text: var VueRuntimeDOM = (function (exports) {
    'use strict';
  
    /**
     * Make a map and return a function for checking if a key
     * is in that map.
     * IMPORTANT: all calls of this function must be prefixed with
     * \/\*#\_\_PURE\_\_\*\/
     * So that rollup can tree-shake them if necessary.
     */
    function makeMap(str, expectsLowerCase) {
        const map = Object.create(null);
        const list = str.split(',');
        for (let i = 0; i < list.length; i++) {
            map[list[i]] = true;
        }
        return expectsLowerCase ? val => !!map[val.toLowerCase()] : val => !!map[val];
    }
  
    const GLOBALS_WHITE_LISTED = 'Infinity,undefined,NaN,isFinite,isNaN,parseFloat,parseInt,decodeURI,' +
        'decodeURIComponent,encodeURI,encodeURIComponent,Math,Number,Date,Array,' +
        'Object,Boolean,String,RegExp,Map,Set,JSON,Intl';
    const isGloballyWhitelisted = /*#__PURE__*/ makeMap(GLOBALS_WHITE_LISTED);
  
    /**
     * On the client we only need to offer special cases for boolean attributes that
     * have different names from their corresponding dom properties:
     * - itemscope -> N/A
     * - allowfullscreen -> allowFullscreen
     * - formnovalidate -> formNoValidate
     * - ismap -> isMap
     * - nomodule -> noModule
     * - novalidate -> noValidate
     * - readonly -> readOnly
     */
    const specialBooleanAttrs = `itemscope,allowfullscreen,formnovalidate,ismap,nomodule,novalidate,readonly`;
    const isSpecialBooleanAttr = /*#__PURE__*/ makeMap(specialBooleanAttrs);
  
    function normalizeStyle(value) {
        if (isArray(value)) {
            const res = {};
            for (let i = 0; i < value.length; i++) {
                const item = value[i];
                const normalized = normalizeStyle(isString(item) ? parseStringStyle(item) : item);
                if (normalized) {
                    for (const key in normalized) {
                        res[key] = normalized[key];
                    }
                }
            }
            return res;
        }
        else if (isObject(value)) {
            return value;
        }
    }
    const listDelimiterRE = /;(?![^(]*\))/g;
    const propertyDelimiterRE = /:(.+)/;
    function parseStringStyle(cssText) {
        const ret = {};
        cssText.split(listDelimiterRE).forEach(item => {
            if (item) {
                const tmp = item.split(propertyDelimiterRE);
                tmp.length > 1 && (ret[tmp[0].trim()] = tmp[1].trim());
            }
        });
        return ret;
    }
    function normalizeClass(value) {
        let res = '';
        if (isString(value)) {
            res = value;
        }
        else if (isArray(value)) {
            for (let i = 0; i < value.length; i++) {
                res += normalizeClass(value[i]) + ' ';
            }
        }
        else if (isObject(value)) {
            for (const name in value) {
                if (value[name]) {
                    res += name + ' ';
                }
            }
        }
        return res.trim();
    }
  
    /**
     * For converting {{ interpolation }} values to displayed strings.
     * @private
     */
    const toDisplayString = (val) => {
        return val == null
            ? ''
            : isObject(val)
                ? JSON.stringify(val, replacer, 2)
                : String(val);
    };
    const replacer = (_key, val) => {
        if (isMap(val)) {
            return {
                [`Map(${val.size})`]: [...val.entries()].reduce((entries, [key, val]) => {
                    entries[`${key} =>`] = val;
                    return entries;
                }, {})
            };
        }
        else if (isSet(val)) {
            return {
                [`Set(${val.size})`]: [...val.values()]
            };
        }
        else if (isObject(val) && !isArray(val) && !isPlainObject(val)) {
            return String(val);
        }
        return val;
    };
  
    const EMPTY_OBJ =  Object.freeze({})
        ;
    const EMPTY_ARR =  Object.freeze([]) ;
    const NOOP = () => { };
    /**
     * Always return false.
     */
    const NO = () => false;
    const onRE = /^on[^a-z]/;
    const isOn = (key) => onRE.test(key);
    const isModelListener = (key) => key.startsWith('onUpdate:');
    const extend = Object.assign;
    const remove = (arr, el) => {
        const i = arr.indexOf(el);
        if (i > -1) {
            arr.splice(i, 1);
        }
    };
    const hasOwnProperty = Object.prototype.hasOwnProperty;
    const hasOwn = (val, key) => hasOwnProperty.call(val, key);
    const isArray = Array.isArray;
    const isMap = (val) => toTypeString(val) === '[object Map]';
    const isSet = (val) => toTypeString(val) === '[object Set]';
    const isFunction = (val) => typeof val === 'function';
    const isString = (val) => typeof val === 'string';
    const isSymbol = (val) => typeof val === 'symbol';
    const isObject = (val) => val !== null && typeof val === 'object';
    const isPromise = (val) => {
        return isObject(val) && isFunction(val.then) && isFunction(val.catch);
    };
    const objectToString = Object.prototype.toString;
    const toTypeString = (value) => objectToString.call(value);
    const toRawType = (value) => {
        // extract "RawType" from strings like "[object RawType]"
        return toTypeString(value).slice(8, -1);
    };
    const isPlainObject = (val) => toTypeString(val) === '[object Object]';
    const isIntegerKey = (key) => isString(key) &&
        key !== 'NaN' &&
        key[0] !== '-' &&
        '' + parseInt(key, 10) === key;
    const isReservedProp = /*#__PURE__*/ makeMap(
    // the leading comma is intentional so empty string "" is also included
    ',key,ref,' +
        'onVnodeBeforeMount,onVnodeMounted,' +
        'onVnodeBeforeUpdate,onVnodeUpdated,' +
        'onVnodeBeforeUnmount,onVnodeUnmounted');
    const cacheStringFunction = (fn) => {
        const cache = Object.create(null);
        return ((str) => {
            const hit = cache[str];
            return hit || (cache[str] = fn(str));
        });
    };
    const camelizeRE = /-(\w)/g;
    /**
     * @private
     */
    const camelize = cacheStringFunction((str) => {
        return str.replace(camelizeRE, (_, c) => (c ? c.toUpperCase() : ''));
    });
    const hyphenateRE = /\B([A-Z])/g;
    /**
     * @private
     */
    const hyphenate = cacheStringFunction((str) => str.replace(hyphenateRE, '-$1').toLowerCase());
    /**
     * @private
     */
    const capitalize = cacheStringFunction((str) => str.charAt(0).toUpperCase() + str.slice(1));
    /**
     * @private
     */
    const toHandlerKey = cacheStringFunction((str) => (str ? `on${capitalize(str)}` : ``));
    // compare whether a value has changed, accounting for NaN.
    const hasChanged = (value, oldValue) => value !== oldValue && (value === value || oldValue === oldValue);
    const invokeArrayFns = (fns, arg) => {
        for (let i = 0; i < fns.length; i++) {
            fns[i](arg);
        }
    };
    const def = (obj, key, value) => {
        Object.defineProperty(obj, key, {
            configurable: true,
            enumerable: false,
            value
        });
    };
    const toNumber = (val) => {
        const n = parseFloat(val);
        return isNaN(n) ? val : n;
    };
  
    const targetMap = new WeakMap();
    // effect 任务队列
    const effectStack = [];
    let activeEffect;
    const ITERATE_KEY = Symbol( 'iterate' );
    const MAP_KEY_ITERATE_KEY = Symbol( 'Map key iterate' );
    // fn 是不是经过封装之后的 ReactiveEffect
    function isEffect(fn) {
        return fn && fn._isEffect === true;
    }
    function effect(fn, options = EMPTY_OBJ) {
        if (isEffect(fn)) {
            fn = fn.raw; // 取出原始的函数，封装之前的
        }
        // 封装成 ReactiveEffect
        const effect = createReactiveEffect(fn, options);
        if (!options.lazy) {
            // 如果并没指定 lazy: true 选项，则立即执行 effect 收集依赖
            // 因为 effect 一般都会有取值操作，此时会触发 proxy get handler
            // 然后执行 track() 结合当前的 activeEffect 即 effect() 执行时候的这个
            // effect，这样取值操作就和当前取值作用域下的依赖函数建立的依赖关系
            effect();
        }
        return effect;
    }
    function stop(effect) {
        if (effect.active) {
            cleanup(effect);
            if (effect.options.onStop) {
                effect.options.onStop();
            }
            effect.active = false;
        }
    }
    let uid = 0;
    function createReactiveEffect(fn, options) {
        // 将 fn 执行封装成  ReactiveEffect 类型的函数
        const effect = function reactiveEffect() {
            if (!effect.active) {
                // 非激活状态，可能是手动调用了 stop
                // 那么执行的时候就需要考虑调用 stop 者是否提供了手动调度该 effect
                // 的函数 scheduler ? 也就是说你停止你可以重新启动
                return options.scheduler ? undefined : fn();
            }
            if (!effectStack.includes(effect)) {
                // 1. cleanup, 保持纯净
                cleanup(effect);
                try {
                    // 2. 使其 tracking 状态有效，track() 中有用
                    enableTracking(); // track() 可以执行收集操作
                    effectStack.push(effect); // effect 入栈
                    // 3. 保存为当前的 activeEffect, track() 中有用
                    activeEffect = effect; // 记录当前的 effect -> track/trigger
                    // 4. 执行 fn 并返回结果
                    return fn(); // 返回执行结果
                }
                finally {
                    // 始终都会执行，避免出现异常将 effect 进程卡死
                    // 5. 如果执行异常，丢弃当前的 effect ，并将状态重置为上一个 effect
                    //   由一个 effect 栈来维护。
                    effectStack.pop();
                    resetTracking();
                    activeEffect = effectStack[effectStack.length - 1];
                }
            }
        };
        effect.id = uid++;
        effect.allowRecurse = !!options.allowRecurse;
        effect._isEffect = true;
        effect.active = true;
        effect.raw = fn; // 这里保存原始函数引用
        effect.deps = [];
        effect.options = options;
        return effect;
    }
    function cleanup(effect) {
        // track() 里面执行dep.add 的同时会将当前被依赖对象存储到
        // activeEffect.deps 里面，这里就是讲这些收集的被依赖者列表全清空
        const { deps } = effect;
        if (deps.length) {
            for (let i = 0; i < deps.length; i++) {
                deps[i].delete(effect);
            }
            deps.length = 0;
        }
    }
    // 当前 effect 没有完成情况下不接受下一个动作
    let shouldTrack = true;
    const trackStack = [];
    function pauseTracking() {
        trackStack.push(shouldTrack);
        shouldTrack = false;
    }
    function enableTracking() {
        trackStack.push(shouldTrack);
        shouldTrack = true;
    }
    function resetTracking() {
        // 重置为上一个 effect track的状态
        const last = trackStack.pop();
        shouldTrack = last === undefined ? true : last;
    }
    /**
     * 负责收集依赖
     * @param {object} target 被代理的原始对象
     * @param {TrackOpTypes} type 操作类型, get/has/iterate
     * @param {unknown} key
     */
    function track(target, type, key) {
        if (!shouldTrack || activeEffect === undefined) {
            return;
        }
        // Map< obj -> Map<key, Set[...deps]> >
        let depsMap = targetMap.get(target);
        if (!depsMap) {
            // 初始化
            targetMap.set(target, (depsMap = new Map()));
        }
        let dep = depsMap.get(key);
        if (!dep) {
            depsMap.set(key, (dep = new Set()));
        }
        // 正在请求收集的 effect ，是初次出现
        if (!dep.has(activeEffect)) {
            dep.add(activeEffect);
            // 自身保存一份被依赖者名单
            activeEffect.deps.push(dep);
            if ( activeEffect.options.onTrack) {
                activeEffect.options.onTrack({
                    effect: activeEffect,
                    target,
                    type,
                    key
                });
            }
        }
    }
    function trigger(target, type, key, newValue, oldValue, oldTarget) {
        const depsMap = targetMap.get(target);
        if (!depsMap) {
            return;
        }
        const effects = new Set();
        const add = (effectsToAdd) => {
            if (effectsToAdd) {
                effectsToAdd.forEach(effect => {
                    if (effect !== activeEffect || effect.allowRecurse) {
                        effects.add(effect);
                    }
                });
            }
        };
        if (type === "clear" /* CLEAR */) {
            depsMap.forEach(add);
        }
        else if (key === 'length' && isArray(target)) {
            depsMap.forEach((dep, key) => {
                if (key === 'length' || key >= newValue) {
                    add(dep);
                }
            });
        }
        else {
            // SET | ADD | DELETE operation
            if (key !== void 0) {
                add(depsMap.get(key));
            }
            // 迭代器 key，for...of, 使用迭代器是对数据的监听变化
            switch (type) {
                case "add" /* ADD */:
                    if (!isArray(target)) {
                        add(depsMap.get(ITERATE_KEY));
                        if (isMap(target)) {
                            add(depsMap.get(MAP_KEY_ITERATE_KEY));
                        }
                    }
                    else if (isIntegerKey(key)) {
                        // 如果是数组添加元素，将 length 依赖添加到执行队列
                        add(depsMap.get('length'));
                    }
                    break;
                case "delete" /* DELETE */:
                    if (!isArray(target)) {
                        add(depsMap.get(ITERATE_KEY));
                        if (isMap(target)) {
                            add(depsMap.get(MAP_KEY_ITERATE_KEY));
                        }
                    }
                    break;
                case "set" /* SET */:
                    if (isMap(target)) {
                        add(depsMap.get(ITERATE_KEY));
                    }
                    break;
            }
        }
        const run = (effect) => {
            if ( effect.options.onTrigger) {
                effect.options.onTrigger({
                    effect,
                    target,
                    key,
                    type,
                    newValue,
                    oldValue,
                    oldTarget
                });
            }
            if (effect.options.scheduler) {
                effect.options.scheduler(effect);
            }
            else {
                effect();
            }
        };
        effects.forEach(run);
    }
  
    const builtInSymbols = new Set(Object.getOwnPropertyNames(Symbol)
        .map(key => Symbol[key])
        .filter(isSymbol));
    const get = /*#__PURE__*/ createGetter();
    const shallowGet = /*#__PURE__*/ createGetter(false, true);
    const readonlyGet = /*#__PURE__*/ createGetter(true);
    const shallowReadonlyGet = /*#__PURE__*/ createGetter(true, true);
    // 数组内置方法处理
    const arrayInstrumentations = {};
    ['includes', 'indexOf', 'lastIndexOf'].forEach((key) => {
        const method = Array.prototype[key];
        arrayInstrumentations[key] = function (...args) {
            const arr = toRaw(this);
            for (let i = 0, l = this.length; i < l; i++) {
                track(arr, "get" /* GET */, i + '');
            }
            const res = method.apply(arr, args);
            if (res === -1 || res === false) {
                return method.apply(arr, args.map(toRaw));
            }
            else {
                return res;
            }
        };
    });
    ['push', 'pop', 'shift', 'unshift', 'splice'].forEach(key => {
        const method = Array.prototype[key];
        arrayInstrumentations[key] = function (...args) {
            pauseTracking();
            const res = method.apply(this, args);
            resetTracking();
            return res;
        };
    });
    /**
     * 创建取值函数@param {boolean} isReadonly 是不是只读，将决定是否代理 set 等改变
     * 对象操作@param {boolean} shallow 指定是否对对象进行浅 reactive(类似浅复制)，
     * 只对一级属性进行 reactive
     */
    function createGetter(isReadonly = false, shallow = false) {
        // target: 被取值的对象，key: 取值的属性，receiver: this 的值
        return function get(target, key, receiver) {
            // 1. key is reactive
            if (key === "__v_isReactive" /* IS_REACTIVE */) {
                // 读取对象的 __v_isReactive
                return !isReadonly;
            }
            else if (key === "__v_isReadonly" /* IS_READONLY */) {
                // 2. key is readonly
                return isReadonly;
            }
            else if (key === "__v_raw" /* RAW */ &&
                receiver === (isReadonly ? readonlyMap : reactiveMap).get(target)) {
                // 3. key is the raw target
                return target;
            }
            // 4. target is array
            const targetIsArray = isArray(target);
            if (!isReadonly && targetIsArray && hasOwn(arrayInstrumentations, key)) {
                return Reflect.get(arrayInstrumentations, key, receiver);
            }
            const res = Reflect.get(target, key, receiver);
            if (isSymbol(key)
                ? builtInSymbols.has(key)
                : key === `__proto__` || key === `__v_isRef`) {
                return res;
            }
            if (!isReadonly) {
                // DONE 6. not readonly, need to track and collect deps
                track(target, "get" /* GET */, key);
            }
            // 是否只需要 reactive 一级属性(不递归 reactive)
            // ADD
            if (shallow) {
                return res;
            }
            // 6. res isRef
            if (isRef(res)) {
                // ref unwrapping - does not apply for Array + integer key.
                const shouldUnwrap = !targetIsArray || !isIntegerKey(key);
                return shouldUnwrap ? res.value : res;
            }
            // 7. res is object -> reactive recursivly
            if (isObject(res)) {
                // 递归 reactive 嵌套对象，feat: b2143f9
                return isReadonly ? readonly(res) : reactive(res);
            }
            return res;
        };
    }
    const set = /*#__PURE__*/ createSetter();
    const shallowSet = /*#__PURE__*/ createSetter(true);
    function createSetter(shallow = false) {
        return function set(target, key, value, receiver) {
            const oldValue = target[key];
            // shallow or not, or ref ?
            if (!shallow) {
                value = toRaw(value);
                // 非数组，旧值是 ref 类型，但是新值不是，则将新值设置到旧值的 value 属性上
                if (!isArray(target) && isRef(oldValue) && !isRef(value)) {
                    oldValue.value = value;
                    return true;
                }
            }
            const hadKey = isArray(target) && isIntegerKey(key)
                ? Number(key) < target.length
                : hasOwn(target, key);
            const result = Reflect.set(target, key, value, receiver);
            if (target === toRaw(receiver)) {
                if (!hadKey) {
                    trigger(target, "add" /* ADD */, key, value);
                }
                else if (hasChanged(value, oldValue)) {
                    trigger(target, "set" /* SET */, key, value, oldValue);
                }
            }
            return result;
        };
    }
    function deleteProperty(target, key) {
        const hadKey = hasOwn(target, key);
        const oldValue = target[key];
        const result = Reflect.deleteProperty(target, key);
        if (result && hadKey) {
            // 删除成功，触发 DELETE
            trigger(target, "delete" /* DELETE */, key, undefined, oldValue);
        }
        return result;
    }
    function has(target, key) {
        const result = Reflect.has(target, key);
        if (!isSymbol(key) || !builtInSymbols.has(key)) {
            track(target, "has" /* HAS */, key);
        }
        return result;
    }
    function ownKeys(target) {
        track(target, "iterate" /* ITERATE */, isArray(target) ? 'length' : ITERATE_KEY);
        return Reflect.ownKeys(target);
    }
    const mutableHandlers = {
        get,
        set,
        deleteProperty,
        has,
        ownKeys
    };
    const readonlyHandlers = {
        get: readonlyGet,
        set(target, key) {
            {
                console.warn(`Set operation on key "${String(key)}" failed: target is readonly.`, target);
            }
            return true;
        },
        deleteProperty(target, key) {
            {
                console.warn(`Delete operation on key "${String(key)}" failed: target is readonly.`, target);
            }
            return true;
        }
    };
    const shallowReactiveHandlers = extend({}, mutableHandlers, {
        get: shallowGet,
        set: shallowSet
    });
    // Props handlers are special in the sense that it should not unwrap top-level
    // refs (in order to allow refs to be explicitly passed down), but should
    // retain the reactivity of the normal readonly object.
    const shallowReadonlyHandlers = extend({}, readonlyHandlers, {
        get: shallowReadonlyGet
    });
  
    const toReactive = (value) => isObject(value) ? reactive(value) : value;
    const toReadonly = (value) => isObject(value) ? readonly(value) : value;
    const toShallow = (value) => value;
    const getProto = (v) => Reflect.getPrototypeOf(v);
    function get$1(target, key, isReadonly = false, isShallow = false) {
        target = target["__v_raw" /* RAW */];
        const rawTarget = toRaw(target);
        // 下面处理是针对 key 可能是 proxy 类型
        // 次数，proxy key 和对应的 raw key 都要收集当前依赖
        const rawKey = toRaw(key); // key 有可能也是 proxy
        if (key !== rawKey) {
            // proxy key
            !isReadonly && track(rawTarget, "get" /* GET */, key);
        }
        // raw key
        !isReadonly && track(rawTarget, "get" /* GET */, rawKey);
        const { has } = getProto(rawTarget);
        // 递归处理对象类型
        const wrap = isReadonly ? toReadonly : isShallow ? toShallow : toReactive;
        // 取值考虑到 rawKey 和 key 不同的情况
        if (has.call(rawTarget, key)) {
            return wrap(target.get(key));
        }
        else if (has.call(rawTarget, rawKey)) {
            return wrap(target.get(rawKey));
        }
    }
    function has$1(key, isReadonly = false) {
        const target = this["__v_raw" /* RAW */];
        const rawTarget = toRaw(target);
        const rawKey = toRaw(key);
        if (key !== rawKey) {
            !isReadonly && track(rawTarget, "has" /* HAS */, key);
        }
        !isReadonly && track(rawTarget, "has" /* HAS */, rawKey);
        return key === rawKey
            ? target.has(key)
            : target.has(key) || target.has(rawKey);
    }
    function size(target, isReadonly = false) {
        target = target["__v_raw" /* RAW */];
        !isReadonly && track(toRaw(target), "iterate" /* ITERATE */, ITERATE_KEY);
        return Reflect.get(target, 'size', target);
    }
    function add(value) {
        value = toRaw(value);
        const target = toRaw(this);
        const proto = getProto(target);
        const hadKey = proto.has.call(target, value);
        target.add(value);
        // 因为 set 是不会存在重复元素的，所以只会在没有当前 key 的情况下才会执行
        // 添加操作
        if (!hadKey) {
            trigger(target, "add" /* ADD */, value, value);
        }
        return this;
    }
    function set$1(key, value) {
        value = toRaw(value);
        const target = toRaw(this);
        const { has, get } = getProto(target);
        let hadKey = has.call(target, key);
        // 考虑 key 可能是 proxy
        if (!hadKey) {
            // to add
            key = toRaw(key);
            hadKey = has.call(target, key);
        }
        else {
            checkIdentityKeys(target, has, key);
        }
        const oldValue = get.call(target, key);
        // 设值结果
        target.set(key, value);
        if (!hadKey) {
            // 添加操作
            trigger(target, "add" /* ADD */, key, value);
        }
        else if (hasChanged(value, oldValue)) {
            // 设值操作
            trigger(target, "set" /* SET */, key, value, oldValue);
        }
        return this;
    }
    function deleteEntry(key) {
        const target = toRaw(this);
        const { has, get } = getProto(target);
        let hadKey = has.call(target, key);
        if (!hadKey) {
            key = toRaw(key);
            hadKey = has.call(target, key);
        }
        else {
            checkIdentityKeys(target, has, key);
        }
        const oldValue = get ? get.call(target, key) : undefined;
        const result = target.delete(key);
        if (hadKey) {
            trigger(target, "delete" /* DELETE */, key, undefined, oldValue);
        }
        return result;
    }
    function clear() {
        const target = toRaw(this);
        const hadItems = target.size !== 0;
        const oldTarget =  isMap(target)
                ? new Map(target)
                : new Set(target)
            ;
        const result = target.clear();
        if (hadItems) {
            trigger(target, "clear" /* CLEAR */, undefined, undefined, oldTarget);
        }
        return result;
    }
    function createForEach(isReadonly, isShallow) {
        return function forEach(callback, thisArg) {
            const observed = this;
            const target = observed["__v_raw" /* RAW */];
            const rawTarget = toRaw(target);
            const wrap = isReadonly ? toReadonly : isShallow ? toShallow : toReactive;
            !isReadonly && track(rawTarget, "iterate" /* ITERATE */, ITERATE_KEY);
            return target.forEach((value, key) => {
                // 重要：确保回调
                // 1. 在 reactive map 作用域下被执行(this, 和第三个参数)
                // 2. 接受的 value 值应该是个 reactive/readonly 类型
                return callback.call(thisArg, wrap(value), wrap(key), observed);
            });
        };
    }
    function createIterableMethod(method, isReadonly, isShallow) {
        return function (...args) {
            const target = this["__v_raw" /* RAW */];
            const rawTarget = toRaw(target);
            const targetIsMap = isMap(rawTarget);
            const isPair = method === 'entries' || (method === Symbol.iterator && targetIsMap);
            const isKeyOnly = method === 'keys' && targetIsMap;
            const innerIterator = target[method](...args);
            const wrap = isReadonly ? toReadonly : isShallow ? toShallow : toReactive;
            !isReadonly &&
                track(rawTarget, "iterate" /* ITERATE */, isKeyOnly ? MAP_KEY_ITERATE_KEY : ITERATE_KEY);
            // return a wrapped iterator which returns observed versions of the
            // values emitted from the real iterator
            return {
                next() {
                    const { value, done } = innerIterator.next();
                    return done
                        ? { value, done }
                        : {
                            value: isPair ? [wrap(value[0]), wrap(value[1])] : wrap(value),
                            done
                        };
                },
                [Symbol.iterator]() {
                    return this;
                }
            };
        };
    }
    function createReadonlyMethod(type) {
        return function (...args) {
            {
                const key = args[0] ? `on key "${args[0]}"` : ``;
                console.warn(`${capitalize(type)} operation ${key} failed: target is readonly.`, toRaw(this));
            }
            return type === "delete" /* DELETE */ ? false : this;
        };
    }
    const mutableInstrumentations = {
        // get proxy handler, this -> target
        get(key) {
            // collection get 执行期间
            return get$1(this, key);
        },
        get size() {
            return size(this);
        },
        has: has$1,
        add,
        set: set$1,
        delete: deleteEntry,
        clear,
        forEach: createForEach(false, false)
    };
    const shallowInstrumentations = {
        get(key) {
            return get$1(this, key, false, true);
        },
        get size() {
            return size(this);
        },
        has: has$1,
        add,
        set: set$1,
        delete: deleteEntry,
        clear,
        forEach: createForEach(false, true)
    };
    const readonlyInstrumentations = {
        get(key) {
            return get$1(this, key, true);
        },
        get size() {
            return size(this, true);
        },
        has(key) {
            return has$1.call(this, key, true);
        },
        add: createReadonlyMethod("add" /* ADD */),
        set: createReadonlyMethod("set" /* SET */),
        delete: createReadonlyMethod("delete" /* DELETE */),
        clear: createReadonlyMethod("clear" /* CLEAR */),
        forEach: createForEach(true, false)
    };
    const iteratorMethods = ['keys', 'values', 'entries', Symbol.iterator];
    iteratorMethods.forEach(method => {
        mutableInstrumentations[method] = createIterableMethod(method, false, false);
        readonlyInstrumentations[method] = createIterableMethod(method, true, false);
        shallowInstrumentations[method] = createIterableMethod(method, false, true);
    });
    function createInstrumentationGetter(isReadonly, shallow) {
        const instrumentations = shallow
            ? shallowInstrumentations
            : isReadonly
                ? readonlyInstrumentations
                : mutableInstrumentations;
        return (target, key, receiver) => {
            if (key === "__v_isReactive" /* IS_REACTIVE */) {
                return !isReadonly;
            }
            else if (key === "__v_isReadonly" /* IS_READONLY */) {
                return isReadonly;
            }
            else if (key === "__v_raw" /* RAW */) {
                return target;
            }
            // collection get 取值期间，这里只是负责将 get/set/... 方法取出来
            // map.get() -> 分给两步: fn = map.get -> fn()
            // 取 fn 在下面，fn() 执行实际在 mutableInstrumentation 里面
            // 所以 mutableInstrumentations.get 的两个参数分别是：
            // 1. this -> map
            // 2. key -> map.get('foo') 的 'foo'
            return Reflect.get(hasOwn(instrumentations, key) && key in target
                ? instrumentations
                : target, key, receiver);
        };
    }
    const mutableCollectionHandlers = {
        get: createInstrumentationGetter(false, false)
    };
    const shallowCollectionHandlers = {
        get: createInstrumentationGetter(false, true)
    };
    const readonlyCollectionHandlers = {
        get: createInstrumentationGetter(true, false)
    };
    function checkIdentityKeys(target, has, key) {
        // 同时有 key 和 proxy key 存在的情况
        const rawKey = toRaw(key);
        if (rawKey !== key && has.call(target, rawKey)) {
            const type = toRawType(target);
            console.warn(`Reactive ${type} contains both the raw and reactive ` +
                `versions of the same object${type === `Map` ? ` as keys` : ``}, ` +
                `which can lead to inconsistencies. ` +
                `Avoid differentiating between the raw and reactive versions ` +
                `of an object and only use the reactive version if possible.`);
        }
    }
  
