/*!
 * Vue.js v2.2.6
 * (c) 2014-2017 Evan You
 * Released under the MIT License.
 */
(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
        typeof define === 'function' && define.amd ? define(factory) :
            (global.Vue = factory());
}(this, (function () {
    'use strict';

    /*  */

    /**
     * Convert a value to a string that is actually rendered.
     */
    function _toString(val) {
        return val == null
            ? ''
            : typeof val === 'object'
                ? JSON.stringify(val, null, 2)
                : String(val)
    }

    /**
     * Convert a input value to a number for persistence.
     * If the conversion fails, return original string.
     */
    function toNumber(val) {
        var n = parseFloat(val);
        return isNaN(n) ? val : n
    }

    /**
     * Make a map and return a function for checking if a key
     * is in that map.
     */
    function makeMap(
        str,
        expectsLowerCase
    ) {
        var map = Object.create(null);
        var list = str.split(',');
        for (var i = 0; i < list.length; i++) {
            map[list[i]] = true;
        }
        return expectsLowerCase
            ? function (val) {
                return map[val.toLowerCase()];
            }
            : function (val) {
                return map[val];
            }
    }

    /**
     * Check if a tag is a built-in tag.
     */
    var isBuiltInTag = makeMap('slot,component', true);

    /**
     * Remove an item from an array
     */
    function remove(arr, item) {
        if (arr.length) {
            var index = arr.indexOf(item);
            if (index > -1) {
                return arr.splice(index, 1)
            }
        }
    }

    /**
     * Check whether the object has the property.
     */
    var hasOwnProperty = Object.prototype.hasOwnProperty;

    function hasOwn(obj, key) {
        return hasOwnProperty.call(obj, key)
    }

    /**
     * Check if value is primitive
     */
    function isPrimitive(value) {
        return typeof value === 'string' || typeof value === 'number'
    }

    /**
     * Create a cached version of a pure function.
     */
    function cached(fn) {
        var cache = Object.create(null);
        return (function cachedFn(str) {
            var hit = cache[str];
            return hit || (cache[str] = fn(str))
        })
    }

    /**
     * Camelize a hyphen-delimited string.
     */
    var camelizeRE = /-(\w)/g;
    var camelize = cached(function (str) {
        return str.replace(camelizeRE, function (_, c) {
            return c ? c.toUpperCase() : '';
        })
    });

    /**
     * Capitalize a string.
     */
    var capitalize = cached(function (str) {
        return str.charAt(0).toUpperCase() + str.slice(1)
    });

    /**
     * Hyphenate a camelCase string.
     */
    var hyphenateRE = /([^-])([A-Z])/g;
    var hyphenate = cached(function (str) {
        return str
            .replace(hyphenateRE, '$1-$2')
            .replace(hyphenateRE, '$1-$2')
            .toLowerCase()
    });

    /**
     * Simple bind, faster than native
     */
    function bind(fn, ctx) {
        function boundFn(a) {
            var l = arguments.length;
            return l
                ? l > 1
                    ? fn.apply(ctx, arguments)
                    : fn.call(ctx, a)
                : fn.call(ctx)
        }

        // record original fn length
        boundFn._length = fn.length;
        return boundFn
    }

    /**
     * Convert an Array-like object to a real Array.
     */
    function toArray(list, start) {
        start = start || 0;
        var i = list.length - start;
        var ret = new Array(i);
        while (i--) {
            ret[i] = list[i + start];
        }
        return ret
    }

    /**
     * Mix properties into target object.
     */
    function extend(to, _from) {
        for (var key in _from) {
            to[key] = _from[key];
        }
        return to
    }

    /**
     * Quick object check - this is primarily used to tell
     * Objects from primitive values when we know the value
     * is a JSON-compliant type.
     */
    function isObject(obj) {
        return obj !== null && typeof obj === 'object'
    }

    /**
     * Strict object type check. Only returns true
     * for plain JavaScript objects.
     */
    var toString = Object.prototype.toString;
    var OBJECT_STRING = '[object Object]';

    function isPlainObject(obj) {
        return toString.call(obj) === OBJECT_STRING
    }

    /**
     * Merge an Array of Objects into a single Object.
     */
    function toObject(arr) {
        var res = {};
        for (var i = 0; i < arr.length; i++) {
            if (arr[i]) {
                extend(res, arr[i]);
            }
        }
        return res
    }

    /**
     * Perform no operation.
     */
    function noop() {
    }

    /**
     * Always return false.
     */
    var no = function () {
        return false;
    };

    /**
     * Return same value
     */
    var identity = function (_) {
        return _;
    };

    /**
     * Generate a static keys string from compiler modules.
     */


    /**
     * Check if two values are loosely equal - that is,
     * if they are plain objects, do they have the same shape?
     */
    function looseEqual(a, b) {
        var isObjectA = isObject(a);
        var isObjectB = isObject(b);
        if (isObjectA && isObjectB) {
            try {
                return JSON.stringify(a) === JSON.stringify(b)
            } catch (e) {
                // possible circular reference
                return a === b
            }
        } else if (!isObjectA && !isObjectB) {
            return String(a) === String(b)
        } else {
            return false
        }
    }

    function looseIndexOf(arr, val) {
        for (var i = 0; i < arr.length; i++) {
            if (looseEqual(arr[i], val)) {
                return i
            }
        }
        return -1
    }

    /**
     * Ensure a function is called only once.
     */
    function once(fn) {
        var called = false;
        return function () {
            if (!called) {
                called = true;
                fn();
            }
        }
    }

    /*  */

    var config = {
        /**
         * Option merge strategies (used in core/util/options)
         */
        optionMergeStrategies: Object.create(null),

        /**
         * Whether to suppress warnings.
         */
        silent: false,

        /**
         * Show production mode tip message on boot?
         */
        productionTip: "development" !== 'production',

        /**
         * Whether to enable devtools
         */
        devtools: "development" !== 'production',

        /**
         * Whether to record perf
         */
        performance: false,

        /**
         * Error handler for watcher errors
         */
        errorHandler: null,

        /**
         * Ignore certain custom elements
         */
        ignoredElements: [],

        /**
         * Custom user key aliases for v-on
         */
        keyCodes: Object.create(null),

        /**
         * Check if a tag is reserved so that it cannot be registered as a
         * component. This is platform-dependent and may be overwritten.
         */
        isReservedTag: no,

        /**
         * Check if a tag is an unknown element.
         * Platform-dependent.
         */
        isUnknownElement: no,

        /**
         * Get the namespace of an element
         */
        getTagNamespace: noop,

        /**
         * Parse the real tag name for the specific platform.
         */
        parsePlatformTagName: identity,

        /**
         * Check if an attribute must be bound using property, e.g. value
         * Platform-dependent.
         */
        mustUseProp: no,

        /**
         * List of asset types that a component can own.
         */
        _assetTypes: [
            'component',
            'directive',
            'filter'
        ],

        /**
         * List of lifecycle hooks.
         */
        _lifecycleHooks: [
            'beforeCreate',
            'created',
            'beforeMount',
            'mounted',
            'beforeUpdate',
            'updated',
            'beforeDestroy',
            'destroyed',
            'activated',
            'deactivated'
        ],

        /**
         * Max circular updates allowed in a scheduler flush cycle.
         */
        _maxUpdateCount: 100
    };

    /*  */

    var emptyObject = Object.freeze({});

    /**
     * Check if a string starts with $ or _
     */
    function isReserved(str) {
        var c = (str + '').charCodeAt(0);
        return c === 0x24 || c === 0x5F
    }

    /**
     * Define a property.
     */
    function def(obj, key, val, enumerable) {
        Object.defineProperty(obj, key, {
            value: val,
            enumerable: !!enumerable,
            writable: true,
            configurable: true
        });
    }

    /**
     * Parse simple path.
     */
    var bailRE = /[^\w.$]/;

    function parsePath(path) {
        if (bailRE.test(path)) {
            return
        }
        var segments = path.split('.');
        return function (obj) {
            for (var i = 0; i < segments.length; i++) {
                if (!obj) {
                    return
                }
                obj = obj[segments[i]];
            }
            return obj
        }
    }

    /*  */
    /* globals MutationObserver */

// can we use __proto__?
    var hasProto = '__proto__' in {};

// Browser environment sniffing
    var inBrowser = typeof window !== 'undefined';
    var UA = inBrowser && window.navigator.userAgent.toLowerCase();
    var isIE = UA && /msie|trident/.test(UA);
    var isIE9 = UA && UA.indexOf('msie 9.0') > 0;
    var isEdge = UA && UA.indexOf('edge/') > 0;
    var isAndroid = UA && UA.indexOf('android') > 0;
    var isIOS = UA && /iphone|ipad|ipod|ios/.test(UA);
    var isChrome = UA && /chrome\/\d+/.test(UA) && !isEdge;

// this needs to be lazy-evaled because vue may be required before
// vue-server-renderer can set VUE_ENV
    var _isServer;
    var isServerRendering = function () {
        if (_isServer === undefined) {
            /* istanbul ignore if */
            if (!inBrowser && typeof global !== 'undefined') {
                // detect presence of vue-server-renderer and avoid
                // Webpack shimming the process
                _isServer = global['process'].env.VUE_ENV === 'server';
            } else {
                _isServer = false;
            }
        }
        return _isServer
    };

// detect devtools
    var devtools = inBrowser && window.__VUE_DEVTOOLS_GLOBAL_HOOK__;

    /* istanbul ignore next */
    function isNative(Ctor) {
        return /native code/.test(Ctor.toString())
    }

    var hasSymbol =
        typeof Symbol !== 'undefined' && isNative(Symbol) &&
        typeof Reflect !== 'undefined' && isNative(Reflect.ownKeys);

    /**
     * Defer a task to execute it asynchronously.
     */
    var nextTick = (function () {
        var callbacks = [];
        var pending = false;
        var timerFunc;

        function nextTickHandler() {
            pending = false;
            var copies = callbacks.slice(0);
            callbacks.length = 0;
            for (var i = 0; i < copies.length; i++) {
                copies[i]();
            }
        }

        // the nextTick behavior leverages the microtask queue, which can be accessed
        // via either native Promise.then or MutationObserver.
        // MutationObserver has wider support, however it is seriously bugged in
        // UIWebView in iOS >= 9.3.3 when triggered in touch event handlers. It
        // completely stops working after triggering a few times... so, if native
        // Promise is available, we will use it:
        /* istanbul ignore if */
        if (typeof Promise !== 'undefined' && isNative(Promise)) {
            var p = Promise.resolve();
            var logError = function (err) {
                console.error(err);
            };
            timerFunc = function () {
                p.then(nextTickHandler).catch(logError);
                // in problematic UIWebViews, Promise.then doesn't completely break, but
                // it can get stuck in a weird state where callbacks are pushed into the
                // microtask queue but the queue isn't being flushed, until the browser
                // needs to do some other work, e.g. handle a timer. Therefore we can
                // "force" the microtask queue to be flushed by adding an empty timer.
                if (isIOS) {
                    setTimeout(noop);
                }
            };
        } else if (typeof MutationObserver !== 'undefined' && (
            isNative(MutationObserver) ||
            // PhantomJS and iOS 7.x
            MutationObserver.toString() === '[object MutationObserverConstructor]'
        )) {
            // use MutationObserver where native Promise is not available,
            // e.g. PhantomJS IE11, iOS7, Android 4.4
            var counter = 1;
            var observer = new MutationObserver(nextTickHandler);
            var textNode = document.createTextNode(String(counter));
            observer.observe(textNode, {
                characterData: true
            });
            timerFunc = function () {
                counter = (counter + 1) % 2;
                textNode.data = String(counter);
            };
        } else {
            // fallback to setTimeout
            /* istanbul ignore next */
            timerFunc = function () {
                setTimeout(nextTickHandler, 0);
            };
        }

        return function queueNextTick(cb, ctx) {
            var _resolve;
            callbacks.push(function () {
                if (cb) {
                    cb.call(ctx);
                }
                if (_resolve) {
                    _resolve(ctx);
                }
            });
            if (!pending) {
                pending = true;
                timerFunc();
            }
            if (!cb && typeof Promise !== 'undefined') {
                return new Promise(function (resolve) {
                    _resolve = resolve;
                })
            }
        }
    })();

    var _Set;
    /* istanbul ignore if */
    if (typeof Set !== 'undefined' && isNative(Set)) {
        // use native Set when available.
        _Set = Set;
    } else {
        // a non-standard Set polyfill that only works with primitive keys.
        _Set = (function () {
            function Set() {
                this.set = Object.create(null);
            }

            Set.prototype.has = function has(key) {
                return this.set[key] === true
            };
            Set.prototype.add = function add(key) {
                this.set[key] = true;
            };
            Set.prototype.clear = function clear() {
                this.set = Object.create(null);
            };

            return Set;
        }());
    }

    var warn = noop;
    var tip = noop;
    var formatComponentName;

    {
        var hasConsole = typeof console !== 'undefined';
        var classifyRE = /(?:^|[-_])(\w)/g;
        var classify = function (str) {
            return str
                .replace(classifyRE, function (c) {
                    return c.toUpperCase();
                })
                .replace(/[-_]/g, '');
        };

        warn = function (msg, vm) {
            if (hasConsole && (!config.silent)) {
                console.error("[Vue warn]: " + msg + " " + (
                    vm ? formatLocation(formatComponentName(vm)) : ''
                ));
            }
        };

        tip = function (msg, vm) {
            if (hasConsole && (!config.silent)) {
                console.warn("[Vue tip]: " + msg + " " + (
                    vm ? formatLocation(formatComponentName(vm)) : ''
                ));
            }
        };

        formatComponentName = function (vm, includeFile) {
            if (vm.$root === vm) {
                return '<Root>'
            }
            var name = typeof vm === 'string'
                ? vm
                : typeof vm === 'function' && vm.options
                    ? vm.options.name
                    : vm._isVue
                        ? vm.$options.name || vm.$options._componentTag
                        : vm.name;

            var file = vm._isVue && vm.$options.__file;
            if (!name && file) {
                var match = file.match(/([^/\\]+)\.vue$/);
                name = match && match[1];
            }

            return (
                (name ? ("<" + (classify(name)) + ">") : "<Anonymous>") +
                (file && includeFile !== false ? (" at " + file) : '')
            )
        };

        var formatLocation = function (str) {
            if (str === "<Anonymous>") {
                str += " - use the \"name\" option for better debugging messages.";
            }
            return ("\n(found in " + str + ")")
        };
    }

    /*  */


    var uid$1 = 0;

    /**
     * A dep is an observable that can have multiple
     * directives subscribing to it.
     */
    var Dep = function Dep() {
        this.id = uid$1++;
        this.subs = [];
    };

    Dep.prototype.addSub = function addSub(sub) {
        this.subs.push(sub);
    };

    Dep.prototype.removeSub = function removeSub(sub) {
        remove(this.subs, sub);
    };

    Dep.prototype.depend = function depend() {
        if (Dep.target) {
            Dep.target.addDep(this);
        }
    };

    Dep.prototype.notify = function notify() {
        // stabilize the subscriber list first
        var subs = this.subs.slice();
        for (var i = 0, l = subs.length; i < l; i++) {
            subs[i].update();
        }
    };

// the current target watcher being evaluated.
// this is globally unique because there could be only one
// watcher being evaluated at any time.
    Dep.target = null;
    var targetStack = [];

    function pushTarget(_target) {
        if (Dep.target) {
            targetStack.push(Dep.target);
        }
        Dep.target = _target;
    }

    function popTarget() {
        Dep.target = targetStack.pop();
    }

    /*
 * not type checking this file because flow doesn't play well with
 * dynamically accessing methods on Array prototype
 */

    var arrayProto = Array.prototype;
    var arrayMethods = Object.create(arrayProto);
    [
        'push',
        'pop',
        'shift',
        'unshift',
        'splice',
        'sort',
        'reverse'
    ]
        .forEach(function (method) {
            // cache original method
            var original = arrayProto[method];
            def(arrayMethods, method, function mutator() {
                var arguments$1 = arguments;

                // avoid leaking arguments:
                // http://jsperf.com/closure-with-arguments
                var i = arguments.length;
                var args = new Array(i);
                while (i--) {
                    args[i] = arguments$1[i];
                }
                var result = original.apply(this, args);
                var ob = this.__ob__;
                var inserted;
                switch (method) {
                    case 'push':
                        inserted = args;
                        break
                    case 'unshift':
                        inserted = args;
                        break
                    case 'splice':
                        inserted = args.slice(2);
                        break
                }
                if (inserted) {
                    ob.observeArray(inserted);
                }
                // notify change
                ob.dep.notify();
                return result
            });
        });

    /*  */

    var arrayKeys = Object.getOwnPropertyNames(arrayMethods);

    /**
     * By default, when a reactive property is set, the new value is
     * also converted to become reactive. However when passing down props,
     * we don't want to force conversion because the value may be a nested value
     * under a frozen data structure. Converting it would defeat the optimization.
     */
    var observerState = {
        shouldConvert: true,
        isSettingProps: false
    };

    /**
     * Observer class that are attached to each observed
     * object. Once attached, the observer converts target
     * object's property keys into getter/setters that
     * collect dependencies and dispatches updates.
     */
    var Observer = function Observer(value) {
        this.value = value;
        this.dep = new Dep();
        this.vmCount = 0;
        def(value, '__ob__', this);
        if (Array.isArray(value)) {
            var augment = hasProto
                ? protoAugment
                : copyAugment;
            augment(value, arrayMethods, arrayKeys);
            this.observeArray(value);
        } else {
            this.walk(value);
        }
    };

    /**
     * Walk through each property and convert them into
     * getter/setters. This method should only be called when
     * value type is Object.
     */
    Observer.prototype.walk = function walk(obj) {
        var keys = Object.keys(obj);
        for (var i = 0; i < keys.length; i++) {
            defineReactive$$1(obj, keys[i], obj[keys[i]]);
        }
    };

    /**
     * Observe a list of Array items.
     */
    Observer.prototype.observeArray = function observeArray(items) {
        for (var i = 0, l = items.length; i < l; i++) {
            observe(items[i]);
        }
    };

// helpers

    /**
     * Augment an target Object or Array by intercepting
     * the prototype chain using __proto__
     */
    function protoAugment(target, src) {
        /* eslint-disable no-proto */
        target.__proto__ = src;
        /* eslint-enable no-proto */
    }

    /**
     * Augment an target Object or Array by defining
     * hidden properties.
     */

    /* istanbul ignore next */
    function copyAugment(target, src, keys) {
        for (var i = 0, l = keys.length; i < l; i++) {
            var key = keys[i];
            def(target, key, src[key]);
        }
    }

    /**
     * Attempt to create an observer instance for a value,
     * returns the new observer if successfully observed,
     * or the existing observer if the value already has one.
     */
    function observe(value, asRootData) {
        if (!isObject(value)) {
            return
        }
        var ob;
        if (hasOwn(value, '__ob__') && value.__ob__ instanceof Observer) {
            ob = value.__ob__;
        } else if (
            observerState.shouldConvert &&
            !isServerRendering() &&
            (Array.isArray(value) || isPlainObject(value)) &&
            Object.isExtensible(value) &&
            !value._isVue
        ) {
            ob = new Observer(value);
        }
        if (asRootData && ob) {
            ob.vmCount++;
        }
        return ob
    }

    /**
     * Define a reactive property on an Object.
     */
    function defineReactive$$1(
        obj,
        key,
        val,
        customSetter
    ) {
        var dep = new Dep();

        var property = Object.getOwnPropertyDescriptor(obj, key);
        if (property && property.configurable === false) {
            return
        }

        // cater for pre-defined getter/setters
        var getter = property && property.get;
        var setter = property && property.set;

        var childOb = observe(val);
        Object.defineProperty(obj, key, {
            enumerable: true,
            configurable: true,
            get: function reactiveGetter() {
                var value = getter ? getter.call(obj) : val;
                if (Dep.target) {
                    dep.depend();
                    if (childOb) {
                        childOb.dep.depend();
                    }
                    if (Array.isArray(value)) {
                        dependArray(value);
                    }
                }
                return value
            },
            set: function reactiveSetter(newVal) {
                var value = getter ? getter.call(obj) : val;
                /* eslint-disable no-self-compare */
                if (newVal === value || (newVal !== newVal && value !== value)) {
                    return
                }
                /* eslint-enable no-self-compare */
                if ("development" !== 'production' && customSetter) {
                    customSetter();
                }
                if (setter) {
                    setter.call(obj, newVal);
                } else {
                    val = newVal;
                }
                childOb = observe(newVal);
                dep.notify();
            }
        });
    }

    /**
     * Set a property on an object. Adds the new property and
     * triggers change notification if the property doesn't
     * already exist.
     */
    function set(target, key, val) {
        if (Array.isArray(target) && typeof key === 'number') {
            target.length = Math.max(target.length, key);
            target.splice(key, 1, val);
            return val
        }
        if (hasOwn(target, key)) {
            target[key] = val;
            return val
        }
        var ob = (target).__ob__;
        if (target._isVue || (ob && ob.vmCount)) {
            "development" !== 'production' && warn(
                'Avoid adding reactive properties to a Vue instance or its root $data ' +
                'at runtime - declare it upfront in the data option.'
            );
            return val
        }
        if (!ob) {
            target[key] = val;
            return val
        }
        defineReactive$$1(ob.value, key, val);
        ob.dep.notify();
        return val
    }

    /**
     * Delete a property and trigger change if necessary.
     */
    function del(target, key) {
        if (Array.isArray(target) && typeof key === 'number') {
            target.splice(key, 1);
            return
        }
        var ob = (target).__ob__;
        if (target._isVue || (ob && ob.vmCount)) {
            "development" !== 'production' && warn(
                'Avoid deleting properties on a Vue instance or its root $data ' +
                '- just set it to null.'
            );
            return
        }
        if (!hasOwn(target, key)) {
            return
        }
        delete target[key];
        if (!ob) {
            return
        }
        ob.dep.notify();
    }

    /**
     * Collect dependencies on array elements when the array is touched, since
     * we cannot intercept array element access like property getters.
     */
    function dependArray(value) {
        for (var e = (void 0), i = 0, l = value.length; i < l; i++) {
            e = value[i];
            e && e.__ob__ && e.__ob__.dep.depend();
            if (Array.isArray(e)) {
                dependArray(e);
            }
        }
    }

    /*  */

    /**
     * Option overwriting strategies are functions that handle
     * how to merge a parent option value and a child option
     * value into the final value.
     */
    var strats = config.optionMergeStrategies;

    /**
     * Options with restrictions
     */
    {
        strats.el = strats.propsData = function (parent, child, vm, key) {
            if (!vm) {
                warn(
                    "option \"" + key + "\" can only be used during instance " +
                    'creation with the `new` keyword.'
                );
            }
            return defaultStrat(parent, child)
        };
    }

