                    var unsubscribe = outerSubscribe(observeState);
                    return { unsubscribe: unsubscribe };
                }
            }, _ref[result] = function () {
                return this;
            }, _ref;
        }

        // When a store is created, an "INIT" action is dispatched so that every
        // reducer returns their initial state. This effectively populates
        // the initial state tree.
        dispatch({ type: ActionTypes.INIT });

        return _ref2 = {
            dispatch: dispatch,
            subscribe: subscribe,
            getState: getState,
            replaceReducer: replaceReducer
        }, _ref2[result] = observable, _ref2;
    }

    /**
     * Prints a warning in the console if it exists.
     *
     * @param {String} message The warning message.
     * @returns {void}
     */
    function warning(message) {
        /* eslint-disable no-console */
        if (typeof console !== 'undefined' && typeof console.error === 'function') {
            console.error(message);
        }
        /* eslint-enable no-console */
        try {
            // This error was thrown as a convenience so that if you enable
            // "break on all exceptions" in your console,
            // it would pause the execution at this line.
            throw new Error(message);
            /* eslint-disable no-empty */
        } catch (e) { }
        /* eslint-enable no-empty */
    }

    function getUndefinedStateErrorMessage(key, action) {
        var actionType = action && action.type;
        var actionName = actionType && '"' + actionType.toString() + '"' || 'an action';

        return 'Given action ' + actionName + ', reducer "' + key + '" returned undefined. ' + 'To ignore an action, you must explicitly return the previous state. ' + 'If you want this reducer to hold no value, you can return null instead of undefined.';
    }

    function getUnexpectedStateShapeWarningMessage(inputState, reducers, action, unexpectedKeyCache) {
        var reducerKeys = Object.keys(reducers);
        var argumentName = action && action.type === ActionTypes.INIT ? 'preloadedState argument passed to createStore' : 'previous state received by the reducer';

        if (reducerKeys.length === 0) {
            return 'Store does not have a valid reducer. Make sure the argument passed ' + 'to combineReducers is an object whose values are reducers.';
        }

        if (!isPlainObject(inputState)) {
            return 'The ' + argumentName + ' has unexpected type of "' + {}.toString.call(inputState).match(/\s([a-z|A-Z]+)/)[1] + '". Expected argument to be an object with the following ' + ('keys: "' + reducerKeys.join('", "') + '"');
        }

        var unexpectedKeys = Object.keys(inputState).filter(function (key) {
            return !reducers.hasOwnProperty(key) && !unexpectedKeyCache[key];
        });

        unexpectedKeys.forEach(function (key) {
            unexpectedKeyCache[key] = true;
        });

        if (unexpectedKeys.length > 0) {
            return 'Unexpected ' + (unexpectedKeys.length > 1 ? 'keys' : 'key') + ' ' + ('"' + unexpectedKeys.join('", "') + '" found in ' + argumentName + '. ') + 'Expected to find one of the known reducer keys instead: ' + ('"' + reducerKeys.join('", "') + '". Unexpected keys will be ignored.');
        }
    }

    function assertReducerShape(reducers) {
        Object.keys(reducers).forEach(function (key) {
            var reducer = reducers[key];
            var initialState = reducer(undefined, { type: ActionTypes.INIT });

            if (typeof initialState === 'undefined') {
                throw new Error('Reducer "' + key + '" returned undefined during initialization. ' + 'If the state passed to the reducer is undefined, you must ' + 'explicitly return the initial state. The initial state may ' + 'not be undefined. If you don\'t want to set a value for this reducer, ' + 'you can use null instead of undefined.');
            }

            var type = '@@redux/PROBE_UNKNOWN_ACTION_' + Math.random().toString(36).substring(7).split('').join('.');
            if (typeof reducer(undefined, { type: type }) === 'undefined') {
                throw new Error('Reducer "' + key + '" returned undefined when probed with a random type. ' + ('Don\'t try to handle ' + ActionTypes.INIT + ' or other actions in "redux/*" ') + 'namespace. They are considered private. Instead, you must return the ' + 'current state for any unknown actions, unless it is undefined, ' + 'in which case you must return the initial state, regardless of the ' + 'action type. The initial state may not be undefined, but can be null.');
            }
        });
    }