    const reactiveMap = new WeakMap();
    const readonlyMap = new WeakMap();
    function targetTypeMap(rawType) {
        switch (rawType) {
            case 'Object':
            case 'Array':
                return 1 /* COMMON */;
            case 'Map':
            case 'Set':
            case 'WeakMap':
            case 'WeakSet':
                return 2 /* COLLECTION */;
            default:
                return 0 /* INVALID */;
        }
    }
    function getTargetType(value) {
        return value["__v_skip" /* SKIP */] || !Object.isExtensible(value)
            ? 0 /* INVALID */
            : targetTypeMap(toRawType(value));
    }
    function reactive(target) {
        // 如果试图 observe 一个只读 proxy，返回只读版本
        if (target && target["__v_isReadonly" /* IS_READONLY */]) {
            return target;
        }
        return createReactiveObject(target, false, mutableHandlers, mutableCollectionHandlers);
    }
    /**
     * Return a shallowly-reactive copy of the original object, where only the root
     * level properties are reactive. It also does not auto-unwrap refs (even at the
     * root level).
     */
    function shallowReactive(target) {
        return createReactiveObject(target, false, shallowReactiveHandlers, shallowCollectionHandlers);
    }
    /**
     * Creates a readonly copy of the original object. Note the returned copy is not
     * made reactive, but `readonly` can be called on an already reactive object.
     */
    function readonly(target) {
        return createReactiveObject(target, true, readonlyHandlers, readonlyCollectionHandlers);
    }
    /**
     * Returns a reactive-copy of the original object, where only the root level
     * properties are readonly, and does NOT unwrap refs nor recursively convert
     * returned properties.
     * This is used for creating the props proxy object for stateful components.
     */
    function shallowReadonly(target) {
        return createReactiveObject(target, true, shallowReadonlyHandlers, readonlyCollectionHandlers);
    }
    function createReactiveObject(target, isReadonly, baseHandlers, collectionHandlers) {
        if (!isObject(target)) {
            {
                console.warn(`value cannot be made reactive: ${String(target)}`);
            }
            return target;
        }
        // target 已经是 Proxy，不用重复代理
        // 异常情况：在一个 reactive object 上调用 readonly()
        if (target["__v_raw" /* RAW */] &&
            !(isReadonly && target["__v_isReactive" /* IS_REACTIVE */])) {
            return target;
        }
        // 代理缓存中有，直接取已缓存的
        const proxyMap = isReadonly ? readonlyMap : reactiveMap;
        const existingProxy = proxyMap.get(target);
        if (existingProxy) {
            return existingProxy;
        }
        // 只有合法的类型(Object|Array|[Weak]Map|[Weak]Set)才能被代理
        const targetType = getTargetType(target);
        if (targetType === 0 /* INVALID */) {
            return target;
        }
        const proxy = new Proxy(target, targetType === 2 /* COLLECTION */ ? collectionHandlers : baseHandlers);
        // 缓存代理映射关系
        proxyMap.set(target, proxy);
        return proxy;
    }
    function isReactive(value) {
        if (isReadonly(value)) {
            // 如果是只读的，判断 value 的原始对象
            return isReactive(value["__v_raw" /* RAW */]);
        }
        return !!(value && value["__v_isReactive" /* IS_REACTIVE */]);
    }
    function isReadonly(value) {
        return !!(value && value["__v_isReadonly" /* IS_READONLY */]);
    }
    function isProxy(value) {
        return isReactive(value) || isReadonly(value);
    }
    function toRaw(observed) {
        // 从 proxy 对象中取其原来的初始对象
        return ((observed && toRaw(observed["__v_raw" /* RAW */])) || observed);
    }
    // 标记为 raw 对象，即不可被代理的对象，设置了 __v_skip 属性
    function markRaw(value) {
        def(value, "__v_skip" /* SKIP */, true);
        return value;
    }
  
    const convert = (val) => isObject(val) ? reactive(val) : val;
    function isRef(r) {
        return Boolean(r && r.__v_isRef === true);
    }
    function ref(value) {
        return createRef(value);
    }
    function shallowRef(value) {
        return createRef(value, true);
    }
    class RefImpl {
        constructor(_rawValue, _shallow = false) {
            this._rawValue = _rawValue;
            this._shallow = _shallow;
            this.__v_isRef = true;
            this._value = _shallow ? _rawValue : convert(_rawValue);
        }
        get value() {
            track(toRaw(this), "get" /* GET */, 'value');
            return this._value;
        }
        set value(newVal) {
            if (hasChanged(toRaw(newVal), this._rawValue)) {
                this._rawValue = newVal;
                this._value = this._shallow ? newVal : convert(newVal);
                trigger(toRaw(this), "set" /* SET */, 'value', newVal);
            }
        }
    }
    function createRef(rawValue, shallow = false) {
        if (isRef(rawValue)) {
            return rawValue;
        }
        return new RefImpl(rawValue, shallow);
    }
    function triggerRef(ref) {
        trigger(toRaw(ref), "set" /* SET */, 'value',  ref.value );
    }
    function unref(ref) {
        return isRef(ref) ? ref.value : ref;
    }
    const shallowUnwrapHandlers = {
        get: (target, key, receiver) => unref(Reflect.get(target, key, receiver)),
        set: (target, key, value, receiver) => {
            const oldValue = target[key];
            if (isRef(oldValue) && !isRef(value)) {
                oldValue.value = value;
                return true;
            }
            else {
                return Reflect.set(target, key, value, receiver);
            }
        }
    };
    function proxyRefs(objectWithRefs) {
        return isReactive(objectWithRefs)
            ? objectWithRefs
            : new Proxy(objectWithRefs, shallowUnwrapHandlers);
    }
    class CustomRefImpl {
        constructor(factory) {
            this.__v_isRef = true;
            const { get, set } = factory(() => track(this, "get" /* GET */, 'value'), () => trigger(this, "set" /* SET */, 'value'));
            this._get = get;
            this._set = set;
        }
        get value() {
            return this._get();
        }
        set value(newVal) {
            this._set(newVal);
        }
    }
    function customRef(factory) {
        return new CustomRefImpl(factory);
    }
    function toRefs(object) {
        if ( !isProxy(object)) {
            console.warn(`toRefs() expects a reactive object but received a plain one.`);
        }
        const ret = isArray(object) ? new Array(object.length) : {};
        for (const key in object) {
            ret[key] = toRef(object, key);
        }
        return ret;
    }
    class ObjectRefImpl {
        constructor(_object, _key) {
            this._object = _object;
            this._key = _key;
            this.__v_isRef = true;
        }
        get value() {
            return this._object[this._key];
        }
        set value(newVal) {
            this._object[this._key] = newVal;
        }
    }
    function toRef(object, key) {
        return isRef(object[key])
            ? object[key]
            : new ObjectRefImpl(object, key);
    }
  
    // 计算属性模板
    class ComputedRefImpl {
        constructor(getter, _setter, isReadonly) {
            this._setter = _setter;
            this._dirty = true;
            this.__v_isRef = true;
            this.effect = effect(getter, {
                lazy: true,
                scheduler: () => {
                    if (!this._dirty) {
                        this._dirty = true;
                        trigger(toRaw(this), "set" /* SET */, 'value');
                    }
                }
            });
            this["__v_isReadonly" /* IS_READONLY */] = isReadonly;
        }
        get value() {
            if (this._dirty) {
                this._value = this.effect();
                this._dirty = false;
            }
            track(toRaw(this), "get" /* GET */, 'value');
            return this._value;
        }
        set value(newValue) {
            this._setter(newValue);
        }
    }
    function computed(getterOrOptions) {
        let getter;
        let setter;
        if (isFunction(getterOrOptions)) {
            getter = getterOrOptions;
            setter =  () => {
                    console.warn('Write operation failed: computed value is readonly');
                }
                ;
        }
        else {
            getter = getterOrOptions.get;
            setter = getterOrOptions.set;
        }
        return new ComputedRefImpl(getter, setter, isFunction(getterOrOptions) || !getterOrOptions.set);
    }
  
    const stack = [];
    function pushWarningContext(vnode) {
        stack.push(vnode);
    }
    function popWarningContext() {
        stack.pop();
    }
    function warn(msg, ...args) {
        // avoid props formatting or warn handler tracking deps that might be mutated
        // during patch, leading to infinite recursion.
        pauseTracking();
        const instance = stack.length ? stack[stack.length - 1].component : null;
        const appWarnHandler = instance && instance.appContext.config.warnHandler;
        const trace = getComponentTrace();
        if (appWarnHandler) {
            callWithErrorHandling(appWarnHandler, instance, 11 /* APP_WARN_HANDLER */, [
                msg + args.join(''),
                instance && instance.proxy,
                trace
                    .map(({ vnode }) => `at <${formatComponentName(instance, vnode.type)}>`)
                    .join('\n'),
                trace
            ]);
        }
        else {
            const warnArgs = [`[Vue warn]: ${msg}`, ...args];
            /* istanbul ignore if */
            if (trace.length &&
                // avoid spamming console during tests
                !false) {
                warnArgs.push(`\n`, ...formatTrace(trace));
            }
            console.warn(...warnArgs);
        }
        resetTracking();
    }
    function getComponentTrace() {
        let currentVNode = stack[stack.length - 1];
        if (!currentVNode) {
            return [];
        }
        // we can't just use the stack because it will be incomplete during updates
        // that did not start from the root. Re-construct the parent chain using
        // instance parent pointers.
        const normalizedStack = [];
        while (currentVNode) {
            const last = normalizedStack[0];
            if (last && last.vnode === currentVNode) {
                last.recurseCount++;
            }
            else {
                normalizedStack.push({
                    vnode: currentVNode,
                    recurseCount: 0
                });
            }
            const parentInstance = currentVNode.component && currentVNode.component.parent;
            currentVNode = parentInstance && parentInstance.vnode;
        }
        return normalizedStack;
    }
    /* istanbul ignore next */
    function formatTrace(trace) {
        const logs = [];
        trace.forEach((entry, i) => {
            logs.push(...(i === 0 ? [] : [`\n`]), ...formatTraceEntry(entry));
        });
        return logs;
    }
    function formatTraceEntry({ vnode, recurseCount }) {
        const postfix = recurseCount > 0 ? `... (${recurseCount} recursive calls)` : ``;
        const isRoot = vnode.component ? vnode.component.parent == null : false;
        const open = ` at <${formatComponentName(vnode.component, vnode.type, isRoot)}`;
        const close = `>` + postfix;
        return vnode.props
            ? [open, ...formatProps(vnode.props), close]
            : [open + close];
    }
    /* istanbul ignore next */
    function formatProps(props) {
        const res = [];
        const keys = Object.keys(props);
        keys.slice(0, 3).forEach(key => {
            res.push(...formatProp(key, props[key]));
        });
        if (keys.length > 3) {
            res.push(` ...`);
        }
        return res;
    }
    /* istanbul ignore next */
    function formatProp(key, value, raw) {
        if (isString(value)) {
            value = JSON.stringify(value);
            return raw ? value : [`${key}=${value}`];
        }
        else if (typeof value === 'number' ||
            typeof value === 'boolean' ||
            value == null) {
            return raw ? value : [`${key}=${value}`];
        }
        else if (isRef(value)) {
            value = formatProp(key, toRaw(value.value), true);
            return raw ? value : [`${key}=Ref<`, value, `>`];
        }
        else if (isFunction(value)) {
            return [`${key}=fn${value.name ? `<${value.name}>` : ``}`];
        }
        else {
            value = toRaw(value);
            return raw ? value : [`${key}=`, value];
        }
    }
  
    const ErrorTypeStrings = {
        ["bc" /* BEFORE_CREATE */]: 'beforeCreate hook',
        ["c" /* CREATED */]: 'created hook',
        ["bm" /* BEFORE_MOUNT */]: 'beforeMount hook',
        ["m" /* MOUNTED */]: 'mounted hook',
        ["bu" /* BEFORE_UPDATE */]: 'beforeUpdate hook',
        ["u" /* UPDATED */]: 'updated',
        ["bum" /* BEFORE_UNMOUNT */]: 'beforeUnmount hook',
        ["um" /* UNMOUNTED */]: 'unmounted hook',
        ["a" /* ACTIVATED */]: 'activated hook',
        ["da" /* DEACTIVATED */]: 'deactivated hook',
        ["ec" /* ERROR_CAPTURED */]: 'errorCaptured hook',
        ["rtc" /* RENDER_TRACKED */]: 'renderTracked hook',
        ["rtg" /* RENDER_TRIGGERED */]: 'renderTriggered hook',
        [0 /* SETUP_FUNCTION */]: 'setup function',
        [1 /* RENDER_FUNCTION */]: 'render function',
        [2 /* WATCH_GETTER */]: 'watcher getter',
        [3 /* WATCH_CALLBACK */]: 'watcher callback',
        [4 /* WATCH_CLEANUP */]: 'watcher cleanup function',
        [5 /* NATIVE_EVENT_HANDLER */]: 'native event handler',
        [6 /* COMPONENT_EVENT_HANDLER */]: 'component event handler',
        [7 /* VNODE_HOOK */]: 'vnode hook',
        [8 /* DIRECTIVE_HOOK */]: 'directive hook',
        [9 /* TRANSITION_HOOK */]: 'transition hook',
        [10 /* APP_ERROR_HANDLER */]: 'app errorHandler',
        [11 /* APP_WARN_HANDLER */]: 'app warnHandler',
        [12 /* FUNCTION_REF */]: 'ref function',
        [13 /* ASYNC_COMPONENT_LOADER */]: 'async component loader',
        [14 /* SCHEDULER */]: 'scheduler flush. This is likely a Vue internals bug. ' +
            'Please open an issue at https://new-issue.vuejs.org/?repo=vuejs/vue-next'
    };
    function callWithErrorHandling(fn, instance, type, args) {
        let res;
        try {
            res = args ? fn(...args) : fn();
        }
        catch (err) {
            handleError(err, instance, type);
        }
        return res;
    }
    function callWithAsyncErrorHandling(fn, instance, type, args) {
        if (isFunction(fn)) {
            const res = callWithErrorHandling(fn, instance, type, args);
            if (res && isPromise(res)) {
                res.catch(err => {
                    handleError(err, instance, type);
                });
            }
            return res;
        }
        const values = [];
        for (let i = 0; i < fn.length; i++) {
            values.push(callWithAsyncErrorHandling(fn[i], instance, type, args));
        }
        return values;
    }
    function handleError(err, instance, type, throwInDev = true) {
        const contextVNode = instance ? instance.vnode : null;
        if (instance) {
            let cur = instance.parent;
            // the exposed instance is the render proxy to keep it consistent with 2.x
            const exposedInstance = instance.proxy;
            // in production the hook receives only the error code
            const errorInfo =  ErrorTypeStrings[type] ;
            while (cur) {
                const errorCapturedHooks = cur.ec;
                if (errorCapturedHooks) {
                    for (let i = 0; i < errorCapturedHooks.length; i++) {
                        if (errorCapturedHooks[i](err, exposedInstance, errorInfo) === false) {
                            return;
                        }
                    }
                }
                cur = cur.parent;
            }
            // app-level handling
            const appErrorHandler = instance.appContext.config.errorHandler;
            if (appErrorHandler) {
                callWithErrorHandling(appErrorHandler, null, 10 /* APP_ERROR_HANDLER */, [err, exposedInstance, errorInfo]);
                return;
            }
        }
        logError(err, type, contextVNode, throwInDev);
    }
    function logError(err, type, contextVNode, throwInDev = true) {
        {
            const info = ErrorTypeStrings[type];
            if (contextVNode) {
                pushWarningContext(contextVNode);
            }
            warn(`Unhandled error${info ? ` during execution of ${info}` : ``}`);
            if (contextVNode) {
                popWarningContext();
            }
            // crash in dev by default so it's more noticeable
            if (throwInDev) {
                throw err;
            }
            else {
                console.error(err);
            }
        }
    }
  
    let isFlushing = false; // 开始 flush pre/job/post
    let isFlushPending = false; // 正在 flush pre cbs
    // job
    const queue = []; // job 队列
    let flushIndex = 0; // for -> job 时候的索引
    // 默认 pre cb 队列
    const pendingPreFlushCbs = [];
    // 正在执行的 pre cbs，由 pendingPreFlushCbs 去重而来的任务队列
    let activePreFlushCbs = null;
    let preFlushIndex = 0;
    // post 类型的 cb 队列
    const pendingPostFlushCbs = [];
    // 当前正在执行的 post cbs 队列，由 pendingPostFlushCbs 去重而来
    // 且它不会执行期间进行扩充，而是在 flushJobs 中 queue jobs 执行完成之后
    // 的 finally 里面检测 post 队列重新调用 flushJobs 来清空
    let activePostFlushCbs = null;
    let postFlushIndex = 0;
    // 空的 Promise 用来进行异步化，实现 nextTick
    const resolvedPromise = Promise.resolve();
    // 当 flushJobs 执行完毕，即当 pre/job/post 队列中所有
    // 任务都完成之后返回的一个 promise ，所以当使用 nextTick()
    // 的时候，对应的代码都是在这个基础完成之后调用
    // 所以 nextTick() 顾名思义就是在当前的 tick 下所有任务(pre/job/post)都
    // 执行完毕之后才执行的代码
    let currentFlushPromise = null;
    // queue job 可以作为 pre cbs 的父级任务
    // 比如：在手动调用 flushPreFlushCbs(seen, parentJob) 就可以
    // 传一个 queue job 当做当前 cbs 的父级任务。
    // 这个用途是为了避免该 job 的上一次入列任务(包括 job 及其子 pre cbs)
    // 还没完成就再次调用 queueJob 重复入列, 说白了就是为了同一个 job 不能在
    // parentJob 完成之前调用 queueJob，就算调了也没用
    let currentPreFlushParentJob = null;
    // pre/job/post 三种任务在同一个 tick 下，一次执行上限是100个
    // 超出视为死循环
    const RECURSION_LIMIT = 100;
    // 这个函数将使得 fn 或使用了 await 时候后面的代码总是在
    // 当前 tick 下的 pre/job/post 队列都 flush 空了之后执行
    function nextTick(fn) {
        const p = currentFlushPromise || resolvedPromise;
        return fn ? p.then(this ? fn.bind(this) : fn) : p;
    }
    function queueJob(job) {
        // the dedupe search uses the startIndex argument of Array.includes()
        // by default the search index includes the current job that is being run
        // so it cannot recursively trigger itself again.
        // if the job is a watch() callback, the search will start with a +1 index to
        // allow it recursively trigger itself - it is the user's responsibility to
        // ensure it doesn't end up in an infinite loop.
        // 1. 队列为空或不包含当前正入列的 job
        // 2. job 非当前 parent job
        if ((!queue.length ||
            !queue.includes(job, isFlushing && job.allowRecurse ? flushIndex + 1 : flushIndex)) &&
            job !== currentPreFlushParentJob) {
            queue.push(job);
            queueFlush();
        }
    }
    // 立即启动异步 flush 操作
    function queueFlush() {
        if (!isFlushing && !isFlushPending) {
            isFlushPending = true;
            currentFlushPromise = resolvedPromise.then(flushJobs);
        }
    }
    // 失效一个任务就是将其删除
    function invalidateJob(job) {
        const i = queue.indexOf(job);
        if (i > -1) {
            queue.splice(i, 1);
        }
    }
    // pre/post 任务入列函数，注意点
    // 1. 不能重复添加同一个 cb
    // 2. 如果指定了 allowRecurse: true 是可以重复添加的
    // 如下面的实现，查找从 index+1 开始肯定是找不到的
    function queueCb(cb, activeQueue, pendingQueue, index) {
        if (!isArray(cb)) {
            if (!activeQueue ||
                !activeQueue.includes(cb, cb.allowRecurse ? index + 1 : index)) {
                pendingQueue.push(cb);
            }
        }
        else {
            // 如果 cb 是个数组，那么它是个组件生命周期的 Hook 函数，这些函数只能被
            // 一个 job 触发，且在对应的 queue flush 函数中进过了去重操作
            // 因为这里直接跳过去重检测提高性能
            // 意思就是，在 flush[Pre|Post]FlushCbs 函数执行期间会进行去重操作，
            // 因此这里不需要重复做(如： activePostFlushCbs, activePreFlushCbs 都是
            // 去重之后待执行的 cbs)
            pendingQueue.push(...cb);
        }
        queueFlush();
    }
    function queuePreFlushCb(cb) {
        queueCb(cb, activePreFlushCbs, pendingPreFlushCbs, preFlushIndex);
    }
    function queuePostFlushCb(cb) {
        queueCb(cb, activePostFlushCbs, pendingPostFlushCbs, postFlushIndex);
    }
    // flush pre cbs，在 flushJobs 中优先调用，也就是说 pre cbs
    // 在同一 tick 内执行优先级最高，即最先执行(pre cbs > job > post cbs)
    // 并且它会一直递归到没有新的 pre cbs 为止
    // 比如： 有10个任务，执行到第5个的时候来了个新的任务(queuePreFlushCb(cb))
    // 那么这个任务会在前面10个执行完成之后作为第 11 个去执行，但记住是下次递归时完成
    function flushPreFlushCbs(seen, parentJob = null) {
        if (pendingPreFlushCbs.length) {
            currentPreFlushParentJob = parentJob;
            activePreFlushCbs = [...new Set(pendingPreFlushCbs)];
            pendingPreFlushCbs.length = 0;
            {
                seen = seen || new Map();
            }
            for (preFlushIndex = 0; preFlushIndex < activePreFlushCbs.length; preFlushIndex++) {
                // 检查递归更新问题
                {
                    checkRecursiveUpdates(seen, activePreFlushCbs[preFlushIndex]);
                }
                activePreFlushCbs[preFlushIndex]();
            }
            activePreFlushCbs = null;
            preFlushIndex = 0;
            currentPreFlushParentJob = null;
            // 递归 flush 直到所有 pre jobs 被执行完成
            flushPreFlushCbs(seen, parentJob);
        }
    }
    // flush post cbs 和 pre cbs 差不多，唯一不同的点在于：
    // 如果执行期间有新的任务进来 (queuePostFlushCb(cb)) 的时候
    // 它不是在当前 post cbs 后面立即执行，而是当 pre cbs -> jobs -> post -cbs
    // 执行完一轮之后在 flushJobs 的 finally 中重启新一轮的 flushJobs
    // 所以，这期间如果有新的 pre cbs 或 Jobs 那么这两个都会在新的 post cbs
    // 之前得到执行
    function flushPostFlushCbs(seen) {
        if (pendingPostFlushCbs.length) {
            const deduped = [...new Set(pendingPostFlushCbs)];
            pendingPostFlushCbs.length = 0;
            // #1947 already has active queue, nested flushPostFlushCbs call
            if (activePostFlushCbs) {
                activePostFlushCbs.push(...deduped);
                return;
            }
            activePostFlushCbs = deduped;
            {
                seen = seen || new Map();
            }
            activePostFlushCbs.sort((a, b) => getId(a) - getId(b));
            for (postFlushIndex = 0; postFlushIndex < activePostFlushCbs.length; postFlushIndex++) {
                // 递归 update 检查
                {
                    checkRecursiveUpdates(seen, activePostFlushCbs[postFlushIndex]);
                }
                activePostFlushCbs[postFlushIndex]();
            }
            activePostFlushCbs = null;
            postFlushIndex = 0;
        }
    }
    const getId = (job) => job.id == null ? Infinity : job.id;
    // 开启三种任务 flush 操作，优先级 pre cbs > jobs > post cbs
    function flushJobs(seen) {
        isFlushPending = false;
        isFlushing = true;
        {
            seen = seen || new Map();
        }
        flushPreFlushCbs(seen); // 默认的 job 类型
        // flush 之前对 queue 排序
        // 1. 组件更新顺序：parent -> child，因为 parent 总是在 child 之前
        //    被创建，因此 parent render effect 有更低的优先级数字(数字越小越先创建？)
        // 2. 如果组件在 parent 更新期间被卸载了，那么它的更新都会被忽略掉
        queue.sort((a, b) => getId(a) - getId(b));
        // 开始 flush
        try {
            for (flushIndex = 0; flushIndex < queue.length; flushIndex++) {
                const job = queue[flushIndex];
                if (job) {
                    // 检查递归更新问题
                    if (true) {
                        checkRecursiveUpdates(seen, job);
                    }
                    callWithErrorHandling(job, null, 14 /* SCHEDULER */);
                }
            }
        }
        finally {
            // 情况队列
            flushIndex = 0;
            queue.length = 0;
            // flush `post` 类型的 flush cbs
            flushPostFlushCbs(seen);
            isFlushing = false;
            currentFlushPromise = null;
            // 代码执行到当前 tick 的时候，有可能有新的 job 加入
            // some postFlushCb queued jobs!
            // keep flushing until it drains.
            if (queue.length || pendingPostFlushCbs.length) {
                flushJobs(seen);
            }
        }
    }
    function checkRecursiveUpdates(seen, fn) {
        if (!seen.has(fn)) {
            seen.set(fn, 1);
        }
        else {
            const count = seen.get(fn);
            if (count > RECURSION_LIMIT) {
                throw new Error(`Maximum recursive updates exceeded. ` +
                    `This means you have a reactive effect that is mutating its own ` +
                    `dependencies and thus recursively triggering itself. Possible sources ` +
                    `include component template, render function, updated hook or ` +
                    `watcher source function.`);
            }
            else {
                seen.set(fn, count + 1);
            }
        }
    }
  
    function setDevtoolsHook(hook) {
        exports.devtools = hook;
    }
    function devtoolsInitApp(app, version) {
        // TODO queue if devtools is undefined
        if (!exports.devtools)
            return;
        exports.devtools.emit("app:init" /* APP_INIT */, app, version, {
            Fragment,
            Text,
            Comment,
            Static
        });
    }
    function devtoolsUnmountApp(app) {
        if (!exports.devtools)
            return;
        exports.devtools.emit("app:unmount" /* APP_UNMOUNT */, app);
    }
    const devtoolsComponentRemoved = /*#__PURE__*/ createDevtoolsComponentHook("component:removed" /* COMPONENT_REMOVED */);
    function createDevtoolsComponentHook(hook) {
        return (component) => {
            if (!exports.devtools)
                return;
            exports.devtools.emit(hook, component.appContext.app, component.uid, component.parent ? component.parent.uid : undefined);
        };
    }
    function devtoolsComponentEmit(component, event, params) {
        if (!exports.devtools)
            return;
        exports.devtools.emit("component:emit" /* COMPONENT_EMIT */, component.appContext.app, component, event, params);
    }
  
    function emit(instance, event, ...rawArgs) {
        const props = instance.vnode.props || EMPTY_OBJ;
        {
            const { emitsOptions, propsOptions: [propsOptions] } = instance;
            if (emitsOptions) {
                if (!(event in emitsOptions)) {
                    if (!propsOptions || !(toHandlerKey(event) in propsOptions)) {
                        warn(`Component emitted event "${event}" but it is neither declared in ` +
                            `the emits option nor as an "${toHandlerKey(event)}" prop.`);
                    }
                }
                else {
                    const validator = emitsOptions[event];
                    if (isFunction(validator)) {
                        const isValid = validator(...rawArgs);
                        if (!isValid) {
                            warn(`Invalid event arguments: event validation failed for event "${event}".`);
                        }
                    }
                }
            }
        }
        let args = rawArgs;
        const isModelListener = event.startsWith('update:');
        // for v-model update:xxx events, apply modifiers on args
        const modelArg = isModelListener && event.slice(7);
        if (modelArg && modelArg in props) {
            const modifiersKey = `${modelArg === 'modelValue' ? 'model' : modelArg}Modifiers`;
            const { number, trim } = props[modifiersKey] || EMPTY_OBJ;
            if (trim) {
                args = rawArgs.map(a => a.trim());
            }
            else if (number) {
                args = rawArgs.map(toNumber);
            }
        }
        {
            devtoolsComponentEmit(instance, event, args);
        }
        {
            const lowerCaseEvent = event.toLowerCase();
            if (lowerCaseEvent !== event && props[toHandlerKey(lowerCaseEvent)]) {
                warn(`Event "${lowerCaseEvent}" is emitted in component ` +
                    `${formatComponentName(instance, instance.type)} 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}".`);
            }
        }
        // convert handler name to camelCase. See issue #2249
        let handlerName = toHandlerKey(camelize(event));
        let handler = props[handlerName];
        // for v-model update:xxx events, also trigger kebab-case equivalent
        // for props passed via kebab-case
        if (!handler && isModelListener) {
            handlerName = toHandlerKey(hyphenate(event));
            handler = props[handlerName];
        }
        if (handler) {
            callWithAsyncErrorHandling(handler, instance, 6 /* COMPONENT_EVENT_HANDLER */, args);
        }
        const onceHandler = props[handlerName + `Once`];
        if (onceHandler) {
            if (!instance.emitted) {
                (instance.emitted = {})[handlerName] = true;
            }
            else if (instance.emitted[handlerName]) {
                return;
            }
            callWithAsyncErrorHandling(onceHandler, instance, 6 /* COMPONENT_EVENT_HANDLER */, args);
        }
    }
    function normalizeEmitsOptions(comp, appContext, asMixin = false) {
        if (!appContext.deopt && comp.__emits !== undefined) {
            return comp.__emits;
        }
        const raw = comp.emits;
        let normalized = {};
        // apply mixin/extends props
        let hasExtends = false;
        if ( !isFunction(comp)) {
            const extendEmits = (raw) => {
                hasExtends = true;
                extend(normalized, normalizeEmitsOptions(raw, appContext, true));
            };
            if (!asMixin && appContext.mixins.length) {
                appContext.mixins.forEach(extendEmits);
            }
            if (comp.extends) {
                extendEmits(comp.extends);
            }
            if (comp.mixins) {
                comp.mixins.forEach(extendEmits);
            }
        }
        if (!raw && !hasExtends) {
            return (comp.__emits = null);
        }
        if (isArray(raw)) {
            raw.forEach(key => (normalized[key] = null));
        }
        else {
            extend(normalized, raw);
        }
        return (comp.__emits = normalized);
    }
    // Check if an incoming prop key is a declared emit event listener.
    // e.g. With `emits: { click: null }`, props named `onClick` and `onclick` are
    // both considered matched listeners.
    function isEmitListener(options, key) {
        if (!options || !isOn(key)) {
            return false;
        }
        //onXxxx or onXxxOnce, 因为 @click.once 会解析成 onClickOnce
        key = key.slice(2).replace(/Once$/, '');
        // 检测条件：
        // 1. slice(1) 应该是去掉 @click 中的 `@` ?
        // 2. clickEvent -> click-event
        // 3. click
        // 支持三种形式的事件名
        return (hasOwn(options, key[0].toLowerCase() + key.slice(1)) ||
            // onClick -> on-click
            hasOwn(options, hyphenate(key)) ||
            hasOwn(options, key));
    }
  