    /**
     * Helper that recursively merges two data objects together.
     */
    function mergeData(to, from) {
        if (!from) {
            return to
        }
        var key, toVal, fromVal;
        var keys = Object.keys(from);
        for (var i = 0; i < keys.length; i++) {
            key = keys[i];
            toVal = to[key];
            fromVal = from[key];
            if (!hasOwn(to, key)) {
                set(to, key, fromVal);
            } else if (isPlainObject(toVal) && isPlainObject(fromVal)) {
                mergeData(toVal, fromVal);
            }
        }
        return to
    }

    /**
     * Data
     */
    strats.data = function (
        parentVal,
        childVal,
        vm
    ) {
        if (!vm) {
            // in a Vue.extend merge, both should be functions
            if (!childVal) {
                return parentVal
            }
            if (typeof childVal !== 'function') {
                "development" !== 'production' && warn(
                    'The "data" option should be a function ' +
                    'that returns a per-instance value in component ' +
                    'definitions.',
                    vm
                );
                return parentVal
            }
            if (!parentVal) {
                return childVal
            }
            // when parentVal & childVal are both present,
            // we need to return a function that returns the
            // merged result of both functions... no need to
            // check if parentVal is a function here because
            // it has to be a function to pass previous merges.
            return function mergedDataFn() {
                return mergeData(
                    childVal.call(this),
                    parentVal.call(this)
                )
            }
        } else if (parentVal || childVal) {
            return function mergedInstanceDataFn() {
                // instance merge
                var instanceData = typeof childVal === 'function'
                    ? childVal.call(vm)
                    : childVal;
                var defaultData = typeof parentVal === 'function'
                    ? parentVal.call(vm)
                    : undefined;
                if (instanceData) {
                    return mergeData(instanceData, defaultData)
                } else {
                    return defaultData
                }
            }
        }
    };

    /**
     * Hooks and props are merged as arrays.
     */
    function mergeHook(
        parentVal,
        childVal
    ) {
        return childVal
            ? parentVal
                ? parentVal.concat(childVal)
                : Array.isArray(childVal)
                    ? childVal
                    : [childVal]
            : parentVal
    }

    config._lifecycleHooks.forEach(function (hook) {
        strats[hook] = mergeHook;
    });

    /**
     * Assets
     *
     * When a vm is present (instance creation), we need to do
     * a three-way merge between constructor options, instance
     * options and parent options.
     */
    function mergeAssets(parentVal, childVal) {
        var res = Object.create(parentVal || null);
        return childVal
            ? extend(res, childVal)
            : res
    }

    config._assetTypes.forEach(function (type) {
        strats[type + 's'] = mergeAssets;
    });

    /**
     * Watchers.
     *
     * Watchers hashes should not overwrite one
     * another, so we merge them as arrays.
     */
    strats.watch = function (parentVal, childVal) {
        /* istanbul ignore if */
        if (!childVal) {
            return Object.create(parentVal || null)
        }
        if (!parentVal) {
            return childVal
        }
        var ret = {};
        extend(ret, parentVal);
        for (var key in childVal) {
            var parent = ret[key];
            var child = childVal[key];
            if (parent && !Array.isArray(parent)) {
                parent = [parent];
            }
            ret[key] = parent
                ? parent.concat(child)
                : [child];
        }
        return ret
    };

    /**
     * Other object hashes.
     */
    strats.props =
        strats.methods =
            strats.computed = function (parentVal, childVal) {
                if (!childVal) {
                    return Object.create(parentVal || null)
                }
                if (!parentVal) {
                    return childVal
                }
                var ret = Object.create(null);
                extend(ret, parentVal);
                extend(ret, childVal);
                return ret
            };

    /**
     * Default strategy.
     */
    var defaultStrat = function (parentVal, childVal) {
        return childVal === undefined
            ? parentVal
            : childVal
    };

    /**
     * Validate component names
     */
    function checkComponents(options) {
        for (var key in options.components) {
            var lower = key.toLowerCase();
            if (isBuiltInTag(lower) || config.isReservedTag(lower)) {
                warn(
                    'Do not use built-in or reserved HTML elements as component ' +
                    'id: ' + key
                );
            }
        }
    }

    /**
     * Ensure all props option syntax are normalized into the
     * Object-based format.
     */
    function normalizeProps(options) {
        var props = options.props;
        if (!props) {
            return
        }
        var res = {};
        var i, val, name;
        if (Array.isArray(props)) {
            i = props.length;
            while (i--) {
                val = props[i];
                if (typeof val === 'string') {
                    name = camelize(val);
                    res[name] = {type: null};
                } else {
                    warn('props must be strings when using array syntax.');
                }
            }
        } else if (isPlainObject(props)) {
            for (var key in props) {
                val = props[key];
                name = camelize(key);
                res[name] = isPlainObject(val)
                    ? val
                    : {type: val};
            }
        }
        options.props = res;
    }

    /**
     * Normalize raw function directives into object format.
     */
    function normalizeDirectives(options) {
        var dirs = options.directives;
        if (dirs) {
            for (var key in dirs) {
                var def = dirs[key];
                if (typeof def === 'function') {
                    dirs[key] = {bind: def, update: def};
                }
            }
        }
    }

    /**
     * Merge two option objects into a new one.
     * Core utility used in both instantiation and inheritance.
     */
    function mergeOptions(
        parent,
        child,
        vm
    ) {
        {
            checkComponents(child);
        }
        normalizeProps(child);
        normalizeDirectives(child);
        var extendsFrom = child.extends;
        if (extendsFrom) {
            parent = typeof extendsFrom === 'function'
                ? mergeOptions(parent, extendsFrom.options, vm)
                : mergeOptions(parent, extendsFrom, vm);
        }
        if (child.mixins) {
            for (var i = 0, l = child.mixins.length; i < l; i++) {
                var mixin = child.mixins[i];
                if (mixin.prototype instanceof Vue$2) {
                    mixin = mixin.options;
                }
                parent = mergeOptions(parent, mixin, vm);
            }
        }
        var options = {};
        var key;
        for (key in parent) {
            mergeField(key);
        }
        for (key in child) {
            if (!hasOwn(parent, key)) {
                mergeField(key);
            }
        }

        function mergeField(key) {
            var strat = strats[key] || defaultStrat;
            options[key] = strat(parent[key], child[key], vm, key);
        }

        return options
    }

    /**
     * Resolve an asset.
     * This function is used because child instances need access
     * to assets defined in its ancestor chain.
     */
    function resolveAsset(
        options,
        type,
        id,
        warnMissing
    ) {
        /* istanbul ignore if */
        if (typeof id !== 'string') {
            return
        }
        var assets = options[type];
        // check local registration variations first
        if (hasOwn(assets, id)) {
            return assets[id]
        }
        var camelizedId = camelize(id);
        if (hasOwn(assets, camelizedId)) {
            return assets[camelizedId]
        }
        var PascalCaseId = capitalize(camelizedId);
        if (hasOwn(assets, PascalCaseId)) {
            return assets[PascalCaseId]
        }
        // fallback to prototype chain
        var res = assets[id] || assets[camelizedId] || assets[PascalCaseId];
        if ("development" !== 'production' && warnMissing && !res) {
            warn(
                'Failed to resolve ' + type.slice(0, -1) + ': ' + id,
                options
            );
        }
        return res
    }

    /*  */

    function validateProp(
        key,
        propOptions,
        propsData,
        vm
    ) {
        var prop = propOptions[key];
        var absent = !hasOwn(propsData, key);
        var value = propsData[key];
        // handle boolean props
        if (isType(Boolean, prop.type)) {
            if (absent && !hasOwn(prop, 'default')) {
                value = false;
            } else if (!isType(String, prop.type) && (value === '' || value === hyphenate(key))) {
                value = true;
            }
        }
        // check default value
        if (value === undefined) {
            value = getPropDefaultValue(vm, prop, key);
            // since the default value is a fresh copy,
            // make sure to observe it.
            var prevShouldConvert = observerState.shouldConvert;
            observerState.shouldConvert = true;
            observe(value);
            observerState.shouldConvert = prevShouldConvert;
        }
        {
            assertProp(prop, key, value, vm, absent);
        }
        return value
    }

    /**
     * Get the default value of a prop.
     */
    function getPropDefaultValue(vm, prop, key) {
        // no default, return undefined
        if (!hasOwn(prop, 'default')) {
            return undefined
        }
        var def = prop.default;
        // warn against non-factory defaults for Object & Array
        if ("development" !== 'production' && isObject(def)) {
            warn(
                'Invalid default value for prop "' + key + '": ' +
                'Props with type Object/Array must use a factory function ' +
                'to return the default value.',
                vm
            );
        }
        // the raw prop value was also undefined from previous render,
        // return previous default value to avoid unnecessary watcher trigger
        if (vm && vm.$options.propsData &&
            vm.$options.propsData[key] === undefined &&
            vm._props[key] !== undefined) {
            return vm._props[key]
        }
        // call factory function for non-Function types
        // a value is Function if its prototype is function even across different execution context
        return typeof def === 'function' && getType(prop.type) !== 'Function'
            ? def.call(vm)
            : def
    }

    /**
     * Assert whether a prop is valid.
     */
    function assertProp(
        prop,
        name,
        value,
        vm,
        absent
    ) {
        if (prop.required && absent) {
            warn(
                'Missing required prop: "' + name + '"',
                vm
            );
            return
        }
        if (value == null && !prop.required) {
            return
        }
        var type = prop.type;
        var valid = !type || type === true;
        var expectedTypes = [];
        if (type) {
            if (!Array.isArray(type)) {
                type = [type];
            }
            for (var i = 0; i < type.length && !valid; i++) {
                var assertedType = assertType(value, type[i]);
                expectedTypes.push(assertedType.expectedType || '');
                valid = assertedType.valid;
            }
        }
        if (!valid) {
            warn(
                'Invalid prop: type check failed for prop "' + name + '".' +
                ' Expected ' + expectedTypes.map(capitalize).join(', ') +
                ', got ' + Object.prototype.toString.call(value).slice(8, -1) + '.',
                vm
            );
            return
        }
        var validator = prop.validator;
        if (validator) {
            if (!validator(value)) {
                warn(
                    'Invalid prop: custom validator check failed for prop "' + name + '".',
                    vm
                );
            }
        }
    }

    /**
     * Assert the type of a value
     */
    function assertType(value, type) {
        var valid;
        var expectedType = getType(type);
        if (expectedType === 'String') {
            valid = typeof value === (expectedType = 'string');
        } else if (expectedType === 'Number') {
            valid = typeof value === (expectedType = 'number');
        } else if (expectedType === 'Boolean') {
            valid = typeof value === (expectedType = 'boolean');
        } else if (expectedType === 'Function') {
            valid = typeof value === (expectedType = 'function');
        } else if (expectedType === 'Object') {
            valid = isPlainObject(value);
        } else if (expectedType === 'Array') {
            valid = Array.isArray(value);
        } else {
            valid = value instanceof type;
        }
        return {
            valid: valid,
            expectedType: expectedType
        }
    }

    /**
     * Use function string name to check built-in types,
     * because a simple equality check will fail when running
     * across different vms / iframes.
     */
    function getType(fn) {
        var match = fn && fn.toString().match(/^\s*function (\w+)/);
        return match && match[1]
    }

    function isType(type, fn) {
        if (!Array.isArray(fn)) {
            return getType(fn) === getType(type)
        }
        for (var i = 0, len = fn.length; i < len; i++) {
            if (getType(fn[i]) === getType(type)) {
                return true
            }
        }
        /* istanbul ignore next */
        return false
    }

    function handleError(err, vm, info) {
        if (config.errorHandler) {
            config.errorHandler.call(null, err, vm, info);
        } else {
            {
                warn(("Error in " + info + ":"), vm);
            }
            /* istanbul ignore else */
            if (inBrowser && typeof console !== 'undefined') {
                console.error(err);
            } else {
                throw err
            }
        }
    }

    /* not type checking this file because flow doesn't play well with Proxy */

    var initProxy;

    {
        var allowedGlobals = makeMap(
            'Infinity,undefined,NaN,isFinite,isNaN,' +
            'parseFloat,parseInt,decodeURI,decodeURIComponent,encodeURI,encodeURIComponent,' +
            'Math,Number,Date,Array,Object,Boolean,String,RegExp,Map,Set,JSON,Intl,' +
            'require' // for Webpack/Browserify
        );

        var warnNonPresent = function (target, key) {
            warn(
                "Property or method \"" + key + "\" is not defined on the instance but " +
                "referenced during render. Make sure to declare reactive data " +
                "properties in the data option.",
                target
            );
        };

        var hasProxy =
            typeof Proxy !== 'undefined' &&
            Proxy.toString().match(/native code/);

        if (hasProxy) {
            var isBuiltInModifier = makeMap('stop,prevent,self,ctrl,shift,alt,meta');
            config.keyCodes = new Proxy(config.keyCodes, {
                set: function set(target, key, value) {
                    if (isBuiltInModifier(key)) {
                        warn(("Avoid overwriting built-in modifier in config.keyCodes: ." + key));
                        return false
                    } else {
                        target[key] = value;
                        return true
                    }
                }
            });
        }

        var hasHandler = {
            has: function has(target, key) {
                var has = key in target;
                var isAllowed = allowedGlobals(key) || key.charAt(0) === '_';
                if (!has && !isAllowed) {
                    warnNonPresent(target, key);
                }
                return has || !isAllowed
            }
        };

        var getHandler = {
            get: function get(target, key) {
                if (typeof key === 'string' && !(key in target)) {
                    warnNonPresent(target, key);
                }
                return target[key]
            }
        };

        initProxy = function initProxy(vm) {
            if (hasProxy) {
                // determine which proxy handler to use
                var options = vm.$options;
                var handlers = options.render && options.render._withStripped
                    ? getHandler
                    : hasHandler;
                vm._renderProxy = new Proxy(vm, handlers);
            } else {
                vm._renderProxy = vm;
            }
        };
    }

    var mark;
    var measure;

    {
        var perf = inBrowser && window.performance;
        /* istanbul ignore if */
        if (
            perf &&
            perf.mark &&
            perf.measure &&
            perf.clearMarks &&
            perf.clearMeasures
        ) {
            mark = function (tag) {
                return perf.mark(tag);
            };
            measure = function (name, startTag, endTag) {
                perf.measure(name, startTag, endTag);
                perf.clearMarks(startTag);
                perf.clearMarks(endTag);
                perf.clearMeasures(name);
            };
        }
    }

    /*  */

    var VNode = function VNode(
        tag,
        data,
        children,
        text,
        elm,
        context,
        componentOptions
    ) {
        this.tag = tag;
        this.data = data;
        this.children = children;
        this.text = text;
        this.elm = elm;
        this.ns = undefined;
        this.context = context;
        this.functionalContext = undefined;
        this.key = data && data.key;
        this.componentOptions = componentOptions;
        this.componentInstance = undefined;
        this.parent = undefined;
        this.raw = false;
        this.isStatic = false;
        this.isRootInsert = true;
        this.isComment = false;
        this.isCloned = false;
        this.isOnce = false;
    };

    var prototypeAccessors = {child: {}};

// DEPRECATED: alias for componentInstance for backwards compat.
    /* istanbul ignore next */
    prototypeAccessors.child.get = function () {
        return this.componentInstance
    };

    Object.defineProperties(VNode.prototype, prototypeAccessors);

    var createEmptyVNode = function () {
        var node = new VNode();
        node.text = '';
        node.isComment = true;
        return node
    };

    function createTextVNode(val) {
        return new VNode(undefined, undefined, undefined, String(val))
    }

// optimized shallow clone
// used for static nodes and slot nodes because they may be reused across
// multiple renders, cloning them avoids errors when DOM manipulations rely
// on their elm reference.
    function cloneVNode(vnode) {
        var cloned = new VNode(
            vnode.tag,
            vnode.data,
            vnode.children,
            vnode.text,
            vnode.elm,
            vnode.context,
            vnode.componentOptions
        );
        cloned.ns = vnode.ns;
        cloned.isStatic = vnode.isStatic;
        cloned.key = vnode.key;
        cloned.isCloned = true;
        return cloned
    }

    function cloneVNodes(vnodes) {
        var len = vnodes.length;
        var res = new Array(len);
        for (var i = 0; i < len; i++) {
            res[i] = cloneVNode(vnodes[i]);
        }
        return res
    }

    /*  */

    var normalizeEvent = cached(function (name) {
        var once$$1 = name.charAt(0) === '~'; // Prefixed last, checked first
        name = once$$1 ? name.slice(1) : name;
        var capture = name.charAt(0) === '!';
        name = capture ? name.slice(1) : name;
        return {
            name: name,
            once: once$$1,
            capture: capture
        }
    });

    function createFnInvoker(fns) {
        function invoker() {
            var arguments$1 = arguments;

            var fns = invoker.fns;
            if (Array.isArray(fns)) {
                for (var i = 0; i < fns.length; i++) {
                    fns[i].apply(null, arguments$1);
                }
            } else {
                // return handler return value for single handlers
                return fns.apply(null, arguments)
            }
        }

        invoker.fns = fns;
        return invoker
    }

    function updateListeners(
        on,
        oldOn,
        add,
        remove$$1,
        vm
    ) {
        var name, cur, old, event;
        for (name in on) {
            cur = on[name];
            old = oldOn[name];
            event = normalizeEvent(name);
            if (!cur) {
                "development" !== 'production' && warn(
                    "Invalid handler for event \"" + (event.name) + "\": got " + String(cur),
                    vm
                );
            } else if (!old) {
                if (!cur.fns) {
                    cur = on[name] = createFnInvoker(cur);
                }
                add(event.name, cur, event.once, event.capture);
            } else if (cur !== old) {
                old.fns = cur;
                on[name] = old;
            }
        }
        for (name in oldOn) {
            if (!on[name]) {
                event = normalizeEvent(name);
                remove$$1(event.name, oldOn[name], event.capture);
            }
        }
    }

    /*  */

    function mergeVNodeHook(def, hookKey, hook) {
        var invoker;
        var oldHook = def[hookKey];

        function wrappedHook() {
            hook.apply(this, arguments);
            // important: remove merged hook to ensure it's called only once
            // and prevent memory leak
            remove(invoker.fns, wrappedHook);
        }

        if (!oldHook) {
            // no existing hook
            invoker = createFnInvoker([wrappedHook]);
        } else {
            /* istanbul ignore if */
            if (oldHook.fns && oldHook.merged) {
                // already a merged invoker
                invoker = oldHook;
                invoker.fns.push(wrappedHook);
            } else {
                // existing plain hook
                invoker = createFnInvoker([oldHook, wrappedHook]);
            }
        }

        invoker.merged = true;
        def[hookKey] = invoker;
    }

    /*  */

// The template compiler attempts to minimize the need for normalization by
// statically analyzing the template at compile time.
//
// For plain HTML markup, normalization can be completely skipped because the
// generated render function is guaranteed to return Array<VNode>. There are
// two cases where extra normalization is needed:

// 1. When the children contains components - because a functional component
// may return an Array instead of a single root. In this case, just a simple
// normalization is needed - if any child is an Array, we flatten the whole
// thing with Array.prototype.concat. It is guaranteed to be only 1-level deep
// because functional components already normalize their own children.
    function simpleNormalizeChildren(children) {
        for (var i = 0; i < children.length; i++) {
            if (Array.isArray(children[i])) {
                return Array.prototype.concat.apply([], children)
            }
        }
        return children
    }

// 2. When the children contains constructs that always generated nested Arrays,
// e.g. <template>, <slot>, v-for, or when the children is provided by user
// with hand-written render functions / JSX. In such cases a full normalization
// is needed to cater to all possible types of children values.
    function normalizeChildren(children) {
        return isPrimitive(children)
            ? [createTextVNode(children)]
            : Array.isArray(children)
                ? normalizeArrayChildren(children)
                : undefined
    }

    function normalizeArrayChildren(children, nestedIndex) {
        var res = [];
        var i, c, last;
        for (i = 0; i < children.length; i++) {
            c = children[i];
            if (c == null || typeof c === 'boolean') {
                continue
            }
            last = res[res.length - 1];
            //  nested
            if (Array.isArray(c)) {
                res.push.apply(res, normalizeArrayChildren(c, ((nestedIndex || '') + "_" + i)));
            } else if (isPrimitive(c)) {
                if (last && last.text) {
                    last.text += String(c);
                } else if (c !== '') {
                    // convert primitive to vnode
                    res.push(createTextVNode(c));
                }
            } else {
                if (c.text && last && last.text) {
                    res[res.length - 1] = createTextVNode(last.text + c.text);
                } else {
                    // default key for nested array children (likely generated by v-for)
                    if (c.tag && c.key == null && nestedIndex != null) {
                        c.key = "__vlist" + nestedIndex + "_" + i + "__";
                    }
                    res.push(c);
                }
            }
        }
        return res
    }

    /*  */

    function getFirstComponentChild(children) {
        return children && children.filter(function (c) {
            return c && c.componentOptions;
        })[0]
    }

    /*  */

    function initEvents(vm) {
        vm._events = Object.create(null);
        vm._hasHookEvent = false;
        // init parent attached events
        var listeners = vm.$options._parentListeners;
        if (listeners) {
            updateComponentListeners(vm, listeners);
        }
    }

    var target;

    function add(event, fn, once$$1) {
        if (once$$1) {
            target.$once(event, fn);
        } else {
            target.$on(event, fn);
        }
    }

    function remove$1(event, fn) {
        target.$off(event, fn);
    }

    function updateComponentListeners(
        vm,
        listeners,
        oldListeners
    ) {
        target = vm;
        updateListeners(listeners, oldListeners || {}, add, remove$1, vm);
    }

    function eventsMixin(Vue) {
        var hookRE = /^hook:/;
        Vue.prototype.$on = function (event, fn) {
            var this$1 = this;

            var vm = this;
            if (Array.isArray(event)) {
                for (var i = 0, l = event.length; i < l; i++) {
                    this$1.$on(event[i], fn);
                }
            } else {
                (vm._events[event] || (vm._events[event] = [])).push(fn);
                // optimize hook:event cost by using a boolean flag marked at registration
                // instead of a hash lookup
                if (hookRE.test(event)) {
                    vm._hasHookEvent = true;
                }
            }
            return vm
        };

        Vue.prototype.$once = function (event, fn) {
            var vm = this;

            function on() {
                vm.$off(event, on);
                fn.apply(vm, arguments);
            }

            on.fn = fn;
            vm.$on(event, on);
            return vm
        };

        Vue.prototype.$off = function (event, fn) {
            var this$1 = this;

            var vm = this;
            // all
            if (!arguments.length) {
                vm._events = Object.create(null);
                return vm
            }
            // array of events
            if (Array.isArray(event)) {
                for (var i$1 = 0, l = event.length; i$1 < l; i$1++) {
                    this$1.$off(event[i$1], fn);
                }
                return vm
            }
            // specific event
            var cbs = vm._events[event];
            if (!cbs) {
                return vm
            }
            if (arguments.length === 1) {
                vm._events[event] = null;
                return vm
            }
            // specific handler
            var cb;
            var i = cbs.length;
            while (i--) {
                cb = cbs[i];
                if (cb === fn || cb.fn === fn) {
                    cbs.splice(i, 1);
                    break
                }
            }
            return vm
        };