    /**
     * Turns an object whose values are different reducer functions, into a single
     * reducer function. It will call every child reducer, and gather their results
     * into a single state object, whose keys correspond to the keys of the passed
     * reducer functions.
     *
     * @param {Object} reducers An object whose values correspond to different
     * reducer functions that need to be combined into one. One handy way to obtain
     * it is to use ES6 `import * as reducers` syntax. The reducers may never return
     * undefined for any action. Instead, they should return their initial state
     * if the state passed to them was undefined, and the current state for any
     * unrecognized action.
     *
     * @returns {Function} A reducer function that invokes every reducer inside the
     * passed object, and builds a state object with the same shape.
     */
    function combineReducers(reducers) {
        var reducerKeys = Object.keys(reducers);
        var finalReducers = {};
        for (var i = 0; i < reducerKeys.length; i++) {
            var key = reducerKeys[i];

            {
                if (typeof reducers[key] === 'undefined') {
                    warning('No reducer provided for key "' + key + '"');
                }
            }

            if (typeof reducers[key] === 'function') {
                finalReducers[key] = reducers[key];
            }
        }
        var finalReducerKeys = Object.keys(finalReducers);

        var unexpectedKeyCache = void 0;
        {
            unexpectedKeyCache = {};
        }

        var shapeAssertionError = void 0;
        try {
            assertReducerShape(finalReducers);
        } catch (e) {
            shapeAssertionError = e;
        }

        return function combination() {
            var state = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
            var action = arguments[1];

            if (shapeAssertionError) {
                throw shapeAssertionError;
            }

            {
                var warningMessage = getUnexpectedStateShapeWarningMessage(state, finalReducers, action, unexpectedKeyCache);
                if (warningMessage) {
                    warning(warningMessage);
                }
            }

            var hasChanged = false;
            var nextState = {};
            for (var _i = 0; _i < finalReducerKeys.length; _i++) {
                var _key = finalReducerKeys[_i];
                var reducer = finalReducers[_key];
                var previousStateForKey = state[_key];
                var nextStateForKey = reducer(previousStateForKey, action);
                if (typeof nextStateForKey === 'undefined') {
                    var errorMessage = getUndefinedStateErrorMessage(_key, action);
                    throw new Error(errorMessage);
                }
                nextState[_key] = nextStateForKey;
                hasChanged = hasChanged || nextStateForKey !== previousStateForKey;
            }
            return hasChanged ? nextState : state;
        };
    }

    function bindActionCreator(actionCreator, dispatch) {
        return function () {
            return dispatch(actionCreator.apply(undefined, arguments));
        };
    }

    /**
     * Turns an object whose values are action creators, into an object with the
     * same keys, but with every function wrapped into a `dispatch` call so they
     * may be invoked directly. This is just a convenience method, as you can call
     * `store.dispatch(MyActionCreators.doSomething())` yourself just fine.
     *
     * For convenience, you can also pass a single function as the first argument,
     * and get a function in return.
     *
     * @param {Function|Object} actionCreators An object whose values are action
     * creator functions. One handy way to obtain it is to use ES6 `import * as`
     * syntax. You may also pass a single function.
     *
     * @param {Function} dispatch The `dispatch` function available on your Redux
     * store.
     *
     * @returns {Function|Object} The object mimicking the original object, but with
     * every action creator wrapped into the `dispatch` call. If you passed a
     * function as `actionCreators`, the return value will also be a single
     * function.
     */
    function bindActionCreators(actionCreators, dispatch) {
        if (typeof actionCreators === 'function') {
            return bindActionCreator(actionCreators, dispatch);
        }