    /**
     * mark the current rendering instance for asset resolution (e.g.
     * resolveComponent, resolveDirective) during render
     */
    let currentRenderingInstance = null;
    function setCurrentRenderingInstance(instance) {
        currentRenderingInstance = instance;
    }
    /**
     * dev only flag to track whether $attrs was used during render.
     * If $attrs was used during render then the warning for failed attrs
     * fallthrough can be suppressed.
     * 开发是用的标识，用来跟踪 $attrs 静态属性在 render 期间是否被使用
     * 如果被使用了，或许就不需要给出警告？啥意思???
     */
    let accessedAttrs = false;
    function markAttrsAccessed() {
        accessedAttrs = true;
    }
    function renderComponentRoot(instance) {
        const { type: Component, vnode, proxy, withProxy, props, propsOptions: [propsOptions], slots, attrs, emit, render, renderCache, data, setupState, ctx } = instance;
        let result;
        currentRenderingInstance = instance;
        {
            accessedAttrs = false;
        }
        try {
            let fallthroughAttrs;
            if (vnode.shapeFlag & 4 /* STATEFUL_COMPONENT */) {
                // withProxy is a proxy with a different `has` trap only for
                // runtime-compiled render functions using `with` block.
                const proxyToUse = withProxy || proxy;
                console.log('normalize vnode');
                result = normalizeVNode(render.call(proxyToUse, proxyToUse, renderCache, props, setupState, data, ctx));
                fallthroughAttrs = attrs;
            }
            else {
                // functional
                const render = Component;
                // in dev, mark attrs accessed if optional props (attrs === props)
                if (true && attrs === props) {
                    markAttrsAccessed();
                }
                result = normalizeVNode(render.length > 1
                    ? render(props, true
                        ? {
                            get attrs() {
                                markAttrsAccessed();
                                return attrs;
                            },
                            slots,
                            emit
                        }
                        : { attrs, slots, emit })
                    : render(props, null /* we know it doesn't need it */));
                fallthroughAttrs = Component.props
                    ? attrs
                    : getFunctionalFallthrough(attrs);
            }
            // attr merging
            // in dev mode, comments are preserved, and it's possible for a template
            // to have comments along side the root element which makes it a fragment
            let root = result;
            let setRoot = undefined;
            if (true && result.patchFlag & 2048 /* DEV_ROOT_FRAGMENT */) {
                ;
                [root, setRoot] = getChildRoot(result);
            }
            if (Component.inheritAttrs !== false && fallthroughAttrs) {
                const keys = Object.keys(fallthroughAttrs);
                const { shapeFlag } = root;
                if (keys.length) {
                    if (shapeFlag & 1 /* ELEMENT */ ||
                        shapeFlag & 6 /* COMPONENT */) {
                        if (propsOptions && keys.some(isModelListener)) {
                            // If a v-model listener (onUpdate:xxx) has a corresponding declared
                            // prop, it indicates this component expects to handle v-model and
                            // it should not fallthrough.
                            // related: #1543, #1643, #1989
                            fallthroughAttrs = filterModelListeners(fallthroughAttrs, propsOptions);
                        }
                        root = cloneVNode(root, fallthroughAttrs);
                    }
                    else if (true && !accessedAttrs && root.type !== Comment) {
                        const allAttrs = Object.keys(attrs);
                        const eventAttrs = [];
                        const extraAttrs = [];
                        for (let i = 0, l = allAttrs.length; i < l; i++) {
                            const key = allAttrs[i];
                            if (isOn(key)) {
                                // ignore v-model handlers when they fail to fallthrough
                                if (!isModelListener(key)) {
                                    // remove `on`, lowercase first letter to reflect event casing
                                    // accurately
                                    eventAttrs.push(key[2].toLowerCase() + key.slice(3));
                                }
                            }
                            else {
                                extraAttrs.push(key);
                            }
                        }
                        if (extraAttrs.length) {
                            warn(`Extraneous non-props attributes (` +
                                `${extraAttrs.join(', ')}) ` +
                                `were passed to component but could not be automatically inherited ` +
                                `because component renders fragment or text root nodes.`);
                        }
                        if (eventAttrs.length) {
                            warn(`Extraneous non-emits event listeners (` +
                                `${eventAttrs.join(', ')}) ` +
                                `were passed to component but could not be automatically inherited ` +
                                `because component renders fragment or text root nodes. ` +
                                `If the listener is intended to be a component custom event listener only, ` +
                                `declare it using the "emits" option.`);
                        }
                    }
                }
            }
            // inherit directives
            if (vnode.dirs) {
                if (true && !isElementRoot(root)) {
                    warn(`Runtime directive used on component with non-element root node. ` +
                        `The directives will not function as intended.`);
                }
                root.dirs = root.dirs ? root.dirs.concat(vnode.dirs) : vnode.dirs;
            }
            // inherit transition data
            if (vnode.transition) {
                if (true && !isElementRoot(root)) {
                    warn(`Component inside <Transition> renders non-element root node ` +
                        `that cannot be animated.`);
                }
                root.transition = vnode.transition;
            }
            if (true && setRoot) {
                setRoot(root);
            }
            else {
                result = root;
            }
        }
        catch (err) {
            handleError(err, instance, 1 /* RENDER_FUNCTION */);
            result = createVNode(Comment);
        }
        currentRenderingInstance = null;
        return result;
    }
    /**
     * dev only
     * In dev mode, template root level comments are rendered, which turns the
     * template into a fragment root, but we need to locate the single element
     * root for attrs and scope id processing.
     */
    const getChildRoot = (vnode) => {
        const rawChildren = vnode.children;
        const dynamicChildren = vnode.dynamicChildren;
        const childRoot = filterSingleRoot(rawChildren);
        if (!childRoot) {
            return [vnode, undefined];
        }
        const index = rawChildren.indexOf(childRoot);
        const dynamicIndex = dynamicChildren ? dynamicChildren.indexOf(childRoot) : -1;
        const setRoot = (updatedRoot) => {
            rawChildren[index] = updatedRoot;
            if (dynamicChildren) {
                if (dynamicIndex > -1) {
                    dynamicChildren[dynamicIndex] = updatedRoot;
                }
                else if (updatedRoot.patchFlag > 0) {
                    vnode.dynamicChildren = [...dynamicChildren, updatedRoot];
                }
            }
        };
        return [normalizeVNode(childRoot), setRoot];
    };
    function filterSingleRoot(children) {
        let singleRoot;
        for (let i = 0; i < children.length; i++) {
            const child = children[i];
            if (isVNode(child)) {
                // ignore user comment
                if (child.type !== Comment || child.children === 'v-if') {
                    if (singleRoot) {
                        // has more than 1 non-comment child, return now
                        return;
                    }
                    else {
                        singleRoot = child;
                    }
                }
            }
            else {
                return;
            }
        }
        return singleRoot;
    }
    const getFunctionalFallthrough = (attrs) => {
        let res;
        for (const key in attrs) {
            if (key === 'class' || key === 'style' || isOn(key)) {
                (res || (res = {}))[key] = attrs[key];
            }
        }
        return res;
    };
    const filterModelListeners = (attrs, props) => {
        const res = {};
        for (const key in attrs) {
            if (!isModelListener(key) || !(key.slice(9) in props)) {
                res[key] = attrs[key];
            }
        }
        return res;
    };
    const isElementRoot = (vnode) => {
        return (vnode.shapeFlag & 6 /* COMPONENT */ ||
            vnode.shapeFlag & 1 /* ELEMENT */ ||
            vnode.type === Comment // potential v-if branch switch
        );
    };
    function shouldUpdateComponent(prevVNode, nextVNode, optimized) {
        console.log('should update component');
        const { props: prevProps, children: prevChildren, component } = prevVNode;
        const { props: nextProps, children: nextChildren, patchFlag } = nextVNode;
        const emits = component.emitsOptions;
        // 运行时 vnode 上的指令或者 transition 动画，强制 child 更新
        if (nextVNode.dirs || nextVNode.transition) {
            return true;
        }
        if (optimized && patchFlag >= 0) {
            if (patchFlag & 1024 /* DYNAMIC_SLOTS */) {
                // 插槽内容引用的值可能发生了改变，比如： v-for 中
                return true;
            }
            if (patchFlag & 16 /* FULL_PROPS */) {
                if (!prevProps) {
                    return !!nextProps;
                }
                return hasPropsChanged(prevProps, nextProps, emits);
            }
            else if (patchFlag & 8 /* PROPS */) {
                const dynamicProps = nextVNode.dynamicProps;
                for (let i = 0; i < dynamicProps.length; i++) {
                    const key = dynamicProps[i];
                    // 只要有一个属性名不一样，就需要更新
                    if (nextProps[key] !== prevProps[key] &&
                        !isEmitListener(emits, key)) {
                        return true;
                    }
                }
            }
        }
        else {
            if (prevChildren || nextChildren) {
                if (!nextChildren || !nextChildren.$stable) {
                    return true;
                }
            }
            if (prevProps === nextProps) {
                return false;
            }
            if (!prevProps) {
                return !!nextProps;
            }
            if (!nextProps) {
                return true;
            }
            return hasPropsChanged(prevProps, nextProps, emits);
        }
        return false;
    }
    function hasPropsChanged(prevProps, nextProps, emitsOptions) {
        console.log('has changed props');
        const nextKeys = Object.keys(nextProps);
        // 包含属性数不一样，可能删除、添加了
        if (nextKeys.length !== Object.keys(prevProps).length) {
            return true;
        }
        for (let i = 0; i < nextKeys.length; i++) {
            const key = nextKeys[i];
            // 值不同，且不是事件属性
            if (nextProps[key] !== prevProps[key] &&
                !isEmitListener(emitsOptions, key)) {
                return true;
            }
        }
        return false;
    }
    function updateHOCHostEl({ vnode, parent }, el // HostNode
    ) {
        while (parent && parent.subTree === vnode) {
            (vnode = parent.vnode).el = el;
            parent = parent.parent;
        }
    }
  
    const isSuspense = (type) => type.__isSuspense;
    // Suspense exposes a component-like API, and is treated like a component
    // in the compiler, but internally it's a special built-in type that hooks
    // directly into the renderer.
    const SuspenseImpl = {
        // In order to make Suspense tree-shakable, we need to avoid importing it
        // directly in the renderer. The renderer checks for the __isSuspense flag
        // on a vnode's type and calls the `process` method, passing in renderer
        // internals.
        // 为了确保 tree-shakable Suspense 组件功能，避免直接在 renderer 中引入
        // 而是在 renderer 中通过 __isSuspense 结合 true 检测
        __isSuspense: true,
        process(n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized, 
        // platform-specific impl passed from renderer
        rendererInternals) {
            if (n1 == null) {
                mountSuspense(n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized, rendererInternals);
            }
            else {
                patchSuspense(n1, n2, container, anchor, parentComponent, isSVG, rendererInternals);
            }
        },
        hydrate: hydrateSuspense,
        create: createSuspenseBoundary
    };
    // Force-casted public typing for h and TSX props inference
    const Suspense = ( SuspenseImpl
        );
    function mountSuspense(vnode, container, anchor, parentComponent, parentSuspense, isSVG, optimized, rendererInternals) {
        const { p: patch, o: { createElement } } = rendererInternals;
        const hiddenContainer = createElement('div');
        const suspense = (vnode.suspense = createSuspenseBoundary(vnode, parentSuspense, parentComponent, container, hiddenContainer, anchor, isSVG, optimized, rendererInternals));
        // start mounting the content subtree in an off-dom container
        patch(null, (suspense.pendingBranch = vnode.ssContent), hiddenContainer, null, parentComponent, suspense, isSVG);
        // now check if we have encountered any async deps
        if (suspense.deps > 0) {
            // has async
            // mount the fallback tree
            patch(null, vnode.ssFallback, container, anchor, parentComponent, null, // fallback tree will not have suspense context
            isSVG);
            setActiveBranch(suspense, vnode.ssFallback);
        }
        else {
            // Suspense has no async deps. Just resolve.
            suspense.resolve();
        }
    }
    function patchSuspense(n1, n2, container, anchor, parentComponent, isSVG, { p: patch, um: unmount, o: { createElement } }) {
        const suspense = (n2.suspense = n1.suspense);
        suspense.vnode = n2;
        n2.el = n1.el;
        const newBranch = n2.ssContent;
        const newFallback = n2.ssFallback;
        const { activeBranch, pendingBranch, isInFallback, isHydrating } = suspense;
        if (pendingBranch) {
            suspense.pendingBranch = newBranch;
            if (isSameVNodeType(newBranch, pendingBranch)) {
                // same root type but content may have changed.
                patch(pendingBranch, newBranch, suspense.hiddenContainer, null, parentComponent, suspense, isSVG);
                if (suspense.deps <= 0) {
                    suspense.resolve();
                }
                else if (isInFallback) {
                    patch(activeBranch, newFallback, container, anchor, parentComponent, null, // fallback tree will not have suspense context
                    isSVG);
                    setActiveBranch(suspense, newFallback);
                }
            }
            else {
                // toggled before pending tree is resolved
                suspense.pendingId++;
                if (isHydrating) {
                    // if toggled before hydration is finished, the current DOM tree is
                    // no longer valid. set it as the active branch so it will be unmounted
                    // when resolved
                    suspense.isHydrating = false;
                    suspense.activeBranch = pendingBranch;
                }
                else {
                    unmount(pendingBranch, parentComponent, suspense);
                }
                // increment pending ID. this is used to invalidate async callbacks
                // reset suspense state
                suspense.deps = 0;
                // discard effects from pending branch
                suspense.effects.length = 0;
                // discard previous container
                suspense.hiddenContainer = createElement('div');
                if (isInFallback) {
                    // already in fallback state
                    patch(null, newBranch, suspense.hiddenContainer, null, parentComponent, suspense, isSVG);
                    if (suspense.deps <= 0) {
                        suspense.resolve();
                    }
                    else {
                        patch(activeBranch, newFallback, container, anchor, parentComponent, null, // fallback tree will not have suspense context
                        isSVG);
                        setActiveBranch(suspense, newFallback);
                    }
                }
                else if (activeBranch && isSameVNodeType(newBranch, activeBranch)) {
                    // toggled "back" to current active branch
                    patch(activeBranch, newBranch, container, anchor, parentComponent, suspense, isSVG);
                    // force resolve
                    suspense.resolve(true);
                }
                else {
                    // switched to a 3rd branch
                    patch(null, newBranch, suspense.hiddenContainer, null, parentComponent, suspense, isSVG);
                    if (suspense.deps <= 0) {
                        suspense.resolve();
                    }
                }
            }
        }
        else {
            if (activeBranch && isSameVNodeType(newBranch, activeBranch)) {
                // root did not change, just normal patch
                patch(activeBranch, newBranch, container, anchor, parentComponent, suspense, isSVG);
                setActiveBranch(suspense, newBranch);
            }
            else {
                // root node toggled
                // invoke @pending event
                const onPending = n2.props && n2.props.onPending;
                if (isFunction(onPending)) {
                    onPending();
                }
                // mount pending branch in off-dom container
                suspense.pendingBranch = newBranch;
                suspense.pendingId++;
                patch(null, newBranch, suspense.hiddenContainer, null, parentComponent, suspense, isSVG);
                if (suspense.deps <= 0) {
                    // incoming branch has no async deps, resolve now.
                    suspense.resolve();
                }
                else {
                    const { timeout, pendingId } = suspense;
                    if (timeout > 0) {
                        setTimeout(() => {
                            if (suspense.pendingId === pendingId) {
                                suspense.fallback(newFallback);
                            }
                        }, timeout);
                    }
                    else if (timeout === 0) {
                        suspense.fallback(newFallback);
                    }
                }
            }
        }
    }
    function createSuspenseBoundary(vnode, parent, parentComponent, container, hiddenContainer, anchor, isSVG, optimized, rendererInternals, isHydrating = false) {
        const { p: patch, m: move, um: unmount, n: next, o: { parentNode, remove } } = rendererInternals;
        const timeout = toNumber(vnode.props && vnode.props.timeout);
        const suspense = {
            vnode,
            parent,
            parentComponent,
            isSVG,
            container,
            hiddenContainer,
            anchor,
            deps: 0,
            pendingId: 0,
            timeout: typeof timeout === 'number' ? timeout : -1,
            activeBranch: null,
            pendingBranch: null,
            isInFallback: true,
            isHydrating,
            isUnmounted: false,
            effects: [],
            resolve(resume = false) {
                const { vnode, activeBranch, pendingBranch, pendingId, effects, parentComponent, container } = suspense;
                if (suspense.isHydrating) {
                    suspense.isHydrating = false;
                }
                else if (!resume) {
                    // 1. transition 支持，将 move() 操作注册到 afterLeave 回调
                    // 2. 卸载当前的 subTree 可能是 fallback
                    // 3. 不是 transition dely enter 进行 move()
                    // 这里最后执行的操作就是 move() 如果是 transition delay enter
                    // 则将 move() 注册到 afterLeave，否则直接执行 move() 将 suspense
                    // 内容渲染到真实DOM上
                    const delayEnter = activeBranch &&
                        pendingBranch.transition &&
                        pendingBranch.transition.mode === 'out-in';
                    if (delayEnter) {
                        activeBranch.transition.afterLeave = () => {
                            if (pendingId === suspense.pendingId) {
                                move(pendingBranch, container, anchor, 0 /* ENTER */);
                            }
                        };
                    }
                    // this is initial anchor on mount
                    let { anchor } = suspense;
                    // unmount current active tree
                    if (activeBranch) {
                        // if the fallback tree was mounted, it may have been moved
                        // as part of a parent suspense. get the latest anchor for insertion
                        anchor = next(activeBranch);
                        unmount(activeBranch, parentComponent, suspense, true);
                    }
                    if (!delayEnter) {
                        // move content from off-dom container to actual container
                        move(pendingBranch, container, anchor, 0 /* ENTER */);
                    }
                }
                // 标记当前激活状态的分支，此时是 #default
                setActiveBranch(suspense, pendingBranch);
                suspense.pendingBranch = null;
                suspense.isInFallback = false;
                // flush buffered effects
                // check if there is a pending parent suspense
                // 注册的 effect 处理，这里的处理说明了 suspense 的父子依赖执行
                // 的顺序问题， effects 是按照数组加入顺序执行的(详情可以查看 reactivity 文章)
                // 所以 effects 的优先级是自上而下的，即 parent-parent > parent > children
                let parent = suspense.parent;
                let hasUnresolvedAncestor = false;
                while (parent) {
                    if (parent.pendingBranch) {
                        // found a pending parent suspense, merge buffered post jobs
                        // into that parent
                        parent.effects.push(...effects);
                        hasUnresolvedAncestor = true;
                        break;
                    }
                    parent = parent.parent;
                }
                // no pending parent suspense, flush all jobs
                // 如果没有挂起的 parent suspense 直接 flush 掉所有任务
                // 结合上面的 while 举例：
                // CompA -> CompB -> CompC
                // 当解析到 CompC 时，一直往上检测 B 和 A 如果 B 有挂起的任务
                // C 这里的任务不会被 flush，而是加入到 B 的队列等待执行
                // 然后 C 解析完成，回溯到 B 的解析，此时又遵循同一套规则检测 A 的
                // 挂起任务，直到最后要么立即执行 B 的任务要么 B 的任务也加入到 A
                // 最后由 A 执行所有的任务(包含子 suspense 的)
                if (!hasUnresolvedAncestor) {
                    queuePostFlushCb(effects);
                }
                suspense.effects = [];
                // invoke @resolve event
                const onResolve = vnode.props && vnode.props.onResolve;
                if (isFunction(onResolve)) {
                    onResolve();
                }
            },
            fallback(fallbackVNode) {
                if (!suspense.pendingBranch) {
                    return;
                }
                const { vnode, activeBranch, parentComponent, container, isSVG } = suspense;
                const onFallback = vnode.props && vnode.props.onFallback;
                if (isFunction(onFallback)) {
                    onFallback();
                }
                const anchor = next(activeBranch);
                const mountFallback = () => {
                    if (!suspense.isInFallback) {
                        return;
                    }
                    // 加载 fallback 分支树
                    patch(null, fallbackVNode, container, anchor, parentComponent, null, // fallback 不会有 suspense 内容
                    isSVG);
                    setActiveBranch(suspense, fallbackVNode);
                };
                const delayEnter = fallbackVNode.transition && fallbackVNode.transition.mode === 'out-in';
                if (delayEnter) {
                    activeBranch.transition.afterLeave = mountFallback;
                }
                // unmount current active branch
                unmount(activeBranch, parentComponent, null, // no suspense so unmount hooks fire now
                true // shouldRemove
                );
                suspense.isInFallback = true;
                if (!delayEnter) {
                    mountFallback();
                }
            },
            move(container, anchor, type) {
                suspense.activeBranch &&
                    move(suspense.activeBranch, container, anchor, type);
                suspense.container = container;
            },
            next() {
                return suspense.activeBranch && next(suspense.activeBranch);
            },
            registerDep(instance, setupRenderEffect) {
                const isInPendingSuspense = !!suspense.pendingBranch;
                if (isInPendingSuspense) {
                    suspense.deps++;
                }
                const hydratedEl = instance.vnode.el;
                // 捕获 setup 执行的异常，或接受执行的结果
                instance
                    .asyncDep.catch(err => {
                    handleError(err, instance, 0 /* SETUP_FUNCTION */);
                })
                    .then(asyncSetupResult => {
                    // 当 setup() 的 promise 状态变更之后重试
                    // 因为在解析之前组件可能已经被卸载了
                    if (instance.isUnmounted ||
                        suspense.isUnmounted ||
                        suspense.pendingId !== instance.suspenseId) {
                        return;
                    }
                    // 从该组件开始重试，状态标记为已经完成
                    instance.asyncResolved = true;
                    const { vnode } = instance;
                    handleSetupResult(instance, asyncSetupResult);
                    if (hydratedEl) {
                        // 虚拟节点可能在 async dep 状态完成之前被某个更新替换掉了
                        vnode.el = hydratedEl;
                    }
                    const placeHolder = !hydratedEl && instance.subTree.el;
                    setupRenderEffect(instance, vnode, 
                    // 组件可能在 resolve 之前被移除了
                    // 如果这个不是一个 hydration，instance.subTree 将会是个注释
                    // 占位节点
                    parentNode(hydratedEl || instance.subTree.el), hydratedEl ? null : next(instance.subTree), suspense, isSVG, optimized);
                    if (placeHolder) {
                        remove(placeHolder);
                    }
                    updateHOCHostEl(instance, vnode.el);
                    // only decrease deps count if suspense is not already resolved
                    // 没有任何依赖了就开始解析 Suspense
                    if (isInPendingSuspense && --suspense.deps === 0) {
                        suspense.resolve();
                    }
                });
            },
            unmount(parentSuspense, doRemove) {
                suspense.isUnmounted = true;
                if (suspense.activeBranch) {
                    unmount(suspense.activeBranch, parentComponent, parentSuspense, doRemove);
                }
                if (suspense.pendingBranch) {
                    unmount(suspense.pendingBranch, parentComponent, parentSuspense, doRemove);
                }
            }
        };
        return suspense;
    }
    function hydrateSuspense(node, vnode, parentComponent, parentSuspense, isSVG, optimized, rendererInternals, hydrateNode) {
        /* eslint-disable no-restricted-globals */
        const suspense = (vnode.suspense = createSuspenseBoundary(vnode, parentSuspense, parentComponent, node.parentNode, document.createElement('div'), null, isSVG, optimized, rendererInternals, true /* hydrating */));
        // there are two possible scenarios for server-rendered suspense:
        // - success: ssr content should be fully resolved
        // - failure: ssr content should be the fallback branch.
        // however, on the client we don't really know if it has failed or not
        // attempt to hydrate the DOM assuming it has succeeded, but we still
        // need to construct a suspense boundary first
        const result = hydrateNode(node, (suspense.pendingBranch = vnode.ssContent), parentComponent, suspense, optimized);
        if (suspense.deps === 0) {
            suspense.resolve();
        }
        return result;
        /* eslint-enable no-restricted-globals */
    }
    function normalizeSuspenseChildren(vnode) {
        const { shapeFlag, children } = vnode;
        let content, fallback;
        if (shapeFlag & 32 /* SLOTS_CHILDREN */) {
            content = normalizeSuspenseSlot(children.default);
            fallback = normalizeSuspenseSlot(children.fallback);
        }
        else {
            content = normalizeSuspenseSlot(children);
            fallback = normalizeVNode(null);
        }
        return {
            content,
            fallback
        };
    }
    function normalizeSuspenseSlot(s) {
        if (isFunction(s)) {
            s = s();
        }
        if (isArray(s)) {
            // ROOT 必须是单节点 <div>...</div>
            const singleChild = filterSingleRoot(s);
            if ( !singleChild) {
                warn(`<Suspense> slots expect a single root node.`);
            }
            s = singleChild;
        }
        return normalizeVNode(s);
    }
    function queueEffectWithSuspense(fn, suspense) {
        if (suspense && suspense.pendingBranch) {
            if (isArray(fn)) {
                suspense.effects.push(...fn);
            }
            else {
                suspense.effects.push(fn);
            }
        }
        else {
            queuePostFlushCb(fn);
        }
    }
    function setActiveBranch(suspense, branch) {
        suspense.activeBranch = branch;
        const { vnode, parentComponent } = suspense;
        const el = (vnode.el = branch.el);
        // in case suspense is the root node of a component,
        // recursively update the HOC el
        if (parentComponent && parentComponent.subTree === vnode) {
            parentComponent.vnode.el = el;
            updateHOCHostEl(parentComponent, el);
        }
    }
  
    let isRenderingCompiledSlot = 0;
    const setCompiledSlotRendering = (n) => (isRenderingCompiledSlot += n);
    /**
     * Compiler runtime helper for rendering `<slot/>`
     * @private
     */
    function renderSlot(slots, name, props = {}, 
    // this is not a user-facing function, so the fallback is always generated by
    // the compiler and guaranteed to be a function returning an array
    fallback) {
        let slot = slots[name];
        if ( slot && slot.length > 1) {
            warn(`SSR-optimized slot function detected in a non-SSR-optimized render ` +
                `function. You need to mark this component with $dynamic-slots in the ` +
                `parent template.`);
            slot = () => [];
        }
        // a compiled slot disables block tracking by default to avoid manual
        // invocation interfering with template-based block tracking, but in
        // `renderSlot` we can be sure that it's template-based so we can force
        // enable it.
        isRenderingCompiledSlot++;
        openBlock();
        const validSlotContent = slot && ensureValidVNode(slot(props));
        const rendered = createBlock(Fragment, { key: props.key || `_${name}` }, validSlotContent || (fallback ? fallback() : []), validSlotContent && slots._ === 1 /* STABLE */
            ? 64 /* STABLE_FRAGMENT */
            : -2 /* BAIL */);
        isRenderingCompiledSlot--;
        return rendered;
    }
    function ensureValidVNode(vnodes) {
        return vnodes.some(child => {
            if (!isVNode(child))
                return true;
            if (child.type === Comment)
                return false;
            if (child.type === Fragment &&
                !ensureValidVNode(child.children))
                return false;
            return true;
        })
            ? vnodes
            : null;
    }
  