        Vue.prototype.$emit = function (event) {
            var vm = this;
            {
                var lowerCaseEvent = event.toLowerCase();
                if (lowerCaseEvent !== event && vm._events[lowerCaseEvent]) {
                    tip(
                        "Event \"" + lowerCaseEvent + "\" is emitted in component " +
                        (formatComponentName(vm)) + " but the handler is registered for \"" + event + "\". " +
                        "Note that HTML attributes are case-insensitive and you cannot use " +
                        "v-on to listen to camelCase events when using in-DOM templates. " +
                        "You should probably use \"" + (hyphenate(event)) + "\" instead of \"" + event + "\"."
                    );
                }
            }
            var cbs = vm._events[event];
            if (cbs) {
                cbs = cbs.length > 1 ? toArray(cbs) : cbs;
                var args = toArray(arguments, 1);
                for (var i = 0, l = cbs.length; i < l; i++) {
                    cbs[i].apply(vm, args);
                }
            }
            return vm
        };
    }

    /*  */

    /**
     * Runtime helper for resolving raw children VNodes into a slot object.
     */
    function resolveSlots(
        children,
        context
    ) {
        var slots = {};
        if (!children) {
            return slots
        }
        var defaultSlot = [];
        var name, child;
        for (var i = 0, l = children.length; i < l; i++) {
            child = children[i];
            // named slots should only be respected if the vnode was rendered in the
            // same context.
            if ((child.context === context || child.functionalContext === context) &&
                child.data && (name = child.data.slot)) {
                var slot = (slots[name] || (slots[name] = []));
                if (child.tag === 'template') {
                    slot.push.apply(slot, child.children);
                } else {
                    slot.push(child);
                }
            } else {
                defaultSlot.push(child);
            }
        }
        // ignore whitespace
        if (!defaultSlot.every(isWhitespace)) {
            slots.default = defaultSlot;
        }
        return slots
    }

    function isWhitespace(node) {
        return node.isComment || node.text === ' '
    }

    function resolveScopedSlots(
        fns
    ) {
        var res = {};
        for (var i = 0; i < fns.length; i++) {
            res[fns[i][0]] = fns[i][1];
        }
        return res
    }

    /*  */

    var activeInstance = null;

    function initLifecycle(vm) {
        var options = vm.$options;

        // locate first non-abstract parent
        var parent = options.parent;
        if (parent && !options.abstract) {
            while (parent.$options.abstract && parent.$parent) {
                parent = parent.$parent;
            }
            parent.$children.push(vm);
        }

        vm.$parent = parent;
        vm.$root = parent ? parent.$root : vm;

        vm.$children = [];
        vm.$refs = {};

        vm._watcher = null;
        vm._inactive = null;
        vm._directInactive = false;
        vm._isMounted = false;
        vm._isDestroyed = false;
        vm._isBeingDestroyed = false;
    }

    function lifecycleMixin(Vue) {
        Vue.prototype._update = function (vnode, hydrating) {
            var vm = this;
            if (vm._isMounted) {
                callHook(vm, 'beforeUpdate');
            }
            var prevEl = vm.$el;
            var prevVnode = vm._vnode;
            var prevActiveInstance = activeInstance;
            activeInstance = vm;
            vm._vnode = vnode;
            // Vue.prototype.__patch__ is injected in entry points
            // based on the rendering backend used.
            if (!prevVnode) {
                // initial render
                vm.$el = vm.__patch__(
                    vm.$el, vnode, hydrating, false /* removeOnly */,
                    vm.$options._parentElm,
                    vm.$options._refElm
                );
            } else {
                // updates
                vm.$el = vm.__patch__(prevVnode, vnode);
            }
            activeInstance = prevActiveInstance;
            // update __vue__ reference
            if (prevEl) {
                prevEl.__vue__ = null;
            }
            if (vm.$el) {
                vm.$el.__vue__ = vm;
            }
            // if parent is an HOC, update its $el as well
            if (vm.$vnode && vm.$parent && vm.$vnode === vm.$parent._vnode) {
                vm.$parent.$el = vm.$el;
            }
            // updated hook is called by the scheduler to ensure that children are
            // updated in a parent's updated hook.
        };

        Vue.prototype.$forceUpdate = function () {
            var vm = this;
            if (vm._watcher) {
                vm._watcher.update();
            }
        };

        Vue.prototype.$destroy = function () {
            var vm = this;
            if (vm._isBeingDestroyed) {
                return
            }
            callHook(vm, 'beforeDestroy');
            vm._isBeingDestroyed = true;
            // remove self from parent
            var parent = vm.$parent;
            if (parent && !parent._isBeingDestroyed && !vm.$options.abstract) {
                remove(parent.$children, vm);
            }
            // teardown watchers
            if (vm._watcher) {
                vm._watcher.teardown();
            }
            var i = vm._watchers.length;
            while (i--) {
                vm._watchers[i].teardown();
            }
            // remove reference from data ob
            // frozen object may not have observer.
            if (vm._data.__ob__) {
                vm._data.__ob__.vmCount--;
            }
            // call the last hook...
            vm._isDestroyed = true;
            // invoke destroy hooks on current rendered tree
            vm.__patch__(vm._vnode, null);
            // fire destroyed hook
            callHook(vm, 'destroyed');
            // turn off all instance listeners.
            vm.$off();
            // remove __vue__ reference
            if (vm.$el) {
                vm.$el.__vue__ = null;
            }
            // remove reference to DOM nodes (prevents leak)
            vm.$options._parentElm = vm.$options._refElm = null;
        };
    }

    function mountComponent(
        vm,
        el,
        hydrating
    ) {
        vm.$el = el;
        if (!vm.$options.render) {
            vm.$options.render = createEmptyVNode;
            {
                /* istanbul ignore if */
                if ((vm.$options.template && vm.$options.template.charAt(0) !== '#') ||
                    vm.$options.el || el) {
                    warn(
                        'You are using the runtime-only build of Vue where the template ' +
                        'compiler is not available. Either pre-compile the templates into ' +
                        'render functions, or use the compiler-included build.',
                        vm
                    );
                } else {
                    warn(
                        'Failed to mount component: template or render function not defined.',
                        vm
                    );
                }
            }
        }
        callHook(vm, 'beforeMount');

        var updateComponent;
        /* istanbul ignore if */
        if ("development" !== 'production' && config.performance && mark) {
            updateComponent = function () {
                var name = vm._name;
                var id = vm._uid;
                var startTag = "vue-perf-start:" + id;
                var endTag = "vue-perf-end:" + id;

                mark(startTag);
                var vnode = vm._render();
                mark(endTag);
                measure((name + " render"), startTag, endTag);

                mark(startTag);
                vm._update(vnode, hydrating);
                mark(endTag);
                measure((name + " patch"), startTag, endTag);
            };
        } else {
            updateComponent = function () {
                vm._update(vm._render(), hydrating);
            };
        }

        vm._watcher = new Watcher(vm, updateComponent, noop);
        hydrating = false;

        // manually mounted instance, call mounted on self
        // mounted is called for render-created child components in its inserted hook
        if (vm.$vnode == null) {
            vm._isMounted = true;
            callHook(vm, 'mounted');
        }
        return vm
    }

    function updateChildComponent(
        vm,
        propsData,
        listeners,
        parentVnode,
        renderChildren
    ) {
        // determine whether component has slot children
        // we need to do this before overwriting $options._renderChildren
        var hasChildren = !!(
            renderChildren ||               // has new static slots
            vm.$options._renderChildren ||  // has old static slots
            parentVnode.data.scopedSlots || // has new scoped slots
            vm.$scopedSlots !== emptyObject // has old scoped slots
        );

        vm.$options._parentVnode = parentVnode;
        vm.$vnode = parentVnode; // update vm's placeholder node without re-render
        if (vm._vnode) { // update child tree's parent
            vm._vnode.parent = parentVnode;
        }
        vm.$options._renderChildren = renderChildren;

        // update props
        if (propsData && vm.$options.props) {
            observerState.shouldConvert = false;
            {
                observerState.isSettingProps = true;
            }
            var props = vm._props;
            var propKeys = vm.$options._propKeys || [];
            for (var i = 0; i < propKeys.length; i++) {
                var key = propKeys[i];
                props[key] = validateProp(key, vm.$options.props, propsData, vm);
            }
            observerState.shouldConvert = true;
            {
                observerState.isSettingProps = false;
            }
            // keep a copy of raw propsData
            vm.$options.propsData = propsData;
        }
        // update listeners
        if (listeners) {
            var oldListeners = vm.$options._parentListeners;
            vm.$options._parentListeners = listeners;
            updateComponentListeners(vm, listeners, oldListeners);
        }
        // resolve slots + force update if has children
        if (hasChildren) {
            vm.$slots = resolveSlots(renderChildren, parentVnode.context);
            vm.$forceUpdate();
        }
    }

    function isInInactiveTree(vm) {
        while (vm && (vm = vm.$parent)) {
            if (vm._inactive) {
                return true
            }
        }
        return false
    }

    function activateChildComponent(vm, direct) {
        if (direct) {
            vm._directInactive = false;
            if (isInInactiveTree(vm)) {
                return
            }
        } else if (vm._directInactive) {
            return
        }
        if (vm._inactive || vm._inactive == null) {
            vm._inactive = false;
            for (var i = 0; i < vm.$children.length; i++) {
                activateChildComponent(vm.$children[i]);
            }
            callHook(vm, 'activated');
        }
    }

    function deactivateChildComponent(vm, direct) {
        if (direct) {
            vm._directInactive = true;
            if (isInInactiveTree(vm)) {
                return
            }
        }
        if (!vm._inactive) {
            vm._inactive = true;
            for (var i = 0; i < vm.$children.length; i++) {
                deactivateChildComponent(vm.$children[i]);
            }
            callHook(vm, 'deactivated');
        }
    }

    function callHook(vm, hook) {
        var handlers = vm.$options[hook];
        if (handlers) {
            for (var i = 0, j = handlers.length; i < j; i++) {
                try {
                    handlers[i].call(vm);
                } catch (e) {
                    handleError(e, vm, (hook + " hook"));
                }
            }
        }
        if (vm._hasHookEvent) {
            vm.$emit('hook:' + hook);
        }
    }

    /*  */


    var queue = [];
    var has = {};
    var circular = {};
    var waiting = false;
    var flushing = false;
    var index = 0;

    /**
     * Reset the scheduler's state.
     */
    function resetSchedulerState() {
        queue.length = 0;
        has = {};
        {
            circular = {};
        }
        waiting = flushing = false;
    }

    /**
     * Flush both queues and run the watchers.
     */
    function flushSchedulerQueue() {
        flushing = true;
        var watcher, id, vm;

        // Sort queue before flush.
        // This ensures that:
        // 1. Components are updated from parent to child. (because parent is always
        //    created before the child)
        // 2. A component's user watchers are run before its render watcher (because
        //    user watchers are created before the render watcher)
        // 3. If a component is destroyed during a parent component's watcher run,
        //    its watchers can be skipped.
        queue.sort(function (a, b) {
            return a.id - b.id;
        });

        // do not cache length because more watchers might be pushed
        // as we run existing watchers
        for (index = 0; index < queue.length; index++) {
            watcher = queue[index];
            id = watcher.id;
            has[id] = null;
            watcher.run();
            // in dev build, check and stop circular updates.
            if ("development" !== 'production' && has[id] != null) {
                circular[id] = (circular[id] || 0) + 1;
                if (circular[id] > config._maxUpdateCount) {
                    warn(
                        'You may have an infinite update loop ' + (
                            watcher.user
                                ? ("in watcher with expression \"" + (watcher.expression) + "\"")
                                : "in a component render function."
                        ),
                        watcher.vm
                    );
                    break
                }
            }
        }

        // reset scheduler before updated hook called
        var oldQueue = queue.slice();
        resetSchedulerState();

        // call updated hooks
        index = oldQueue.length;
        while (index--) {
            watcher = oldQueue[index];
            vm = watcher.vm;
            if (vm._watcher === watcher && vm._isMounted) {
                callHook(vm, 'updated');
            }
        }

        // devtool hook
        /* istanbul ignore if */
        if (devtools && config.devtools) {
            devtools.emit('flush');
        }
    }

    /**
     * Push a watcher into the watcher queue.
     * Jobs with duplicate IDs will be skipped unless it's
     * pushed when the queue is being flushed.
     */
    function queueWatcher(watcher) {
        var id = watcher.id;
        if (has[id] == null) {
            has[id] = true;
            if (!flushing) {
                queue.push(watcher);
            } else {
                // if already flushing, splice the watcher based on its id
                // if already past its id, it will be run next immediately.
                var i = queue.length - 1;
                while (i >= 0 && queue[i].id > watcher.id) {
                    i--;
                }
                queue.splice(Math.max(i, index) + 1, 0, watcher);
            }
            // queue the flush
            if (!waiting) {
                waiting = true;
                nextTick(flushSchedulerQueue);
            }
        }
    }

    /*  */

    var uid$2 = 0;

    /**
     * A watcher parses an expression, collects dependencies,
     * and fires callback when the expression value changes.
     * This is used for both the $watch() api and directives.
     */
    var Watcher = function Watcher(
        vm,
        expOrFn,
        cb,
        options
    ) {
        this.vm = vm;
        vm._watchers.push(this);
        // options
        if (options) {
            this.deep = !!options.deep;
            this.user = !!options.user;
            this.lazy = !!options.lazy;
            this.sync = !!options.sync;
        } else {
            this.deep = this.user = this.lazy = this.sync = false;
        }
        this.cb = cb;
        this.id = ++uid$2; // uid for batching
        this.active = true;
        this.dirty = this.lazy; // for lazy watchers
        this.deps = [];
        this.newDeps = [];
        this.depIds = new _Set();
        this.newDepIds = new _Set();
        this.expression = expOrFn.toString();
        // parse expression for getter
        if (typeof expOrFn === 'function') {
            this.getter = expOrFn;
        } else {
            this.getter = parsePath(expOrFn);
            if (!this.getter) {
                this.getter = function () {
                };
                "development" !== 'production' && warn(
                    "Failed watching path: \"" + expOrFn + "\" " +
                    'Watcher only accepts simple dot-delimited paths. ' +
                    'For full control, use a function instead.',
                    vm
                );
            }
        }
        this.value = this.lazy
            ? undefined
            : this.get();
    };

    /**
     * Evaluate the getter, and re-collect dependencies.
     */
    Watcher.prototype.get = function get() {
        pushTarget(this);
        var value;
        var vm = this.vm;
        if (this.user) {
            try {
                value = this.getter.call(vm, vm);
            } catch (e) {
                handleError(e, vm, ("getter for watcher \"" + (this.expression) + "\""));
            }
        } else {
            value = this.getter.call(vm, vm);
        }
        // "touch" every property so they are all tracked as
        // dependencies for deep watching
        if (this.deep) {
            traverse(value);
        }
        popTarget();
        this.cleanupDeps();
        return value
    };

    /**
     * Add a dependency to this directive.
     */
    Watcher.prototype.addDep = function addDep(dep) {
        var id = dep.id;
        if (!this.newDepIds.has(id)) {
            this.newDepIds.add(id);
            this.newDeps.push(dep);
            if (!this.depIds.has(id)) {
                dep.addSub(this);
            }
        }
    };

    /**
     * Clean up for dependency collection.
     */
    Watcher.prototype.cleanupDeps = function cleanupDeps() {
        var this$1 = this;

        var i = this.deps.length;
        while (i--) {
            var dep = this$1.deps[i];
            if (!this$1.newDepIds.has(dep.id)) {
                dep.removeSub(this$1);
            }
        }
        var tmp = this.depIds;
        this.depIds = this.newDepIds;
        this.newDepIds = tmp;
        this.newDepIds.clear();
        tmp = this.deps;
        this.deps = this.newDeps;
        this.newDeps = tmp;
        this.newDeps.length = 0;
    };

    /**
     * Subscriber interface.
     * Will be called when a dependency changes.
     */
    Watcher.prototype.update = function update() {
        /* istanbul ignore else */
        if (this.lazy) {
            this.dirty = true;
        } else if (this.sync) {
            this.run();
        } else {
            queueWatcher(this);
        }
    };

    /**
     * Scheduler job interface.
     * Will be called by the scheduler.
     */
    Watcher.prototype.run = function run() {
        if (this.active) {
            var value = this.get();
            if (
                value !== this.value ||
                // Deep watchers and watchers on Object/Arrays should fire even
                // when the value is the same, because the value may
                // have mutated.
                isObject(value) ||
                this.deep
            ) {
                // set new value
                var oldValue = this.value;
                this.value = value;
                if (this.user) {
                    try {
                        this.cb.call(this.vm, value, oldValue);
                    } catch (e) {
                        handleError(e, this.vm, ("callback for watcher \"" + (this.expression) + "\""));
                    }
                } else {
                    this.cb.call(this.vm, value, oldValue);
                }
            }
        }
    };

    /**
     * Evaluate the value of the watcher.
     * This only gets called for lazy watchers.
     */
    Watcher.prototype.evaluate = function evaluate() {
        this.value = this.get();
        this.dirty = false;
    };

    /**
     * Depend on all deps collected by this watcher.
     */
    Watcher.prototype.depend = function depend() {
        var this$1 = this;

        var i = this.deps.length;
        while (i--) {
            this$1.deps[i].depend();
        }
    };

    /**
     * Remove self from all dependencies' subscriber list.
     */
    Watcher.prototype.teardown = function teardown() {
        var this$1 = this;

        if (this.active) {
            // remove self from vm's watcher list
            // this is a somewhat expensive operation so we skip it
            // if the vm is being destroyed.
            if (!this.vm._isBeingDestroyed) {
                remove(this.vm._watchers, this);
            }
            var i = this.deps.length;
            while (i--) {
                this$1.deps[i].removeSub(this$1);
            }
            this.active = false;
        }
    };

    /**
     * Recursively traverse an object to evoke all converted
     * getters, so that every nested property inside the object
     * is collected as a "deep" dependency.
     */
    var seenObjects = new _Set();

    function traverse(val) {
        seenObjects.clear();
        _traverse(val, seenObjects);
    }

    function _traverse(val, seen) {
        var i, keys;
        var isA = Array.isArray(val);
        if ((!isA && !isObject(val)) || !Object.isExtensible(val)) {
            return
        }
        if (val.__ob__) {
            var depId = val.__ob__.dep.id;
            if (seen.has(depId)) {
                return
            }
            seen.add(depId);
        }
        if (isA) {
            i = val.length;
            while (i--) {
                _traverse(val[i], seen);
            }
        } else {
            keys = Object.keys(val);
            i = keys.length;
            while (i--) {
                _traverse(val[keys[i]], seen);
            }
        }
    }

    /*  */

    var sharedPropertyDefinition = {
        enumerable: true,
        configurable: true,
        get: noop,
        set: noop
    };

    function proxy(target, sourceKey, key) {
        sharedPropertyDefinition.get = function proxyGetter() {
            return this[sourceKey][key]
        };
        sharedPropertyDefinition.set = function proxySetter(val) {
            this[sourceKey][key] = val;
        };
        Object.defineProperty(target, key, sharedPropertyDefinition);
    }

    function initState(vm) {
        vm._watchers = [];
        var opts = vm.$options;
        if (opts.props) {
            initProps(vm, opts.props);
        }
        if (opts.methods) {
            initMethods(vm, opts.methods);
        }
        if (opts.data) {
            initData(vm);
        } else {
            observe(vm._data = {}, true /* asRootData */);
        }
        if (opts.computed) {
            initComputed(vm, opts.computed);
        }
        if (opts.watch) {
            initWatch(vm, opts.watch);
        }
    }

    var isReservedProp = {key: 1, ref: 1, slot: 1};

    function initProps(vm, propsOptions) {
        var propsData = vm.$options.propsData || {};
        var props = vm._props = {};
        // cache prop keys so that future props updates can iterate using Array
        // instead of dynamic object key enumeration.
        var keys = vm.$options._propKeys = [];
        var isRoot = !vm.$parent;
        // root instance props should be converted
        observerState.shouldConvert = isRoot;
        var loop = function (key) {
            keys.push(key);
            var value = validateProp(key, propsOptions, propsData, vm);
            /* istanbul ignore else */
            {
                if (isReservedProp[key]) {
                    warn(
                        ("\"" + key + "\" is a reserved attribute and cannot be used as component prop."),
                        vm
                    );
                }
                defineReactive$$1(props, key, value, function () {
                    if (vm.$parent && !observerState.isSettingProps) {
                        warn(
                            "Avoid mutating a prop directly since the value will be " +
                            "overwritten whenever the parent component re-renders. " +
                            "Instead, use a data or computed property based on the prop's " +
                            "value. Prop being mutated: \"" + key + "\"",
                            vm
                        );
                    }
                });
            }
            // static props are already proxied on the component's prototype
            // during Vue.extend(). We only need to proxy props defined at
            // instantiation here.
            if (!(key in vm)) {
                proxy(vm, "_props", key);
            }
        };

        for (var key in propsOptions) loop(key);
        observerState.shouldConvert = true;
    }

    function initData(vm) {
        var data = vm.$options.data;
        data = vm._data = typeof data === 'function'
            ? getData(data, vm)
            : data || {};
        if (!isPlainObject(data)) {
            data = {};
            "development" !== 'production' && warn(
                'data functions should return an object:\n' +
                'https://vuejs.org/v2/guide/components.html#data-Must-Be-a-Function',
                vm
            );
        }
        // proxy data on instance
        var keys = Object.keys(data);
        var props = vm.$options.props;
        var i = keys.length;
        while (i--) {
            if (props && hasOwn(props, keys[i])) {
                "development" !== 'production' && warn(
                    "The data property \"" + (keys[i]) + "\" is already declared as a prop. " +
                    "Use prop default value instead.",
                    vm
                );
            } else if (!isReserved(keys[i])) {
                proxy(vm, "_data", keys[i]);
            }
        }
        // observe data
        observe(data, true /* asRootData */);
    }

    function getData(data, vm) {
        try {
            return data.call(vm)
        } catch (e) {
            handleError(e, vm, "data()");
            return {}
        }
    }

    var computedWatcherOptions = {lazy: true};

    function initComputed(vm, computed) {
        var watchers = vm._computedWatchers = Object.create(null);

        for (var key in computed) {
            var userDef = computed[key];
            var getter = typeof userDef === 'function' ? userDef : userDef.get;
            {
                if (getter === undefined) {
                    warn(
                        ("No getter function has been defined for computed property \"" + key + "\"."),
                        vm
                    );
                    getter = noop;
                }
            }
            // create internal watcher for the computed property.
            watchers[key] = new Watcher(vm, getter, noop, computedWatcherOptions);