        if (typeof actionCreators !== 'object' || actionCreators === null) {
            throw new Error('bindActionCreators expected an object or a function, instead received ' + (actionCreators === null ? 'null' : typeof actionCreators) + '. ' + 'Did you write "import ActionCreators from" instead of "import * as ActionCreators from"?');
        }

        var keys = Object.keys(actionCreators);
        var boundActionCreators = {};
        for (var i = 0; i < keys.length; i++) {
            var key = keys[i];
            var actionCreator = actionCreators[key];
            if (typeof actionCreator === 'function') {
                boundActionCreators[key] = bindActionCreator(actionCreator, dispatch);
            }
        }
        return boundActionCreators;
    }

    /**
     * Composes single-argument functions from right to left. The rightmost
     * function can take multiple arguments as it provides the signature for
     * the resulting composite function.
     *
     * @param {...Function} funcs The functions to compose.
     * @returns {Function} A function obtained by composing the argument functions
     * from right to left. For example, compose(f, g, h) is identical to doing
     * (...args) => f(g(h(...args))).
     */

    function compose() {
        for (var _len = arguments.length, funcs = Array(_len), _key = 0; _key < _len; _key++) {
            funcs[_key] = arguments[_key];
        }

        if (funcs.length === 0) {
            return function (arg) {
                return arg;
            };
        }

        if (funcs.length === 1) {
            return funcs[0];
        }

        return funcs.reduce(function (a, b) {
            return function () {
                return a(b.apply(undefined, arguments));
            };
        });
    }

    var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

    /**
     * Creates a store enhancer that applies middleware to the dispatch method
     * of the Redux store. This is handy for a variety of tasks, such as expressing
     * asynchronous actions in a concise manner, or logging every action payload.
     *
     * See `redux-thunk` package as an example of the Redux middleware.
     *
     * Because middleware is potentially asynchronous, this should be the first
     * store enhancer in the composition chain.
     *
     * Note that each middleware will be given the `dispatch` and `getState` functions
     * as named arguments.
     *
     * @param {...Function} middlewares The middleware chain to be applied.
     * @returns {Function} A store enhancer applying the middleware.
     */
    function applyMiddleware() {
        for (var _len = arguments.length, middlewares = Array(_len), _key = 0; _key < _len; _key++) {
            middlewares[_key] = arguments[_key];
        }

        return function (createStore) {
            return function (reducer, preloadedState, enhancer) {
                var store = createStore(reducer, preloadedState, enhancer);
                var _dispatch = store.dispatch;
                var chain = [];

                var middlewareAPI = {
                    getState: store.getState,
                    dispatch: function dispatch(action) {
                        return _dispatch(action);
                    }
                };
                chain = middlewares.map(function (middleware) {
                    return middleware(middlewareAPI);
                });
                _dispatch = compose.apply(undefined, chain)(store.dispatch);

                return _extends({}, store, {
                    dispatch: _dispatch
                });
            };
        };
    }

    /*
    * This is a dummy function to check if the function name has been altered by minification.
    * If the function has been minified and NODE_ENV !== 'production', warn the user.
    */
    function isCrushed() { }

    if ("development" !== 'production' && typeof isCrushed.name === 'string' && isCrushed.name !== 'isCrushed') {
        warning('You are currently using minified code outside of NODE_ENV === \'production\'. ' + 'This means that you are running a slower development build of Redux. ' + 'You can use loose-envify (https://github.com/zertosh/loose-envify) for browserify ' + 'or DefinePlugin for webpack (http://stackoverflow.com/questions/30030031) ' + 'to ensure you have the correct code for your production build.');
    }

    exports.createStore = createStore;
    exports.combineReducers = combineReducers;
    exports.bindActionCreators = bindActionCreators;
    exports.applyMiddleware = applyMiddleware;
    exports.compose = compose;

    Object.defineProperty(exports, '__esModule', { value: true });

})));