    /**
     * Wrap a slot function to memoize current rendering instance
     * @private
     */
    function withCtx(fn, ctx = currentRenderingInstance) {
        if (!ctx)
            return fn;
        const renderFnWithContext = (...args) => {
            // If a user calls a compiled slot inside a template expression (#1745), it
            // can mess up block tracking, so by default we need to push a null block to
            // avoid that. This isn't necessary if rendering a compiled `<slot>`.
            if (!isRenderingCompiledSlot) {
                openBlock(true /* null block that disables tracking */);
            }
            const owner = currentRenderingInstance;
            setCurrentRenderingInstance(ctx);
            const res = fn(...args);
            setCurrentRenderingInstance(owner);
            if (!isRenderingCompiledSlot) {
                closeBlock();
            }
            return res;
        };
        renderFnWithContext._c = true;
        return renderFnWithContext;
    }
  
    // SFC scoped style ID management.
    let currentScopeId = null;
    const scopeIdStack = [];
    /**
     * @private
     */
    function pushScopeId(id) {
        scopeIdStack.push((currentScopeId = id));
    }
    /**
     * @private
     */
    function popScopeId() {
        scopeIdStack.pop();
        currentScopeId = scopeIdStack[scopeIdStack.length - 1] || null;
    }
    /**
     * @private
     */
    function withScopeId(id) {
        return ((fn) => withCtx(function () {
            pushScopeId(id);
            const res = fn.apply(this, arguments);
            popScopeId();
            return res;
        }));
    }
  
    const isTeleport = (type) => type.__isTeleport;
    const isTeleportDisabled = (props) => props && (props.disabled || props.disabled === '');
    const isTargetSVG = (target) => typeof SVGElement !== 'undefined' && target instanceof SVGElement;
    const resolveTarget = (props, select) => {
        const targetSelector = props && props.to;
        if (isString(targetSelector)) {
            if (!select) {
                
                    warn(`Current renderer does not support string target for Teleports. ` +
                        `(missing querySelector renderer option)`);
                return null;
            }
            else {
                const target = select(targetSelector);
                if (!target) {
                    
                        warn(`Failed to locate Teleport target with selector "${targetSelector}". ` +
                            `Note the target element must exist before the component is mounted - ` +
                            `i.e. the target cannot be rendered by the component itself, and ` +
                            `ideally should be outside of the entire Vue component tree.`);
                }
                return target;
            }
        }
        else {
            if ( !targetSelector && !isTeleportDisabled(props)) {
                warn(`Invalid Teleport target: ${targetSelector}`);
            }
            return targetSelector;
        }
    };
    const TeleportImpl = {
        __isTeleport: true,
        process(n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized, internals) {
            const { mc: mountChildren, pc: patchChildren, pbc: patchBlockChildren, o: { insert, querySelector, createText, createComment } } = internals;
            const disabled = isTeleportDisabled(n2.props);
            const { shapeFlag, children } = n2;
            if (n1 == null) {
                // insert anchors in the main view
                const placeholder = (n2.el =  createComment('teleport start')
                    );
                const mainAnchor = (n2.anchor =  createComment('teleport end')
                    );
                insert(placeholder, container, anchor);
                insert(mainAnchor, container, anchor);
                const target = (n2.target = resolveTarget(n2.props, querySelector));
                const targetAnchor = (n2.targetAnchor = createText(''));
                if (target) {
                    insert(targetAnchor, target);
                    // #2652 we could be teleporting from a non-SVG tree into an SVG tree
                    isSVG = isSVG || isTargetSVG(target);
                }
                else if ( !disabled) {
                    warn('Invalid Teleport target on mount:', target, `(${typeof target})`);
                }
                const mount = (container, anchor) => {
                    // Teleport *always* has Array children. This is enforced in both the
                    // compiler and vnode children normalization.
                    if (shapeFlag & 16 /* ARRAY_CHILDREN */) {
                        mountChildren(children, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    }
                };
                if (disabled) {
                    mount(container, mainAnchor);
                }
                else if (target) {
                    mount(target, targetAnchor);
                }
            }
            else {
                // update content
                n2.el = n1.el;
                const mainAnchor = (n2.anchor = n1.anchor);
                const target = (n2.target = n1.target);
                const targetAnchor = (n2.targetAnchor = n1.targetAnchor);
                const wasDisabled = isTeleportDisabled(n1.props);
                const currentContainer = wasDisabled ? container : target;
                const currentAnchor = wasDisabled ? mainAnchor : targetAnchor;
                isSVG = isSVG || isTargetSVG(target);
                if (n2.dynamicChildren) {
                    // fast path when the teleport happens to be a block root
                    patchBlockChildren(n1.dynamicChildren, n2.dynamicChildren, currentContainer, parentComponent, parentSuspense, isSVG);
                    // even in block tree mode we need to make sure all root-level nodes
                    // in the teleport inherit previous DOM references so that they can
                    // be moved in future patches.
                    traverseStaticChildren(n1, n2, true);
                }
                else if (!optimized) {
                    patchChildren(n1, n2, currentContainer, currentAnchor, parentComponent, parentSuspense, isSVG);
                }
                if (disabled) {
                    if (!wasDisabled) {
                        // enabled -> disabled
                        // move into main container
                        moveTeleport(n2, container, mainAnchor, internals, 1 /* TOGGLE */);
                    }
                }
                else {
                    // target changed
                    if ((n2.props && n2.props.to) !== (n1.props && n1.props.to)) {
                        const nextTarget = (n2.target = resolveTarget(n2.props, querySelector));
                        if (nextTarget) {
                            moveTeleport(n2, nextTarget, null, internals, 0 /* TARGET_CHANGE */);
                        }
                        else {
                            warn('Invalid Teleport target on update:', target, `(${typeof target})`);
                        }
                    }
                    else if (wasDisabled) {
                        // disabled -> enabled
                        // move into teleport target
                        moveTeleport(n2, target, targetAnchor, internals, 1 /* TOGGLE */);
                    }
                }
            }
        },
        remove(vnode, { r: remove, o: { remove: hostRemove } }) {
            const { shapeFlag, children, anchor } = vnode;
            hostRemove(anchor);
            if (shapeFlag & 16 /* ARRAY_CHILDREN */) {
                for (let i = 0; i < children.length; i++) {
                    remove(children[i]);
                }
            }
        },
        move: moveTeleport,
        hydrate: hydrateTeleport
    };
    function moveTeleport(vnode, container, parentAnchor, { o: { insert }, m: move }, moveType = 2 /* REORDER */) {
        // move target anchor if this is a target change.
        if (moveType === 0 /* TARGET_CHANGE */) {
            insert(vnode.targetAnchor, container, parentAnchor);
        }
        const { el, anchor, shapeFlag, children, props } = vnode;
        const isReorder = moveType === 2 /* REORDER */;
        // move main view anchor if this is a re-order.
        if (isReorder) {
            insert(el, container, parentAnchor);
        }
        // if this is a re-order and teleport is enabled (content is in target)
        // do not move children. So the opposite is: only move children if this
        // is not a reorder, or the teleport is disabled
        if (!isReorder || isTeleportDisabled(props)) {
            // Teleport has either Array children or no children.
            if (shapeFlag & 16 /* ARRAY_CHILDREN */) {
                for (let i = 0; i < children.length; i++) {
                    move(children[i], container, parentAnchor, 2 /* REORDER */);
                }
            }
        }
        // move main view anchor if this is a re-order.
        if (isReorder) {
            insert(anchor, container, parentAnchor);
        }
    }
    function hydrateTeleport(node, vnode, parentComponent, parentSuspense, optimized, { o: { nextSibling, parentNode, querySelector } }, hydrateChildren) {
        const target = (vnode.target = resolveTarget(vnode.props, querySelector));
        if (target) {
            // if multiple teleports rendered to the same target element, we need to
            // pick up from where the last teleport finished instead of the first node
            const targetNode = target._lpa || target.firstChild;
            if (vnode.shapeFlag & 16 /* ARRAY_CHILDREN */) {
                if (isTeleportDisabled(vnode.props)) {
                    vnode.anchor = hydrateChildren(nextSibling(node), vnode, parentNode(node), parentComponent, parentSuspense, optimized);
                    vnode.targetAnchor = targetNode;
                }
                else {
                    vnode.anchor = nextSibling(node);
                    vnode.targetAnchor = hydrateChildren(targetNode, vnode, target, parentComponent, parentSuspense, optimized);
                }
                target._lpa =
                    vnode.targetAnchor && nextSibling(vnode.targetAnchor);
            }
        }
        return vnode.anchor && nextSibling(vnode.anchor);
    }
    // Force-casted public typing for h and TSX props inference
    const Teleport = TeleportImpl;
  
    const COMPONENTS = 'components';
    const DIRECTIVES = 'directives';
    /**
     * @private
     */
    function resolveComponent(name) {
        return resolveAsset(COMPONENTS, name) || name;
    }
    const NULL_DYNAMIC_COMPONENT = Symbol();
    /**
     * @private
     */
    function resolveDynamicComponent(component) {
        if (isString(component)) {
            return resolveAsset(COMPONENTS, component, false) || component;
        }
        else {
            // invalid types will fallthrough to createVNode and raise warning
            return (component || NULL_DYNAMIC_COMPONENT);
        }
    }
    /**
     * @private
     */
    function resolveDirective(name) {
        return resolveAsset(DIRECTIVES, name);
    }
    // implementation
    function resolveAsset(type, name, warnMissing = true) {
        const instance = currentRenderingInstance || currentInstance;
        if (instance) {
            const Component = instance.type;
            // self name has highest priority
            if (type === COMPONENTS) {
                // special self referencing call generated by compiler
                // inferred from SFC filename
                if (name === `_self`) {
                    return Component;
                }
                const selfName = getComponentName(Component);
                if (selfName &&
                    (selfName === name ||
                        selfName === camelize(name) ||
                        selfName === capitalize(camelize(name)))) {
                    return Component;
                }
            }
            const res = 
            // local registration
            // check instance[type] first for components with mixin or extends.
            resolve(instance[type] || Component[type], name) ||
                // global registration
                resolve(instance.appContext[type], name);
            if ( warnMissing && !res) {
                warn(`Failed to resolve ${type.slice(0, -1)}: ${name}`);
            }
            return res;
        }
        else {
            warn(`resolve${capitalize(type.slice(0, -1))} ` +
                `can only be used in render() or setup().`);
        }
    }
    function resolve(registry, name) {
        return (registry &&
            (registry[name] ||
                registry[camelize(name)] ||
                registry[capitalize(camelize(name))]));
    }
  
    /* eslint-disable no-restricted-globals */
    let isHmrUpdating = false;
    const hmrDirtyComponents = new Set();
    // Expose the HMR runtime on the global object
    // This makes it entirely tree-shakable without polluting the exports and makes
    // it easier to be used in toolings like vue-loader
    // Note: for a component to be eligible for HMR it also needs the __hmrId option
    // to be set so that its instances can be registered / removed.
    {
        const globalObject = typeof global !== 'undefined'
            ? global
            : typeof self !== 'undefined'
                ? self
                : typeof window !== 'undefined'
                    ? window
                    : {};
        globalObject.__VUE_HMR_RUNTIME__ = {
            createRecord: tryWrap(createRecord),
            rerender: tryWrap(rerender),
            reload: tryWrap(reload)
        };
    }
    const map = new Map();
    function createRecord(id, component) {
        if (!component) {
            warn(`HMR API usage is out of date.\n` +
                `Please upgrade vue-loader/vite/rollup-plugin-vue or other relevant ` +
                `depdendency that handles Vue SFC compilation.`);
            component = {};
        }
        if (map.has(id)) {
            return false;
        }
        map.set(id, {
            component: isClassComponent(component) ? component.__vccOpts : component,
            instances: new Set()
        });
        return true;
    }
    function rerender(id, newRender) {
        const record = map.get(id);
        if (!record)
            return;
        if (newRender)
            record.component.render = newRender;
        // Array.from creates a snapshot which avoids the set being mutated during
        // updates
        Array.from(record.instances).forEach(instance => {
            if (newRender) {
                instance.render = newRender;
            }
            instance.renderCache = [];
            // this flag forces child components with slot content to update
            isHmrUpdating = true;
            instance.update();
            isHmrUpdating = false;
        });
    }
    function reload(id, newComp) {
        const record = map.get(id);
        if (!record)
            return;
        // Array.from creates a snapshot which avoids the set being mutated during
        // updates
        const { component, instances } = record;
        if (!hmrDirtyComponents.has(component)) {
            // 1. Update existing comp definition to match new one
            newComp = isClassComponent(newComp) ? newComp.__vccOpts : newComp;
            extend(component, newComp);
            for (const key in component) {
                if (!(key in newComp)) {
                    delete component[key];
                }
            }
            // 2. Mark component dirty. This forces the renderer to replace the component
            // on patch.
            hmrDirtyComponents.add(component);
            // 3. Make sure to unmark the component after the reload.
            queuePostFlushCb(() => {
                hmrDirtyComponents.delete(component);
            });
        }
        Array.from(instances).forEach(instance => {
            if (instance.parent) {
                // 4. Force the parent instance to re-render. This will cause all updated
                // components to be unmounted and re-mounted. Queue the update so that we
                // don't end up forcing the same parent to re-render multiple times.
                queueJob(instance.parent.update);
            }
            else if (instance.appContext.reload) {
                // root instance mounted via createApp() has a reload method
                instance.appContext.reload();
            }
            else if (typeof window !== 'undefined') {
                // root instance inside tree created via raw render(). Force reload.
                window.location.reload();
            }
            else {
                console.warn('[HMR] Root or manually mounted instance modified. Full reload required.');
            }
        });
    }
    function tryWrap(fn) {
        return (id, arg) => {
            try {
                return fn(id, arg);
            }
            catch (e) {
                console.error(e);
                console.warn(`[HMR] Something went wrong during Vue component hot-reload. ` +
                    `Full reload required.`);
            }
        };
    }
  
    const Fragment = Symbol( 'Fragment' );
    const Text = Symbol( 'Text' );
    const Comment = Symbol( 'Comment' );
    const Static = Symbol( 'Static' );
    // Since v-if and v-for are the two possible ways node structure can dynamically
    // change, once we consider v-if branches and each v-for fragment a block, we
    // can divide a template into nested blocks, and within each block the node
    // structure would be stable. This allows us to skip most children diffing
    // and only worry about the dynamic nodes (indicated by patch flags).
    // 针对 v-if, v-for 动态性做的由于，减少对静态节点的 diff ，只需要关心动态节点即可
    const blockStack = [];
    let currentBlock = null;
    /**
     * Open a block.
     * This must be called before `createBlock`. It cannot be part of `createBlock`
     * because the children of the block are evaluated before `createBlock` itself
     * is called. The generated code typically looks like this:
     *
     * ```js
     * function render() {
     *   return (openBlock(),createBlock('div', null, [...]))
     * }
     * ```
     * disableTracking is true when creating a v-for fragment block, since a v-for
     * fragment always diffs its children.
     *
     * @private
     */
    function openBlock(disableTracking = false) {
        blockStack.push((currentBlock = disableTracking ? null : []));
    }
    function closeBlock() {
        blockStack.pop();
        currentBlock = blockStack[blockStack.length - 1] || null;
    }
    // Whether we should be tracking dynamic child nodes inside a block.
    // Only tracks when this value is > 0
    // We are not using a simple boolean because this value may need to be
    // incremented/decremented by nested usage of v-once (see below)
    // 是否应该 tracking block 内动态的孩子节点
    let shouldTrack$1 = 1;
    /**
     * Block tracking sometimes needs to be disabled, for example during the
     * creation of a tree that needs to be cached by v-once. The compiler generates
     * code like this:
     *
     * ``` js
     * _cache[1] || (
     *   setBlockTracking(-1),
     *   _cache[1] = createVNode(...),
     *   setBlockTracking(1),
     *   _cache[1]
     * )
     * ```
     *
     * @private
     */
    function setBlockTracking(value) {
        shouldTrack$1 += value;
    }
    /**
     * Create a block root vnode. Takes the same exact arguments as `createVNode`.
     * A block root keeps track of dynamic nodes within the block in the
     * `dynamicChildren` array.
     *
     * @private
     */
    function createBlock(type, props, children, patchFlag, dynamicProps) {
        const vnode = createVNode(type, props, children, patchFlag, dynamicProps, true /* isBlock: prevent a block from tracking itself */);
        // save current block children on the block vnode
        vnode.dynamicChildren = currentBlock || EMPTY_ARR;
        // close block
        closeBlock();
        // a block is always going to be patched, so track it as a child of its
        // parent block
        if (shouldTrack$1 > 0 && currentBlock) {
            currentBlock.push(vnode);
        }
        return vnode;
    }
    function isVNode(value) {
        return value ? value.__v_isVNode === true : false;
    }
    function isSameVNodeType(n1, n2) {
        if (
            n2.shapeFlag & 6 /* COMPONENT */ &&
            hmrDirtyComponents.has(n2.type)) {
            // HMR only: if the component has been hot-updated, force a reload.
            // 组件被热更新，强制重新加载
            return false;
        }
        return n1.type === n2.type && n1.key === n2.key;
    }
    let vnodeArgsTransformer;
    /**
     * Internal API for registering an arguments transform for createVNode
     * used for creating stubs in the test-utils
     * It is *internal* but needs to be exposed for test-utils to pick up proper
     * typings
     */
    function transformVNodeArgs(transformer) {
        vnodeArgsTransformer = transformer;
    }
    const createVNodeWithArgsTransform = (...args) => {
        return _createVNode(...(vnodeArgsTransformer
            ? vnodeArgsTransformer(args, currentRenderingInstance)
            : args));
    };
    const InternalObjectKey = `__vInternal`;
    const normalizeKey = ({ key }) => key != null ? key : null;
    const normalizeRef = ({ ref }) => {
        return (ref != null
            ? isString(ref) || isRef(ref) || isFunction(ref)
                ? { i: currentRenderingInstance, r: ref }
                : ref
            : null);
    };
    const createVNode = ( createVNodeWithArgsTransform
        );
    function _createVNode(type, props = null, children = null, patchFlag = 0, dynamicProps = null, isBlockNode = false) {
        // 无效的 tag 类型
        if (!type || type === NULL_DYNAMIC_COMPONENT) {
            if ( !type) {
                warn(`Invalid vnode type when creating vnode: ${type}.`);
            }
            type = Comment;
        }
        // 1. type is vnode
        if (isVNode(type)) {
            // createVNode receiving an existing vnode. This happens in cases like
            // <component :is="vnode"/>
            // #2078 make sure to merge refs during the clone instead of overwriting it
            const cloned = cloneVNode(type, props, true /* mergeRef: true */);
            if (children) {
                normalizeChildren(cloned, children);
            }
            return cloned;
        }
        // 2. class component
        if (isClassComponent(type)) {
            type = type.__vccOpts;
        }
        // 3. props 处理, class & style normalization
        if (props) {
            // for reactive or proxy objects, we need to clone it to enable mutation.
            if (isProxy(props) || InternalObjectKey in props) {
                props = extend({}, props);
            }
            let { class: klass, style } = props;
            if (klass && !isString(klass)) {
                // 1. string -> klass
                // 'foo' -> 'foo'
                // 2. array -> '' + arr.join(' ')
                // ['foo', 'bar'] -> 'foo bar'
                // 3. object -> '' + value ? ' value' : ''
                // { foo: true, bar: false, baz: true } -> 'foo baz'
                props.class = normalizeClass(klass);
            }
            if (isObject(style)) {
                // reactive state objects need to be cloned since they are likely to be
                // mutated
                if (isProxy(style) && !isArray(style)) {
                    style = extend({}, style);
                }
                // 1. array -> object
                // [{ color: 'red' }, 'font-size:10px;height:100px;'] ->
                // { color: 'red', 'font-size': '10px', height: '100px' }
                // 2. object -> object 原样返回
                props.style = normalizeStyle(style);
            }
        }
        // encode the vnode type information into a bitmap
        const shapeFlag = isString(type)
            ? 1 /* ELEMENT */
            :  isSuspense(type)
                ? 128 /* SUSPENSE */
                : isTeleport(type)
                    ? 64 /* TELEPORT */
                    : isObject(type)
                        ? 4 /* STATEFUL_COMPONENT */
                        : isFunction(type)
                            ? 2 /* FUNCTIONAL_COMPONENT */
                            : 0;
        // 4. warn STATEFUL_COMPONENT
        if ( shapeFlag & 4 /* STATEFUL_COMPONENT */ && isProxy(type)) {
            type = toRaw(type);
            warn(`Vue received a Component which was made a reactive object. This can ` +
                `lead to unnecessary performance overhead, and should be avoided by ` +
                `marking the component with \`markRaw\` or using \`shallowRef\` ` +
                `instead of \`ref\`.`, `\nComponent that was made reactive: `, type);
        }
        // 构建 vnode 对象
        const vnode = {
            __v_isVNode: true,
            ["__v_skip" /* SKIP */]: true /*不用做响应式处理*/,
            type,
            props,
            key: props && normalizeKey(props),
            ref: props && normalizeRef(props),
            scopeId: currentScopeId,
            children: null,
            component: null,
            suspense: null,
            ssContent: null,
            ssFallback: null,
            dirs: null,
            transition: null,
            el: null,
            anchor: null,
            target: null,
            targetAnchor: null,
            staticCount: 0,
            shapeFlag,
            patchFlag,
            dynamicProps,
            dynamicChildren: null,
            appContext: null
        };
        // 5. 检查 key, 不能是 NaN
        if ( vnode.key !== vnode.key) {
            warn(`VNode created with invalid key (NaN). VNode type:`, vnode.type);
        }
        // 6. normalize children
        normalizeChildren(vnode, children);
        // 7. normalize suspense children
        if ( shapeFlag & 128 /* SUSPENSE */) {
            const { content, fallback } = normalizeSuspenseChildren(vnode);
            vnode.ssContent = content;
            vnode.ssFallback = fallback;
        }
        // 8. currentBlock
        if (shouldTrack$1 > 0 &&
            // 避免 block 节点 tracking 自己
            !isBlockNode &&
            // has current parent block
            currentBlock &&
            // presence of a patch flag indicates this node needs patching on updates.
            // component nodes also should always be patched, because even if the
            // component doesn't need to update, it needs to persist the instance on to
            // the next vnode so that it can be properly unmounted later.
            (patchFlag > 0 || shapeFlag & 6 /* COMPONENT */) &&
            // the EVENTS flag is only for hydration and if it is the only flag, the
            // vnode should not be considered dynamic due to handler caching.
            patchFlag !== 32 /* HYDRATE_EVENTS */) {
            currentBlock.push(vnode);
        }
        return vnode;
    }
    function cloneVNode(vnode, extraProps, mergeRef = false) {
        // This is intentionally NOT using spread or extend to avoid the runtime
        // key enumeration cost.
        const { props, ref, patchFlag } = vnode;
        const mergedProps = extraProps ? mergeProps(props || {}, extraProps) : props;
        return {
            __v_isVNode: true,
            ["__v_skip" /* SKIP */]: true,
            type: vnode.type,
            props: mergedProps,
            key: mergedProps && normalizeKey(mergedProps),
            ref: extraProps && extraProps.ref
                ? // #2078 in the case of <component :is="vnode" ref="extra"/>
                    // if the vnode itself already has a ref, cloneVNode will need to merge
                    // the refs so the single vnode can be set on multiple refs
                    mergeRef && ref
                        ? isArray(ref)
                            ? ref.concat(normalizeRef(extraProps))
                            : [ref, normalizeRef(extraProps)]
                        : normalizeRef(extraProps)
                : ref,
            scopeId: vnode.scopeId,
            children: vnode.children,
            target: vnode.target,
            targetAnchor: vnode.targetAnchor,
            staticCount: vnode.staticCount,
            shapeFlag: vnode.shapeFlag,
            // if the vnode is cloned with extra props, we can no longer assume its
            // existing patch flag to be reliable and need to add the FULL_PROPS flag.
            // note: perserve flag for fragments since they use the flag for children
            // fast paths only.
            patchFlag: extraProps && vnode.type !== Fragment
                ? patchFlag === -1 // hoisted node
                    ? 16 /* FULL_PROPS */
                    : patchFlag | 16 /* FULL_PROPS */
                : patchFlag,
            dynamicProps: vnode.dynamicProps,
            dynamicChildren: vnode.dynamicChildren,
            appContext: vnode.appContext,
            dirs: vnode.dirs,
            transition: vnode.transition,
            // These should technically only be non-null on mounted VNodes. However,
            // they *should* be copied for kept-alive vnodes. So we just always copy
            // them since them being non-null during a mount doesn't affect the logic as
            // they will simply be overwritten.
            component: vnode.component,
            suspense: vnode.suspense,
            ssContent: vnode.ssContent && cloneVNode(vnode.ssContent),
            ssFallback: vnode.ssFallback && cloneVNode(vnode.ssFallback),
            el: vnode.el,
            anchor: vnode.anchor
        };
    }
    /**
     * @private
     */
    function createTextVNode(text = ' ', flag = 0) {
        return createVNode(Text, null, text, flag);
    }
    /**
     * @private
     */
    function createStaticVNode(content, numberOfNodes) {
        // A static vnode can contain multiple stringified elements, and the number
        // of elements is necessary for hydration.
        const vnode = createVNode(Static, null, content);
        vnode.staticCount = numberOfNodes;
        return vnode;
    }
    /**
     * @private
     */
    function createCommentVNode(text = '', 
    // when used as the v-else branch, the comment node must be created as a
    // block to ensure correct updates.
    asBlock = false) {
        return asBlock
            ? (openBlock(), createBlock(Comment, null, text))
            : createVNode(Comment, null, text);
    }
    function normalizeVNode(child) {
        if (child == null || typeof child === 'boolean') {
            // empty placeholder
            return createVNode(Comment);
        }
        else if (isArray(child)) {
            // fragment
            return createVNode(Fragment, null, child);
        }
        else if (typeof child === 'object') {
            // already vnode, this should be the most common since compiled templates
            // always produce all-vnode children arrays
            // 这是最常用的情况，因为使用模板的时候最后生成的 children 是数组
            return child.el === null ? child : cloneVNode(child);
        }
        else {
            // strings and numbers
            return createVNode(Text, null, String(child));
        }
    }
    // 针对 template-compiled render fns 做的优化
    function cloneIfMounted(child) {
        // child.el 如果存在的话，child 属于静态节点会被静态提升
        // 所以需要 clone 一份出来，否则直接返回 child
        return child.el === null ? child : cloneVNode(child);
    }
    function normalizeChildren(vnode, children) {
        let type = 0;
        const { shapeFlag } = vnode;
        if (children == null) {
            children = null;
        }
        else if (isArray(children)) {
            type = 16 /* ARRAY_CHILDREN */;
        }
        else if (typeof children === 'object') {
            // & 操作，这里等于是检测是 ELEMENT 还是 TELEPORT
            // 因为 ShapeFlags 内的值是通过左移位得到的
            if (shapeFlag & 1 /* ELEMENT */ || shapeFlag & 64 /* TELEPORT */) {
                // Normalize slot to plain children for plain element and Teleport
                const slot = children.default;
                if (slot) {
                    // _c marker is added by withCtx() indicating this is a compiled slot
                    slot._c && setCompiledSlotRendering(1);
                    normalizeChildren(vnode, slot());
                    slot._c && setCompiledSlotRendering(-1);
                }
                return;
            }
            else {
                type = 32 /* SLOTS_CHILDREN */;
                const slotFlag = children._;
                if (!slotFlag && !(InternalObjectKey in children)) {
                    children._ctx = currentRenderingInstance;
                }
                else if (slotFlag === 3 /* FORWARDED */ && currentRenderingInstance) {
                    // a child component receives forwarded slots from the parent.
                    // its slot type is determined by its parent's slot type.
                    if (currentRenderingInstance.vnode.patchFlag & 1024 /* DYNAMIC_SLOTS */) {
                        children._ = 2 /* DYNAMIC */;
                        vnode.patchFlag |= 1024 /* DYNAMIC_SLOTS */;
                    }
                    else {
                        children._ = 1 /* STABLE */;
                    }
                }
            }
        }
        else if (isFunction(children)) {
            // 如果是函数当做 slot children ?
            children = { default: children, _ctx: currentRenderingInstance };
            type = 32 /* SLOTS_CHILDREN */;
        }
        else {
            children = String(children);
            // force teleport children to array so it can be moved around
            if (shapeFlag & 64 /* TELEPORT */) {
                type = 16 /* ARRAY_CHILDREN */;
                children = [createTextVNode(children)];
            }
            else {
                type = 8 /* TEXT_CHILDREN */;
            }
        }
        vnode.children = children;
        vnode.shapeFlag |= type;
    }
    function mergeProps(...args) {
        const ret = extend({}, args[0]);
        for (let i = 1; i < args.length; i++) {
            const toMerge = args[i];
            for (const key in toMerge) {
                if (key === 'class') {
                    if (ret.class !== toMerge.class) {
                        ret.class = normalizeClass([ret.class, toMerge.class]);
                    }
                }
                else if (key === 'style') {
                    ret.style = normalizeStyle([ret.style, toMerge.style]);
                }
                else if (isOn(key)) {
                    const existing = ret[key];
                    const incoming = toMerge[key];
                    if (existing !== incoming) {
                        ret[key] = existing
                            ? [].concat(existing, toMerge[key])
                            : incoming;
                    }
                }
                else if (key !== '') {
                    ret[key] = toMerge[key];
                }
            }
        }
        return ret;
    }
  