            // component-defined computed properties are already defined on the
            // component prototype. We only need to define computed properties defined
            // at instantiation here.
            if (!(key in vm)) {
                defineComputed(vm, key, userDef);
            }
        }
    }

    function defineComputed(target, key, userDef) {
        if (typeof userDef === 'function') {
            sharedPropertyDefinition.get = createComputedGetter(key);
            sharedPropertyDefinition.set = noop;
        } else {
            sharedPropertyDefinition.get = userDef.get
                ? userDef.cache !== false
                    ? createComputedGetter(key)
                    : userDef.get
                : noop;
            sharedPropertyDefinition.set = userDef.set
                ? userDef.set
                : noop;
        }
        Object.defineProperty(target, key, sharedPropertyDefinition);
    }

    function createComputedGetter(key) {
        return function computedGetter() {
            var watcher = this._computedWatchers && this._computedWatchers[key];
            if (watcher) {
                if (watcher.dirty) {
                    watcher.evaluate();
                }
                if (Dep.target) {
                    watcher.depend();
                }
                return watcher.value
            }
        }
    }

    function initMethods(vm, methods) {
        var props = vm.$options.props;
        for (var key in methods) {
            vm[key] = methods[key] == null ? noop : bind(methods[key], vm);
            {
                if (methods[key] == null) {
                    warn(
                        "method \"" + key + "\" has an undefined value in the component definition. " +
                        "Did you reference the function correctly?",
                        vm
                    );
                }
                if (props && hasOwn(props, key)) {
                    warn(
                        ("method \"" + key + "\" has already been defined as a prop."),
                        vm
                    );
                }
            }
        }
    }

    function initWatch(vm, watch) {
        for (var key in watch) {
            var handler = watch[key];
            if (Array.isArray(handler)) {
                for (var i = 0; i < handler.length; i++) {
                    createWatcher(vm, key, handler[i]);
                }
            } else {
                createWatcher(vm, key, handler);
            }
        }
    }

    function createWatcher(vm, key, handler) {
        var options;
        if (isPlainObject(handler)) {
            options = handler;
            handler = handler.handler;
        }
        if (typeof handler === 'string') {
            handler = vm[handler];
        }
        vm.$watch(key, handler, options);
    }

    function stateMixin(Vue) {
        // flow somehow has problems with directly declared definition object
        // when using Object.defineProperty, so we have to procedurally build up
        // the object here.
        var dataDef = {};
        dataDef.get = function () {
            return this._data
        };
        var propsDef = {};
        propsDef.get = function () {
            return this._props
        };
        {
            dataDef.set = function (newData) {
                warn(
                    'Avoid replacing instance root $data. ' +
                    'Use nested data properties instead.',
                    this
                );
            };
            propsDef.set = function () {
                warn("$props is readonly.", this);
            };
        }
        Object.defineProperty(Vue.prototype, '$data', dataDef);
        Object.defineProperty(Vue.prototype, '$props', propsDef);

        Vue.prototype.$set = set;
        Vue.prototype.$delete = del;

        Vue.prototype.$watch = function (
            expOrFn,
            cb,
            options
        ) {
            var vm = this;
            options = options || {};
            options.user = true;
            var watcher = new Watcher(vm, expOrFn, cb, options);
            if (options.immediate) {
                cb.call(vm, watcher.value);
            }
            return function unwatchFn() {
                watcher.teardown();
            }
        };
    }

    /*  */

// hooks to be invoked on component VNodes during patch
    var componentVNodeHooks = {
        init: function init(
            vnode,
            hydrating,
            parentElm,
            refElm
        ) {
            if (!vnode.componentInstance || vnode.componentInstance._isDestroyed) {
                var child = vnode.componentInstance = createComponentInstanceForVnode(
                    vnode,
                    activeInstance,
                    parentElm,
                    refElm
                );
                child.$mount(hydrating ? vnode.elm : undefined, hydrating);
            } else if (vnode.data.keepAlive) {
                // kept-alive components, treat as a patch
                var mountedNode = vnode; // work around flow
                componentVNodeHooks.prepatch(mountedNode, mountedNode);
            }
        },

        prepatch: function prepatch(oldVnode, vnode) {
            var options = vnode.componentOptions;
            var child = vnode.componentInstance = oldVnode.componentInstance;
            updateChildComponent(
                child,
                options.propsData, // updated props
                options.listeners, // updated listeners
                vnode, // new parent vnode
                options.children // new children
            );
        },

        insert: function insert(vnode) {
            if (!vnode.componentInstance._isMounted) {
                vnode.componentInstance._isMounted = true;
                callHook(vnode.componentInstance, 'mounted');
            }
            if (vnode.data.keepAlive) {
                activateChildComponent(vnode.componentInstance, true /* direct */);
            }
        },

        destroy: function destroy(vnode) {
            if (!vnode.componentInstance._isDestroyed) {
                if (!vnode.data.keepAlive) {
                    vnode.componentInstance.$destroy();
                } else {
                    deactivateChildComponent(vnode.componentInstance, true /* direct */);
                }
            }
        }
    };

    var hooksToMerge = Object.keys(componentVNodeHooks);

    function createComponent(
        Ctor,
        data,
        context,
        children,
        tag
    ) {
        if (!Ctor) {
            return
        }

        var baseCtor = context.$options._base;
        if (isObject(Ctor)) {
            Ctor = baseCtor.extend(Ctor);
        }

        if (typeof Ctor !== 'function') {
            {
                warn(("Invalid Component definition: " + (String(Ctor))), context);
            }
            return
        }

        // async component
        if (!Ctor.cid) {
            if (Ctor.resolved) {
                Ctor = Ctor.resolved;
            } else {
                Ctor = resolveAsyncComponent(Ctor, baseCtor, function () {
                    // it's ok to queue this on every render because
                    // $forceUpdate is buffered by the scheduler.
                    context.$forceUpdate();
                });
                if (!Ctor) {
                    // return nothing if this is indeed an async component
                    // wait for the callback to trigger parent update.
                    return
                }
            }
        }

        // resolve constructor options in case global mixins are applied after
        // component constructor creation
        resolveConstructorOptions(Ctor);

        data = data || {};

        // transform component v-model data into props & events
        if (data.model) {
            transformModel(Ctor.options, data);
        }

        // extract props
        var propsData = extractProps(data, Ctor, tag);

        // functional component
        if (Ctor.options.functional) {
            return createFunctionalComponent(Ctor, propsData, data, context, children)
        }

        // extract listeners, since these needs to be treated as
        // child component listeners instead of DOM listeners
        var listeners = data.on;
        // replace with listeners with .native modifier
        data.on = data.nativeOn;

        if (Ctor.options.abstract) {
            // abstract components do not keep anything
            // other than props & listeners
            data = {};
        }

        // merge component management hooks onto the placeholder node
        mergeHooks(data);

        // return a placeholder vnode
        var name = Ctor.options.name || tag;
        var vnode = new VNode(
            ("vue-component-" + (Ctor.cid) + (name ? ("-" + name) : '')),
            data, undefined, undefined, undefined, context,
            {Ctor: Ctor, propsData: propsData, listeners: listeners, tag: tag, children: children}
        );
        return vnode
    }

    function createFunctionalComponent(
        Ctor,
        propsData,
        data,
        context,
        children
    ) {
        var props = {};
        var propOptions = Ctor.options.props;
        if (propOptions) {
            for (var key in propOptions) {
                props[key] = validateProp(key, propOptions, propsData);
            }
        }
        // ensure the createElement function in functional components
        // gets a unique context - this is necessary for correct named slot check
        var _context = Object.create(context);
        var h = function (a, b, c, d) {
            return createElement(_context, a, b, c, d, true);
        };
        var vnode = Ctor.options.render.call(null, h, {
            props: props,
            data: data,
            parent: context,
            children: children,
            slots: function () {
                return resolveSlots(children, context);
            }
        });
        if (vnode instanceof VNode) {
            vnode.functionalContext = context;
            if (data.slot) {
                (vnode.data || (vnode.data = {})).slot = data.slot;
            }
        }
        return vnode
    }

    function createComponentInstanceForVnode(
        vnode, // we know it's MountedComponentVNode but flow doesn't
        parent, // activeInstance in lifecycle state
        parentElm,
        refElm
    ) {
        var vnodeComponentOptions = vnode.componentOptions;
        var options = {
            _isComponent: true,
            parent: parent,
            propsData: vnodeComponentOptions.propsData,
            _componentTag: vnodeComponentOptions.tag,
            _parentVnode: vnode,
            _parentListeners: vnodeComponentOptions.listeners,
            _renderChildren: vnodeComponentOptions.children,
            _parentElm: parentElm || null,
            _refElm: refElm || null
        };
        // check inline-template render functions
        var inlineTemplate = vnode.data.inlineTemplate;
        if (inlineTemplate) {
            options.render = inlineTemplate.render;
            options.staticRenderFns = inlineTemplate.staticRenderFns;
        }
        return new vnodeComponentOptions.Ctor(options)
    }

    function resolveAsyncComponent(
        factory,
        baseCtor,
        cb
    ) {
        if (factory.requested) {
            // pool callbacks
            factory.pendingCallbacks.push(cb);
        } else {
            factory.requested = true;
            var cbs = factory.pendingCallbacks = [cb];
            var sync = true;

            var resolve = function (res) {
                if (isObject(res)) {
                    res = baseCtor.extend(res);
                }
                // cache resolved
                factory.resolved = res;
                // invoke callbacks only if this is not a synchronous resolve
                // (async resolves are shimmed as synchronous during SSR)
                if (!sync) {
                    for (var i = 0, l = cbs.length; i < l; i++) {
                        cbs[i](res);
                    }
                }
            };

            var reject = function (reason) {
                "development" !== 'production' && warn(
                    "Failed to resolve async component: " + (String(factory)) +
                    (reason ? ("\nReason: " + reason) : '')
                );
            };

            var res = factory(resolve, reject);

            // handle promise
            if (res && typeof res.then === 'function' && !factory.resolved) {
                res.then(resolve, reject);
            }

            sync = false;
            // return in case resolved synchronously
            return factory.resolved
        }
    }

    function extractProps(data, Ctor, tag) {
        // we are only extracting raw values here.
        // validation and default values are handled in the child
        // component itself.
        var propOptions = Ctor.options.props;
        if (!propOptions) {
            return
        }
        var res = {};
        var attrs = data.attrs;
        var props = data.props;
        var domProps = data.domProps;
        if (attrs || props || domProps) {
            for (var key in propOptions) {
                var altKey = hyphenate(key);
                {
                    var keyInLowerCase = key.toLowerCase();
                    if (
                        key !== keyInLowerCase &&
                        attrs && attrs.hasOwnProperty(keyInLowerCase)
                    ) {
                        tip(
                            "Prop \"" + keyInLowerCase + "\" is passed to component " +
                            (formatComponentName(tag || Ctor)) + ", but the declared prop name is" +
                            " \"" + key + "\". " +
                            "Note that HTML attributes are case-insensitive and camelCased " +
                            "props need to use their kebab-case equivalents when using in-DOM " +
                            "templates. You should probably use \"" + altKey + "\" instead of \"" + key + "\"."
                        );
                    }
                }
                checkProp(res, props, key, altKey, true) ||
                checkProp(res, attrs, key, altKey) ||
                checkProp(res, domProps, key, altKey);
            }
        }
        return res
    }

    function checkProp(
        res,
        hash,
        key,
        altKey,
        preserve
    ) {
        if (hash) {
            if (hasOwn(hash, key)) {
                res[key] = hash[key];
                if (!preserve) {
                    delete hash[key];
                }
                return true
            } else if (hasOwn(hash, altKey)) {
                res[key] = hash[altKey];
                if (!preserve) {
                    delete hash[altKey];
                }
                return true
            }
        }
        return false
    }

    function mergeHooks(data) {
        if (!data.hook) {
            data.hook = {};
        }
        for (var i = 0; i < hooksToMerge.length; i++) {
            var key = hooksToMerge[i];
            var fromParent = data.hook[key];
            var ours = componentVNodeHooks[key];
            data.hook[key] = fromParent ? mergeHook$1(ours, fromParent) : ours;
        }
    }

    function mergeHook$1(one, two) {
        return function (a, b, c, d) {
            one(a, b, c, d);
            two(a, b, c, d);
        }
    }

// transform component v-model info (value and callback) into
// prop and event handler respectively.
    function transformModel(options, data) {
        var prop = (options.model && options.model.prop) || 'value';
        var event = (options.model && options.model.event) || 'input';
        (data.props || (data.props = {}))[prop] = data.model.value;
        var on = data.on || (data.on = {});
        if (on[event]) {
            on[event] = [data.model.callback].concat(on[event]);
        } else {
            on[event] = data.model.callback;
        }
    }

    /*  */

    var SIMPLE_NORMALIZE = 1;
    var ALWAYS_NORMALIZE = 2;

// wrapper function for providing a more flexible interface
// without getting yelled at by flow
    function createElement(
        context,
        tag,
        data,
        children,
        normalizationType,
        alwaysNormalize
    ) {
        if (Array.isArray(data) || isPrimitive(data)) {
            normalizationType = children;
            children = data;
            data = undefined;
        }
        if (alwaysNormalize) {
            normalizationType = ALWAYS_NORMALIZE;
        }
        return _createElement(context, tag, data, children, normalizationType)
    }

    function _createElement(
        context,
        tag,
        data,
        children,
        normalizationType
    ) {
        if (data && data.__ob__) {
            "development" !== 'production' && warn(
                "Avoid using observed data object as vnode data: " + (JSON.stringify(data)) + "\n" +
                'Always create fresh vnode data objects in each render!',
                context
            );
            return createEmptyVNode()
        }
        if (!tag) {
            // in case of component :is set to falsy value
            return createEmptyVNode()
        }
        // support single function children as default scoped slot
        if (Array.isArray(children) &&
            typeof children[0] === 'function') {
            data = data || {};
            data.scopedSlots = {default: children[0]};
            children.length = 0;
        }
        if (normalizationType === ALWAYS_NORMALIZE) {
            children = normalizeChildren(children);
        } else if (normalizationType === SIMPLE_NORMALIZE) {
            children = simpleNormalizeChildren(children);
        }
        var vnode, ns;
        if (typeof tag === 'string') {
            var Ctor;
            ns = config.getTagNamespace(tag);
            if (config.isReservedTag(tag)) {
                // platform built-in elements
                vnode = new VNode(
                    config.parsePlatformTagName(tag), data, children,
                    undefined, undefined, context
                );
            } else if ((Ctor = resolveAsset(context.$options, 'components', tag))) {
                // component
                vnode = createComponent(Ctor, data, context, children, tag);
            } else {
                // unknown or unlisted namespaced elements
                // check at runtime because it may get assigned a namespace when its
                // parent normalizes children
                vnode = new VNode(
                    tag, data, children,
                    undefined, undefined, context
                );
            }
        } else {
            // direct component options / constructor
            vnode = createComponent(tag, data, context, children);
        }
        if (vnode) {
            if (ns) {
                applyNS(vnode, ns);
            }
            return vnode
        } else {
            return createEmptyVNode()
        }
    }

    function applyNS(vnode, ns) {
        vnode.ns = ns;
        if (vnode.tag === 'foreignObject') {
            // use default namespace inside foreignObject
            return
        }
        if (vnode.children) {
            for (var i = 0, l = vnode.children.length; i < l; i++) {
                var child = vnode.children[i];
                if (child.tag && !child.ns) {
                    applyNS(child, ns);
                }
            }
        }
    }

    /*  */

    /**
     * Runtime helper for rendering v-for lists.
     */
    function renderList(
        val,
        render
    ) {
        var ret, i, l, keys, key;
        if (Array.isArray(val) || typeof val === 'string') {
            ret = new Array(val.length);
            for (i = 0, l = val.length; i < l; i++) {
                ret[i] = render(val[i], i);
            }
        } else if (typeof val === 'number') {
            ret = new Array(val);
            for (i = 0; i < val; i++) {
                ret[i] = render(i + 1, i);
            }
        } else if (isObject(val)) {
            keys = Object.keys(val);
            ret = new Array(keys.length);
            for (i = 0, l = keys.length; i < l; i++) {
                key = keys[i];
                ret[i] = render(val[key], key, i);
            }
        }
        return ret
    }

    /*  */

    /**
     * Runtime helper for rendering <slot>
     */
    function renderSlot(
        name,
        fallback,
        props,
        bindObject
    ) {
        var scopedSlotFn = this.$scopedSlots[name];
        if (scopedSlotFn) { // scoped slot
            props = props || {};
            if (bindObject) {
                extend(props, bindObject);
            }
            return scopedSlotFn(props) || fallback
        } else {
            var slotNodes = this.$slots[name];
            // warn duplicate slot usage
            if (slotNodes && "development" !== 'production') {
                slotNodes._rendered && warn(
                    "Duplicate presence of slot \"" + name + "\" found in the same render tree " +
                    "- this will likely cause render errors.",
                    this
                );
                slotNodes._rendered = true;
            }
            return slotNodes || fallback
        }
    }

    /*  */

    /**
     * Runtime helper for resolving filters
     */
    function resolveFilter(id) {
        return resolveAsset(this.$options, 'filters', id, true) || identity
    }

    /*  */

    /**
     * Runtime helper for checking keyCodes from config.
     */
    function checkKeyCodes(
        eventKeyCode,
        key,
        builtInAlias
    ) {
        var keyCodes = config.keyCodes[key] || builtInAlias;
        if (Array.isArray(keyCodes)) {
            return keyCodes.indexOf(eventKeyCode) === -1
        } else {
            return keyCodes !== eventKeyCode
        }
    }

    /*  */

    /**
     * Runtime helper for merging v-bind="object" into a VNode's data.
     */
    function bindObjectProps(
        data,
        tag,
        value,
        asProp
    ) {
        if (value) {
            if (!isObject(value)) {
                "development" !== 'production' && warn(
                    'v-bind without argument expects an Object or Array value',
                    this
                );
            } else {
                if (Array.isArray(value)) {
                    value = toObject(value);
                }
                var hash;
                for (var key in value) {
                    if (key === 'class' || key === 'style') {
                        hash = data;
                    } else {
                        var type = data.attrs && data.attrs.type;
                        hash = asProp || config.mustUseProp(tag, type, key)
                            ? data.domProps || (data.domProps = {})
                            : data.attrs || (data.attrs = {});
                    }
                    if (!(key in hash)) {
                        hash[key] = value[key];
                    }
                }
            }
        }
        return data
    }

    /*  */

    /**
     * Runtime helper for rendering static trees.
     */
    function renderStatic(
        index,
        isInFor
    ) {
        var tree = this._staticTrees[index];
        // if has already-rendered static tree and not inside v-for,
        // we can reuse the same tree by doing a shallow clone.
        if (tree && !isInFor) {
            return Array.isArray(tree)
                ? cloneVNodes(tree)
                : cloneVNode(tree)
        }
        // otherwise, render a fresh tree.
        tree = this._staticTrees[index] =
            this.$options.staticRenderFns[index].call(this._renderProxy);
        markStatic(tree, ("__static__" + index), false);
        return tree
    }

    /**
     * Runtime helper for v-once.
     * Effectively it means marking the node as static with a unique key.
     */
    function markOnce(
        tree,
        index,
        key
    ) {
        markStatic(tree, ("__once__" + index + (key ? ("_" + key) : "")), true);
        return tree
    }

    function markStatic(
        tree,
        key,
        isOnce
    ) {
        if (Array.isArray(tree)) {
            for (var i = 0; i < tree.length; i++) {
                if (tree[i] && typeof tree[i] !== 'string') {
                    markStaticNode(tree[i], (key + "_" + i), isOnce);
                }
            }
        } else {
            markStaticNode(tree, key, isOnce);
        }
    }

    function markStaticNode(node, key, isOnce) {
        node.isStatic = true;
        node.key = key;
        node.isOnce = isOnce;
    }

    /*  */

    function initRender(vm) {
        vm.$vnode = null; // the placeholder node in parent tree
        vm._vnode = null; // the root of the child tree
        vm._staticTrees = null;
        var parentVnode = vm.$options._parentVnode;
        var renderContext = parentVnode && parentVnode.context;
        vm.$slots = resolveSlots(vm.$options._renderChildren, renderContext);
        vm.$scopedSlots = emptyObject;
        // bind the createElement fn to this instance
        // so that we get proper render context inside it.
        // args order: tag, data, children, normalizationType, alwaysNormalize
        // internal version is used by render functions compiled from templates
        vm._c = function (a, b, c, d) {
            return createElement(vm, a, b, c, d, false);
        };
        // normalization is always applied for the public version, used in
        // user-written render functions.
        vm.$createElement = function (a, b, c, d) {
            return createElement(vm, a, b, c, d, true);
        };
    }

    function renderMixin(Vue) {
        Vue.prototype.$nextTick = function (fn) {
            return nextTick(fn, this)
        };

        Vue.prototype._render = function () {
            var vm = this;
            var ref = vm.$options;
            var render = ref.render;
            var staticRenderFns = ref.staticRenderFns;
            var _parentVnode = ref._parentVnode;

            if (vm._isMounted) {
                // clone slot nodes on re-renders
                for (var key in vm.$slots) {
                    vm.$slots[key] = cloneVNodes(vm.$slots[key]);
                }
            }

            vm.$scopedSlots = (_parentVnode && _parentVnode.data.scopedSlots) || emptyObject;

            if (staticRenderFns && !vm._staticTrees) {
                vm._staticTrees = [];
            }
            // set parent vnode. this allows render functions to have access
            // to the data on the placeholder node.
            vm.$vnode = _parentVnode;
            // render self
            var vnode;
            try {
                vnode = render.call(vm._renderProxy, vm.$createElement);
            } catch (e) {
                handleError(e, vm, "render function");
                // return error render result,
                // or previous vnode to prevent render error causing blank component
                /* istanbul ignore else */
                {
                    vnode = vm.$options.renderError
                        ? vm.$options.renderError.call(vm._renderProxy, vm.$createElement, e)
                        : vm._vnode;
                }
            }
            // return empty vnode in case the render function errored out
            if (!(vnode instanceof VNode)) {
                if ("development" !== 'production' && Array.isArray(vnode)) {
                    warn(
                        'Multiple root nodes returned from render function. Render function ' +
                        'should return a single root node.',
                        vm
                    );
                }
                vnode = createEmptyVNode();
            }
            // set parent
            vnode.parent = _parentVnode;
            return vnode
        };

        // internal render helpers.
        // these are exposed on the instance prototype to reduce generated render
        // code size.
        Vue.prototype._o = markOnce;
        Vue.prototype._n = toNumber;
        Vue.prototype._s = _toString;
        Vue.prototype._l = renderList;
        Vue.prototype._t = renderSlot;
        Vue.prototype._q = looseEqual;
        Vue.prototype._i = looseIndexOf;
        Vue.prototype._m = renderStatic;
        Vue.prototype._f = resolveFilter;
        Vue.prototype._k = checkKeyCodes;
        Vue.prototype._b = bindObjectProps;
        Vue.prototype._v = createTextVNode;
        Vue.prototype._e = createEmptyVNode;
        Vue.prototype._u = resolveScopedSlots;
    }