    function initProps(instance, rawProps, isStateful, isSSR = false) {
        const props = {};
        const attrs = {};
        def(attrs, InternalObjectKey, 1);
        setFullProps(instance, rawProps, props, attrs);
        // TODO validation
        if (isStateful) {
            instance.props = isSSR ? props : shallowReactive(props);
        }
        else {
            if (!instance.type.props) {
                // functional optional props, props === attrs
                instance.props = attrs;
            }
            else {
                // functional declared props
                instance.props = props;
            }
        }
        instance.attrs = attrs;
    }
    function updateProps(instance, rawProps, rawPrevProps, optimized) {
        const { props, attrs, vnode: { patchFlag } } = instance;
        const rawCurrentProps = toRaw(props);
        const [options] = instance.propsOptions;
        if (
        // 开发模式下，总是强制进行 full diff
        !(
            (instance.type.__hmrId ||
                (instance.parent && instance.parent.type.__hmrId))) &&
            (optimized || patchFlag > 0) &&
            !(patchFlag & 16 /* FULL_PROPS */)) {
            if (patchFlag & 8 /* PROPS */) {
                const propsToUpdate = instance.vnode.dynamicProps;
                for (let i = 0; i < propsToUpdate.length; i++) {
                    const key = propsToUpdate[i];
                    const value = rawProps[key];
                    if (options) {
                        // attr / props 在初始化阶段会被分离开，在这里只需要检测
                        // attrs 有没有该属性
                        if (hasOwn(attrs, key)) {
                            attrs[key] = value;
                        }
                        else {
                            const camelizedKey = camelize(key);
                            props[camelizedKey] = resolvePropValue(options, rawCurrentProps, camelizedKey, value, instance);
                        }
                    }
                    else {
                        attrs[key] = value;
                    }
                }
            }
        }
        else {
            // full props update
            setFullProps(instance, rawProps, props, attrs);
            // in case of dynamic props, check if we need to delete keys from
            // the props object
            let kebabKey;
            for (const key in rawCurrentProps) {
                if (!rawProps ||
                    // for camelcase
                    (!hasOwn(rawProps, key) &&
                        ((kebabKey = hyphenate(key)) === key || !hasOwn(rawProps, kebabKey)))) {
                    if (options) {
                        if (rawPrevProps &&
                            // for camelCase
                            (rawPrevProps[key] !== undefined ||
                                // for kebad-case
                                rawPrevProps[kebabKey] !== undefined)) {
                            props[key] = resolvePropValue(options, rawProps || EMPTY_OBJ, key, undefined, instance);
                        }
                    }
                    else {
                        delete props[key];
                    }
                }
            }
            if (attrs !== rawCurrentProps) {
                for (const key in attrs) {
                    if (!rawProps || !hasOwn(rawProps, key)) {
                        delete attrs[key];
                    }
                }
            }
        }
        // trigger updates for $attrs in case it's used in component slots
        trigger(instance, "set" /* SET */, '$attrs');
    }
    function setFullProps(instance, rawProps, props, attrs) {
        const [options, needCastKeys] = instance.propsOptions;
        if (rawProps) {
            for (const key in rawProps) {
                const value = rawProps[key];
                // key, ref 保留，不往下传
                // 即这两个属性不会继承给 child
                if (isReservedProp(key)) {
                    continue;
                }
                let camelKey;
                if (options && hasOwn(options, (camelKey = camelize(key)))) {
                    props[camelKey] = value;
                }
                else if (!isEmitListener(instance.emitsOptions, key)) {
                    attrs[key] = value;
                }
            }
        }
        if (needCastKeys) {
            const rawCurrentProps = toRaw(props);
            for (let i = 0; i < needCastKeys.length; i++) {
                const key = needCastKeys[i];
                props[key] = resolvePropValue(options, rawCurrentProps, key, rawCurrentProps[key], instance);
            }
        }
    }
    function resolvePropValue(options, props, key, value, instance) {
        /*
         * 这里面的处理是针对 props: { name: { ... } } 类型而言
         * 1. 默认值的处理， default 可能是函数或普通类型值，如果是函数应该得到
         * 函数执行的结果作为它的值，注意下面的检测函数时前置条件是该类型不是函数，
         * 如果类型也是函数，默认值就是该函数本身，而非执行后的结果值
         * 2. 布尔值的处理，值转成 true or false
         */
        const opt = options[key];
        if (opt != null) {
            const hasDefault = hasOwn(opt, 'default');
            // 默认值
            if (hasDefault && value === undefined) {
                const defaultValue = opt.default;
                // props: { name: { default: (props) => 'xxx' } }
                // 类型不是函数？但是默认值是函数，执行得到结果
                if (opt.type !== Function && isFunction(defaultValue)) {
                    setCurrentInstance(instance);
                    value = defaultValue(props);
                    setCurrentInstance(null);
                }
                else {
                    // props: { name: { default: 'xxx' } }
                    value = defaultValue;
                }
            }
            // boolean casting
            if (opt[0 /* shouldCast */]) {
                if (!hasOwn(props, key) && !hasDefault) {
                    value = false;
                }
                else if (opt[1 /* shouldCastTrue */] &&
                    (value === '' || value === hyphenate(key))) {
                    value = true;
                }
            }
        }
        return value;
    }
    function normalizePropsOptions(comp, appContext, asMixin = false) {
        if (!appContext.deopt && comp.__props) {
            return comp.__props;
        }
        const raw = comp.props;
        const normalized = {};
        const needCastKeys = [];
        // mixin/extends props 应用
        let hasExtends = false;
        // 必须开支 2.x options api 支持，且不是函数式组件
        // 继承来的属性，用法： ~CompA = { extends: CompB, ... }~
        // CompA 会继承 CompB 的 props
        if ( !isFunction(comp)) {
            const extendProps = (raw) => {
                hasExtends = true;
                const [props, keys] = normalizePropsOptions(raw, appContext, true);
                extend(normalized, props);
                if (keys) {
                    needCastKeys.push(...keys);
                }
            };
            // Comp: { mixins: [mixin] } 处理
            if (!asMixin && appContext.mixins.length) {
                appContext.mixins.forEach(extendProps);
            }
            // Comp: { extends: CompA } 处理
            if (comp.extends) {
                extendProps(comp.extends);
            }
            if (comp.mixins) {
                comp.mixins.forEach(extendProps);
            }
        }
        // 既没有自身的 props 也没有 extends 继承来的 props 初始化为 []
        if (!raw && !hasExtends) {
            return (comp.__props = EMPTY_ARR);
        }
        if (isArray(raw)) {
            // 当 props 是数组的时候，必须是字符类型，如: props: ['foo', 'bar', 'foo-bar']
            // 'foo-bar' 会转成 'fooBar'，不允许 '$xxx' 形式的变量名
            for (let i = 0; i < raw.length; i++) {
                const normalizedKey = camelize(raw[i]);
                // 组件的属性名不能是以 $xx 开头的名称，这个是作为内部属性的
                if (validatePropName(normalizedKey)) {
                    normalized[normalizedKey] = EMPTY_OBJ;
                }
            }
        }
        else if (raw) {
            // 对象类型 props: { foo: 1, bar: 2, ... }
            for (const key in raw) {
                // 'foo-bar' -> 'fooBar'
                const normalizedKey = camelize(key);
                // 检查 $xxx 非法属性
                if (validatePropName(normalizedKey)) {
                    const opt = raw[key];
                    // ? 值为数组或函数变成： { type: opt } ?
                    // 这里含义其实是： ~props: { foo: [Boolean, Function] }~
                    // 可以用数组定义该属性可以是多种类型的其中一种
                    const prop = (normalized[normalizedKey] =
                        isArray(opt) || isFunction(opt) ? { type: opt } : opt);
                    if (prop) {
                        // 找到 Boolean 在 foo: [Boolean, Function] 中的索引
                        const booleanIndex = getTypeIndex(Boolean, prop.type);
                        const stringIndex = getTypeIndex(String, prop.type);
                        prop[0 /* shouldCast */] = booleanIndex > -1;
                        // [String, Boolean] 类型，String 在 Boolean 前面
                        prop[1 /* shouldCastTrue */] =
                            stringIndex < 0 || booleanIndex < stringIndex;
                        // 如果是布尔类型的值或者有默认值的属性需要转换
                        // 转换是根据 type 和 default 值处理
                        // type非函数，default是函数，执行 default() 得到默认值
                        if (booleanIndex > -1 || hasOwn(prop, 'default')) {
                            needCastKeys.push(normalizedKey);
                        }
                    }
                }
            }
        }
        return (comp.__props = [normalized, needCastKeys]);
    }
    function validatePropName(key) {
        // 非内部属性？
        if (key[0] !== '$') {
            return true;
        }
        else {
            // $xxx 为保留属性
            warn(`Invalid prop name: "${key}" is a reserved property.`);
        }
        return false;
    }
    // use function string name to check type constructors
    // so that it works across vms / iframes.
    function getType(ctor) {
        const match = ctor && ctor.toString().match(/^\s*function (\w+)/);
        return match ? match[1] : '';
    }
    function isSameType(a, b) {
        return getType(a) === getType(b);
    }
    function getTypeIndex(type, expectedTypes) {
        if (isArray(expectedTypes)) {
            for (let i = 0, len = expectedTypes.length; i < len; i++) {
                if (isSameType(expectedTypes[i], type)) {
                    return i;
                }
            }
        }
        else if (isFunction(expectedTypes)) {
            return isSameType(expectedTypes, type) ? 0 : -1;
        }
        return -1;
    }
  
    const isInternalKey = (key) => key[0] === '_' || key === '$stable';
    const normalizeSlotValue = (value) => isArray(value)
        ? value.map(normalizeVNode)
        : [normalizeVNode(value)];
    const normalizeSlot = (key, rawSlot, ctx) => withCtx((props) => {
        // warn: 在 Render 函数外执行了 slot function
        return normalizeSlotValue(rawSlot(props));
    }, ctx);
    const normalizeObjectSlots = (rawSlots, slots) => {
        const ctx = rawSlots._ctx;
        for (const key in rawSlots) {
            if (isInternalKey(key)) {
                continue;
            }
            const value = rawSlots[key];
            if (isFunction(value)) {
                slots[key] = normalizeSlot(key, value, ctx);
            }
            else if (value != null) {
                // warn: 使用 function slots 性能更好
                const normalized = normalizeSlotValue(value);
                slots[key] = () => normalized;
            }
        }
    };
    const normalizeVNodeSlots = (instance, children) => {
        const normalized = normalizeSlotValue(children);
        instance.slots.default = () => normalized;
    };
    const initSlots = (instance, children) => {
        if (instance.vnode.shapeFlag & 32 /* SLOTS_CHILDREN */) {
            const type = children._;
            if (type) {
                instance.slots = children;
                // make compiler marker non-enumerable
                def(children, '_', type);
            }
            else {
                normalizeObjectSlots(children, (instance.slots = {}));
            }
        }
        else {
            instance.slots = {};
            if (children) {
                normalizeVNodeSlots(instance, children);
            }
        }
        def(instance.slots, InternalObjectKey, 1);
    };
    const updateSlots = (instance, children) => {
        const { vnode, slots } = instance;
        let needDeletionCheck = true;
        let deletionComparisonTarget = EMPTY_OBJ;
        if (vnode.shapeFlag & 32 /* SLOTS_CHILDREN */) {
            const type = children._;
            if (type) {
                // compiled slots.
                if ( isHmrUpdating) ;
                else if (type === 1 /* STABLE */) {
                    // compiled AND stable
                    // 不需要更新，跳过 slots 删除操作
                    needDeletionCheck = false;
                }
                else {
                    // compiled but dynamic (v-if/v-for on slots)
                    // update slots, but skip normalization
                    extend(slots, children);
                }
            }
            else {
                needDeletionCheck = !children.$stable;
                normalizeObjectSlots(children, slots);
            }
            deletionComparisonTarget = children;
        }
        else if (children) {
            // non slot object children (direct value)
            // passed to a component
            normalizeVNodeSlots(instance, children);
            deletionComparisonTarget = { default: 1 };
        }
        // delete stale slots
        // 删除旧的 slots
        if (needDeletionCheck) {
            for (const key in slots) {
                // 非 `_` 内部插槽，且不再新的 children 中的
                if (!isInternalKey(key) && !(key in deletionComparisonTarget)) {
                    delete slots[key];
                }
            }
        }
    };
  
    /**
    Runtime helper for applying directives to a vnode. Example usage:
  
    const comp = resolveComponent('comp')
    const foo = resolveDirective('foo')
    const bar = resolveDirective('bar')
  
    return withDirectives(h(comp), [
      [foo, this.x],
      [bar, this.y]
    ])
    */
    const isBuiltInDirective = /*#__PURE__*/ makeMap('bind,cloak,else-if,else,for,html,if,model,on,once,pre,show,slot,text');
    function validateDirectiveName(name) {
        if (isBuiltInDirective(name)) {
            warn('Do not use built-in directive ids as custom directive id: ' + name);
        }
    }
    /**
     * Adds directives to a VNode.
     */
    function withDirectives(vnode, directives) {
        const internalInstance = currentRenderingInstance;
        if (internalInstance === null) {
             warn(`withDirectives can only be used inside render functions.`);
            return vnode;
        }
        const instance = internalInstance.proxy;
        const bindings = vnode.dirs || (vnode.dirs = []);
        for (let i = 0; i < directives.length; i++) {
            let [dir, value, arg, modifiers = EMPTY_OBJ] = directives[i];
            if (isFunction(dir)) {
                dir = {
                    mounted: dir,
                    updated: dir
                };
            }
            bindings.push({
                dir,
                instance,
                value,
                oldValue: void 0,
                arg,
                modifiers
            });
        }
        return vnode;
    }
    function invokeDirectiveHook(vnode, prevVNode, instance, name) {
        const bindings = vnode.dirs;
        const oldBindings = prevVNode && prevVNode.dirs;
        for (let i = 0; i < bindings.length; i++) {
            const binding = bindings[i];
            if (oldBindings) {
                binding.oldValue = oldBindings[i].value;
            }
            const hook = binding.dir[name];
            if (hook) {
                callWithAsyncErrorHandling(hook, instance, 8 /* DIRECTIVE_HOOK */, [
                    vnode.el,
                    binding,
                    vnode,
                    prevVNode
                ]);
            }
        }
    }
  
    function createAppContext() {
        return {
            app: null,
            config: {
                isNativeTag: NO,
                performance: false,
                globalProperties: {},
                optionMergeStrategies: {},
                isCustomElement: NO,
                errorHandler: undefined,
                warnHandler: undefined
            },
            mixins: [],
            components: {},
            directives: {},
            provides: Object.create(null)
        };
    }
    let uid$1 = 0;
    function createAppAPI(render, hydrate) {
        return function createApp(rootComponent, rootProps = null) {
            if (rootProps != null && !isObject(rootProps)) {
                 warn(`root props passed to app.mount() must be an object.`);
                rootProps = null;
            }
            const context = createAppContext();
            const installedPlugins = new Set();
            let isMounted = false;
            const app = (context.app = {
                _uid: uid$1++,
                _component: rootComponent,
                _props: rootProps,
                _container: null,
                _context: context,
                version,
                get config() {
                    return context.config;
                },
                set config(v) {
                    {
                        warn(`app.config cannot be replaced. Modify individual options instead.`);
                    }
                },
                use(plugin, ...options) {
                    if (installedPlugins.has(plugin)) {
                         warn(`Plugin has already been applied to target app.`);
                    }
                    else if (plugin && isFunction(plugin.install)) {
                        // 函数直接执行
                        installedPlugins.add(plugin);
                        plugin.install(app, ...options);
                    }
                    else if (isFunction(plugin)) {
                        // 没有 install 函数时
                        installedPlugins.add(plugin);
                        plugin(app, ...options);
                    }
                    else {
                        // plugin 必须要么自己是函数，要么是包含 install 函数的对象
                        warn(`A plugin must either be a function or an object with an "install" ` +
                            `function.`);
                    }
                    return app;
                },
                mixin(mixin) {
                    {
                        if (!context.mixins.includes(mixin)) {
                            context.mixins.push(mixin);
                            // 带有 props/emits 的全局 mixin 会是的 props/emits 缓存优化失效
                            if (mixin.props || mixin.emits) {
                                context.deopt = true;
                            }
                        }
                        else {
                            warn('Mixin has already been applied to target app' +
                                (mixin.name ? `: ${mixin.name}` : ''));
                        }
                    }
                    return app;
                },
                component(name, component) {
                    {
                        // 验证组件名称是否合法
                        validateComponentName(name, context.config);
                    }
                    // 没有对应组件，视为根据名称获取组件操作
                    if (!component) {
                        return context.components[name];
                    }
                    if ( context.components[name]) {
                        // 组件已经注册过了，再次注册等于覆盖原有的
                        warn(`Component "${name}" has already been registered in target app.`);
                    }
                    context.components[name] = component;
                    return app;
                },
                directive(name, directive) {
                    {
                        validateDirectiveName(name);
                    }
                    if (!directive) {
                        return context.directives[name];
                    }
                    if ( context.directives[name]) {
                        warn(`Directive "${name}" has already been registered in target app.`);
                    }
                    context.directives[name] = directive;
                    return app;
                },
                mount(rootContainer, isHydrate) {
                    if (!isMounted) {
                        const vnode = createVNode(rootComponent, rootProps);
                        // 保存 app context 到 root VNode 节点上
                        // 这个将会在初始化 mount 时候被设置到根实例上
                        vnode.appContext = context;
                        // HMR root reload
                        {
                            context.reload = () => {
                                render(cloneVNode(vnode), rootContainer);
                            };
                        }
                        if (isHydrate && hydrate) {
                            hydrate(vnode, rootContainer);
                        }
                        else {
                            render(vnode, rootContainer);
                        }
                        isMounted = true;
                        app._container = rootContainer;
                        rootContainer.__vue_app__ = app;
                        {
                            devtoolsInitApp(app, version);
                        }
                        return vnode.component.proxy;
                    }
                    else {
                        warn(`App has already been mounted.\n` +
                            `If you want to remount the same app, move your app creation logic ` +
                            `into a factory function and create fresh app instances for each ` +
                            `mount - e.g. \`const createMyApp = () => createApp(App)\``);
                    }
                },
                unmount() {
                    if (isMounted) {
                        render(null, app._container);
                        {
                            devtoolsUnmountApp(app);
                        }
                    }
                    else {
                        warn(`Cannot unmount an app that is not mounted.`);
                    }
                },
                provide(key, value) {
                    if ( key in context.provides) {
                        warn(`App already provides property with key "${String(key)}". ` +
                            `It will be overwritten with the new value.`);
                    }
                    // TypeScript doesn't allow symbols as index type
                    // https://github.com/Microsoft/TypeScript/issues/24587
                    context.provides[key] = value;
                    return app;
                }
            });
            return app;
        };
    }
  
    function injectHook(type, hook, target = currentInstance, prepend = false) {
        if (target) {
            const hooks = target[type] || (target[type] = []);
            // 将 hook 的执行封装成一个 error handling warpper 函数，并且缓存到 hook.__weh
            // 上，这样在调度器里面调用的时候可以进行去重，因为 scheduler 里面执行的时候
            // 有去重操作，这里的 __weh = 'with error handling'
            const wrappedHook = hook.__weh ||
                (hook.__weh = (...args) => {
                    if (target.isUnmounted) {
                        return;
                    }
                    // 在所有的声明周期函数中都 disable tracking
                    // 因为它们有可能在 effects 中被调用
                    pauseTracking();
                    // 在 hook 执行期间设置 currentInstance = targt
                    // 假设 hook 没有同步地触发其他 hooks，即在一个 hook 里面同步调用
                    // 另一个声明周期函数？
                    setCurrentInstance(target);
                    const res = callWithAsyncErrorHandling(hook, target, type, args);
                    setCurrentInstance(null);
                    resetTracking();
                    return res;
                });
            prepend ? hooks.unshift(wrappedHook) : hooks.push(wrappedHook);
            return wrappedHook;
        }
        else {
            // xxx -> onXxx
            const apiName = toHandlerKey(ErrorTypeStrings[type].replace(/ hook$/, ''));
            warn(`${apiName} is called when there is no active component instance to be ` +
                `associated with. ` +
                `Lifecycle injection APIs can only be used during execution of setup().` +
                ( ` If you are using async setup(), make sure to register lifecycle ` +
                        `hooks before the first await statement.`
                    ));
        }
    }
    const createHook = (lifecycle) => (hook, target = currentInstance) => !isInSSRComponentSetup && injectHook(lifecycle, hook, target);
    const onBeforeMount = createHook("bm" /* BEFORE_MOUNT */);
    const onMounted = createHook("m" /* MOUNTED */);
    const onBeforeUpdate = createHook("bu" /* BEFORE_UPDATE */);
    const onUpdated = createHook("u" /* UPDATED */);
    const onBeforeUnmount = createHook("bum" /* BEFORE_UNMOUNT */);
    const onUnmounted = createHook("um" /* UNMOUNTED */);
    const onRenderTriggered = createHook("rtg" /* RENDER_TRIGGERED */);
    const onRenderTracked = createHook("rtc" /* RENDER_TRACKED */);
    const onErrorCaptured = (hook, target = currentInstance) => {
        injectHook("ec" /* ERROR_CAPTURED */, hook, target);
    };
  
    function useTransitionState() {
        const state = {
            isMounted: false,
            isLeaving: false,
            isUnmounting: false,
            leavingVNodes: new Map()
        };
        onMounted(() => {
            state.isMounted = true;
        });
        onBeforeUnmount(() => {
            state.isUnmounting = true;
        });
        return state;
    }
    const TransitionHookValidator = [Function, Array];
    const BaseTransitionImpl = {
        name: `BaseTransition`,
        props: {
            mode: String,
            appear: Boolean,
            persisted: Boolean,
            // enter
            onBeforeEnter: TransitionHookValidator,
            onEnter: TransitionHookValidator,
            onAfterEnter: TransitionHookValidator,
            onEnterCancelled: TransitionHookValidator,
            // leave
            onBeforeLeave: TransitionHookValidator,
            onLeave: TransitionHookValidator,
            onAfterLeave: TransitionHookValidator,
            onLeaveCancelled: TransitionHookValidator,
            // appear
            onBeforeAppear: TransitionHookValidator,
            onAppear: TransitionHookValidator,
            onAfterAppear: TransitionHookValidator,
            onAppearCancelled: TransitionHookValidator
        },
        setup(props, { slots }) {
            const instance = getCurrentInstance();
            const state = useTransitionState();
            let prevTransitionKey;
            return () => {
                const children = slots.default && getTransitionRawChildren(slots.default(), true);
                if (!children || !children.length) {
                    return;
                }
                // warn multiple elements
                if ( children.length > 1) {
                    warn('<transition> can only be used on a single element or component. Use ' +
                        '<transition-group> for lists.');
                }
                // there's no need to track reactivity for these props so use the raw
                // props for a bit better perf
                const rawProps = toRaw(props);
                const { mode } = rawProps;
                // check mode
                if ( mode && !['in-out', 'out-in', 'default'].includes(mode)) {
                    warn(`invalid <transition> mode: ${mode}`);
                }
                // at this point children has a guaranteed length of 1.
                const child = children[0];
                if (state.isLeaving) {
                    return emptyPlaceholder(child);
                }
                // in the case of <transition><keep-alive/></transition>, we need to
                // compare the type of the kept-alive children.
                const innerChild = getKeepAliveChild(child);
                if (!innerChild) {
                    return emptyPlaceholder(child);
                }
                const enterHooks = resolveTransitionHooks(innerChild, rawProps, state, instance);
                setTransitionHooks(innerChild, enterHooks);
                const oldChild = instance.subTree;
                const oldInnerChild = oldChild && getKeepAliveChild(oldChild);
                let transitionKeyChanged = false;
                const { getTransitionKey } = innerChild.type;
                if (getTransitionKey) {
                    const key = getTransitionKey();
                    if (prevTransitionKey === undefined) {
                        prevTransitionKey = key;
                    }
                    else if (key !== prevTransitionKey) {
                        prevTransitionKey = key;
                        transitionKeyChanged = true;
                    }
                }
                // handle mode
                if (oldInnerChild &&
                    oldInnerChild.type !== Comment &&
                    (!isSameVNodeType(innerChild, oldInnerChild) || transitionKeyChanged)) {
                    const leavingHooks = resolveTransitionHooks(oldInnerChild, rawProps, state, instance);
                    // update old tree's hooks in case of dynamic transition
                    setTransitionHooks(oldInnerChild, leavingHooks);
                    // switching between different views
                    if (mode === 'out-in') {
                        state.isLeaving = true;
                        // return placeholder node and queue update when leave finishes
                        leavingHooks.afterLeave = () => {
                            state.isLeaving = false;
                            instance.update();
                        };
                        return emptyPlaceholder(child);
                    }
                    else if (mode === 'in-out') {
                        leavingHooks.delayLeave = (el, earlyRemove, delayedLeave) => {
                            const leavingVNodesCache = getLeavingNodesForType(state, oldInnerChild);
                            leavingVNodesCache[String(oldInnerChild.key)] = oldInnerChild;
                            // early removal callback
                            el._leaveCb = () => {
                                earlyRemove();
                                el._leaveCb = undefined;
                                delete enterHooks.delayedLeave;
                            };
                            enterHooks.delayedLeave = delayedLeave;
                        };
                    }
                }
                return child;
            };
        }
    };
    // export the public type for h/tsx inference
    // also to avoid inline import() in generated d.ts files
    const BaseTransition = BaseTransitionImpl;
    function getLeavingNodesForType(state, vnode) {
        const { leavingVNodes } = state;
        let leavingVNodesCache = leavingVNodes.get(vnode.type);
        if (!leavingVNodesCache) {
            leavingVNodesCache = Object.create(null);
            leavingVNodes.set(vnode.type, leavingVNodesCache);
        }
        return leavingVNodesCache;
    }
    // The transition hooks are attached to the vnode as vnode.transition
    // and will be called at appropriate timing in the renderer.
    function resolveTransitionHooks(vnode, props, state, instance) {
        const { appear, mode, persisted = false, onBeforeEnter, onEnter, onAfterEnter, onEnterCancelled, onBeforeLeave, onLeave, onAfterLeave, onLeaveCancelled, onBeforeAppear, onAppear, onAfterAppear, onAppearCancelled } = props;
        const key = String(vnode.key);
        const leavingVNodesCache = getLeavingNodesForType(state, vnode);
        const callHook = (hook, args) => {
            hook &&
                callWithAsyncErrorHandling(hook, instance, 9 /* TRANSITION_HOOK */, args);
        };
        const hooks = {
            mode,
            persisted,
            beforeEnter(el) {
                let hook = onBeforeEnter;
                if (!state.isMounted) {
                    if (appear) {
                        hook = onBeforeAppear || onBeforeEnter;
                    }
                    else {
                        return;
                    }
                }
                // for same element (v-show)
                if (el._leaveCb) {
                    el._leaveCb(true /* cancelled */);
                }
                // for toggled element with same key (v-if)
                const leavingVNode = leavingVNodesCache[key];
                if (leavingVNode &&
                    isSameVNodeType(vnode, leavingVNode) &&
                    leavingVNode.el._leaveCb) {
                    // force early removal (not cancelled)
                    leavingVNode.el._leaveCb();
                }
                callHook(hook, [el]);
            },
            enter(el) {
                let hook = onEnter;
                let afterHook = onAfterEnter;
                let cancelHook = onEnterCancelled;
                if (!state.isMounted) {
                    if (appear) {
                        hook = onAppear || onEnter;
                        afterHook = onAfterAppear || onAfterEnter;
                        cancelHook = onAppearCancelled || onEnterCancelled;
                    }
                    else {
                        return;
                    }
                }
                let called = false;
                const done = (el._enterCb = (cancelled) => {
                    if (called)
                        return;
                    called = true;
                    if (cancelled) {
                        callHook(cancelHook, [el]);
                    }
                    else {
                        callHook(afterHook, [el]);
                    }
                    if (hooks.delayedLeave) {
                        hooks.delayedLeave();
                    }
                    el._enterCb = undefined;
                });
                if (hook) {
                    hook(el, done);
                    if (hook.length <= 1) {
                        done();
                    }
                }
                else {
                    done();
                }
            },
            leave(el, remove) {
                const key = String(vnode.key);
                if (el._enterCb) {
                    el._enterCb(true /* cancelled */);
                }
                if (state.isUnmounting) {
                    return remove();
                }
                callHook(onBeforeLeave, [el]);
                let called = false;
                const done = (el._leaveCb = (cancelled) => {
                    if (called)
                        return;
                    called = true;
                    remove();
                    if (cancelled) {
                        callHook(onLeaveCancelled, [el]);
                    }
                    else {
                        callHook(onAfterLeave, [el]);
                    }
                    el._leaveCb = undefined;
                    if (leavingVNodesCache[key] === vnode) {
                        delete leavingVNodesCache[key];
                    }
                });
                leavingVNodesCache[key] = vnode;
                if (onLeave) {
                    onLeave(el, done);
                    if (onLeave.length <= 1) {
                        done();
                    }
                }
                else {
                    done();
                }
            },
            clone(vnode) {
                return resolveTransitionHooks(vnode, props, state, instance);
            }
        };
        return hooks;
    }
    // the placeholder really only handles one special case: KeepAlive
    // in the case of a KeepAlive in a leave phase we need to return a KeepAlive
    // placeholder with empty content to avoid the KeepAlive instance from being
    // unmounted.
    function emptyPlaceholder(vnode) {
        if (isKeepAlive(vnode)) {
            vnode = cloneVNode(vnode);
            vnode.children = null;
            return vnode;
        }
    }
    function getKeepAliveChild(vnode) {
        return isKeepAlive(vnode)
            ? vnode.children
                ? vnode.children[0]
                : undefined
            : vnode;
    }
    function setTransitionHooks(vnode, hooks) {
        if (vnode.shapeFlag & 6 /* COMPONENT */ && vnode.component) {
            setTransitionHooks(vnode.component.subTree, hooks);
        }
        else if ( vnode.shapeFlag & 128 /* SUSPENSE */) {
            vnode.ssContent.transition = hooks.clone(vnode.ssContent);
            vnode.ssFallback.transition = hooks.clone(vnode.ssFallback);
        }
        else {
            vnode.transition = hooks;
        }
    }
    function getTransitionRawChildren(children, keepComment = false) {
        let ret = [];
        let keyedFragmentCount = 0;
        for (let i = 0; i < children.length; i++) {
            const child = children[i];
            // handle fragment children case, e.g. v-for
            if (child.type === Fragment) {
                if (child.patchFlag & 128 /* KEYED_FRAGMENT */)
                    keyedFragmentCount++;
                ret = ret.concat(getTransitionRawChildren(child.children, keepComment));
            }
            // comment placeholders should be skipped, e.g. v-if
            else if (keepComment || child.type !== Comment) {
                ret.push(child);
            }
        }
        // #1126 if a transition children list contains multiple sub fragments, these
        // fragments will be merged into a flat children array. Since each v-for
        // fragment may contain different static bindings inside, we need to de-op
        // these children to force full diffs to ensure correct behavior.
        if (keyedFragmentCount > 1) {
            for (let i = 0; i < ret.length; i++) {
                ret[i].patchFlag = -2 /* BAIL */;
            }
        }
        return ret;
    }
  
    const isKeepAlive = (vnode) => vnode.type.__isKeepAlive;
    const KeepAliveImpl = {
        name: `KeepAlive`,
        __isKeepAlive: true,
        inheritRef: true,
        props: {
            include: [String, RegExp, Array],
            exclude: [String, RegExp, Array],
            max: [String, Number]
        },
        setup(props, { slots }) {
            const cache = new Map();
            const keys = new Set();
            let current = null;
            const instance = getCurrentInstance();
            const parentSuspense = instance.suspense;
            const sharedContext = instance.ctx;
            const { renderer: { p: patch, m: move, um: _unmount, o: { createElement } } } = sharedContext;
            const storageContainer = createElement('div');
            sharedContext.activate = (vnode, container, anchor, isSVG, optimized) => {
                const instance = vnode.component;
                move(vnode, container, anchor, 0 /* ENTER */, parentSuspense);
                // props 可能发生变化，这里执行一次 patch 操作
                patch(instance.vnode, vnode, container, anchor, instance, parentSuspense, isSVG, optimized);
                queuePostRenderEffect(() => {
                    instance.isDeactivated = false;
                    if (instance.a) {
                        // activated 周期函数
                        invokeArrayFns(instance.a);
                    }
                    const vnodeHook = vnode.props && vnode.props.onVnodeMounted;
                    if (vnodeHook) {
                        invokeVNodeHook(vnodeHook, instance.parent, vnode);
                    }
                }, parentSuspense);
            };
            sharedContext.deactivate = (vnode) => {
                const instance = vnode.component;
                move(vnode, storageContainer, null, 1 /* LEAVE */, parentSuspense);
                queuePostRenderEffect(() => {
                    if (instance.da) {
                        invokeArrayFns(instance.da);
                    }
                    const vnodeHook = vnode.props && vnode.props.onVnodeUnmounted;
                    if (vnodeHook) {
                        invokeVNodeHook(vnodeHook, instance.parent, vnode);
                    }
                    instance.isDeactivated = true;
                }, parentSuspense);
            };
            // 对 renderer unmount 的一次封装
            function unmount(vnode) {
                resetShapeFlag(vnode);
                _unmount(vnode, instance, parentSuspense);
            }
            // 过滤掉缓存
            function pruneCache(filter) {
                cache.forEach((vnode, key) => {
                    const name = getComponentName(vnode.type);
                    if (name && (!filter || !filter(name))) {
                        pruneCacheEntry(key);
                    }
                });
            }
            function pruneCacheEntry(key) {
                const cached = cache.get(key);
                if (!current || cached.type !== current.type) {
                    // 新增或节点类型发生变化，直接卸载掉老的
                    unmount(cached);
                }
                else if (current) {
                    // 重置标记就可以了？
                    // 当前激活的实例不该再是 kept-alive
                    // 我们不能立即卸载但是稍后会进行卸载，所以这里先重置其标记
                    // 不能立即卸载？
                    // 是因为在 activate 和 deactivate 中的周期函数调用
                    // 是采用的 post 类型异步执行的缘故吗？
                    resetShapeFlag(current);
                }
                cache.delete(key);
                keys.delete(key);
            }
            // 监听 include/exclude 属性变化
            watch(() => [props.include, props.exclude], ([include, exclude]) => {
                // 支持三种类型
                // 1. 字符串, 'a,b,c'
                // 2. 正则表达式， /a|b|c/
                // 3. 数组， ['a', 'b', 'c', /d/, /e|f/]
                include && pruneCache(name => matches(include, name));
                exclude && pruneCache(name => !matches(exclude, name));
            }, { flush: 'post', deep: true });
            // 在 render 之后缓存子树(subTree)
            let pendingCacheKey = null;
            const cacheSubtree = () => {
                if (pendingCacheKey != null) {
                    cache.set(pendingCacheKey, getInnerChild(instance.subTree));
                }
            };
            // 注册生命周期
            onMounted(cacheSubtree);
            onUpdated(cacheSubtree);
            onBeforeUnmount(() => {
                cache.forEach(cached => {
                    const { subTree, suspense } = instance;
                    const vnode = getInnerChild(subTree);
                    if (cached.type === vnode.type) {
                        // 有缓存的节点
                        // 当前实例会成为 keep-alive 的 unmount 一部分
                        resetShapeFlag(vnode);
                        // 但是在这里执行它的 deactivated 钩子函数
                        const da = vnode.component.da;
                        da && queuePostRenderEffect(da, suspense);
                        return;
                    }
                    // 没有缓存的直接 unmount
                    unmount(cached);
                });
            });
            return () => {
                // 根据组件的执行流程，这个函数将会在 setupComponent() 中
                // 执行 setup() 得到 setupResult ，传递给 handleSetupResult()
                // 函数，这里面检测 setupResult 也就是这个匿名函数，如果它是函数
                // 会直接被当做 render 函数处理(instance.render 或 instance.ssrRender)
                // 结论就是，这个匿名函数是 render() 函数
                pendingCacheKey = null;
                if (!slots.default) {
                    // 组件支持默认插槽使用方式
                    return null;
                }
                const children = slots.default();
                const rawVNode = children[0];
                if (children.length > 1) {
                    // KeepAlive 组件只能包含一个组件作为 child
                    // 也就是说 ~<keep-alive><CompA/><CompB/></keep-alive/>~
                    // 是不合法的使用
                    current = null;
                    // warn...
                    return children;
                }
                else if (!isVNode(rawVNode) ||
                    (!(rawVNode.shapeFlag & 4 /* STATEFUL_COMPONENT */) &&
                        !(rawVNode.shapeFlag & 128 /* SUSPENSE */))) {
                    // 1. 非 VNode 类型节点
                    // 2. 既不是有状态组件(对象类型组件)也不是 Suspense 的时候
                    // 相反意味着，节点必须满足下面几种情况
                    // 1. 是 VNode 类型且是有状态组件(非函数式组件)
                    // 2. 或者是 VNode 类型且是Suspense 组件
                    current = null;
                    return rawVNode;
                }
                // 也就是说 keep-alive 只接受有状态组件或者 Suspense 作为唯一的 child
                let vnode = getInnerChild(rawVNode);
                const comp = vnode.type;
                const name = getComponentName(comp);
                const { include, exclude, max } = props;
                if (
                // 无缓存的节点
                (include && (!name || !matches(include, name))) ||
                    // 在不缓存的节点们之列
                    (exclude && name && matches(exclude, name))) {
                    current = vnode;
                    return rawVNode;
                }
                const key = vnode.key == null ? comp : vnode.key;
                const cachedVNode = cache.get(key);
                // 克隆一份如果它有被复用的话，因为我们即将修改它
                if (vnode.el) {
                    vnode = cloneVNode(vnode);
                    if (rawVNode.shapeFlag & 128 /* SUSPENSE */) {
                        rawVNode.ssContent = vnode;
                    }
                }
                pendingCacheKey = key;
                if (cachedVNode) {
                    vnode.el = cachedVNode.el;
                    vnode.component = cachedVNode.component;
                    if (vnode.transition) {
                        // 在 subTree 上递归更新 transition 钩子函数
                        setTransitionHooks(vnode, vnode.transition);
                    }
                    // 避免 vnode 正在首次 mount
                    vnode.shapeFlag |= 512 /* COMPONENT_KEPT_ALIVE */;
                    // 标记 key 为最新的
                    keys.delete(key);
                    keys.add(key);
                }
                else {
                    // 没有缓存的情况
                    keys.add(key);
                    // 删除最老的 entry，缓冲池已经满了，删除掉最老的那个
                    if (max && keys.size > parseInt(max, 10)) {
                        // 因为 Set 没有直接取指定位置元素的值
                        // 这里的目的是变相的取 Set 中第一个元素，即最早 add 的那个 key
                        // 如： new Set([1,2,3,4]) => keys.values() => <1,2,3,4>
                        // next() 得到迭代器下一个值 { value: 1, done: false }
                        // .value 得到第一个集合元素的值
                        pruneCacheEntry(keys.values().next().value);
                    }
                }
                // 避免 vnode 正在被卸载，在renderer unmount 中会检测
                vnode.shapeFlag |= 256 /* COMPONENT_SHOULD_KEEP_ALIVE */;
                current = vnode;
                return rawVNode;
            };
        }
    };
    const KeepAlive = KeepAliveImpl;
    function matches(pattern, name) {
        if (isArray(pattern)) {
            return pattern.some((p) => matches(p, name));
        }
        else if (isString(pattern)) {
            return pattern.split(',').indexOf(name) > -1;
        }
        else if (pattern.test) {
            return pattern.test(name);
        }
        /* istanbul ignore next */
        return false;
    }
    function onActivated(hook, target) {
        registerKeepAliveHook(hook, "a" /* ACTIVATED */, target);
    }
    function onDeactivated(hook, target) {
        registerKeepAliveHook(hook, "da" /* DEACTIVATED */, target);
    }
    function registerKeepAliveHook(hook, type, target = currentInstance) {
        // cache the deactivate branch check wrapper for injected hooks so the same
        // hook can be properly deduped by the scheduler. "__wdc" stands for "with
        // deactivation check".
        const wrappedHook = hook.__wdc ||
            (hook.__wdc = () => {
                // only fire the hook if the target instance is NOT in a deactivated branch.
                let current = target;
                while (current) {
                    if (current.isDeactivated) {
                        return;
                    }
                    current = current.parent;
                }
                hook();
            });
        injectHook(type, wrappedHook, target);
        // In addition to registering it on the target instance, we walk up the parent
        // chain and register it on all ancestor instances that are keep-alive roots.
        // This avoids the need to walk the entire component tree when invoking these
        // hooks, and more importantly, avoids the need to track child components in
        // arrays.
        if (target) {
            let current = target.parent;
            while (current && current.parent) {
                if (isKeepAlive(current.parent.vnode)) {
                    injectToKeepAliveRoot(wrappedHook, type, target, current);
                }
                current = current.parent;
            }
        }
    }
    function injectToKeepAliveRoot(hook, type, target, keepAliveRoot) {
        // injectHook wraps the original for error handling, so make sure to remove
        // the wrapped version.
        const injected = injectHook(type, hook, keepAliveRoot, true /* prepend */);
        onUnmounted(() => {
            remove(keepAliveRoot[type], injected);
        }, target);
    }
    function resetShapeFlag(vnode) {
        let shapeFlag = vnode.shapeFlag;
        if (shapeFlag & 256 /* COMPONENT_SHOULD_KEEP_ALIVE */) {
            shapeFlag -= 256 /* COMPONENT_SHOULD_KEEP_ALIVE */;
        }
        if (shapeFlag & 512 /* COMPONENT_KEPT_ALIVE */) {
            shapeFlag -= 512 /* COMPONENT_KEPT_ALIVE */;
        }
        vnode.shapeFlag = shapeFlag;
    }
    function getInnerChild(vnode) {
        return vnode.shapeFlag & 128 /* SUSPENSE */ ? vnode.ssContent : vnode;
    }
  
    let hasMismatch = false;
    const isSVGContainer = (container) => /svg/.test(container.namespaceURI) && container.tagName !== 'foreignObject';
    const isComment = (node) => node.nodeType === 8 /* COMMENT */;
    // Note: hydration is DOM-specific
    // But we have to place it in core due to tight coupling with core - splitting
    // it out creates a ton of unnecessary complexity.
    // Hydration also depends on some renderer internal logic which needs to be
    // passed in via arguments.
    function createHydrationFunctions(rendererInternals) {
        const { mt: mountComponent, p: patch, o: { patchProp, nextSibling, parentNode, remove, insert, createComment } } = rendererInternals;
        const hydrate = (vnode, container) => {
            if ( !container.hasChildNodes()) {
                warn(`Attempting to hydrate existing markup but container is empty. ` +
                    `Performing full mount instead.`);
                patch(null, vnode, container);
                return;
            }
            hasMismatch = false;
            hydrateNode(container.firstChild, vnode, null, null);
            flushPostFlushCbs();
            if (hasMismatch && !false) {
                // this error should show up in production
                console.error(`Hydration completed but contains mismatches.`);
            }
        };
        const hydrateNode = (node, vnode, parentComponent, parentSuspense, optimized = false) => {
            const isFragmentStart = isComment(node) && node.data === '[';
            const onMismatch = () => handleMismatch(node, vnode, parentComponent, parentSuspense, isFragmentStart);
            const { type, ref, shapeFlag } = vnode;
            const domType = node.nodeType;
            vnode.el = node;
            let nextNode = null;
            switch (type) {
                case Text:
                    if (domType !== 3 /* TEXT */) {
                        nextNode = onMismatch();
                    }
                    else {
                        if (node.data !== vnode.children) {
                            hasMismatch = true;
                            
                                warn(`Hydration text mismatch:` +
                                    `\n- Client: ${JSON.stringify(node.data)}` +
                                    `\n- Server: ${JSON.stringify(vnode.children)}`);
                            node.data = vnode.children;
                        }
                        nextNode = nextSibling(node);
                    }
                    break;
                case Comment:
                    if (domType !== 8 /* COMMENT */ || isFragmentStart) {
                        nextNode = onMismatch();
                    }
                    else {
                        nextNode = nextSibling(node);
                    }
                    break;
                case Static:
                    if (domType !== 1 /* ELEMENT */) {
                        nextNode = onMismatch();
                    }
                    else {
                        // determine anchor, adopt content
                        nextNode = node;
                        // if the static vnode has its content stripped during build,
                        // adopt it from the server-rendered HTML.
                        const needToAdoptContent = !vnode.children.length;
                        for (let i = 0; i < vnode.staticCount; i++) {
                            if (needToAdoptContent)
                                vnode.children += nextNode.outerHTML;
                            if (i === vnode.staticCount - 1) {
                                vnode.anchor = nextNode;
                            }
                            nextNode = nextSibling(nextNode);
                        }
                        return nextNode;
                    }
                    break;
                case Fragment:
                    if (!isFragmentStart) {
                        nextNode = onMismatch();
                    }
                    else {
                        nextNode = hydrateFragment(node, vnode, parentComponent, parentSuspense, optimized);
                    }
                    break;
                default:
                    if (shapeFlag & 1 /* ELEMENT */) {
                        if (domType !== 1 /* ELEMENT */ ||
                            vnode.type !== node.tagName.toLowerCase()) {
                            nextNode = onMismatch();
                        }
                        else {
                            nextNode = hydrateElement(node, vnode, parentComponent, parentSuspense, optimized);
                        }
                    }
                    else if (shapeFlag & 6 /* COMPONENT */) {
                        // when setting up the render effect, if the initial vnode already
                        // has .el set, the component will perform hydration instead of mount
                        // on its sub-tree.
                        const container = parentNode(node);
                        const hydrateComponent = () => {
                            mountComponent(vnode, container, null, parentComponent, parentSuspense, isSVGContainer(container), optimized);
                        };
                        // async component
                        const loadAsync = vnode.type.__asyncLoader;
                        if (loadAsync) {
                            loadAsync().then(hydrateComponent);
                        }
                        else {
                            hydrateComponent();
                        }
                        // component may be async, so in the case of fragments we cannot rely
                        // on component's rendered output to determine the end of the fragment
                        // instead, we do a lookahead to find the end anchor node.
                        nextNode = isFragmentStart
                            ? locateClosingAsyncAnchor(node)
                            : nextSibling(node);
                    }
                    else if (shapeFlag & 64 /* TELEPORT */) {
                        if (domType !== 8 /* COMMENT */) {
                            nextNode = onMismatch();
                        }
                        else {
                            nextNode = vnode.type.hydrate(node, vnode, parentComponent, parentSuspense, optimized, rendererInternals, hydrateChildren);
                        }
                    }
                    else if ( shapeFlag & 128 /* SUSPENSE */) {
                        nextNode = vnode.type.hydrate(node, vnode, parentComponent, parentSuspense, isSVGContainer(parentNode(node)), optimized, rendererInternals, hydrateNode);
                    }
                    else {
                        warn('Invalid HostVNode type:', type, `(${typeof type})`);
                    }
            }
            if (ref != null) {
                setRef(ref, null, parentSuspense, vnode);
            }
            return nextNode;
        };
        const hydrateElement = (el, vnode, parentComponent, parentSuspense, optimized) => {
            optimized = optimized || !!vnode.dynamicChildren;
            const { props, patchFlag, shapeFlag, dirs } = vnode;
            // skip props & children if this is hoisted static nodes
            if (patchFlag !== -1 /* HOISTED */) {
                if (dirs) {
                    invokeDirectiveHook(vnode, null, parentComponent, 'created');
                }
                // props
                if (props) {
                    if (!optimized ||
                        (patchFlag & 16 /* FULL_PROPS */ ||
                            patchFlag & 32 /* HYDRATE_EVENTS */)) {
                        for (const key in props) {
                            if (!isReservedProp(key) && isOn(key)) {
                                patchProp(el, key, null, props[key]);
                            }
                        }
                    }
                    else if (props.onClick) {
                        // Fast path for click listeners (which is most often) to avoid
                        // iterating through props.
                        patchProp(el, 'onClick', null, props.onClick);
                    }
                }
                // vnode / directive hooks
                let vnodeHooks;
                if ((vnodeHooks = props && props.onVnodeBeforeMount)) {
                    invokeVNodeHook(vnodeHooks, parentComponent, vnode);
                }
                if (dirs) {
                    invokeDirectiveHook(vnode, null, parentComponent, 'beforeMount');
                }
                if ((vnodeHooks = props && props.onVnodeMounted) || dirs) {
                    queueEffectWithSuspense(() => {
                        vnodeHooks && invokeVNodeHook(vnodeHooks, parentComponent, vnode);
                        dirs && invokeDirectiveHook(vnode, null, parentComponent, 'mounted');
                    }, parentSuspense);
                }
                // children
                if (shapeFlag & 16 /* ARRAY_CHILDREN */ &&
                    // skip if element has innerHTML / textContent
                    !(props && (props.innerHTML || props.textContent))) {
                    let next = hydrateChildren(el.firstChild, vnode, el, parentComponent, parentSuspense, optimized);
                    let hasWarned = false;
                    while (next) {
                        hasMismatch = true;
                        if ( !hasWarned) {
                            warn(`Hydration children mismatch in <${vnode.type}>: ` +
                                `server rendered element contains more child nodes than client vdom.`);
                            hasWarned = true;
                        }
                        // The SSRed DOM contains more nodes than it should. Remove them.
                        const cur = next;
                        next = next.nextSibling;
                        remove(cur);
                    }
                }
                else if (shapeFlag & 8 /* TEXT_CHILDREN */) {
                    if (el.textContent !== vnode.children) {
                        hasMismatch = true;
                        
                            warn(`Hydration text content mismatch in <${vnode.type}>:\n` +
                                `- Client: ${el.textContent}\n` +
                                `- Server: ${vnode.children}`);
                        el.textContent = vnode.children;
                    }
                }
            }
            return el.nextSibling;
        };
        const hydrateChildren = (node, parentVNode, container, parentComponent, parentSuspense, optimized) => {
            optimized = optimized || !!parentVNode.dynamicChildren;
            const children = parentVNode.children;
            const l = children.length;
            let hasWarned = false;
            for (let i = 0; i < l; i++) {
                const vnode = optimized
                    ? children[i]
                    : (children[i] = normalizeVNode(children[i]));
                if (node) {
                    node = hydrateNode(node, vnode, parentComponent, parentSuspense, optimized);
                }
                else {
                    hasMismatch = true;
                    if ( !hasWarned) {
                        warn(`Hydration children mismatch in <${container.tagName.toLowerCase()}>: ` +
                            `server rendered element contains fewer child nodes than client vdom.`);
                        hasWarned = true;
                    }
                    // the SSRed DOM didn't contain enough nodes. Mount the missing ones.
                    patch(null, vnode, container, null, parentComponent, parentSuspense, isSVGContainer(container));
                }
            }
            return node;
        };
        const hydrateFragment = (node, vnode, parentComponent, parentSuspense, optimized) => {
            const container = parentNode(node);
            const next = hydrateChildren(nextSibling(node), vnode, container, parentComponent, parentSuspense, optimized);
            if (next && isComment(next) && next.data === ']') {
                return nextSibling((vnode.anchor = next));
            }
            else {
                // fragment didn't hydrate successfully, since we didn't get a end anchor
                // back. This should have led to node/children mismatch warnings.
                hasMismatch = true;
                // since the anchor is missing, we need to create one and insert it
                insert((vnode.anchor = createComment(`]`)), container, next);
                return next;
            }
        };
        const handleMismatch = (node, vnode, parentComponent, parentSuspense, isFragment) => {
            hasMismatch = true;
            
                warn(`Hydration node mismatch:\n- Client vnode:`, vnode.type, `\n- Server rendered DOM:`, node, node.nodeType === 3 /* TEXT */
                    ? `(text)`
                    : isComment(node) && node.data === '['
                        ? `(start of fragment)`
                        : ``);
            vnode.el = null;
            if (isFragment) {
                // remove excessive fragment nodes
                const end = locateClosingAsyncAnchor(node);
                while (true) {
                    const next = nextSibling(node);
                    if (next && next !== end) {
                        remove(next);
                    }
                    else {
                        break;
                    }
                }
            }
            const next = nextSibling(node);
            const container = parentNode(node);
            remove(node);
            patch(null, vnode, container, next, parentComponent, parentSuspense, isSVGContainer(container));
            return next;
        };
        const locateClosingAsyncAnchor = (node) => {
            let match = 0;
            while (node) {
                node = nextSibling(node);
                if (node && isComment(node)) {
                    if (node.data === '[')
                        match++;
                    if (node.data === ']') {
                        if (match === 0) {
                            return nextSibling(node);
                        }
                        else {
                            match--;
                        }
                    }
                }
            }
            return node;
        };
        return [hydrate, hydrateNode];
    }
  