    /*  */

    function initProvide(vm) {
        var provide = vm.$options.provide;
        if (provide) {
            vm._provided = typeof provide === 'function'
                ? provide.call(vm)
                : provide;
        }
    }

    function initInjections(vm) {
        var inject = vm.$options.inject;
        if (inject) {
            // inject is :any because flow is not smart enough to figure out cached
            // isArray here
            var isArray = Array.isArray(inject);
            var keys = isArray
                ? inject
                : hasSymbol
                    ? Reflect.ownKeys(inject)
                    : Object.keys(inject);

            var loop = function (i) {
                var key = keys[i];
                var provideKey = isArray ? key : inject[key];
                var source = vm;
                while (source) {
                    if (source._provided && provideKey in source._provided) {
                        /* istanbul ignore else */
                        {
                            defineReactive$$1(vm, key, source._provided[provideKey], function () {
                                warn(
                                    "Avoid mutating an injected value directly since the changes will be " +
                                    "overwritten whenever the provided component re-renders. " +
                                    "injection being mutated: \"" + key + "\"",
                                    vm
                                );
                            });
                        }
                        break
                    }
                    source = source.$parent;
                }
            };

            for (var i = 0; i < keys.length; i++) loop(i);
        }
    }

    /*  */

    var uid = 0;

    function initMixin(Vue) {
        Vue.prototype._init = function (options) {
            var vm = this;
            // a uid
            vm._uid = uid++;

            var startTag, endTag;
            /* istanbul ignore if */
            if ("development" !== 'production' && config.performance && mark) {
                startTag = "vue-perf-init:" + (vm._uid);
                endTag = "vue-perf-end:" + (vm._uid);
                mark(startTag);
            }

            // a flag to avoid this being observed
            vm._isVue = true;
            // merge options
            if (options && options._isComponent) {
                // optimize internal component instantiation
                // since dynamic options merging is pretty slow, and none of the
                // internal component options needs special treatment.
                initInternalComponent(vm, options);
            } else {
                vm.$options = mergeOptions(
                    resolveConstructorOptions(vm.constructor),
                    options || {},
                    vm
                );
            }
            /* istanbul ignore else */
            {
                initProxy(vm);
            }
            // expose real self
            vm._self = vm;
            initLifecycle(vm);
            initEvents(vm);
            initRender(vm);
            callHook(vm, 'beforeCreate');
            initInjections(vm); // resolve injections before data/props
            initState(vm);
            initProvide(vm); // resolve provide after data/props
            callHook(vm, 'created');

            /* istanbul ignore if */
            if ("development" !== 'production' && config.performance && mark) {
                vm._name = formatComponentName(vm, false);
                mark(endTag);
                measure(((vm._name) + " init"), startTag, endTag);
            }

            if (vm.$options.el) {
                vm.$mount(vm.$options.el);
            }
        };
    }

    function initInternalComponent(vm, options) {
        var opts = vm.$options = Object.create(vm.constructor.options);
        // doing this because it's faster than dynamic enumeration.
        opts.parent = options.parent;
        opts.propsData = options.propsData;
        opts._parentVnode = options._parentVnode;
        opts._parentListeners = options._parentListeners;
        opts._renderChildren = options._renderChildren;
        opts._componentTag = options._componentTag;
        opts._parentElm = options._parentElm;
        opts._refElm = options._refElm;
        if (options.render) {
            opts.render = options.render;
            opts.staticRenderFns = options.staticRenderFns;
        }
    }

    function resolveConstructorOptions(Ctor) {
        var options = Ctor.options;
        if (Ctor.super) {
            var superOptions = resolveConstructorOptions(Ctor.super);
            var cachedSuperOptions = Ctor.superOptions;
            if (superOptions !== cachedSuperOptions) {
                // super option changed,
                // need to resolve new options.
                Ctor.superOptions = superOptions;
                // check if there are any late-modified/attached options (#4976)
                var modifiedOptions = resolveModifiedOptions(Ctor);
                // update base extend options
                if (modifiedOptions) {
                    extend(Ctor.extendOptions, modifiedOptions);
                }
                options = Ctor.options = mergeOptions(superOptions, Ctor.extendOptions);
                if (options.name) {
                    options.components[options.name] = Ctor;
                }
            }
        }
        return options
    }

    function resolveModifiedOptions(Ctor) {
        var modified;
        var latest = Ctor.options;
        var sealed = Ctor.sealedOptions;
        for (var key in latest) {
            if (latest[key] !== sealed[key]) {
                if (!modified) {
                    modified = {};
                }
                modified[key] = dedupe(latest[key], sealed[key]);
            }
        }
        return modified
    }

    function dedupe(latest, sealed) {
        // compare latest and sealed to ensure lifecycle hooks won't be duplicated
        // between merges
        if (Array.isArray(latest)) {
            var res = [];
            sealed = Array.isArray(sealed) ? sealed : [sealed];
            for (var i = 0; i < latest.length; i++) {
                if (sealed.indexOf(latest[i]) < 0) {
                    res.push(latest[i]);
                }
            }
            return res
        } else {
            return latest
        }
    }

    function Vue$2(options) {
        if ("development" !== 'production' &&
            !(this instanceof Vue$2)) {
            warn('Vue is a constructor and should be called with the `new` keyword');
        }
        this._init(options);
    }

    initMixin(Vue$2);
    stateMixin(Vue$2);
    eventsMixin(Vue$2);
    lifecycleMixin(Vue$2);
    renderMixin(Vue$2);

    /*  */

    function initUse(Vue) {
        Vue.use = function (plugin) {
            /* istanbul ignore if */
            if (plugin.installed) {
                return
            }
            // additional parameters
            var args = toArray(arguments, 1);
            args.unshift(this);
            if (typeof plugin.install === 'function') {
                plugin.install.apply(plugin, args);
            } else if (typeof plugin === 'function') {
                plugin.apply(null, args);
            }
            plugin.installed = true;
            return this
        };
    }

    /*  */

    function initMixin$1(Vue) {
        Vue.mixin = function (mixin) {
            this.options = mergeOptions(this.options, mixin);
        };
    }

    /*  */

    function initExtend(Vue) {
        /**
         * Each instance constructor, including Vue, has a unique
         * cid. This enables us to create wrapped "child
         * constructors" for prototypal inheritance and cache them.
         */
        Vue.cid = 0;
        var cid = 1;

        /**
         * Class inheritance
         */
        Vue.extend = function (extendOptions) {
            extendOptions = extendOptions || {};
            var Super = this;
            var SuperId = Super.cid;
            var cachedCtors = extendOptions._Ctor || (extendOptions._Ctor = {});
            if (cachedCtors[SuperId]) {
                return cachedCtors[SuperId]
            }

            var name = extendOptions.name || Super.options.name;
            {
                if (!/^[a-zA-Z][\w-]*$/.test(name)) {
                    warn(
                        'Invalid component name: "' + name + '". Component names ' +
                        'can only contain alphanumeric characters and the hyphen, ' +
                        'and must start with a letter.'
                    );
                }
            }

            var Sub = function VueComponent(options) {
                this._init(options);
            };
            Sub.prototype = Object.create(Super.prototype);
            Sub.prototype.constructor = Sub;
            Sub.cid = cid++;
            Sub.options = mergeOptions(
                Super.options,
                extendOptions
            );
            Sub['super'] = Super;

            // For props and computed properties, we define the proxy getters on
            // the Vue instances at extension time, on the extended prototype. This
            // avoids Object.defineProperty calls for each instance created.
            if (Sub.options.props) {
                initProps$1(Sub);
            }
            if (Sub.options.computed) {
                initComputed$1(Sub);
            }

            // allow further extension/mixin/plugin usage
            Sub.extend = Super.extend;
            Sub.mixin = Super.mixin;
            Sub.use = Super.use;

            // create asset registers, so extended classes
            // can have their private assets too.
            config._assetTypes.forEach(function (type) {
                Sub[type] = Super[type];
            });
            // enable recursive self-lookup
            if (name) {
                Sub.options.components[name] = Sub;
            }

            // keep a reference to the super options at extension time.
            // later at instantiation we can check if Super's options have
            // been updated.
            Sub.superOptions = Super.options;
            Sub.extendOptions = extendOptions;
            Sub.sealedOptions = extend({}, Sub.options);

            // cache constructor
            cachedCtors[SuperId] = Sub;
            return Sub
        };
    }

    function initProps$1(Comp) {
        var props = Comp.options.props;
        for (var key in props) {
            proxy(Comp.prototype, "_props", key);
        }
    }

    function initComputed$1(Comp) {
        var computed = Comp.options.computed;
        for (var key in computed) {
            defineComputed(Comp.prototype, key, computed[key]);
        }
    }

    /*  */

    function initAssetRegisters(Vue) {
        /**
         * Create asset registration methods.
         */
        config._assetTypes.forEach(function (type) {
            Vue[type] = function (
                id,
                definition
            ) {
                if (!definition) {
                    return this.options[type + 's'][id]
                } else {
                    /* istanbul ignore if */
                    {
                        if (type === 'component' && config.isReservedTag(id)) {
                            warn(
                                'Do not use built-in or reserved HTML elements as component ' +
                                'id: ' + id
                            );
                        }
                    }
                    if (type === 'component' && isPlainObject(definition)) {
                        definition.name = definition.name || id;
                        definition = this.options._base.extend(definition);
                    }
                    if (type === 'directive' && typeof definition === 'function') {
                        definition = {bind: definition, update: definition};
                    }
                    this.options[type + 's'][id] = definition;
                    return definition
                }
            };
        });
    }

    /*  */

    var patternTypes = [String, RegExp];

    function getComponentName(opts) {
        return opts && (opts.Ctor.options.name || opts.tag)
    }

    function matches(pattern, name) {
        if (typeof pattern === 'string') {
            return pattern.split(',').indexOf(name) > -1
        } else if (pattern instanceof RegExp) {
            return pattern.test(name)
        }
        /* istanbul ignore next */
        return false
    }

    function pruneCache(cache, filter) {
        for (var key in cache) {
            var cachedNode = cache[key];
            if (cachedNode) {
                var name = getComponentName(cachedNode.componentOptions);
                if (name && !filter(name)) {
                    pruneCacheEntry(cachedNode);
                    cache[key] = null;
                }
            }
        }
    }

    function pruneCacheEntry(vnode) {
        if (vnode) {
            if (!vnode.componentInstance._inactive) {
                callHook(vnode.componentInstance, 'deactivated');
            }
            vnode.componentInstance.$destroy();
        }
    }

    var KeepAlive = {
        name: 'keep-alive',
        abstract: true,

        props: {
            include: patternTypes,
            exclude: patternTypes
        },

        created: function created() {
            this.cache = Object.create(null);
        },

        destroyed: function destroyed() {
            var this$1 = this;

            for (var key in this$1.cache) {
                pruneCacheEntry(this$1.cache[key]);
            }
        },

        watch: {
            include: function include(val) {
                pruneCache(this.cache, function (name) {
                    return matches(val, name);
                });
            },
            exclude: function exclude(val) {
                pruneCache(this.cache, function (name) {
                    return !matches(val, name);
                });
            }
        },

        render: function render() {
            var vnode = getFirstComponentChild(this.$slots.default);
            var componentOptions = vnode && vnode.componentOptions;
            if (componentOptions) {
                // check pattern
                var name = getComponentName(componentOptions);
                if (name && (
                    (this.include && !matches(this.include, name)) ||
                    (this.exclude && matches(this.exclude, name))
                )) {
                    return vnode
                }
                var key = vnode.key == null
                    // same constructor may get registered as different local components
                    // so cid alone is not enough (#3269)
                    ? componentOptions.Ctor.cid + (componentOptions.tag ? ("::" + (componentOptions.tag)) : '')
                    : vnode.key;
                if (this.cache[key]) {
                    vnode.componentInstance = this.cache[key].componentInstance;
                } else {
                    this.cache[key] = vnode;
                }
                vnode.data.keepAlive = true;
            }
            return vnode
        }
    };

    var builtInComponents = {
        KeepAlive: KeepAlive
    };

    /*  */

    function initGlobalAPI(Vue) {
        // config
        var configDef = {};
        configDef.get = function () {
            return config;
        };
        {
            configDef.set = function () {
                warn(
                    'Do not replace the Vue.config object, set individual fields instead.'
                );
            };
        }
        Object.defineProperty(Vue, 'config', configDef);

        // exposed util methods.
        // NOTE: these are not considered part of the public API - avoid relying on
        // them unless you are aware of the risk.
        Vue.util = {
            warn: warn,
            extend: extend,
            mergeOptions: mergeOptions,
            defineReactive: defineReactive$$1
        };

        Vue.set = set;
        Vue.delete = del;
        Vue.nextTick = nextTick;

        Vue.options = Object.create(null);
        config._assetTypes.forEach(function (type) {
            Vue.options[type + 's'] = Object.create(null);
        });

        // this is used to identify the "base" constructor to extend all plain-object
        // components with in Weex's multi-instance scenarios.
        Vue.options._base = Vue;

        extend(Vue.options.components, builtInComponents);

        initUse(Vue);
        initMixin$1(Vue);
        initExtend(Vue);
        initAssetRegisters(Vue);
    }

    initGlobalAPI(Vue$2);

    Object.defineProperty(Vue$2.prototype, '$isServer', {
        get: isServerRendering
    });

    Vue$2.version = '2.2.6';

    /*  */

// attributes that should be using props for binding
    var acceptValue = makeMap('input,textarea,option,select');
    var mustUseProp = function (tag, type, attr) {
        return (
            (attr === 'value' && acceptValue(tag)) && type !== 'button' ||
            (attr === 'selected' && tag === 'option') ||
            (attr === 'checked' && tag === 'input') ||
            (attr === 'muted' && tag === 'video')
        )
    };

    var isEnumeratedAttr = makeMap('contenteditable,draggable,spellcheck');

    var isBooleanAttr = makeMap(
        'allowfullscreen,async,autofocus,autoplay,checked,compact,controls,declare,' +
        'default,defaultchecked,defaultmuted,defaultselected,defer,disabled,' +
        'enabled,formnovalidate,hidden,indeterminate,inert,ismap,itemscope,loop,multiple,' +
        'muted,nohref,noresize,noshade,novalidate,nowrap,open,pauseonexit,readonly,' +
        'required,reversed,scoped,seamless,selected,sortable,translate,' +
        'truespeed,typemustmatch,visible'
    );

    var xlinkNS = 'http://www.w3.org/1999/xlink';

    var isXlink = function (name) {
        return name.charAt(5) === ':' && name.slice(0, 5) === 'xlink'
    };

    var getXlinkProp = function (name) {
        return isXlink(name) ? name.slice(6, name.length) : ''
    };

    var isFalsyAttrValue = function (val) {
        return val == null || val === false
    };

    /*  */

    function genClassForVnode(vnode) {
        var data = vnode.data;
        var parentNode = vnode;
        var childNode = vnode;
        while (childNode.componentInstance) {
            childNode = childNode.componentInstance._vnode;
            if (childNode.data) {
                data = mergeClassData(childNode.data, data);
            }
        }
        while ((parentNode = parentNode.parent)) {
            if (parentNode.data) {
                data = mergeClassData(data, parentNode.data);
            }
        }
        return genClassFromData(data)
    }

    function mergeClassData(child, parent) {
        return {
            staticClass: concat(child.staticClass, parent.staticClass),
            class: child.class
                ? [child.class, parent.class]
                : parent.class
        }
    }

    function genClassFromData(data) {
        var dynamicClass = data.class;
        var staticClass = data.staticClass;
        if (staticClass || dynamicClass) {
            return concat(staticClass, stringifyClass(dynamicClass))
        }
        /* istanbul ignore next */
        return ''
    }

    function concat(a, b) {
        return a ? b ? (a + ' ' + b) : a : (b || '')
    }

    function stringifyClass(value) {
        var res = '';
        if (!value) {
            return res
        }
        if (typeof value === 'string') {
            return value
        }
        if (Array.isArray(value)) {
            var stringified;
            for (var i = 0, l = value.length; i < l; i++) {
                if (value[i]) {
                    if ((stringified = stringifyClass(value[i]))) {
                        res += stringified + ' ';
                    }
                }
            }
            return res.slice(0, -1)
        }
        if (isObject(value)) {
            for (var key in value) {
                if (value[key]) {
                    res += key + ' ';
                }
            }
            return res.slice(0, -1)
        }
        /* istanbul ignore next */
        return res
    }

    /*  */

    var namespaceMap = {
        svg: 'http://www.w3.org/2000/svg',
        math: 'http://www.w3.org/1998/Math/MathML'
    };

    var isHTMLTag = makeMap(
        'html,body,base,head,link,meta,style,title,' +
        'address,article,aside,footer,header,h1,h2,h3,h4,h5,h6,hgroup,nav,section,' +
        'div,dd,dl,dt,figcaption,figure,hr,img,li,main,ol,p,pre,ul,' +
        'a,b,abbr,bdi,bdo,br,cite,code,data,dfn,em,i,kbd,mark,q,rp,rt,rtc,ruby,' +
        's,samp,small,span,strong,sub,sup,time,u,var,wbr,area,audio,map,track,video,' +
        'embed,object,param,source,canvas,script,noscript,del,ins,' +
        'caption,col,colgroup,table,thead,tbody,td,th,tr,' +
        'button,datalist,fieldset,form,input,label,legend,meter,optgroup,option,' +
        'output,progress,select,textarea,' +
        'details,dialog,menu,menuitem,summary,' +
        'content,element,shadow,template'
    );

// this map is intentionally selective, only covering SVG elements that may
// contain child elements.
    var isSVG = makeMap(
        'svg,animate,circle,clippath,cursor,defs,desc,ellipse,filter,font-face,' +
        'foreignObject,g,glyph,image,line,marker,mask,missing-glyph,path,pattern,' +
        'polygon,polyline,rect,switch,symbol,text,textpath,tspan,use,view',
        true
    );


    var isReservedTag = function (tag) {
        return isHTMLTag(tag) || isSVG(tag)
    };

    function getTagNamespace(tag) {
        if (isSVG(tag)) {
            return 'svg'
        }
        // basic support for MathML
        // note it doesn't support other MathML elements being component roots
        if (tag === 'math') {
            return 'math'
        }
    }

    var unknownElementCache = Object.create(null);

    function isUnknownElement(tag) {
        /* istanbul ignore if */
        if (!inBrowser) {
            return true
        }
        if (isReservedTag(tag)) {
            return false
        }
        tag = tag.toLowerCase();
        /* istanbul ignore if */
        if (unknownElementCache[tag] != null) {
            return unknownElementCache[tag]
        }
        var el = document.createElement(tag);
        if (tag.indexOf('-') > -1) {
            // http://stackoverflow.com/a/28210364/1070244
            return (unknownElementCache[tag] = (
                el.constructor === window.HTMLUnknownElement ||
                el.constructor === window.HTMLElement
            ))
        } else {
            return (unknownElementCache[tag] = /HTMLUnknownElement/.test(el.toString()))
        }
    }

    /*  */

    /**
     * Query an element selector if it's not an element already.
     */
    function query(el) {
        if (typeof el === 'string') {
            var selected = document.querySelector(el);
            if (!selected) {
                "development" !== 'production' && warn(
                    'Cannot find element: ' + el
                );
                return document.createElement('div')
            }
            return selected
        } else {
            return el
        }
    }

    /*  */

    function createElement$1(tagName, vnode) {
        var elm = document.createElement(tagName);
        if (tagName !== 'select') {
            return elm
        }
        // false or null will remove the attribute but undefined will not
        if (vnode.data && vnode.data.attrs && vnode.data.attrs.multiple !== undefined) {
            elm.setAttribute('multiple', 'multiple');
        }
        return elm
    }

    function createElementNS(namespace, tagName) {
        return document.createElementNS(namespaceMap[namespace], tagName)
    }

    function createTextNode(text) {
        return document.createTextNode(text)
    }

    function createComment(text) {
        return document.createComment(text)
    }

    function insertBefore(parentNode, newNode, referenceNode) {
        parentNode.insertBefore(newNode, referenceNode);
    }

    function removeChild(node, child) {
        node.removeChild(child);
    }

    function appendChild(node, child) {
        node.appendChild(child);
    }

    function parentNode(node) {
        return node.parentNode
    }

    function nextSibling(node) {
        return node.nextSibling
    }

    function tagName(node) {
        return node.tagName
    }

    function setTextContent(node, text) {
        node.textContent = text;
    }

    function setAttribute(node, key, val) {
        node.setAttribute(key, val);
    }


    var nodeOps = Object.freeze({
        createElement: createElement$1,
        createElementNS: createElementNS,
        createTextNode: createTextNode,
        createComment: createComment,
        insertBefore: insertBefore,
        removeChild: removeChild,
        appendChild: appendChild,
        parentNode: parentNode,
        nextSibling: nextSibling,
        tagName: tagName,
        setTextContent: setTextContent,
        setAttribute: setAttribute
    });

    /*  */

    var ref = {
        create: function create(_, vnode) {
            registerRef(vnode);
        },
        update: function update(oldVnode, vnode) {
            if (oldVnode.data.ref !== vnode.data.ref) {
                registerRef(oldVnode, true);
                registerRef(vnode);
            }
        },
        destroy: function destroy(vnode) {
            registerRef(vnode, true);
        }
    };

    function registerRef(vnode, isRemoval) {
        var key = vnode.data.ref;
        if (!key) {
            return
        }

        var vm = vnode.context;
        var ref = vnode.componentInstance || vnode.elm;
        var refs = vm.$refs;
        if (isRemoval) {
            if (Array.isArray(refs[key])) {
                remove(refs[key], ref);
            } else if (refs[key] === ref) {
                refs[key] = undefined;
            }
        } else {
            if (vnode.data.refInFor) {
                if (Array.isArray(refs[key]) && refs[key].indexOf(ref) < 0) {
                    refs[key].push(ref);
                } else {
                    refs[key] = [ref];
                }
            } else {
                refs[key] = ref;
            }
        }
    }

    /**
     * Virtual DOM patching algorithm based on Snabbdom by
     * Simon Friis Vindum (@paldepind)
     * Licensed under the MIT License
     * https://github.com/paldepind/snabbdom/blob/master/LICENSE
     *
     * modified by Evan You (@yyx990803)
     *

     /*
     * Not type-checking this because this file is perf-critical and the cost
     * of making flow understand it is not worth it.
     */

    var emptyNode = new VNode('', {}, []);

    var hooks = ['create', 'activate', 'update', 'remove', 'destroy'];

    function isUndef(v) {
        return v === undefined || v === null
    }

    function isDef(v) {
        return v !== undefined && v !== null
    }

    function isTrue(v) {
        return v === true
    }

    function sameVnode(a, b) {
        return (
            a.key === b.key &&
            a.tag === b.tag &&
            a.isComment === b.isComment &&
            isDef(a.data) === isDef(b.data) &&
            sameInputType(a, b)
        )
    }