    // implementation, close to no-op
    function defineComponent(options) {
        return isFunction(options) ? { setup: options, name: options.name } : options;
    }
  
    const isAsyncWrapper = (i) => !!i.type.__asyncLoader;
    function defineAsyncComponent(source) {
        if (isFunction(source)) {
            source = { loader: source };
        }
        const { loader, loadingComponent: loadingComponent, errorComponent: errorComponent, delay = 200, timeout, // undefined = never times out
        suspensible = true, onError: userOnError } = source;
        // 1. TODO retry 封装
        let pendingRequest = null;
        let resolvedComp;
        let retries = 0;
        const retry = () => {
            retries++;
            pendingRequest = null;
            return load();
        };
        // 2. TODO 函数封装
        const load = () => {
            let thisRequest;
            return (pendingRequest ||
                (thisRequest = pendingRequest = loader()
                    .catch(err => {
                    err = err instanceof Error ? err : new Error(String(err));
                    if (userOnError) {
                        return new Promise((resolve, reject) => {
                            const userRetry = () => resolve(retry());
                            const userFail = () => reject(err);
                            userOnError(err, userRetry, userFail, retries + 1);
                        });
                    }
                    else {
                        throw err;
                    }
                })
                    .then((comp) => {
                    if (thisRequest !== pendingRequest && pendingRequest) {
                        return pendingRequest;
                    }
                    if ( !comp) {
                        warn(`Async component loader resolved to undefined. ` +
                            `If you are using retry(), make sure to return its return value.`);
                    }
                    // interop module default
                    if (comp &&
                        (comp.__esModule || comp[Symbol.toStringTag] === 'Module')) {
                        comp = comp.default;
                    }
                    if ( comp && !isObject(comp) && !isFunction(comp)) {
                        throw new Error(`Invalid async component load result: ${comp}`);
                    }
                    resolvedComp = comp;
                    return comp;
                })));
        };
        //
        // 3. TODO 返回组件
        return defineComponent({
            __asyncLoader: load,
            name: 'AsyncComponentWrapper',
            setup() {
                const instance = currentInstance;
                console.log('\n resolved comp before');
                // 异步组件已经完成了
                if (resolvedComp) {
                    console.log('\n resolved comp');
                    return createInnerComp(resolvedComp, instance);
                }
                const onError = (err) => {
                    pendingRequest = null;
                    handleError(err, instance, 13 /* ASYNC_COMPONENT_LOADER */, !errorComponent /* do not throw in dev if user provided error component */);
                };
                // suspense-controlled or SSR.
                if (( suspensible && instance.suspense) ||
                    (false )) {
                    return load()
                        .then(comp => {
                        return () => createInnerComp(comp, instance);
                    })
                        .catch(err => {
                        onError(err);
                        return () => errorComponent
                            ? createVNode(errorComponent, {
                                error: err
                            })
                            : null;
                    });
                }
                const loaded = ref(false);
                const error = ref();
                const delayed = ref(!!delay);
                if (delay) {
                    setTimeout(() => {
                        delayed.value = false;
                    }, delay);
                }
                if (timeout != null) {
                    setTimeout(() => {
                        if (!loaded.value && !error.value) {
                            const err = new Error(`Async component timed out after ${timeout}ms.`);
                            onError(err);
                            error.value = err;
                        }
                    }, timeout);
                }
                // 开始执行异步任务加载异步组件
                load()
                    .then(() => {
                    loaded.value = true;
                })
                    .catch(err => {
                    onError(err);
                    error.value = err;
                });
                return () => {
                    console.log('loaded.value = ', loaded.value);
                    if (loaded.value && resolvedComp) {
                        // 组件正常加载完成
                        return createInnerComp(resolvedComp, instance);
                    }
                    else if (error.value && errorComponent) {
                        return createVNode(errorComponent, {
                            error: error.value
                        });
                    }
                    else if (loadingComponent && !delayed.value) {
                        return createVNode(loadingComponent);
                    }
                };
            }
        });
    }
    function createInnerComp(comp, { vnode: { ref, props, children } }) {
        const vnode = createVNode(comp, props, children);
        // ensure inner component inherits the async wrapper's ref owner
        vnode.ref = ref;
        return vnode;
    }
  