// Some browsers do not support dynamically changing type for <input>
// so they need to be treated as different nodes
    function sameInputType(a, b) {
        if (a.tag !== 'input') {
            return true
        }
        var i;
        var typeA = isDef(i = a.data) && isDef(i = i.attrs) && i.type;
        var typeB = isDef(i = b.data) && isDef(i = i.attrs) && i.type;
        return typeA === typeB
    }

    function createKeyToOldIdx(children, beginIdx, endIdx) {
        var i, key;
        var map = {};
        for (i = beginIdx; i <= endIdx; ++i) {
            key = children[i].key;
            if (isDef(key)) {
                map[key] = i;
            }
        }
        return map
    }

    function createPatchFunction(backend) {
        var i, j;
        var cbs = {};

        var modules = backend.modules;
        var nodeOps = backend.nodeOps;

        for (i = 0; i < hooks.length; ++i) {
            cbs[hooks[i]] = [];
            for (j = 0; j < modules.length; ++j) {
                if (isDef(modules[j][hooks[i]])) {
                    cbs[hooks[i]].push(modules[j][hooks[i]]);
                }
            }
        }

        function emptyNodeAt(elm) {
            return new VNode(nodeOps.tagName(elm).toLowerCase(), {}, [], undefined, elm)
        }

        function createRmCb(childElm, listeners) {
            function remove$$1() {
                if (--remove$$1.listeners === 0) {
                    removeNode(childElm);
                }
            }

            remove$$1.listeners = listeners;
            return remove$$1
        }

        function removeNode(el) {
            var parent = nodeOps.parentNode(el);
            // element may have already been removed due to v-html / v-text
            if (isDef(parent)) {
                nodeOps.removeChild(parent, el);
            }
        }

        var inPre = 0;

        function createElm(vnode, insertedVnodeQueue, parentElm, refElm, nested) {
            vnode.isRootInsert = !nested; // for transition enter check
            if (createComponent(vnode, insertedVnodeQueue, parentElm, refElm)) {
                return
            }

            var data = vnode.data;
            var children = vnode.children;
            var tag = vnode.tag;
            if (isDef(tag)) {
                {
                    if (data && data.pre) {
                        inPre++;
                    }
                    if (
                        !inPre &&
                        !vnode.ns &&
                        !(config.ignoredElements.length && config.ignoredElements.indexOf(tag) > -1) &&
                        config.isUnknownElement(tag)
                    ) {
                        warn(
                            'Unknown custom element: <' + tag + '> - did you ' +
                            'register the component correctly? For recursive components, ' +
                            'make sure to provide the "name" option.',
                            vnode.context
                        );
                    }
                }
                vnode.elm = vnode.ns
                    ? nodeOps.createElementNS(vnode.ns, tag)
                    : nodeOps.createElement(tag, vnode);
                setScope(vnode);

                /* istanbul ignore if */
                {
                    createChildren(vnode, children, insertedVnodeQueue);
                    if (isDef(data)) {
                        invokeCreateHooks(vnode, insertedVnodeQueue);
                    }
                    insert(parentElm, vnode.elm, refElm);
                }

                if ("development" !== 'production' && data && data.pre) {
                    inPre--;
                }
            } else if (isTrue(vnode.isComment)) {
                vnode.elm = nodeOps.createComment(vnode.text);
                insert(parentElm, vnode.elm, refElm);
            } else {
                vnode.elm = nodeOps.createTextNode(vnode.text);
                insert(parentElm, vnode.elm, refElm);
            }
        }

        function createComponent(vnode, insertedVnodeQueue, parentElm, refElm) {
            var i = vnode.data;
            if (isDef(i)) {
                var isReactivated = isDef(vnode.componentInstance) && i.keepAlive;
                if (isDef(i = i.hook) && isDef(i = i.init)) {
                    i(vnode, false /* hydrating */, parentElm, refElm);
                }
                // after calling the init hook, if the vnode is a child component
                // it should've created a child instance and mounted it. the child
                // component also has set the placeholder vnode's elm.
                // in that case we can just return the element and be done.
                if (isDef(vnode.componentInstance)) {
                    initComponent(vnode, insertedVnodeQueue);
                    if (isTrue(isReactivated)) {
                        reactivateComponent(vnode, insertedVnodeQueue, parentElm, refElm);
                    }
                    return true
                }
            }
        }

        function initComponent(vnode, insertedVnodeQueue) {
            if (isDef(vnode.data.pendingInsert)) {
                insertedVnodeQueue.push.apply(insertedVnodeQueue, vnode.data.pendingInsert);
            }
            vnode.elm = vnode.componentInstance.$el;
            if (isPatchable(vnode)) {
                invokeCreateHooks(vnode, insertedVnodeQueue);
                setScope(vnode);
            } else {
                // empty component root.
                // skip all element-related modules except for ref (#3455)
                registerRef(vnode);
                // make sure to invoke the insert hook
                insertedVnodeQueue.push(vnode);
            }
        }

        function reactivateComponent(vnode, insertedVnodeQueue, parentElm, refElm) {
            var i;
            // hack for #4339: a reactivated component with inner transition
            // does not trigger because the inner node's created hooks are not called
            // again. It's not ideal to involve module-specific logic in here but
            // there doesn't seem to be a better way to do it.
            var innerNode = vnode;
            while (innerNode.componentInstance) {
                innerNode = innerNode.componentInstance._vnode;
                if (isDef(i = innerNode.data) && isDef(i = i.transition)) {
                    for (i = 0; i < cbs.activate.length; ++i) {
                        cbs.activate[i](emptyNode, innerNode);
                    }
                    insertedVnodeQueue.push(innerNode);
                    break
                }
            }
            // unlike a newly created component,
            // a reactivated keep-alive component doesn't insert itself
            insert(parentElm, vnode.elm, refElm);
        }

        function insert(parent, elm, ref) {
            if (isDef(parent)) {
                if (isDef(ref)) {
                    nodeOps.insertBefore(parent, elm, ref);
                } else {
                    nodeOps.appendChild(parent, elm);
                }
            }
        }

        function createChildren(vnode, children, insertedVnodeQueue) {
            if (Array.isArray(children)) {
                for (var i = 0; i < children.length; ++i) {
                    createElm(children[i], insertedVnodeQueue, vnode.elm, null, true);
                }
            } else if (isPrimitive(vnode.text)) {
                nodeOps.appendChild(vnode.elm, nodeOps.createTextNode(vnode.text));
            }
        }

        function isPatchable(vnode) {
            while (vnode.componentInstance) {
                vnode = vnode.componentInstance._vnode;
            }
            return isDef(vnode.tag)
        }

        function invokeCreateHooks(vnode, insertedVnodeQueue) {
            for (var i$1 = 0; i$1 < cbs.create.length; ++i$1) {
                cbs.create[i$1](emptyNode, vnode);
            }
            i = vnode.data.hook; // Reuse variable
            if (isDef(i)) {
                if (isDef(i.create)) {
                    i.create(emptyNode, vnode);
                }
                if (isDef(i.insert)) {
                    insertedVnodeQueue.push(vnode);
                }
            }
        }

        // set scope id attribute for scoped CSS.
        // this is implemented as a special case to avoid the overhead
        // of going through the normal attribute patching process.
        function setScope(vnode) {
            var i;
            var ancestor = vnode;
            while (ancestor) {
                if (isDef(i = ancestor.context) && isDef(i = i.$options._scopeId)) {
                    nodeOps.setAttribute(vnode.elm, i, '');
                }
                ancestor = ancestor.parent;
            }
            // for slot content they should also get the scopeId from the host instance.
            if (isDef(i = activeInstance) &&
                i !== vnode.context &&
                isDef(i = i.$options._scopeId)) {
                nodeOps.setAttribute(vnode.elm, i, '');
            }
        }

        function addVnodes(parentElm, refElm, vnodes, startIdx, endIdx, insertedVnodeQueue) {
            for (; startIdx <= endIdx; ++startIdx) {
                createElm(vnodes[startIdx], insertedVnodeQueue, parentElm, refElm);
            }
        }

        function invokeDestroyHook(vnode) {
            var i, j;
            var data = vnode.data;
            if (isDef(data)) {
                if (isDef(i = data.hook) && isDef(i = i.destroy)) {
                    i(vnode);
                }
                for (i = 0; i < cbs.destroy.length; ++i) {
                    cbs.destroy[i](vnode);
                }
            }
            if (isDef(i = vnode.children)) {
                for (j = 0; j < vnode.children.length; ++j) {
                    invokeDestroyHook(vnode.children[j]);
                }
            }
        }

        function removeVnodes(parentElm, vnodes, startIdx, endIdx) {
            for (; startIdx <= endIdx; ++startIdx) {
                var ch = vnodes[startIdx];
                if (isDef(ch)) {
                    if (isDef(ch.tag)) {
                        removeAndInvokeRemoveHook(ch);
                        invokeDestroyHook(ch);
                    } else { // Text node
                        removeNode(ch.elm);
                    }
                }
            }
        }

        function removeAndInvokeRemoveHook(vnode, rm) {
            if (isDef(rm) || isDef(vnode.data)) {
                var listeners = cbs.remove.length + 1;
                if (isDef(rm)) {
                    // we have a recursively passed down rm callback
                    // increase the listeners count
                    rm.listeners += listeners;
                } else {
                    // directly removing
                    rm = createRmCb(vnode.elm, listeners);
                }
                // recursively invoke hooks on child component root node
                if (isDef(i = vnode.componentInstance) && isDef(i = i._vnode) && isDef(i.data)) {
                    removeAndInvokeRemoveHook(i, rm);
                }
                for (i = 0; i < cbs.remove.length; ++i) {
                    cbs.remove[i](vnode, rm);
                }
                if (isDef(i = vnode.data.hook) && isDef(i = i.remove)) {
                    i(vnode, rm);
                } else {
                    rm();
                }
            } else {
                removeNode(vnode.elm);
            }
        }

        function updateChildren(parentElm, oldCh, newCh, insertedVnodeQueue, removeOnly) {
            var oldStartIdx = 0;
            var newStartIdx = 0;
            var oldEndIdx = oldCh.length - 1;
            var oldStartVnode = oldCh[0];
            var oldEndVnode = oldCh[oldEndIdx];
            var newEndIdx = newCh.length - 1;
            var newStartVnode = newCh[0];
            var newEndVnode = newCh[newEndIdx];
            var oldKeyToIdx, idxInOld, elmToMove, refElm;

            // removeOnly is a special flag used only by <transition-group>
            // to ensure removed elements stay in correct relative positions
            // during leaving transitions
            var canMove = !removeOnly;

            while (oldStartIdx <= oldEndIdx && newStartIdx <= newEndIdx) {
                if (isUndef(oldStartVnode)) {
                    oldStartVnode = oldCh[++oldStartIdx]; // Vnode has been moved left
                } else if (isUndef(oldEndVnode)) {
                    oldEndVnode = oldCh[--oldEndIdx];
                } else if (sameVnode(oldStartVnode, newStartVnode)) {
                    patchVnode(oldStartVnode, newStartVnode, insertedVnodeQueue);
                    oldStartVnode = oldCh[++oldStartIdx];
                    newStartVnode = newCh[++newStartIdx];
                } else if (sameVnode(oldEndVnode, newEndVnode)) {
                    patchVnode(oldEndVnode, newEndVnode, insertedVnodeQueue);
                    oldEndVnode = oldCh[--oldEndIdx];
                    newEndVnode = newCh[--newEndIdx];
                } else if (sameVnode(oldStartVnode, newEndVnode)) { // Vnode moved right
                    patchVnode(oldStartVnode, newEndVnode, insertedVnodeQueue);
                    canMove && nodeOps.insertBefore(parentElm, oldStartVnode.elm, nodeOps.nextSibling(oldEndVnode.elm));
                    oldStartVnode = oldCh[++oldStartIdx];
                    newEndVnode = newCh[--newEndIdx];
                } else if (sameVnode(oldEndVnode, newStartVnode)) { // Vnode moved left
                    patchVnode(oldEndVnode, newStartVnode, insertedVnodeQueue);
                    canMove && nodeOps.insertBefore(parentElm, oldEndVnode.elm, oldStartVnode.elm);
                    oldEndVnode = oldCh[--oldEndIdx];
                    newStartVnode = newCh[++newStartIdx];
                } else {
                    if (isUndef(oldKeyToIdx)) {
                        oldKeyToIdx = createKeyToOldIdx(oldCh, oldStartIdx, oldEndIdx);
                    }
                    idxInOld = isDef(newStartVnode.key) ? oldKeyToIdx[newStartVnode.key] : null;
                    if (isUndef(idxInOld)) { // New element
                        createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm);
                        newStartVnode = newCh[++newStartIdx];
                    } else {
                        elmToMove = oldCh[idxInOld];
                        /* istanbul ignore if */
                        if ("development" !== 'production' && !elmToMove) {
                            warn(
                                'It seems there are duplicate keys that is causing an update error. ' +
                                'Make sure each v-for item has a unique key.'
                            );
                        }
                        if (sameVnode(elmToMove, newStartVnode)) {
                            patchVnode(elmToMove, newStartVnode, insertedVnodeQueue);
                            oldCh[idxInOld] = undefined;
                            canMove && nodeOps.insertBefore(parentElm, newStartVnode.elm, oldStartVnode.elm);
                            newStartVnode = newCh[++newStartIdx];
                        } else {
                            // same key but different element. treat as new element
                            createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm);
                            newStartVnode = newCh[++newStartIdx];
                        }
                    }
                }
            }
            if (oldStartIdx > oldEndIdx) {
                refElm = isUndef(newCh[newEndIdx + 1]) ? null : newCh[newEndIdx + 1].elm;
                addVnodes(parentElm, refElm, newCh, newStartIdx, newEndIdx, insertedVnodeQueue);
            } else if (newStartIdx > newEndIdx) {
                removeVnodes(parentElm, oldCh, oldStartIdx, oldEndIdx);
            }
        }

        function patchVnode(oldVnode, vnode, insertedVnodeQueue, removeOnly) {
            if (oldVnode === vnode) {
                return
            }
            // reuse element for static trees.
            // note we only do this if the vnode is cloned -
            // if the new node is not cloned it means the render functions have been
            // reset by the hot-reload-api and we need to do a proper re-render.
            if (isTrue(vnode.isStatic) &&
                isTrue(oldVnode.isStatic) &&
                vnode.key === oldVnode.key &&
                (isTrue(vnode.isCloned) || isTrue(vnode.isOnce))) {
                vnode.elm = oldVnode.elm;
                vnode.componentInstance = oldVnode.componentInstance;
                return
            }
            var i;
            var data = vnode.data;
            if (isDef(data) && isDef(i = data.hook) && isDef(i = i.prepatch)) {
                i(oldVnode, vnode);
            }
            var elm = vnode.elm = oldVnode.elm;
            var oldCh = oldVnode.children;
            var ch = vnode.children;
            if (isDef(data) && isPatchable(vnode)) {
                for (i = 0; i < cbs.update.length; ++i) {
                    cbs.update[i](oldVnode, vnode);
                }
                if (isDef(i = data.hook) && isDef(i = i.update)) {
                    i(oldVnode, vnode);
                }
            }
            if (isUndef(vnode.text)) {
                if (isDef(oldCh) && isDef(ch)) {
                    if (oldCh !== ch) {
                        updateChildren(elm, oldCh, ch, insertedVnodeQueue, removeOnly);
                    }
                } else if (isDef(ch)) {
                    if (isDef(oldVnode.text)) {
                        nodeOps.setTextContent(elm, '');
                    }
                    addVnodes(elm, null, ch, 0, ch.length - 1, insertedVnodeQueue);
                } else if (isDef(oldCh)) {
                    removeVnodes(elm, oldCh, 0, oldCh.length - 1);
                } else if (isDef(oldVnode.text)) {
                    nodeOps.setTextContent(elm, '');
                }
            } else if (oldVnode.text !== vnode.text) {
                nodeOps.setTextContent(elm, vnode.text);
            }
            if (isDef(data)) {
                if (isDef(i = data.hook) && isDef(i = i.postpatch)) {
                    i(oldVnode, vnode);
                }
            }
        }

        function invokeInsertHook(vnode, queue, initial) {
            // delay insert hooks for component root nodes, invoke them after the
            // element is really inserted
            if (isTrue(initial) && isDef(vnode.parent)) {
                vnode.parent.data.pendingInsert = queue;
            } else {
                for (var i = 0; i < queue.length; ++i) {
                    queue[i].data.hook.insert(queue[i]);
                }
            }
        }

        var bailed = false;
        // list of modules that can skip create hook during hydration because they
        // are already rendered on the client or has no need for initialization
        var isRenderedModule = makeMap('attrs,style,class,staticClass,staticStyle,key');

        // Note: this is a browser-only function so we can assume elms are DOM nodes.
        function hydrate(elm, vnode, insertedVnodeQueue) {
            {
                if (!assertNodeMatch(elm, vnode)) {
                    return false
                }
            }
            vnode.elm = elm;
            var tag = vnode.tag;
            var data = vnode.data;
            var children = vnode.children;
            if (isDef(data)) {
                if (isDef(i = data.hook) && isDef(i = i.init)) {
                    i(vnode, true /* hydrating */);
                }
                if (isDef(i = vnode.componentInstance)) {
                    // child component. it should have hydrated its own tree.
                    initComponent(vnode, insertedVnodeQueue);
                    return true
                }
            }
            if (isDef(tag)) {
                if (isDef(children)) {
                    // empty element, allow client to pick up and populate children
                    if (!elm.hasChildNodes()) {
                        createChildren(vnode, children, insertedVnodeQueue);
                    } else {
                        var childrenMatch = true;
                        var childNode = elm.firstChild;
                        for (var i$1 = 0; i$1 < children.length; i$1++) {
                            if (!childNode || !hydrate(childNode, children[i$1], insertedVnodeQueue)) {
                                childrenMatch = false;
                                break
                            }
                            childNode = childNode.nextSibling;
                        }
                        // if childNode is not null, it means the actual childNodes list is
                        // longer than the virtual children list.
                        if (!childrenMatch || childNode) {
                            if ("development" !== 'production' &&
                                typeof console !== 'undefined' &&
                                !bailed) {
                                bailed = true;
                                console.warn('Parent: ', elm);
                                console.warn('Mismatching childNodes vs. VNodes: ', elm.childNodes, children);
                            }
                            return false
                        }
                    }
                }
                if (isDef(data)) {
                    for (var key in data) {
                        if (!isRenderedModule(key)) {
                            invokeCreateHooks(vnode, insertedVnodeQueue);
                            break
                        }
                    }
                }
            } else if (elm.data !== vnode.text) {
                elm.data = vnode.text;
            }
            return true
        }

        function assertNodeMatch(node, vnode) {
            if (isDef(vnode.tag)) {
                return (
                    vnode.tag.indexOf('vue-component') === 0 ||
                    vnode.tag.toLowerCase() === (node.tagName && node.tagName.toLowerCase())
                )
            } else {
                return node.nodeType === (vnode.isComment ? 8 : 3)
            }
        }

        return function patch(oldVnode, vnode, hydrating, removeOnly, parentElm, refElm) {
            if (isUndef(vnode)) {
                if (isDef(oldVnode)) {
                    invokeDestroyHook(oldVnode);
                }
                return
            }

            var isInitialPatch = false;
            var insertedVnodeQueue = [];

            if (isUndef(oldVnode)) {
                // empty mount (likely as component), create new root element
                isInitialPatch = true;
                createElm(vnode, insertedVnodeQueue, parentElm, refElm);
            } else {
                var isRealElement = isDef(oldVnode.nodeType);
                if (!isRealElement && sameVnode(oldVnode, vnode)) {
                    // patch existing root node
                    patchVnode(oldVnode, vnode, insertedVnodeQueue, removeOnly);
                } else {
                    if (isRealElement) {
                        // mounting to a real element
                        // check if this is server-rendered content and if we can perform
                        // a successful hydration.
                        if (oldVnode.nodeType === 1 && oldVnode.hasAttribute('server-rendered')) {
                            oldVnode.removeAttribute('server-rendered');
                            hydrating = true;
                        }
                        if (isTrue(hydrating)) {
                            if (hydrate(oldVnode, vnode, insertedVnodeQueue)) {
                                invokeInsertHook(vnode, insertedVnodeQueue, true);
                                return oldVnode
                            } else {
                                warn(
                                    'The client-side rendered virtual DOM tree is not matching ' +
                                    'server-rendered content. This is likely caused by incorrect ' +
                                    'HTML markup, for example nesting block-level elements inside ' +
                                    '<p>, or missing <tbody>. Bailing hydration and performing ' +
                                    'full client-side render.'
                                );
                            }
                        }
                        // either not server-rendered, or hydration failed.
                        // create an empty node and replace it
                        oldVnode = emptyNodeAt(oldVnode);
                    }
                    // replacing existing element
                    var oldElm = oldVnode.elm;
                    var parentElm$1 = nodeOps.parentNode(oldElm);
                    createElm(
                        vnode,
                        insertedVnodeQueue,
                        // extremely rare edge case: do not insert if old element is in a
                        // leaving transition. Only happens when combining transition +
                        // keep-alive + HOCs. (#4590)
                        oldElm._leaveCb ? null : parentElm$1,
                        nodeOps.nextSibling(oldElm)
                    );

                    if (isDef(vnode.parent)) {
                        // component root element replaced.
                        // update parent placeholder node element, recursively
                        var ancestor = vnode.parent;
                        while (ancestor) {
                            ancestor.elm = vnode.elm;
                            ancestor = ancestor.parent;
                        }
                        if (isPatchable(vnode)) {
                            for (var i = 0; i < cbs.create.length; ++i) {
                                cbs.create[i](emptyNode, vnode.parent);
                            }
                        }
                    }

                    if (isDef(parentElm$1)) {
                        removeVnodes(parentElm$1, [oldVnode], 0, 0);
                    } else if (isDef(oldVnode.tag)) {
                        invokeDestroyHook(oldVnode);
                    }
                }
            }

            invokeInsertHook(vnode, insertedVnodeQueue, isInitialPatch);
            return vnode.elm
        }
    }

    /*  */

    var directives = {
        create: updateDirectives,
        update: updateDirectives,
        destroy: function unbindDirectives(vnode) {
            updateDirectives(vnode, emptyNode);
        }
    };

    function updateDirectives(oldVnode, vnode) {
        if (oldVnode.data.directives || vnode.data.directives) {
            _update(oldVnode, vnode);
        }
    }

    function _update(oldVnode, vnode) {
        var isCreate = oldVnode === emptyNode;
        var isDestroy = vnode === emptyNode;
        var oldDirs = normalizeDirectives$1(oldVnode.data.directives, oldVnode.context);
        var newDirs = normalizeDirectives$1(vnode.data.directives, vnode.context);

        var dirsWithInsert = [];
        var dirsWithPostpatch = [];

        var key, oldDir, dir;
        for (key in newDirs) {
            oldDir = oldDirs[key];
            dir = newDirs[key];
            if (!oldDir) {
                // new directive, bind
                callHook$1(dir, 'bind', vnode, oldVnode);
                if (dir.def && dir.def.inserted) {
                    dirsWithInsert.push(dir);
                }
            } else {
                // existing directive, update
                dir.oldValue = oldDir.value;
                callHook$1(dir, 'update', vnode, oldVnode);
                if (dir.def && dir.def.componentUpdated) {
                    dirsWithPostpatch.push(dir);
                }
            }
        }

        if (dirsWithInsert.length) {
            var callInsert = function () {
                for (var i = 0; i < dirsWithInsert.length; i++) {
                    callHook$1(dirsWithInsert[i], 'inserted', vnode, oldVnode);
                }
            };
            if (isCreate) {
                mergeVNodeHook(vnode.data.hook || (vnode.data.hook = {}), 'insert', callInsert);
            } else {
                callInsert();
            }
        }

        if (dirsWithPostpatch.length) {
            mergeVNodeHook(vnode.data.hook || (vnode.data.hook = {}), 'postpatch', function () {
                for (var i = 0; i < dirsWithPostpatch.length; i++) {
                    callHook$1(dirsWithPostpatch[i], 'componentUpdated', vnode, oldVnode);
                }
            });
        }

        if (!isCreate) {
            for (key in oldDirs) {
                if (!newDirs[key]) {
                    // no longer present, unbind
                    callHook$1(oldDirs[key], 'unbind', oldVnode, oldVnode, isDestroy);
                }
            }
        }
    }

    var emptyModifiers = Object.create(null);

    function normalizeDirectives$1(
        dirs,
        vm
    ) {
        var res = Object.create(null);
        if (!dirs) {
            return res
        }
        var i, dir;
        for (i = 0; i < dirs.length; i++) {
            dir = dirs[i];
            if (!dir.modifiers) {
                dir.modifiers = emptyModifiers;
            }
            res[getRawDirName(dir)] = dir;
            dir.def = resolveAsset(vm.$options, 'directives', dir.name, true);
        }
        return res
    }

    function getRawDirName(dir) {
        return dir.rawName || ((dir.name) + "." + (Object.keys(dir.modifiers || {}).join('.')))
    }

    function callHook$1(dir, hook, vnode, oldVnode, isDestroy) {
        var fn = dir.def && dir.def[hook];
        if (fn) {
            fn(vnode.elm, dir, vnode, oldVnode, isDestroy);
        }
    }

    var baseModules = [
        ref,
        directives
    ];

    /*  */

    function updateAttrs(oldVnode, vnode) {
        if (!oldVnode.data.attrs && !vnode.data.attrs) {
            return
        }
        var key, cur, old;
        var elm = vnode.elm;
        var oldAttrs = oldVnode.data.attrs || {};
        var attrs = vnode.data.attrs || {};
        // clone observed objects, as the user probably wants to mutate it
        if (attrs.__ob__) {
            attrs = vnode.data.attrs = extend({}, attrs);
        }

        for (key in attrs) {
            cur = attrs[key];
            old = oldAttrs[key];
            if (old !== cur) {
                setAttr(elm, key, cur);
            }
        }
        // #4391: in IE9, setting type can reset value for input[type=radio]
        /* istanbul ignore if */
        if (isIE9 && attrs.value !== oldAttrs.value) {
            setAttr(elm, 'value', attrs.value);
        }
        for (key in oldAttrs) {
            if (attrs[key] == null) {
                if (isXlink(key)) {
                    elm.removeAttributeNS(xlinkNS, getXlinkProp(key));
                } else if (!isEnumeratedAttr(key)) {
                    elm.removeAttribute(key);
                }
            }
        }
    }

    function setAttr(el, key, value) {
        if (isBooleanAttr(key)) {
            // set attribute for blank value
            // e.g. <option disabled>Select one</option>
            if (isFalsyAttrValue(value)) {
                el.removeAttribute(key);
            } else {
                el.setAttribute(key, key);
            }
        } else if (isEnumeratedAttr(key)) {
            el.setAttribute(key, isFalsyAttrValue(value) || value === 'false' ? 'false' : 'true');
        } else if (isXlink(key)) {
            if (isFalsyAttrValue(value)) {
                el.removeAttributeNS(xlinkNS, getXlinkProp(key));
            } else {
                el.setAttributeNS(xlinkNS, key, value);
            }
        } else {
            if (isFalsyAttrValue(value)) {
                el.removeAttribute(key);
            } else {
                el.setAttribute(key, value);
            }
        }
    }

    var attrs = {
        create: updateAttrs,
        update: updateAttrs
    };

    /*  */

    function updateClass(oldVnode, vnode) {
        var el = vnode.elm;
        var data = vnode.data;
        var oldData = oldVnode.data;
        if (!data.staticClass && !data.class &&
            (!oldData || (!oldData.staticClass && !oldData.class))) {
            return
        }

        var cls = genClassForVnode(vnode);

        // handle transition classes
        var transitionClass = el._transitionClasses;
        if (transitionClass) {
            cls = concat(cls, stringifyClass(transitionClass));
        }

        // set the class
        if (cls !== el._prevClass) {
            el.setAttribute('class', cls);
            el._prevClass = cls;
        }
    }

    var klass = {
        create: updateClass,
        update: updateClass
    };

    /*  */

    var validDivisionCharRE = /[\w).+\-_$\]]/;


    function wrapFilter(exp, filter) {
        var i = filter.indexOf('(');
        if (i < 0) {
            // _f: resolveFilter
            return ("_f(\"" + filter + "\")(" + exp + ")")
        } else {
            var name = filter.slice(0, i);
            var args = filter.slice(i + 1);
            return ("_f(\"" + name + "\")(" + exp + "," + args)
        }
    }

    /*  */

    /*  */

    /**
     * Cross-platform code generation for component v-model
     */


    /**
     * Cross-platform codegen helper for generating v-model value assignment code.
     */


    /**
     * parse directive model to do the array update transform. a[idx] = val => $$a.splice($$idx, 1, val)
     *
     * for loop possible cases:
     *
     * - test
     * - test[idx]
     * - test[test1[idx]]
     * - test["a"][idx]
     * - xxx.test[a[a].test1[idx]]
     * - test.xxx.a["asa"][test1[idx]]
     *
     */

    var str;
    var index$1;

    /*  */

// in some cases, the event used has to be determined at runtime
// so we used some reserved tokens during compile.
    var RANGE_TOKEN = '__r';
    var CHECKBOX_RADIO_TOKEN = '__c';

    /*  */

// normalize v-model event tokens that can only be determined at runtime.
// it's important to place the event as the first in the array because
// the whole point is ensuring the v-model callback gets called before
// user-attached handlers.
    function normalizeEvents(on) {
        var event;
        /* istanbul ignore if */
        if (on[RANGE_TOKEN]) {
            // IE input[type=range] only supports `change` event
            event = isIE ? 'change' : 'input';
            on[event] = [].concat(on[RANGE_TOKEN], on[event] || []);
            delete on[RANGE_TOKEN];
        }
        if (on[CHECKBOX_RADIO_TOKEN]) {
            // Chrome fires microtasks in between click/change, leads to #4521
            event = isChrome ? 'click' : 'change';
            on[event] = [].concat(on[CHECKBOX_RADIO_TOKEN], on[event] || []);
            delete on[CHECKBOX_RADIO_TOKEN];
        }
    }

    var target$1;

    function add$1(
        event,
        handler,
        once,
        capture
    ) {
        if (once) {
            var oldHandler = handler;
            var _target = target$1; // save current target element in closure
            handler = function (ev) {
                var res = arguments.length === 1
                    ? oldHandler(ev)
                    : oldHandler.apply(null, arguments);
                if (res !== null) {
                    remove$2(event, handler, capture, _target);
                }
            };
        }
        target$1.addEventListener(event, handler, capture);
    }

    function remove$2(
        event,
        handler,
        capture,
        _target
    ) {
        (_target || target$1).removeEventListener(event, handler, capture);
    }

    function updateDOMListeners(oldVnode, vnode) {
        if (!oldVnode.data.on && !vnode.data.on) {
            return
        }
        var on = vnode.data.on || {};
        var oldOn = oldVnode.data.on || {};
        target$1 = vnode.elm;
        normalizeEvents(on);
        updateListeners(on, oldOn, add$1, remove$2, vnode.context);
    }

    var events = {
        create: updateDOMListeners,
        update: updateDOMListeners
    };

    /*  */

    function updateDOMProps(oldVnode, vnode) {
        if (!oldVnode.data.domProps && !vnode.data.domProps) {
            return
        }
        var key, cur;
        var elm = vnode.elm;
        var oldProps = oldVnode.data.domProps || {};
        var props = vnode.data.domProps || {};
        // clone observed objects, as the user probably wants to mutate it
        if (props.__ob__) {
            props = vnode.data.domProps = extend({}, props);
        }

        for (key in oldProps) {
            if (props[key] == null) {
                elm[key] = '';
            }
        }
        for (key in props) {
            cur = props[key];
            // ignore children if the node has textContent or innerHTML,
            // as these will throw away existing DOM nodes and cause removal errors
            // on subsequent patches (#3360)
            if (key === 'textContent' || key === 'innerHTML') {
                if (vnode.children) {
                    vnode.children.length = 0;
                }
                if (cur === oldProps[key]) {
                    continue
                }
            }

            if (key === 'value') {
                // store value as _value as well since
                // non-string values will be stringified
                elm._value = cur;
                // avoid resetting cursor position when value is the same
                var strCur = cur == null ? '' : String(cur);
                if (shouldUpdateValue(elm, vnode, strCur)) {
                    elm.value = strCur;
                }
            } else {
                elm[key] = cur;
            }
        }
    }

// check platforms/web/util/attrs.js acceptValue


    function shouldUpdateValue(
        elm,
        vnode,
        checkVal
    ) {
        return (!elm.composing && (
            vnode.tag === 'option' ||
            isDirty(elm, checkVal) ||
            isInputChanged(elm, checkVal)
        ))
    }

    function isDirty(elm, checkVal) {
        // return true when textbox (.number and .trim) loses focus and its value is not equal to the updated value
        return document.activeElement !== elm && elm.value !== checkVal
    }

    function isInputChanged(elm, newVal) {
        var value = elm.value;
        var modifiers = elm._vModifiers; // injected by v-model runtime
        if ((modifiers && modifiers.number) || elm.type === 'number') {
            return toNumber(value) !== toNumber(newVal)
        }
        if (modifiers && modifiers.trim) {
            return value.trim() !== newVal.trim()
        }
        return value !== newVal
    }

    var domProps = {
        create: updateDOMProps,
        update: updateDOMProps
    };

    /*  */

    var parseStyleText = cached(function (cssText) {
        var res = {};
        var listDelimiter = /;(?![^(]*\))/g;
        var propertyDelimiter = /:(.+)/;
        cssText.split(listDelimiter).forEach(function (item) {
            if (item) {
                var tmp = item.split(propertyDelimiter);
                tmp.length > 1 && (res[tmp[0].trim()] = tmp[1].trim());
            }
        });
        return res
    });

// merge static and dynamic style data on the same vnode
    function normalizeStyleData(data) {
        var style = normalizeStyleBinding(data.style);
        // static style is pre-processed into an object during compilation
        // and is always a fresh object, so it's safe to merge into it
        return data.staticStyle
            ? extend(data.staticStyle, style)
            : style
    }

// normalize possible array / string values into Object
    function normalizeStyleBinding(bindingStyle) {
        if (Array.isArray(bindingStyle)) {
            return toObject(bindingStyle)
        }
        if (typeof bindingStyle === 'string') {
            return parseStyleText(bindingStyle)
        }
        return bindingStyle
    }

    /**
     * parent component style should be after child's
     * so that parent component's style could override it
     */
    function getStyle(vnode, checkChild) {
        var res = {};
        var styleData;

        if (checkChild) {
            var childNode = vnode;
            while (childNode.componentInstance) {
                childNode = childNode.componentInstance._vnode;
                if (childNode.data && (styleData = normalizeStyleData(childNode.data))) {
                    extend(res, styleData);
                }
            }
        }

        if ((styleData = normalizeStyleData(vnode.data))) {
            extend(res, styleData);
        }

        var parentNode = vnode;
        while ((parentNode = parentNode.parent)) {
            if (parentNode.data && (styleData = normalizeStyleData(parentNode.data))) {
                extend(res, styleData);
            }
        }
        return res
    }

    /*  */

    var cssVarRE = /^--/;
    var importantRE = /\s*!important$/;
    var setProp = function (el, name, val) {
        /* istanbul ignore if */
        if (cssVarRE.test(name)) {
            el.style.setProperty(name, val);
        } else if (importantRE.test(val)) {
            el.style.setProperty(name, val.replace(importantRE, ''), 'important');
        } else {
            el.style[normalize(name)] = val;
        }
    };

    var prefixes = ['Webkit', 'Moz', 'ms'];

    var testEl;
    var normalize = cached(function (prop) {
        testEl = testEl || document.createElement('div');
        prop = camelize(prop);
        if (prop !== 'filter' && (prop in testEl.style)) {
            return prop
        }
        var upper = prop.charAt(0).toUpperCase() + prop.slice(1);
        for (var i = 0; i < prefixes.length; i++) {
            var prefixed = prefixes[i] + upper;
            if (prefixed in testEl.style) {
                return prefixed
            }
        }
    });

    function updateStyle(oldVnode, vnode) {
        var data = vnode.data;
        var oldData = oldVnode.data;

        if (!data.staticStyle && !data.style &&
            !oldData.staticStyle && !oldData.style) {
            return
        }

        var cur, name;
        var el = vnode.elm;
        var oldStaticStyle = oldVnode.data.staticStyle;
        var oldStyleBinding = oldVnode.data.style || {};

        // if static style exists, stylebinding already merged into it when doing normalizeStyleData
        var oldStyle = oldStaticStyle || oldStyleBinding;

        var style = normalizeStyleBinding(vnode.data.style) || {};

        vnode.data.style = style.__ob__ ? extend({}, style) : style;

        var newStyle = getStyle(vnode, true);

        for (name in oldStyle) {
            if (newStyle[name] == null) {
                setProp(el, name, '');
            }
        }
        for (name in newStyle) {
            cur = newStyle[name];
            if (cur !== oldStyle[name]) {
                // ie9 setting to null has no effect, must use empty string
                setProp(el, name, cur == null ? '' : cur);
            }
        }
    }

    var style = {
        create: updateStyle,
        update: updateStyle
    };

    /*  */

    /**
     * Add class with compatibility for SVG since classList is not supported on
     * SVG elements in IE
     */
    function addClass(el, cls) {
        /* istanbul ignore if */
        if (!cls || !(cls = cls.trim())) {
            return
        }

        /* istanbul ignore else */
        if (el.classList) {
            if (cls.indexOf(' ') > -1) {
                cls.split(/\s+/).forEach(function (c) {
                    return el.classList.add(c);
                });
            } else {
                el.classList.add(cls);
            }
        } else {
            var cur = " " + (el.getAttribute('class') || '') + " ";
            if (cur.indexOf(' ' + cls + ' ') < 0) {
                el.setAttribute('class', (cur + cls).trim());
            }
        }
    }

    /**
     * Remove class with compatibility for SVG since classList is not supported on
     * SVG elements in IE
     */
    function removeClass(el, cls) {
        /* istanbul ignore if */
        if (!cls || !(cls = cls.trim())) {
            return
        }

        /* istanbul ignore else */
        if (el.classList) {
            if (cls.indexOf(' ') > -1) {
                cls.split(/\s+/).forEach(function (c) {
                    return el.classList.remove(c);
                });
            } else {
                el.classList.remove(cls);
            }
        } else {
            var cur = " " + (el.getAttribute('class') || '') + " ";
            var tar = ' ' + cls + ' ';
            while (cur.indexOf(tar) >= 0) {
                cur = cur.replace(tar, ' ');
            }
            el.setAttribute('class', cur.trim());
        }
    }

    /*  */

    function resolveTransition(def$$1) {
        if (!def$$1) {
            return
        }
        /* istanbul ignore else */
        if (typeof def$$1 === 'object') {
            var res = {};
            if (def$$1.css !== false) {
                extend(res, autoCssTransition(def$$1.name || 'v'));
            }
            extend(res, def$$1);
            return res
        } else if (typeof def$$1 === 'string') {
            return autoCssTransition(def$$1)
        }
    }

    var autoCssTransition = cached(function (name) {
        return {
            enterClass: (name + "-enter"),
            enterToClass: (name + "-enter-to"),
            enterActiveClass: (name + "-enter-active"),
            leaveClass: (name + "-leave"),
            leaveToClass: (name + "-leave-to"),
            leaveActiveClass: (name + "-leave-active")
        }
    });

    var hasTransition = inBrowser && !isIE9;
    var TRANSITION = 'transition';
    var ANIMATION = 'animation';

// Transition property/event sniffing
    var transitionProp = 'transition';
    var transitionEndEvent = 'transitionend';
    var animationProp = 'animation';
    var animationEndEvent = 'animationend';
    if (hasTransition) {
        /* istanbul ignore if */
        if (window.ontransitionend === undefined &&
            window.onwebkittransitionend !== undefined) {
            transitionProp = 'WebkitTransition';
            transitionEndEvent = 'webkitTransitionEnd';
        }
        if (window.onanimationend === undefined &&
            window.onwebkitanimationend !== undefined) {
            animationProp = 'WebkitAnimation';
            animationEndEvent = 'webkitAnimationEnd';
        }
    }

// binding to window is necessary to make hot reload work in IE in strict mode
    var raf = inBrowser && window.requestAnimationFrame
        ? window.requestAnimationFrame.bind(window)
        : setTimeout;

    function nextFrame(fn) {
        raf(function () {
            raf(fn);
        });
    }

    function addTransitionClass(el, cls) {
        (el._transitionClasses || (el._transitionClasses = [])).push(cls);
        addClass(el, cls);
    }

    function removeTransitionClass(el, cls) {
        if (el._transitionClasses) {
            remove(el._transitionClasses, cls);
        }
        removeClass(el, cls);
    }

    function whenTransitionEnds(
        el,
        expectedType,
        cb
    ) {
        var ref = getTransitionInfo(el, expectedType);
        var type = ref.type;
        var timeout = ref.timeout;
        var propCount = ref.propCount;
        if (!type) {
            return cb()
        }
        var event = type === TRANSITION ? transitionEndEvent : animationEndEvent;
        var ended = 0;
        var end = function () {
            el.removeEventListener(event, onEnd);
            cb();
        };
        var onEnd = function (e) {
            if (e.target === el) {
                if (++ended >= propCount) {
                    end();
                }
            }
        };
        setTimeout(function () {
            if (ended < propCount) {
                end();
            }
        }, timeout + 1);
        el.addEventListener(event, onEnd);
    }

    var transformRE = /\b(transform|all)(,|$)/;

    function getTransitionInfo(el, expectedType) {
        var styles = window.getComputedStyle(el);
        var transitionDelays = styles[transitionProp + 'Delay'].split(', ');
        var transitionDurations = styles[transitionProp + 'Duration'].split(', ');
        var transitionTimeout = getTimeout(transitionDelays, transitionDurations);
        var animationDelays = styles[animationProp + 'Delay'].split(', ');
        var animationDurations = styles[animationProp + 'Duration'].split(', ');
        var animationTimeout = getTimeout(animationDelays, animationDurations);

        var type;
        var timeout = 0;
        var propCount = 0;
        /* istanbul ignore if */
        if (expectedType === TRANSITION) {
            if (transitionTimeout > 0) {
                type = TRANSITION;
                timeout = transitionTimeout;
                propCount = transitionDurations.length;
            }
        } else if (expectedType === ANIMATION) {
            if (animationTimeout > 0) {
                type = ANIMATION;
                timeout = animationTimeout;
                propCount = animationDurations.length;
            }
        } else {
            timeout = Math.max(transitionTimeout, animationTimeout);
            type = timeout > 0
                ? transitionTimeout > animationTimeout
                    ? TRANSITION
                    : ANIMATION
                : null;
            propCount = type
                ? type === TRANSITION
                    ? transitionDurations.length
                    : animationDurations.length
                : 0;
        }
        var hasTransform =
            type === TRANSITION &&
            transformRE.test(styles[transitionProp + 'Property']);
        return {
            type: type,
            timeout: timeout,
            propCount: propCount,
            hasTransform: hasTransform
        }
    }

    function getTimeout(delays, durations) {
        /* istanbul ignore next */
        while (delays.length < durations.length) {
            delays = delays.concat(delays);
        }

        return Math.max.apply(null, durations.map(function (d, i) {
            return toMs(d) + toMs(delays[i])
        }))
    }

    function toMs(s) {
        return Number(s.slice(0, -1)) * 1000
    }

    /*  */

    function enter(vnode, toggleDisplay) {
        var el = vnode.elm;

        // call leave callback now
        if (el._leaveCb) {
            el._leaveCb.cancelled = true;
            el._leaveCb();
        }

        var data = resolveTransition(vnode.data.transition);
        if (!data) {
            return
        }

        /* istanbul ignore if */
        if (el._enterCb || el.nodeType !== 1) {
            return
        }

        var css = data.css;
        var type = data.type;
        var enterClass = data.enterClass;
        var enterToClass = data.enterToClass;
        var enterActiveClass = data.enterActiveClass;
        var appearClass = data.appearClass;
        var appearToClass = data.appearToClass;
        var appearActiveClass = data.appearActiveClass;
        var beforeEnter = data.beforeEnter;
        var enter = data.enter;
        var afterEnter = data.afterEnter;
        var enterCancelled = data.enterCancelled;
        var beforeAppear = data.beforeAppear;
        var appear = data.appear;
        var afterAppear = data.afterAppear;
        var appearCancelled = data.appearCancelled;
        var duration = data.duration;

        // activeInstance will always be the <transition> component managing this
        // transition. One edge case to check is when the <transition> is placed
        // as the root node of a child component. In that case we need to check
        // <transition>'s parent for appear check.
        var context = activeInstance;
        var transitionNode = activeInstance.$vnode;
        while (transitionNode && transitionNode.parent) {
            transitionNode = transitionNode.parent;
            context = transitionNode.context;
        }

        var isAppear = !context._isMounted || !vnode.isRootInsert;

        if (isAppear && !appear && appear !== '') {
            return
        }

        var startClass = isAppear && appearClass
            ? appearClass
            : enterClass;
        var activeClass = isAppear && appearActiveClass
            ? appearActiveClass
            : enterActiveClass;
        var toClass = isAppear && appearToClass
            ? appearToClass
            : enterToClass;

        var beforeEnterHook = isAppear
            ? (beforeAppear || beforeEnter)
            : beforeEnter;
        var enterHook = isAppear
            ? (typeof appear === 'function' ? appear : enter)
            : enter;
        var afterEnterHook = isAppear
            ? (afterAppear || afterEnter)
            : afterEnter;
        var enterCancelledHook = isAppear
            ? (appearCancelled || enterCancelled)
            : enterCancelled;

        var explicitEnterDuration = toNumber(
            isObject(duration)
                ? duration.enter
                : duration
        );

        if ("development" !== 'production' && explicitEnterDuration != null) {
            checkDuration(explicitEnterDuration, 'enter', vnode);
        }

        var expectsCSS = css !== false && !isIE9;
        var userWantsControl = getHookArgumentsLength(enterHook);

        var cb = el._enterCb = once(function () {
            if (expectsCSS) {
                removeTransitionClass(el, toClass);
                removeTransitionClass(el, activeClass);
            }
            if (cb.cancelled) {
                if (expectsCSS) {
                    removeTransitionClass(el, startClass);
                }
                enterCancelledHook && enterCancelledHook(el);
            } else {
                afterEnterHook && afterEnterHook(el);
            }
            el._enterCb = null;
        });

        if (!vnode.data.show) {
            // remove pending leave element on enter by injecting an insert hook
            mergeVNodeHook(vnode.data.hook || (vnode.data.hook = {}), 'insert', function () {
                var parent = el.parentNode;
                var pendingNode = parent && parent._pending && parent._pending[vnode.key];
                if (pendingNode &&
                    pendingNode.tag === vnode.tag &&
                    pendingNode.elm._leaveCb) {
                    pendingNode.elm._leaveCb();
                }
                enterHook && enterHook(el, cb);
            });
        }

        // start enter transition
        beforeEnterHook && beforeEnterHook(el);
        if (expectsCSS) {
            addTransitionClass(el, startClass);
            addTransitionClass(el, activeClass);
            nextFrame(function () {
                addTransitionClass(el, toClass);
                removeTransitionClass(el, startClass);
                if (!cb.cancelled && !userWantsControl) {
                    if (isValidDuration(explicitEnterDuration)) {
                        setTimeout(cb, explicitEnterDuration);
                    } else {
                        whenTransitionEnds(el, type, cb);
                    }
                }
            });
        }

        if (vnode.data.show) {
            toggleDisplay && toggleDisplay();
            enterHook && enterHook(el, cb);
        }

        if (!expectsCSS && !userWantsControl) {
            cb();
        }
    }

    function leave(vnode, rm) {
        var el = vnode.elm;

        // call enter callback now
        if (el._enterCb) {
            el._enterCb.cancelled = true;
            el._enterCb();
        }

        var data = resolveTransition(vnode.data.transition);
        if (!data) {
            return rm()
        }

        /* istanbul ignore if */
        if (el._leaveCb || el.nodeType !== 1) {
            return
        }

        var css = data.css;
        var type = data.type;
        var leaveClass = data.leaveClass;
        var leaveToClass = data.leaveToClass;
        var leaveActiveClass = data.leaveActiveClass;
        var beforeLeave = data.beforeLeave;
        var leave = data.leave;
        var afterLeave = data.afterLeave;
        var leaveCancelled = data.leaveCancelled;
        var delayLeave = data.delayLeave;
        var duration = data.duration;

        var expectsCSS = css !== false && !isIE9;
        var userWantsControl = getHookArgumentsLength(leave);

        var explicitLeaveDuration = toNumber(
            isObject(duration)
                ? duration.leave
                : duration
        );

        if ("development" !== 'production' && explicitLeaveDuration != null) {
            checkDuration(explicitLeaveDuration, 'leave', vnode);
        }

        var cb = el._leaveCb = once(function () {
            if (el.parentNode && el.parentNode._pending) {
                el.parentNode._pending[vnode.key] = null;
            }
            if (expectsCSS) {
                removeTransitionClass(el, leaveToClass);
                removeTransitionClass(el, leaveActiveClass);
            }
            if (cb.cancelled) {
                if (expectsCSS) {
                    removeTransitionClass(el, leaveClass);
                }
                leaveCancelled && leaveCancelled(el);
            } else {
                rm();
                afterLeave && afterLeave(el);
            }
            el._leaveCb = null;
        });

        if (delayLeave) {
            delayLeave(performLeave);
        } else {
            performLeave();
        }

        function performLeave() {
            // the delayed leave may have already been cancelled
            if (cb.cancelled) {
                return
            }
            // record leaving element
            if (!vnode.data.show) {
                (el.parentNode._pending || (el.parentNode._pending = {}))[vnode.key] = vnode;
            }
            beforeLeave && beforeLeave(el);
            if (expectsCSS) {
                addTransitionClass(el, leaveClass);
                addTransitionClass(el, leaveActiveClass);
                nextFrame(function () {
                    addTransitionClass(el, leaveToClass);
                    removeTransitionClass(el, leaveClass);
                    if (!cb.cancelled && !userWantsControl) {
                        if (isValidDuration(explicitLeaveDuration)) {
                            setTimeout(cb, explicitLeaveDuration);
                        } else {
                            whenTransitionEnds(el, type, cb);
                        }
                    }
                });
            }
            leave && leave(el, cb);
            if (!expectsCSS && !userWantsControl) {
                cb();
            }
        }
    }

// only used in dev mode
    function checkDuration(val, name, vnode) {
        if (typeof val !== 'number') {
            warn(
                "<transition> explicit " + name + " duration is not a valid number - " +
                "got " + (JSON.stringify(val)) + ".",
                vnode.context
            );
        } else if (isNaN(val)) {
            warn(
                "<transition> explicit " + name + " duration is NaN - " +
                'the duration expression might be incorrect.',
                vnode.context
            );
        }
    }

    function isValidDuration(val) {
        return typeof val === 'number' && !isNaN(val)
    }

    /**
     * Normalize a transition hook's argument length. The hook may be:
     * - a merged hook (invoker) with the original in .fns
     * - a wrapped component method (check ._length)
     * - a plain function (.length)
     */
    function getHookArgumentsLength(fn) {
        if (!fn) {
            return false
        }
        var invokerFns = fn.fns;
        if (invokerFns) {
            // invoker
            return getHookArgumentsLength(
                Array.isArray(invokerFns)
                    ? invokerFns[0]
                    : invokerFns
            )
        } else {
            return (fn._length || fn.length) > 1
        }
    }

    function _enter(_, vnode) {
        if (!vnode.data.show) {
            enter(vnode);
        }
    }

    var transition = inBrowser ? {
        create: _enter,
        activate: _enter,
        remove: function remove$$1(vnode, rm) {
            /* istanbul ignore else */
            if (!vnode.data.show) {
                leave(vnode, rm);
            } else {
                rm();
            }
        }
    } : {};

    var platformModules = [
        attrs,
        klass,
        events,
        domProps,
        style,
        transition
    ];

    /*  */

// the directive module should be applied last, after all
// built-in modules have been applied.
    var modules = platformModules.concat(baseModules);

    var patch = createPatchFunction({nodeOps: nodeOps, modules: modules});

    /**
     * Not type checking this file because flow doesn't like attaching
     * properties to Elements.
     */

    /* istanbul ignore if */
    if (isIE9) {
        // http://www.matts411.com/post/internet-explorer-9-oninput/
        document.addEventListener('selectionchange', function () {
            var el = document.activeElement;
            if (el && el.vmodel) {
                trigger(el, 'input');
            }
        });
    }

    var model$1 = {
        inserted: function inserted(el, binding, vnode) {
            if (vnode.tag === 'select') {
                var cb = function () {
                    setSelected(el, binding, vnode.context);
                };
                cb();
                /* istanbul ignore if */
                if (isIE || isEdge) {
                    setTimeout(cb, 0);
                }
            } else if (vnode.tag === 'textarea' || el.type === 'text' || el.type === 'password') {
                el._vModifiers = binding.modifiers;
                if (!binding.modifiers.lazy) {
                    if (!isAndroid) {
                        el.addEventListener('compositionstart', onCompositionStart);
                        el.addEventListener('compositionend', onCompositionEnd);
                    }
                    /* istanbul ignore if */
                    if (isIE9) {
                        el.vmodel = true;
                    }
                }
            }
        },
        componentUpdated: function componentUpdated(el, binding, vnode) {
            if (vnode.tag === 'select') {
                setSelected(el, binding, vnode.context);
                // in case the options rendered by v-for have changed,
                // it's possible that the value is out-of-sync with the rendered options.
                // detect such cases and filter out values that no longer has a matching
                // option in the DOM.
                var needReset = el.multiple
                    ? binding.value.some(function (v) {
                        return hasNoMatchingOption(v, el.options);
                    })
                    : binding.value !== binding.oldValue && hasNoMatchingOption(binding.value, el.options);
                if (needReset) {
                    trigger(el, 'change');
                }
            }
        }
    };

    function setSelected(el, binding, vm) {
        var value = binding.value;
        var isMultiple = el.multiple;
        if (isMultiple && !Array.isArray(value)) {
            "development" !== 'production' && warn(
                "<select multiple v-model=\"" + (binding.expression) + "\"> " +
                "expects an Array value for its binding, but got " + (Object.prototype.toString.call(value).slice(8, -1)),
                vm
            );
            return
        }
        var selected, option;
        for (var i = 0, l = el.options.length; i < l; i++) {
            option = el.options[i];
            if (isMultiple) {
                selected = looseIndexOf(value, getValue(option)) > -1;
                if (option.selected !== selected) {
                    option.selected = selected;
                }
            } else {
                if (looseEqual(getValue(option), value)) {
                    if (el.selectedIndex !== i) {
                        el.selectedIndex = i;
                    }
                    return
                }
            }
        }
        if (!isMultiple) {
            el.selectedIndex = -1;
        }
    }

    function hasNoMatchingOption(value, options) {
        for (var i = 0, l = options.length; i < l; i++) {
            if (looseEqual(getValue(options[i]), value)) {
                return false
            }
        }
        return true
    }

    function getValue(option) {
        return '_value' in option
            ? option._value
            : option.value
    }

    function onCompositionStart(e) {
        e.target.composing = true;
    }

    function onCompositionEnd(e) {
        e.target.composing = false;
        trigger(e.target, 'input');
    }

    function trigger(el, type) {
        var e = document.createEvent('HTMLEvents');
        e.initEvent(type, true, true);
        el.dispatchEvent(e);
    }

    /*  */

// recursively search for possible transition defined inside the component root
    function locateNode(vnode) {
        return vnode.componentInstance && (!vnode.data || !vnode.data.transition)
            ? locateNode(vnode.componentInstance._vnode)
            : vnode
    }

    var show = {
        bind: function bind(el, ref, vnode) {
            var value = ref.value;

            vnode = locateNode(vnode);
            var transition = vnode.data && vnode.data.transition;
            var originalDisplay = el.__vOriginalDisplay =
                el.style.display === 'none' ? '' : el.style.display;
            if (value && transition && !isIE9) {
                vnode.data.show = true;
                enter(vnode, function () {
                    el.style.display = originalDisplay;
                });
            } else {
                el.style.display = value ? originalDisplay : 'none';
            }
        },

        update: function update(el, ref, vnode) {
            var value = ref.value;
            var oldValue = ref.oldValue;

            /* istanbul ignore if */
            if (value === oldValue) {
                return
            }
            vnode = locateNode(vnode);
            var transition = vnode.data && vnode.data.transition;
            if (transition && !isIE9) {
                vnode.data.show = true;
                if (value) {
                    enter(vnode, function () {
                        el.style.display = el.__vOriginalDisplay;
                    });
                } else {
                    leave(vnode, function () {
                        el.style.display = 'none';
                    });
                }
            } else {
                el.style.display = value ? el.__vOriginalDisplay : 'none';
            }
        },

        unbind: function unbind(
            el,
            binding,
            vnode,
            oldVnode,
            isDestroy
        ) {
            if (!isDestroy) {
                el.style.display = el.__vOriginalDisplay;
            }
        }
    };

    var platformDirectives = {
        model: model$1,
        show: show
    };

    /*  */

// Provides transition support for a single element/component.
// supports transition mode (out-in / in-out)

    var transitionProps = {
        name: String,
        appear: Boolean,
        css: Boolean,
        mode: String,
        type: String,
        enterClass: String,
        leaveClass: String,
        enterToClass: String,
        leaveToClass: String,
        enterActiveClass: String,
        leaveActiveClass: String,
        appearClass: String,
        appearActiveClass: String,
        appearToClass: String,
        duration: [Number, String, Object]
    };

// in case the child is also an abstract component, e.g. <keep-alive>
// we want to recursively retrieve the real component to be rendered
    function getRealChild(vnode) {
        var compOptions = vnode && vnode.componentOptions;
        if (compOptions && compOptions.Ctor.options.abstract) {
            return getRealChild(getFirstComponentChild(compOptions.children))
        } else {
            return vnode
        }
    }

    function extractTransitionData(comp) {
        var data = {};
        var options = comp.$options;
        // props
        for (var key in options.propsData) {
            data[key] = comp[key];
        }
        // events.
        // extract listeners and pass them directly to the transition methods
        var listeners = options._parentListeners;
        for (var key$1 in listeners) {
            data[camelize(key$1)] = listeners[key$1];
        }
        return data
    }

    function placeholder(h, rawChild) {
        return /\d-keep-alive$/.test(rawChild.tag)
            ? h('keep-alive')
            : null
    }

    function hasParentTransition(vnode) {
        while ((vnode = vnode.parent)) {
            if (vnode.data.transition) {
                return true
            }
        }
    }

    function isSameChild(child, oldChild) {
        return oldChild.key === child.key && oldChild.tag === child.tag
    }

    var Transition = {
        name: 'transition',
        props: transitionProps,
        abstract: true,

        render: function render(h) {
            var this$1 = this;

            var children = this.$slots.default;
            if (!children) {
                return
            }

            // filter out text nodes (possible whitespaces)
            children = children.filter(function (c) {
                return c.tag;
            });
            /* istanbul ignore if */
            if (!children.length) {
                return
            }

            // warn multiple elements
            if ("development" !== 'production' && children.length > 1) {
                warn(
                    '<transition> can only be used on a single element. Use ' +
                    '<transition-group> for lists.',
                    this.$parent
                );
            }

            var mode = this.mode;

            // warn invalid mode
            if ("development" !== 'production' &&
                mode && mode !== 'in-out' && mode !== 'out-in') {
                warn(
                    'invalid <transition> mode: ' + mode,
                    this.$parent
                );
            }

            var rawChild = children[0];

            // if this is a component root node and the component's
            // parent container node also has transition, skip.
            if (hasParentTransition(this.$vnode)) {
                return rawChild
            }

            // apply transition data to child
            // use getRealChild() to ignore abstract components e.g. keep-alive
            var child = getRealChild(rawChild);
            /* istanbul ignore if */
            if (!child) {
                return rawChild
            }

            if (this._leaving) {
                return placeholder(h, rawChild)
            }

            // ensure a key that is unique to the vnode type and to this transition
            // component instance. This key will be used to remove pending leaving nodes
            // during entering.
            var id = "__transition-" + (this._uid) + "-";
            child.key = child.key == null
                ? id + child.tag
                : isPrimitive(child.key)
                    ? (String(child.key).indexOf(id) === 0 ? child.key : id + child.key)
                    : child.key;

            var data = (child.data || (child.data = {})).transition = extractTransitionData(this);
            var oldRawChild = this._vnode;
            var oldChild = getRealChild(oldRawChild);

            // mark v-show
            // so that the transition module can hand over the control to the directive
            if (child.data.directives && child.data.directives.some(function (d) {
                return d.name === 'show';
            })) {
                child.data.show = true;
            }

            if (oldChild && oldChild.data && !isSameChild(child, oldChild)) {
                // replace old child transition data with fresh one
                // important for dynamic transitions!
                var oldData = oldChild && (oldChild.data.transition = extend({}, data));
                // handle transition mode
                if (mode === 'out-in') {
                    // return placeholder node and queue update when leave finishes
                    this._leaving = true;
                    mergeVNodeHook(oldData, 'afterLeave', function () {
                        this$1._leaving = false;
                        this$1.$forceUpdate();
                    });
                    return placeholder(h, rawChild)
                } else if (mode === 'in-out') {
                    var delayedLeave;
                    var performLeave = function () {
                        delayedLeave();
                    };
                    mergeVNodeHook(data, 'afterEnter', performLeave);
                    mergeVNodeHook(data, 'enterCancelled', performLeave);
                    mergeVNodeHook(oldData, 'delayLeave', function (leave) {
                        delayedLeave = leave;
                    });
                }
            }

            return rawChild
        }
    };

    /*  */

// Provides transition support for list items.
// supports move transitions using the FLIP technique.

// Because the vdom's children update algorithm is "unstable" - i.e.
// it doesn't guarantee the relative positioning of removed elements,
// we force transition-group to update its children into two passes:
// in the first pass, we remove all nodes that need to be removed,
// triggering their leaving transition; in the second pass, we insert/move
// into the final desired state. This way in the second pass removed
// nodes will remain where they should be.

    var props = extend({
        tag: String,
        moveClass: String
    }, transitionProps);

    delete props.mode;

    var TransitionGroup = {
        props: props,

        render: function render(h) {
            var tag = this.tag || this.$vnode.data.tag || 'span';
            var map = Object.create(null);
            var prevChildren = this.prevChildren = this.children;
            var rawChildren = this.$slots.default || [];
            var children = this.children = [];
            var transitionData = extractTransitionData(this);

            for (var i = 0; i < rawChildren.length; i++) {
                var c = rawChildren[i];
                if (c.tag) {
                    if (c.key != null && String(c.key).indexOf('__vlist') !== 0) {
                        children.push(c);
                        map[c.key] = c
                        ;(c.data || (c.data = {})).transition = transitionData;
                    } else {
                        var opts = c.componentOptions;
                        var name = opts ? (opts.Ctor.options.name || opts.tag || '') : c.tag;
                        warn(("<transition-group> children must be keyed: <" + name + ">"));
                    }
                }
            }

            if (prevChildren) {
                var kept = [];
                var removed = [];
                for (var i$1 = 0; i$1 < prevChildren.length; i$1++) {
                    var c$1 = prevChildren[i$1];
                    c$1.data.transition = transitionData;
                    c$1.data.pos = c$1.elm.getBoundingClientRect();
                    if (map[c$1.key]) {
                        kept.push(c$1);
                    } else {
                        removed.push(c$1);
                    }
                }
                this.kept = h(tag, null, kept);
                this.removed = removed;
            }

            return h(tag, null, children)
        },

        beforeUpdate: function beforeUpdate() {
            // force removing pass
            this.__patch__(
                this._vnode,
                this.kept,
                false, // hydrating
                true // removeOnly (!important, avoids unnecessary moves)
            );
            this._vnode = this.kept;
        },

        updated: function updated() {
            var children = this.prevChildren;
            var moveClass = this.moveClass || ((this.name || 'v') + '-move');
            if (!children.length || !this.hasMove(children[0].elm, moveClass)) {
                return
            }

            // we divide the work into three loops to avoid mixing DOM reads and writes
            // in each iteration - which helps prevent layout thrashing.
            children.forEach(callPendingCbs);
            children.forEach(recordPosition);
            children.forEach(applyTranslation);

            // force reflow to put everything in position
            var body = document.body;
            var f = body.offsetHeight; // eslint-disable-line

            children.forEach(function (c) {
                if (c.data.moved) {
                    var el = c.elm;
                    var s = el.style;
                    addTransitionClass(el, moveClass);
                    s.transform = s.WebkitTransform = s.transitionDuration = '';
                    el.addEventListener(transitionEndEvent, el._moveCb = function cb(e) {
                        if (!e || /transform$/.test(e.propertyName)) {
                            el.removeEventListener(transitionEndEvent, cb);
                            el._moveCb = null;
                            removeTransitionClass(el, moveClass);
                        }
                    });
                }
            });
        },

        methods: {
            hasMove: function hasMove(el, moveClass) {
                /* istanbul ignore if */
                if (!hasTransition) {
                    return false
                }
                if (this._hasMove != null) {
                    return this._hasMove
                }
                // Detect whether an element with the move class applied has
                // CSS transitions. Since the element may be inside an entering
                // transition at this very moment, we make a clone of it and remove
                // all other transition classes applied to ensure only the move class
                // is applied.
                var clone = el.cloneNode();
                if (el._transitionClasses) {
                    el._transitionClasses.forEach(function (cls) {
                        removeClass(clone, cls);
                    });
                }
                addClass(clone, moveClass);
                clone.style.display = 'none';
                this.$el.appendChild(clone);
                var info = getTransitionInfo(clone);
                this.$el.removeChild(clone);
                return (this._hasMove = info.hasTransform)
            }
        }
    };

    function callPendingCbs(c) {
        /* istanbul ignore if */
        if (c.elm._moveCb) {
            c.elm._moveCb();
        }
        /* istanbul ignore if */
        if (c.elm._enterCb) {
            c.elm._enterCb();
        }
    }

    function recordPosition(c) {
        c.data.newPos = c.elm.getBoundingClientRect();
    }

    function applyTranslation(c) {
        var oldPos = c.data.pos;
        var newPos = c.data.newPos;
        var dx = oldPos.left - newPos.left;
        var dy = oldPos.top - newPos.top;
        if (dx || dy) {
            c.data.moved = true;
            var s = c.elm.style;
            s.transform = s.WebkitTransform = "translate(" + dx + "px," + dy + "px)";
            s.transitionDuration = '0s';
        }
    }

    var platformComponents = {
        Transition: Transition,
        TransitionGroup: TransitionGroup
    };

    /*  */

// install platform specific utils
    Vue$2.config.mustUseProp = mustUseProp;
    Vue$2.config.isReservedTag = isReservedTag;
    Vue$2.config.getTagNamespace = getTagNamespace;
    Vue$2.config.isUnknownElement = isUnknownElement;

// install platform runtime directives & components
    extend(Vue$2.options.directives, platformDirectives);
    extend(Vue$2.options.components, platformComponents);

// install platform patch function
    Vue$2.prototype.__patch__ = inBrowser ? patch : noop;

// public mount method
    Vue$2.prototype.$mount = function (
        el,
        hydrating
    ) {
        el = el && inBrowser ? query(el) : undefined;
        return mountComponent(this, el, hydrating)
    };

// devtools global hook
    /* istanbul ignore next */
    setTimeout(function () {
        if (config.devtools) {
            if (devtools) {
                devtools.emit('init', Vue$2);
            } else if ("development" !== 'production' && isChrome) {
                console[console.info ? 'info' : 'log'](
                    'Download the Vue Devtools extension for a better development experience:\n' +
                    'https://github.com/vuejs/vue-devtools'
                );
            }
        }
        if ("development" !== 'production' &&
            config.productionTip !== false &&
            inBrowser && typeof console !== 'undefined') {
            console[console.info ? 'info' : 'log'](
                "You are running Vue in development mode.\n" +
                "Make sure to turn on production mode when deploying for production.\n" +
                "See more tips at https://vuejs.org/guide/deployment.html"
            );
        }
    }, 0);

    return Vue$2;

})));