    function createDevEffectOptions(instance) {
        return {
            scheduler: queueJob,
            allowRecurse: true,
            onTrack: instance.rtc ? e => invokeArrayFns(instance.rtc, e) : void 0,
            onTrigger: instance.rtg ? e => invokeArrayFns(instance.rtg, e) : void 0
        };
    }
    const queuePostRenderEffect =  queueEffectWithSuspense
        ;
    const setRef = (rawRef, oldRawRef, parentSuspense, vnode) => {
        if (isArray(rawRef)) {
            rawRef.forEach((r, i) => setRef(r, oldRawRef && (isArray(oldRawRef) ? oldRawRef[i] : oldRawRef), parentSuspense, vnode));
            return;
        }
        let value;
        if (!vnode || isAsyncWrapper(vnode)) {
            value = null;
        }
        else {
            if (vnode.shapeFlag & 4 /* STATEFUL_COMPONENT */) {
                value = vnode.component.exposed || vnode.component.proxy;
            }
            else {
                value = vnode.el;
            }
        }
        const { i: owner, r: ref } = rawRef;
        if ( !owner) {
            // warn 丢失 ref owner 上下文
            return;
        }
        const oldRef = oldRawRef && oldRawRef.r;
        const refs = owner.refs === EMPTY_OBJ ? (owner.refs = {}) : owner.refs;
        const setupState = owner.setupState;
        // unset old ref
        if (oldRef != null && oldRef !== ref) {
            if (isString(oldRef)) {
                refs[oldRef] = null;
                if (hasOwn(setupState, oldRef)) {
                    setupState[oldRef] = null;
                }
            }
            else if (isRef(oldRef)) {
                oldRef.value = null;
            }
        }
        if (isString(ref)) {
            const doSet = () => {
                refs[ref] = value;
                if (hasOwn(setupState, ref)) {
                    setupState[ref] = value;
                }
            };
            // #1789: 非空值，在 render 结束后设置
            // 控制意味着是 unmount，它不应该重写同key 的其他 ref
            if (value) {
                doSet.id = -1;
                queuePostRenderEffect(doSet, parentSuspense);
            }
            else {
                doSet();
            }
        }
        else if (isRef(ref)) {
            const doSet = () => {
                ref.value = value;
            };
            if (value) {
                doSet.id = -1;
                queuePostRenderEffect(doSet, parentSuspense);
            }
            else {
                doSet();
            }
        }
        else if (isFunction(ref)) {
            callWithErrorHandling(ref, owner, 12 /* FUNCTION_REF */, [value, refs]);
        }
        else ;
    };
    /**
     * The createRenderer function accepts two generic arguments:
     * HostNode and HostElement, corresponding to Node and Element types in the
     * host environment. For example, for runtime-dom, HostNode would be the DOM
     * `Node` interface and HostElement would be the DOM `Element` interface.
     *
     * Custom renderers can pass in the platform specific types like this:
     *
     * ``` js
     * const { render, createApp } = createRenderer<Node, Element>({
     *   patchProp,
     *   ...nodeOps
     * })
     * ```
     */
    function createRenderer(options) {
        return baseCreateRenderer(options);
    }
    // Separate API for creating hydration-enabled renderer.
    // Hydration logic is only used when calling this function, making it
    // tree-shakable.
    function createHydrationRenderer(options) {
        return baseCreateRenderer(options, createHydrationFunctions);
    }
    // overload 2: with hydration
    // function baseCreateRenderer(
    //   options: RendererOptions<Node, Element>,
    //   createHydrationFns: typeof createHydrationFunctions
    // ): HydrationRenderer
    // implementation
    function baseCreateRenderer(options, createHydrationFns) {
        // 1. 解构 options
        const { insert: hostInsert, remove: hostRemove, patchProp: hostPatchProp, forcePatchProp: hostForcePatchProp, createElement: hostCreateElement, createText: hostCreateText, createComment: hostCreateComment, setText: hostSetText, setElementText: hostSetElementText, parentNode: hostParentNode, nextSibling: hostNextSibling, setScopeId: hostSetScopeId = NOOP, cloneNode: hostCloneNode, insertStaticContent: hostInsertStaticContent } = options;
        // 2. patch 函数
        const patch = (n1, n2, container, anchor = null, parentComponent = null, parentSuspense = null, isSVG = false, optimized = false) => {
            // 不同类型节点，直接卸载老的🌲
            if (n1 && !isSameVNodeType(n1, n2)) {
                // 去下一个兄弟节点
                anchor = getNextHostNode(n1);
                unmount(n1, parentComponent, parentSuspense, true /* doRemove */);
                n1 = null;
            }
            if (n2.patchFlag === -2 /* BAIL */) {
                optimized = false;
                n2.dynamicChildren = null;
            }
            // 新节点处理
            const { type, ref, shapeFlag } = n2;
            switch (type) {
                case Text:
                    processText(n1, n2, container, anchor);
                    break;
                case Comment:
                    processCommentNode(n1, n2, container, anchor);
                    break;
                case Static:
                    if (n1 == null) {
                        mountStaticNode(n2, container, anchor, isSVG);
                    }
                    else {
                        patchStaticNode(n1, n2, container, isSVG);
                    }
                    break;
                case Fragment:
                    processFragment(n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    break;
                default:
                    // ELEMENT/COMPONENT/TELEPORT/SUSPENSE
                    // 默认只支持这四种组件
                    if (shapeFlag & 1 /* ELEMENT */) {
                        processElement(n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    }
                    else if (shapeFlag & 6 /* COMPONENT */) {
                        processComponent(n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    }
                    else if (shapeFlag & 64 /* TELEPORT */) {
                        type.process(n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized, internals);
                    }
                    else if ( shapeFlag & 128 /* SUSPENSE */) {
                        type.process(n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized, internals);
                    }
                    break;
            }
            // set ref
            if (ref != null && parentComponent) {
                setRef(ref, n1 && n1.ref, parentSuspense, n2);
            }
        };
        // 3. processText 处理文本
        const processText = (n1, n2, container, anchor) => {
            if (n1 == null /* old */) {
                // 新节点，插入处理
                hostInsert((n2.el = hostCreateText(n2.children)), container, anchor);
            }
            else {
                // has old vnode, need to diff
                const el = (n2.el = n1.el);
                if (n2.children !== n1.children) {
                    hostSetText(el, n2.children);
                }
            }
        };
        // 4. processCommentNode 处理注释节点
        const processCommentNode = (n1, n2, container, anchor) => {
            if (n1 == null) {
                hostInsert((n2.el = hostCreateComment(n2.children || '')), container, anchor);
            }
            else {
                // there's no support for dynamic comments
                n2.el = n1.el;
            }
        };
        // 5. mountStaticNode 加载静态节点
        const mountStaticNode = (n2, container, anchor, isSVG) => {
            [n2.el, n2.anchor] = hostInsertStaticContent(n2.children, container, anchor, isSVG);
        };
        // 6. patchStaticNode, Dev/HMR only
        const patchStaticNode = (n1, n2, container, isSVG) => {
            // static nodes are only patched during dev for HMR
            if (n2.children !== n1.children) {
                const anchor = hostNextSibling(n1.anchor);
                // remove existing
                removeStaticNode(n1);
                [n2.el, n2.anchor] = hostInsertStaticContent(n2.children, container, anchor, isSVG);
            }
            else {
                n2.el = n1.el;
                n2.anchor = n1.anchor;
            }
        };
        // 7. moveStaticNode，移动静态节点
        const moveStaticNode = ({ el, anchor }, container, nextSibling) => {
            let next;
            while (el && el !== anchor) {
                next = hostNextSibling(el);
                hostInsert(el, container, nextSibling);
                el = next;
            }
            hostInsert(anchor, container, nextSibling);
        };
        // 8. removeStaticNode, 删除静态节点
        const removeStaticNode = ({ el, anchor }) => {
            let next;
            while (el && el !== anchor) {
                next = hostNextSibling(el);
                hostRemove(el);
                el = next;
            }
            hostRemove(anchor);
        };
        // 9. processElement, 处理元素
        const processElement = (n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized) => {
            isSVG = isSVG || n2.type === 'svg';
            if (n1 == null) {
                // no old
                mountElement(n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
            }
            else {
                patchElement(n1, n2, parentComponent, parentSuspense, isSVG, optimized);
            }
        };
        // 10. mountElement, 加载元素
        const mountElement = (vnode, container, anchor, parentComponent, parentSuspense, isSVG, optimized) => {
            let el;
            let vnodeHook;
            const { type, props, shapeFlag, transition, scopeId, patchFlag, dirs } = vnode;
            {
                el = vnode.el = hostCreateElement(vnode.type, isSVG, props && props.is);
                // 在处理 props 之前先 mount children ，因为
                // 有些 props 可能会依赖于 child 是否已经渲染出来
                // 比如： `<select value>`
                if (shapeFlag & 8 /* TEXT_CHILDREN */) {
                    // 文本节点处理(纯文本，插值)
                    hostSetElementText(el, vnode.children);
                }
                else if (shapeFlag & 16 /* ARRAY_CHILDREN */) {
                    mountChildren(vnode.children, el, null, parentComponent, parentSuspense, isSVG && type !== 'foreignObject', optimized || !!vnode.dynamicChildren);
                }
                if (dirs) {
                    invokeDirectiveHook(vnode, null, parentComponent, 'created');
                }
                if (props) {
                    for (const key in props) {
                        // vue 保留属性 ref/key/onVnodeXxx 生命周期
                        if (!isReservedProp(key)) {
                            hostPatchProp(el, key, null, props[key], isSVG, vnode.children, parentComponent, parentSuspense, unmountChildren);
                        }
                    }
                    if ((vnodeHook = props.onVnodeBeforeMount)) {
                        // 执行 before mount hook
                        invokeVNodeHook(vnodeHook, parentComponent, vnode);
                    }
                }
                // scopeId
                setScopeId(el, scopeId, vnode, parentComponent);
            }
            {
                Object.defineProperty(el, '__vnode', {
                    value: vnode,
                    enumerable: false
                });
                Object.defineProperty(el, '__vueParentComponent', {
                    value: parentComponent,
                    enumerable: false
                });
            }
            if (dirs) {
                invokeDirectiveHook(vnode, null, parentComponent, 'beforeMount');
            }
            // #1583 For inside suspense + suspense not resolved case, enter hook should call when suspense resolved
            // #1689 For inside suspense + suspense resolved case, just call it
            const needCallTransitionHooks = (!parentSuspense || (parentSuspense && !parentSuspense.pendingBranch)) &&
                transition &&
                !transition.persisted;
            if (needCallTransitionHooks) {
                transition.beforeEnter(el);
            }
            hostInsert(el, container, anchor);
            if ((vnodeHook = props && props.onVnodeMounted) ||
                needCallTransitionHooks ||
                dirs) {
                queuePostRenderEffect(() => {
                    vnodeHook && invokeVNodeHook(vnodeHook, parentComponent, vnode);
                    needCallTransitionHooks && transition.enter(el);
                    dirs && invokeDirectiveHook(vnode, null, parentComponent, 'mounted');
                }, parentSuspense);
            }
        };
        // 11. setScopeId, 设置 scope id
        const setScopeId = (el, scopeId, vnode, parentComponent) => {
            if (scopeId) {
                hostSetScopeId(el, scopeId);
            }
            if (parentComponent) {
                const treeOwnerId = parentComponent.type.__scopeId;
                // vnode's own scopeId and the current patched component's scopeId is
                // different - this is a slot content node.
                if (treeOwnerId && treeOwnerId !== scopeId) {
                    hostSetScopeId(el, treeOwnerId + '-s');
                }
                let subTree = parentComponent.subTree;
                if ( subTree.type === Fragment) {
                    subTree =
                        filterSingleRoot(subTree.children) || subTree;
                }
                if (vnode === subTree) {
                    setScopeId(el, parentComponent.vnode.scopeId, parentComponent.vnode, parentComponent.parent);
                }
            }
        };
        // 12. mountChildren, 加载孩子节点
        const mountChildren = (children, container, anchor, parentComponent, parentSuspense, isSVG, optimized, start = 0) => {
            for (let i = start; i < children.length; i++) {
                const child = (children[i] = optimized
                    ? // 这里是检测 child.el 是不是存在，如果存在则是可服用的 vnode
                        // 即需要提升的静态节点，则需要进行 cloneVNode 之后返回
                        // 新的 vnode 对象
                        cloneIfMounted(children[i])
                    : // 根据 child 的类型进行拆分处理
                        // 1. boolean, 创建一个空的 Comment
                        // 2. array, 使用 Fragment 将 child 包起来
                        // 3. object, 如果是对象，child.el 存在与否进行 clone
                        // 4. 其他情况，字符串或数字，当做 Text 类型处理
                        normalizeVNode(children[i]));
                // 然后进入 patch 递归处理 children
                patch(null, child, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
            }
        };
        // 13. patchElement
        const patchElement = (n1, n2, parentComponent, parentSuspense, isSVG, optimized) => {
            // 旧的 el 替换掉新的 el ?
            const el = (n2.el = n1.el);
            let { patchFlag, dynamicChildren, dirs } = n2;
            // #1426 take the old vnode's patch flag into account since user may clone a
            // compiler-generated vnode, which de-opts to FULL_PROPS
            patchFlag |= n1.patchFlag & 16 /* FULL_PROPS */;
            const oldProps = n1.props || EMPTY_OBJ;
            const newProps = n2.props || EMPTY_OBJ;
            let vnodeHook;
            // before update hooks
            if ((vnodeHook = newProps.onVnodeBeforeUpdate)) {
                invokeVNodeHook(vnodeHook, parentComponent, n2, n1);
            }
            // dirs, 指令处理
            if (dirs) {
                invokeDirectiveHook(n2, n1, parentComponent, 'beforeUpdate');
            }
            // TODO HRM updating
            // patch props 处理
            if (patchFlag > 0) {
                // 这个标记的意义是表示该元素的 render 函数代码是由 compiler 生成
                // 的并且可以进行快速寻址(fast path)的
                // 在这个路径中，old node 和 new node 可以确认是同一Shape的节点
                // 例如：在源模板中确定同一位置
                if (patchFlag & 16 /* FULL_PROPS */) {
                    // 元素属性包含动态 keys ，进行 full-diff
                    patchProps(el, n2, oldProps, newProps, parentComponent, parentSuspense, isSVG);
                }
                else {
                    // class 属性
                    // 当元素有绑定动态 class 时
                    if (patchFlag & 2 /* CLASS */) {
                        if (oldProps.class !== newProps.class) {
                            hostPatchProp(el, 'class', null, newProps.class, isSVG);
                        }
                    }
                    // style, 标记含义：元素包含动态 style 属性
                    if (patchFlag & 4 /* STYLE */) {
                        hostPatchProp(el, 'style', oldProps.style, newProps.style, isSVG);
                    }
                    // props
                    // 该标记含义：元素有绑定动态的 prop/attr 绑定了非 class&style 的属性
                    // 动态属性的 keys 属性会保存起来，方便将来能快速的进行迭代。
                    // 例如： `:[foo]="bar"` 这里 foo 是 v-bind 绑定的动态属性，这会
                    // 导致放弃优化，而选择 full-diff ，因为我们需要重新设置 old key
                    if (patchFlag & 8 /* PROPS */) {
                        // 到这里的话 dynamicProps 必须不能为空，即必须要有动态属性
                        const propsToUpdate = n2.dynamicProps;
                        for (let i = 0; i < propsToUpdate.length; i++) {
                            const key = propsToUpdate[i];
                            const prev = oldProps[key];
                            const next = newProps[key];
                            if (next !== prev ||
                                (hostForcePatchProp && hostForcePatchProp(el, key))) {
                                hostPatchProp(el, key, prev, next, isSVG, n1.children, parentComponent, parentSuspense, unmountChildren);
                            }
                        }
                    }
                }
                // text
                // This flag is matched when the element has only dynamic text children.
                if (patchFlag & 1 /* TEXT */) {
                    if (n1.children !== n2.children) {
                        hostSetElementText(el, n2.children);
                    }
                }
            }
            else if (!optimized && dynamicChildren == null) {
                // 未优化的，需要 full diff
                patchProps(el, n2, oldProps, newProps, parentComponent, parentSuspense, isSVG);
            }
            const areChildrenSVG = isSVG && n2.type !== 'foreignObject';
            // patch children
            if (dynamicChildren) {
                patchBlockChildren(n1.dynamicChildren, dynamicChildren, el, parentComponent, parentSuspense, areChildrenSVG);
                if ( parentComponent && parentComponent.type.__hmrId) {
                    traverseStaticChildren(n1, n2);
                }
            }
            else if (!optimized) {
                // full diff
                patchChildren(n1, n2, el, null, parentComponent, parentSuspense, areChildrenSVG);
            }
            // vnode hook or dirs 处理
            if ((vnodeHook = newProps.onVnodeUpdated) || dirs) {
                queuePostRenderEffect(() => {
                    vnodeHook && invokeVNodeHook(vnodeHook, parentComponent, n2, n1);
                    dirs && invokeDirectiveHook(n2, n1, parentComponent, 'updated');
                }, parentSuspense);
            }
        };
        // 14. patchBlockChildren
        // The fast path for blocks.
        const patchBlockChildren = (oldChildren, newChildren, fallbackContainer, parentComponent, parentSuspense, isSVG) => {
            for (let i = 0; i < newChildren.length; i++) {
                const oldVNode = oldChildren[i];
                const newVNode = newChildren[i];
                // Determine the container (parent element) for the patch.
                const container = 
                // - In the case of a Fragment, we need to provide the actual parent
                // of the Fragment itself so it can move its children.
                oldVNode.type === Fragment ||
                    // - In the case of different nodes, there is going to be a replacement
                    // which also requires the correct parent container
                    !isSameVNodeType(oldVNode, newVNode) ||
                    // - In the case of a component, it could contain anything.
                    oldVNode.shapeFlag & 6 /* COMPONENT */ ||
                    oldVNode.shapeFlag & 64 /* TELEPORT */
                    ? hostParentNode(oldVNode.el)
                    : // In other cases, the parent container is not actually used so we
                        // just pass the block element here to avoid a DOM parentNode call.
                        fallbackContainer;
                patch(oldVNode, newVNode, container, null, parentComponent, parentSuspense, isSVG, true);
            }
        };
        // 15. patchProps
        const patchProps = (el, vnode, oldProps, newProps, parentComponent, parentSuspense, isSVG) => {
            // 属性变化了才执行 patch 操作
            if (oldProps !== newProps) {
                for (const key in newProps) {
                    // 空字符串不是有效的属性
                    if (isReservedProp(key))
                        continue;
                    const next = newProps[key];
                    const prev = oldProps[key];
                    if (next !== prev ||
                        (hostForcePatchProp && hostForcePatchProp(el, key))) {
                        hostPatchProp(el, key, prev, next, isSVG, vnode.children, parentComponent, parentSuspense, unmountChildren);
                    }
                }
                if (oldProps !== EMPTY_OBJ) {
                    for (const key in oldProps) {
                        if (!isReservedProp(key) && !(key in newProps)) {
                            // 删除 old prop
                            hostPatchProp(el, key, oldProps[key], null, isSVG, vnode.children, parentComponent, parentSuspense, unmountChildren);
                        }
                    }
                }
            }
        };
        // 16. processFragment
        const processFragment = (n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized) => {
            const fragmentStartAnchor = (n2.el = n1 ? n1.el : hostCreateText(''));
            const fragmentEndAnchor = (n2.anchor = n1 ? n1.anchor : hostCreateText(''));
            let { patchFlag, dynamicChildren } = n2;
            if (patchFlag > 0) {
                optimized = true;
            }
            if ( isHmrUpdating) {
                // HMR updated, force full diff
                patchFlag = 0;
                optimized = false;
                dynamicChildren = null;
            }
            if (n1 == null) {
                hostInsert(fragmentStartAnchor, container, anchor);
                hostInsert(fragmentEndAnchor, container, anchor);
                // fragment 的 children 只会是 array children
                // 因为他们要么是通过 compiler 生成的，要么是由数组创建的
                mountChildren(n2.children, container, fragmentEndAnchor, parentComponent, parentSuspense, isSVG, optimized);
            }
            else {
                if (patchFlag > 0 &&
                    patchFlag & 64 /* STABLE_FRAGMENT */ &&
                    dynamicChildren &&
                    // #2715 the previous fragment could've been a BAILed one as a result
                    // of renderSlot() with no valid children
                    n1.dynamicChildren) {
                    // a stable fragment (template root or <template v-for>) doesn't need to
                    // patch children order, but it may contain dynamicChildren.
                    patchBlockChildren(n1.dynamicChildren, dynamicChildren, container, parentComponent, parentSuspense, isSVG);
                    if ( parentComponent && parentComponent.type.__hmrId) {
                        traverseStaticChildren(n1, n2);
                    }
                    else if (
                    // #2080 if the stable fragment has a key, it's a <template v-for> that may
                    //  get moved around. Make sure all root level vnodes inherit el.
                    // #2134 or if it's a component root, it may also get moved around
                    // as the component is being moved.
                    n2.key != null ||
                        (parentComponent && n2 === parentComponent.subTree)) {
                        traverseStaticChildren(n1, n2, true /* shallow */);
                    }
                }
                else {
                    // keyed / unkeyed, or manual fragments.
                    // for keyed & unkeyed, since they are compiler generated from v-for,
                    // each child is guaranteed to be a block so the fragment will never
                    // have dynamicChildren.
                    patchChildren(n1, n2, container, fragmentEndAnchor, parentComponent, parentSuspense, isSVG, optimized);
                }
            }
        };
        // 17. processComponent
        const processComponent = (n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized) => {
            if (n1 == null) {
                // mount
                if (n2.shapeFlag & 512 /* COMPONENT_KEPT_ALIVE */) {
                    parentComponent.ctx.activate(n2, container, anchor, isSVG, optimized);
                }
                else {
                    mountComponent(n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                }
            }
            else {
                updateComponent(n1, n2, optimized);
            }
        };
        // 18. mountComponent
        const mountComponent = (initialVNode, container, anchor, parentComponent, parentSuspense, isSVG, optimized) => {
            const instance = (initialVNode.component = createComponentInstance(initialVNode, parentComponent, parentSuspense));
            if (isKeepAlive(initialVNode)) {
                instance.ctx.renderer = internals;
            }
            setupComponent(instance);
            // setup() 是个异步函数，返回了 promise ，在 setupComponent
            // 中会将 setup 执行结果赋值给 instance.asyncDep，即 SUSPENSE 处理
            if ( instance.asyncDep) {
                // 将 setupRenderEffect 注册到 parent deps 这里的 deps 执行由一定的规则
                // 如果 parent suspense 没有结束，child deps 不会立即执行，而是将它们
                // 合并到 parent suspense deps 中等待 parent 状态完成了才会执行，对于
                // parent deps 也遵循这个规则，直到没有未完成的 parent suspense 为止
                parentSuspense && parentSuspense.registerDep(instance, setupRenderEffect);
                // 这里等于是说先用一个注释节点占位，等异步完成之后替换
                if (!initialVNode.el) {
                    const placeholder = (instance.subTree = createVNode(Comment));
                    processCommentNode(null, placeholder, container, anchor);
                }
                return;
            }
            setupRenderEffect(instance, initialVNode, container, anchor, parentSuspense, isSVG, optimized);
        };
        // 19. updateComponent
        const updateComponent = (n1, n2, optimized) => {
            const instance = (n2.component = n1.component);
            if (shouldUpdateComponent(n1, n2, optimized)) {
                if (
                    instance.asyncDep && // async setup
                    instance.asyncResolved) {
                    // async & still pending - just update props and slots
                    // since the component's reactive effect for render isn't set-up yet
                    updateComponentPreRender(instance, n2, optimized);
                    return;
                }
                else {
                    // 正常更新
                    instance.next = n2;
                    // 考虑到 child 组件可能正在队列中排队，移除它避免
                    // 在同一个 flush tick 重复更新同一个子组件
                    // 当下一次更新来到时，之前的一次更新取消？
                    invalidateJob(instance.update);
                    // instance.update 是在 setupRenderEffect 中
                    // 定义的一个 reactive effect runner
                    // 主动触发更新
                    instance.update();
                }
                return;
            }
            else {
                // 没有更新，仅用 old child 的属性覆盖 new child
                n2.component = n1.component;
                n2.el = n1.el;
                instance.vnode = n2;
            }
        };
        // 20. setupRenderEffect
        const setupRenderEffect = (instance, initialVNode, container, anchor, parentSuspense, isSVG, optimized) => {
            instance.update = effect(function componentEffect() {
                // 监听更新
                if (!instance.isMounted) {
                    // 还没加载完成，可能是第一次 mount 操作
                    let vnodeHook;
                    const { el, props } = initialVNode;
                    const { bm, m, parent } = instance;
                    // 1. beforeMount hook
                    if (bm) {
                        invokeArrayFns(bm);
                    }
                    // 2. onVnodeBeforeMount
                    if ((vnodeHook = props && props.onVnodeBeforeMount)) {
                        invokeVNodeHook(vnodeHook, parent, initialVNode);
                    }
                    // 3. render
                    // TODO start, end measure
                    const subTree = (instance.subTree = renderComponentRoot(instance));
                    if (el && hydrateNode) ;
                    else {
                        patch(null, subTree, container, anchor, instance, parentSuspense, isSVG);
                        initialVNode.el = subTree.el;
                    }
                    // mounted hook
                    if (m) {
                        queuePostRenderEffect(m, parentSuspense);
                    }
                    // onVnodemounted
                    if ((vnodeHook = props && props.onVnodeMounted)) {
                        const scopedInitialVNode = initialVNode;
                        queuePostRenderEffect(() => {
                            invokeVNodeHook(vnodeHook, parent, scopedInitialVNode);
                        }, parentSuspense);
                    }
                    // activated hook for keep-alive roots.
                    // #1742 activated hook must be accessed after first render
                    // since the hook may be injected by a child keep-alive
                    const { a } = instance;
                    if (a &&
                        initialVNode.shapeFlag & 256 /* COMPONENT_SHOULD_KEEP_ALIVE */) {
                        queuePostRenderEffect(a, parentSuspense);
                    }
                    instance.isMounted = true;
                    // #2458: deference mount-only object parameters to prevent memleaks
                    // 释放资源
                    initialVNode = container = anchor = null;
                }
                else {
                    // updateComponent
                    // 当组件自身的状态或父组件调用 processComponent 时触发
                    let { next, bu, u, parent, vnode } = instance;
                    let originNext = next;
                    let vnodeHook;
                    if (next) {
                        next.el = vnode.el;
                        updateComponentPreRender(instance, next, optimized);
                    }
                    else {
                        next = vnode;
                    }
                    // beforeUpdate hook
                    if (bu) {
                        invokeArrayFns(bu);
                    }
                    // onVnodeBeforeUpdate
                    if ((vnodeHook = next.props && next.props.onVnodeBeforeUpdate)) {
                        invokeVNodeHook(vnodeHook, parent, next, vnode);
                    }
                    //render
                    const nextTree = renderComponentRoot(instance);
                    const prevTree = instance.subTree;
                    instance.subTree = nextTree;
                    patch(prevTree, nextTree, 
                    // 如果在 teleport 中，parent 可能会发生改变
                    hostParentNode(prevTree.el), 
                    // anchor may have changed if it's in a fragment
                    getNextHostNode(prevTree), instance, parentSuspense, isSVG);
                    next.el = nextTree.el;
                    if (originNext === null) {
                        // self-triggered update. In case of HOC, update parent component
                        // vnode el. HOC is indicated by parent instance's subTree pointing
                        // to child component's vnode
                        updateHOCHostEl(instance, nextTree.el);
                    }
                    // updated hook
                    if (u) {
                        queuePostRenderEffect(u, parentSuspense);
                    }
                    // onVnodeUpdated
                    if ((vnodeHook = next.props && next.props.onVnodeUpdated)) {
                        queuePostRenderEffect(() => {
                            invokeVNodeHook(vnodeHook, parent, next, vnode);
                        }, parentSuspense);
                    }
                }
            },  // 提供 onTrack/onTrigger 选项执行 rtc&rtg 两个周期函数
                    createDevEffectOptions(instance)
                );
        };
        // 21. updateComponentPreRender
        const updateComponentPreRender = (instance, nextVNode, optimized) => {
            nextVNode.component = instance;
            const prevProps = instance.vnode.props;
            instance.vnode = nextVNode;
            instance.next = null;
            // update props
            updateProps(instance, nextVNode.props, prevProps, optimized);
            updateSlots(instance, nextVNode.children);
            // props update may have triggered pre-flush watchers.
            // flush them before the render update.
            flushPreFlushCbs(undefined, instance.update);
        };
        // 22. patchChildren
        const patchChildren = (n1, n2, container, anchor, parentComponent, parentSuspense, isSVG, optimized = false) => {
            const c1 = n1 && n1.children;
            const prevShapeFlag = n1 ? n1.shapeFlag : 0;
            const c2 = n2.children;
            const { patchFlag, shapeFlag } = n2;
            // fast path
            if (patchFlag > 0) {
                if (patchFlag & 128 /* KEYED_FRAGMENT */) {
                    // this could be either fully-keyed or mixed (some keyed some not)
                    // presence of patchFlag means children are guaranteed to be arrays
                    patchKeyedChildren(c1, c2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    return;
                }
                else if (patchFlag & 256 /* UNKEYED_FRAGMENT */) {
                    patchUnkeyedChildren(c1, c2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    return;
                }
            }
            // children 有三种可能： text, array, 或没有 children
            if (shapeFlag & 8 /* TEXT_CHILDREN */) {
                // text children fast path
                if (prevShapeFlag & 16 /* ARRAY_CHILDREN */) {
                    unmountChildren(c1, parentComponent, parentSuspense);
                }
                if (c2 !== c1) {
                    hostSetElementText(container, c2);
                }
            }
            else {
                if (prevShapeFlag & 16 /* ARRAY_CHILDREN */) {
                    if (shapeFlag & 16 /* ARRAY_CHILDREN */) {
                        patchKeyedChildren(c1, c2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    }
                    else {
                        // new null, old array 直接卸载 old
                        unmountChildren(c1, parentComponent, parentSuspense, true /* doRemove */);
                    }
                }
                else {
                    // prev children was text or null
                    // new children is array or null
                    // 老的 children 是 text，新的又是数组情况
                    if (prevShapeFlag & 8 /* TEXT_CHILDREN */) {
                        // 先清空？
                        hostSetElementText(container, '');
                    }
                    // 然后直接重新加载新的 array children -> c2
                    // old children 是 array
                    if (shapeFlag & 16 /* ARRAY_CHILDREN */) {
                        mountChildren(c2, container, anchor, parentComponent, parentSuspense, isSVG, optimized);
                    }
                }
            }
        };
        // 23. patchUnkeyedChildren
        const patchUnkeyedChildren = (c1, c2, container, anchor, parentComponent, parentSuspense, isSVG, optimized) => {
            c1 = c1 || EMPTY_ARR;
            c2 = c2 || EMPTY_ARR;
            const oldLength = c1.length;
            const newLength = c2.length;
            const commonLength = Math.min(oldLength, newLength);
            let i;
            for (i = 0; i < commonLength; i++) {
                const nextChild = (c2[i] = optimized
                    ? cloneIfMounted(c2[i])
                    : normalizeVNode(c2[i]));
                patch(c1[i], nextChild, container, null, parentComponent, parentSuspense, isSVG, optimized);
            }
            if (oldLength > newLength) {
                // remove old
                unmountChildren(c1, parentComponent, parentSuspense, true, false, commonLength);
            }
            else {
                // mount new
                mountChildren(c2, container, anchor, parentComponent, parentSuspense, isSVG, optimized, commonLength);
            }
        };
        // 24. 可能所有都是 keyed 也可能部分
        const patchKeyedChildren = (c1, c2, container, parentAnchor, parentComponent, parentSuspense, isSVG, optimized) => {
            let i = 0;
            const l2 = c2.length;
            let e1 = c1.length - 1; // 上一个结束索引
            let e2 = l2 - 1; // 下一个结束索引
            // 1. sync from start
            // (a b) c
            // (a b) d e
            // 这里结束之后 i 就会定位到第一个不同类型的位置，即 2
            while (i <= e1 && i <= e2) {
                const n1 = c1[i];
                const n2 = (c2[i] = optimized // 静态节点
                    ? cloneIfMounted(c2[i])
                    : normalizeVNode(c2[i]));
                // type & key 相同
                if (isSameVNodeType(n1, n2)) {
                    patch(n1, n2, container, null, parentComponent, parentSuspense, isSVG, optimized);
                }
                else {
                    break;
                }
                i++;
            }
            // 2. sync from end
            // a (b c)
            // d e (b c)
            // 这里结束之后，后面相同的节点就被处理掉了，此时 e1 = 0, e2 = 1
            while (i <= e1 && i <= e2) {
                const n1 = c1[e1];
                const n2 = (c2[e2] = optimized
                    ? cloneIfMounted(c2[e2])
                    : normalizeVNode(c2[e2]));
                if (isSameVNodeType(n1, n2)) {
                    patch(n1, n2, container, null, parentComponent, parentSuspense, isSVG, optimized);
                }
                else {
                    break;
                }
                e1--;
                e2--;
            }
            // 3. common sequence + mount
            // (a b)
            // (a b) c
            // i = 2, e1 = 1, e2 = 2
            // (a b)
            // c (a b)
            // i = 0, e1 = -1, e2 = 0
            if (i > e1) {
                if (i <= e2) {
                    const nextPos = e2 + 1;
                    const anchor = nextPos < l2 ? c2[nextPos].el : parentAnchor;
                    while (i <= e2) {
                        patch(null, (c2[i] = optimized
                            ? cloneIfMounted(c2[i])
                            : normalizeVNode(c2[i])), container, anchor, parentComponent, parentSuspense, isSVG);
                        i++;
                    }
                }
            }
            // 4. common sequence + unmount
            // (a b) c
            // (a b)
            // i = 2, e1 = 2, e2 = 1
            // a (b c)
            // (b c)
            // i = 0, e1 = 0, e2 = -1
            else if (i > e2) {
                while (i <= e1) {
                    unmount(c1[i], parentComponent, parentSuspense, true /* doRemove */);
                    i++;
                }
            }
            // 5. unknown sequence, 未知序列
            // [i ... e1 + 1]: a b [c d e] f g
            // [i ... e2 + 1]: a b [e d c h] f g
            // i = 2, e1 = 4, e2 = 5
            else {
                const s1 = i; // prev starting index
                const s2 = i; // next starting index
                // 5.1 build key:index map for newChildren
                // 给新的 children 创建新的 key
                const keyToNewIndexMap = new Map();
                // 从 new nodes 开始，可处理删除和新增操作
                // 这里目的是保存 new nodes 中 child 的 key 和索引的对应关系
                for (i = s2; i <= e2; i++) {
                    const nextChild = (c2[i] = optimized
                        ? cloneIfMounted(c2[i])
                        : normalizeVNode(c2[i]));
                    if (nextChild.key != null) {
                        // 新的 child 有自己的 Key
                        // TODO warn 重复 key
                        keyToNewIndexMap.set(nextChild.key, i);
                    }
                }
                // 5.2 遍历 old children，执行 patch 或 remove 操作
                let j;
                let patched = 0;
                // 需要被 patch 的 old child 数
                // 如：
                // old: (a b) c
                // new: (a b) d e
                // 那么需要处理的数为 2(d,e 位置)
                const toBePatched = e2 - s2 + 1;
                let moved = false;
                // 用来跟踪有多少节点被移除了
                let maxNewIndexSoFar = 0;
                // works as Map<newIndex, oldIndex>
                // Note that oldIndex is offset by +1
                // and oldIndex = 0 is a special value indicating the new node has
                // no corresponding old node.
                // used for determining longest stable subsequence
                const newIndexToOldIndexMap = new Array(toBePatched);
                for (i = 0; i < toBePatched; i++) {
                    // 初始化
                    newIndexToOldIndexMap[i] = 0;
                }
                // 遍历 old children 剩余的不同节点
                for (i = s1; i <= e1; i++) {
                    const prevChild = c1[i];
                    if (patched >= toBePatched) {
                        // 移除 old child
                        unmount(prevChild, parentComponent, parentSuspense, true);
                        continue;
                    }
                    let newIndex;
                    // old child 也有自己的 key
                    if (prevChild.key != null) {
                        // 用 old child 的 key 从 new children key map 里面
                        // 找到相同 key 的 new child，所以替换不是按照顺序来替换的
                        // (a b) c -> (a b) d e 很有可能 c 会被 e 给替换了
                        newIndex = keyToNewIndexMap.get(prevChild.key);
                    }
                    else {
                        // 没有 key 的 old child，尝试将一个同类型的无 key 的 new child
                        // 放进来，遍历 new children
                        for (j = s2; j <= e2; j++) {
                            // 从 d 位置开始搜索，同类型无 key 的 new child
                            if (newIndexToOldIndexMap[j - s2] === 0 &&
                                isSameVNodeType(prevChild, c2[j])) {
                                newIndex = j;
                                break;
                            }
                        }
                    }
                    // 这个 newIndex 是可以用来替换当前的 old child 的那个节点
                    if (newIndex === undefined) {
                        // 没有找到可替换的节点，直接删除 old child
                        unmount(prevChild, parentComponent, parentSuspense, true);
                    }
                    else {
                        // 找到可用来替换的，将这个标识位填充为当前 old child index + 1
                        // 此处的 i 即 for old children 时的索引，说明这个 new child
                        // 已经用来替换过了，下次循环不能再用了
                        newIndexToOldIndexMap[newIndex - s2] = i + 1;
                        if (newIndex >= maxNewIndexSoFar) {
                            maxNewIndexSoFar = newIndex;
                        }
                        else {
                            moved = true;
                        }
                        patch(prevChild, c2[newIndex], container, null, parentComponent, parentSuspense, isSVG, optimized);
                        patched++;
                    }
                }
                // 5.3 move and mount
                // generate longest stable subsequence only when nodes have moved
                // 最长有序递增序列，从一串数字中找到最长的有序数列，结果序列中的数字顺序
                // 必须符合原序列中的先后顺序
                // 首先 newIndexToOldIndexMap 这个是用来保存 new children 中曾经
                // 用来替换 old child 的那个 new child 的索引，上面在替换的时候
                // 会赋值给 i + 1 给当前 newIndex - s2 索引位置值
                // 如： (a b) c 和 (a b) d e 假如 e 符合替换 c 的条件
                // 那么 newIndexToOldIndexMap[3 - 2] = 3 + 1
                const increasingNewIndexSequence = moved
                    ? getSequence(newIndexToOldIndexMap)
                    : EMPTY_ARR;
                j = increasingNewIndexSequence.length - 1;
                for (i = toBePatched - 1; i >= 0; i--) {
                    const nextIndex = s2 + i;
                    const nextChild = c2[nextIndex];
                    const anchor = nextIndex + 1 < l2 ? c2[nextIndex + 1].el : parentAnchor;
                    if (newIndexToOldIndexMap[i] === 0) {
                        // mount new，这个 old children 位置没有 new child 替换
                        // 所以执行 mount new child
                        patch(null, nextChild, container, anchor, parentComponent, parentSuspense, isSVG);
                    }
                    else if (moved) {
                        // move if:
                        // There is no stable subsequence (e.g. a reverse)
                        // OR current node is not among the stable sequence
                        if (j < 0 || i !== increasingNewIndexSequence[j]) {
                            move(nextChild, container, anchor, 2 /* REORDER */);
                        }
                        else {
                            j--;
                        }
                    }
                }
            }
        };
        // 25. move， 交换操作
        const move = (vnode, container, anchor, moveType, parentSuspense = null) => {
            const { el, type, transition, children, shapeFlag } = vnode;
            if (shapeFlag & 6 /* COMPONENT */) {
                move(vnode.component.subTree, container, anchor, moveType);
                return;
            }
            // SUSPENSE
            if ( shapeFlag & 128 /* SUSPENSE */) {
                vnode.suspense.move(container, anchor, moveType);
                return;
            }
            if (shapeFlag & 64 /* TELEPORT */) {
                type.move(vnode, container, anchor, internals);
                return;
            }
            if (type === Fragment) {
                hostInsert(el, container, anchor);
                for (let i = 0; i < children.length; i++) {
                    move(children[i], container, anchor, moveType);
                }
                hostInsert(vnode.anchor, container, anchor);
                return;
            }
            if (type === Static) {
                moveStaticNode(vnode, container, anchor);
            }
            // single nodes
            const needTransition = moveType !== 2 /* REORDER */ &&
                shapeFlag & 1 /* ELEMENT */ &&
                transition;
            if (needTransition) {
                if (moveType === 0 /* ENTER */) {
                    transition.beforeEnter(el);
                    hostInsert(el, container, anchor);
                    queuePostRenderEffect(() => transition.enter(el), parentSuspense);
                }
                else {
                    const { leave, delayLeave, afterLeave } = transition;
                    const remove = () => hostInsert(el, container, anchor);
                    const performLeave = () => {
                        leave(el, () => {
                            remove();
                            afterLeave && afterLeave();
                        });
                    };
                    if (delayLeave) {
                        delayLeave(el, remove, performLeave);
                    }
                    else {
                        performLeave();
                    }
                }
            }
            else {
                // 目前只实现普通元素的逻辑
                hostInsert(el, container, anchor);
            }
        };
        // 26. unmount
        const unmount = (vnode, parentComponent, parentSuspense, doRemove = false, optimized = false) => {
            const { type, props, ref, children, dynamicChildren, shapeFlag, patchFlag, dirs } = vnode;
            // unset ref
            if (ref != null) {
                setRef(ref, null, parentSuspense, null);
            }
            // keep-alive
            if (shapeFlag & 256 /* COMPONENT_SHOULD_KEEP_ALIVE */) {
                parentComponent.ctx.deactivate(vnode);
                return;
            }
            const shouldInvokeDirs = shapeFlag & 1 /* ELEMENT */ && dirs;
            let vnodeHook;
            // 执行 onVnodeBeforeUnmount hook
            if ((vnodeHook = props && props.onVnodeBeforeUnmount)) {
                invokeVNodeHook(vnodeHook, parentComponent, vnode);
            }
            if (shapeFlag & 6 /* COMPONENT */) {
                // unmount component
                unmountComponent(vnode.component, parentSuspense, doRemove);
            }
            else {
                //  SUSPENSE
                if ( shapeFlag & 128 /* SUSPENSE */) {
                    vnode.suspense.unmount(parentSuspense, doRemove);
                    return;
                }
                // should invoke dirs
                if (shouldInvokeDirs) {
                    invokeDirectiveHook(vnode, null, parentComponent, 'beforeUnmount');
                }
                if (dynamicChildren &&
                    // #1153: fast path should not be taken for non-stable (v-for) fragments
                    (type !== Fragment ||
                        (patchFlag > 0 &&
                            patchFlag & 64 /* STABLE_FRAGMENT */)) /* dyanmic children */) {
                    // fast path for block nodes: only need to unmount dynamic children.
                    unmountChildren(dynamicChildren, parentComponent, parentSuspense, false, true);
                }
                else if ((type === Fragment &&
                    (patchFlag & 128 /* KEYED_FRAGMENT */ ||
                        patchFlag & 256 /* UNKEYED_FRAGMENT */)) ||
                    (!optimized && shapeFlag & 16 /* ARRAY_CHILDREN */)) {
                    unmountChildren(children, parentComponent, parentSuspense);
                }
                // TELEPORT
                // an unmounted teleport should always remove its children if not disabled
                if (shapeFlag & 64 /* TELEPORT */ &&
                    (doRemove || !isTeleportDisabled(vnode.props))) {
                    vnode.type.remove(vnode, internals);
                }
                if (doRemove) {
                    remove(vnode);
                }
            }
            // 执行 onVnodeUnmounted hook
            if ((vnodeHook = props && props.onVnodeUnmounted) || shouldInvokeDirs) {
                queuePostRenderEffect(() => {
                    vnodeHook && invokeVNodeHook(vnodeHook, parentComponent, vnode);
                    shouldInvokeDirs &&
                        invokeDirectiveHook(vnode, null, parentComponent, 'unmounted');
                }, parentSuspense);
            }
        };
        // 27. remove
        const remove = vnode => {
            const { type, el, anchor, transition } = vnode;
            if (type === Fragment) {
                removeFragment(el, anchor);
                return;
            }
            if (type === Static) {
                removeStaticNode(vnode);
                return;
            }
            const performRemove = () => {
                // 将 el 从它的 parenNode.children 中删除
                hostRemove(el);
                if (transition && !transition.persisted && transition.afterLeave) {
                    transition.afterLeave();
                }
            };
            if (vnode.shapeFlag & 1 /* ELEMENT */ &&
                transition &&
                !transition.persisted) {
                const { leave, delayLeave } = transition;
                const performLeave = () => leave(el, performRemove);
                if (delayLeave) {
                    delayLeave(vnode.el, performRemove, performLeave);
                }
                else {
                    performLeave();
                }
            }
            else {
                performRemove();
            }
        };
        const removeFragment = (cur, end) => {
            // For fragments, directly remove all contained DOM nodes.
            // (fragment child nodes cannot have transition)
            let next;
            while (cur !== end) {
                next = hostNextSibling(cur);
                hostRemove(cur);
                cur = next;
            }
            hostRemove(end);
        };
        const unmountComponent = (instance, parentSuspense, doRemove) => {
            const { bum, effects, update, subTree, um } = instance;
            // beforeUnmount hook
            if (bum) {
                invokeArrayFns(bum);
            }
            if (effects) {
                for (let i = 0; i < effects.length; i++) {
                    stop(effects[i]);
                }
            }
            // update may be null if a component is unmounted before its async
            // setup has resolved.
            if (update) {
                stop(update);
                unmount(subTree, instance, parentSuspense, doRemove);
            }
            // unmounted hook
            if (um) {
                queuePostRenderEffect(um, parentSuspense);
            }
            queuePostRenderEffect(() => {
                instance.isUnmounted = true;
            }, parentSuspense);
            // A component with async dep inside a pending suspense is unmounted before
            // its async dep resolves. This should remove the dep from the suspense, and
            // cause the suspense to resolve immediately if that was the last dep.
            if (
                parentSuspense &&
                parentSuspense.pendingBranch &&
                !parentSuspense.isUnmounted &&
                instance.asyncDep &&
                !instance.asyncResolved &&
                instance.suspenseId === parentSuspense.pendingId) {
                parentSuspense.deps--;
                if (parentSuspense.deps === 0) {
                    parentSuspense.resolve();
                }
            }
            {
                devtoolsComponentRemoved(instance);
            }
        };
        // 30. unmountChildren
        const unmountChildren = (children, parentComponent, parentSuspense, doRemove = false, optimized = false, start = 0) => {
            for (let i = start; i < children.length; i++) {
                unmount(children[i], parentComponent, parentSuspense, doRemove, optimized);
            }
        };
        // 31. getNextHostNode
        const getNextHostNode = vnode => {
            // COMPONENT
            if (vnode.shapeFlag & 6 /* COMPONENT */) {
                return getNextHostNode(vnode.component.subTree);
            }
            if ( vnode.shapeFlag & 128 /* SUSPENSE */) {
                return vnode.suspense.next();
            }
            return hostNextSibling((vnode.anchor || vnode.el));
        };
        // 32. render
        const render = (vnode, container) => {
            // render(h('div'), root)
            if (vnode == null) {
                if (container._vnode) {
                    unmount(container._vnode, null, null, true);
                }
            }
            else {
                patch(container._vnode || null, vnode, container);
            }
            // 执行所有 post 异步任务
            flushPostFlushCbs();
            container._vnode = vnode;
        };
        // 33. internals object, 函数别名
        const internals = {
            p: patch,
            um: unmount,
            m: move,
            r: remove,
            mt: mountComponent,
            mc: mountChildren,
            pc: patchChildren,
            pbc: patchBlockChildren,
            n: getNextHostNode,
            o: options
        };
        // 34. createHydrationFns
        let hydrate;
        let hydrateNode;
        if (createHydrationFns) {
            [hydrate, hydrateNode] = createHydrationFns(internals);
        }
        // 35. return { render, hydrate, createApp }
        return {
            render,
            hydrate,
            createApp: createAppAPI(render, hydrate)
        };
    }
    function invokeVNodeHook(hook, instance, vnode, prevVNode = null) {
        callWithAsyncErrorHandling(hook, instance, 7 /* VNODE_HOOK */, [
            vnode,
            prevVNode
        ]);
    }
    /**
     * #1156
     * When a component is HMR-enabled, we need to make sure that all static nodes
     * inside a block also inherit the DOM element from the previous tree so that
     * HMR updates (which are full updates) can retrieve the element for patching.
     *
     * #2080
     * Inside keyed `template` fragment static children, if a fragment is moved,
     * the children will always moved so that need inherit el form previous nodes
     * to ensure correct moved position.
     */
    function traverseStaticChildren(n1, n2, shallow = false) {
        const ch1 = n1.children;
        const ch2 = n2.children;
        if (isArray(ch1) && isArray(ch2)) {
            for (let i = 0; i < ch1.length; i++) {
                // this is only called in the optimized path so array children are
                // guaranteed to be vnodes
                const c1 = ch1[i];
                let c2 = ch2[i];
                if (c2.shapeFlag & 1 /* ELEMENT */ && !c2.dynamicChildren) {
                    if (c2.patchFlag <= 0 || c2.patchFlag === 32 /* HYDRATE_EVENTS */) {
                        c2 = ch2[i] = cloneIfMounted(ch2[i]);
                        c2.el = c1.el;
                    }
                    if (!shallow)
                        traverseStaticChildren(c1, c2);
                }
                // also inherit for comment nodes, but not placeholders (e.g. v-if which
                // would have received .el during block patch)
                if ( c2.type === Comment && !c2.el) {
                    c2.el = c1.el;
                }
            }
        }
    }
    // https://en.wikipedia.org/wiki/Longest_increasing_subsequence
    function getSequence(arr) {
        const p = arr.slice();
        const result = [0];
        let i, j, u, v, c;
        const len = arr.length;
        for (i = 0; i < len; i++) {
            const arrI = arr[i];
            if (arrI !== 0) {
                j = result[result.length - 1];
                if (arr[j] < arrI) {
                    p[i] = j;
                    result.push(i);
                    continue;
                }
                u = 0;
                v = result.length - 1;
                while (u < v) {
                    c = ((u + v) / 2) | 0;
                    if (arr[result[c]] < arrI) {
                        u = c + 1;
                    }
                    else {
                        v = c;
                    }
                }
                if (arrI < arr[result[u]]) {
                    if (u > 0) {
                        p[i] = result[u - 1];
                    }
                    result[u] = i;
                }
            }
        }
        u = result.length;
        v = result[u - 1];
        while (u-- > 0) {
            result[u] = v;
            v = p[v];
        }
        return result;
    }
  
    // simple effect
    function watchEffect(effect, options) {
        return doWatch(effect, null, options);
    }
    // initial value for watchers to trigger on undefined initial values
    const INITIAL_WATCHER_VALUE = {};
    // implementation
    function watch(source, cb, options) {
        if ( !isFunction(cb)) {
            warn(`\`watch(fn, options?)\` signature has been moved to a separate API. ` +
                `Use \`watchEffect(fn, options?)\` instead. \`watch\` now only ` +
                `supports \`watch(source, cb, options?) signature.`);
        }
        return doWatch(source, cb, options);
    }
    function doWatch(source, cb, { immediate, deep, flush, onTrack, onTrigger } = EMPTY_OBJ, instance = currentInstance) {
        // 1. cb, immediate, deep 检测
        if ( !cb) {
            if (immediate !== undefined) {
                warn(`watch() "immediate" option is only respected when using the ` +
                    `watch(source, callback, options?) signature.`);
            }
            if (deep !== undefined) {
                warn(`watch() "deep" option is only respected when using the ` +
                    `watch(source, callback, options?) signature.`);
            }
        }
        const warnInvalidSource = (s) => {
            warn(`Invalid watch source: `, s, `A watch source can only be a getter/effect function, a ref, ` +
                `a reactive object, or an array of these types.`);
        };
        // 2. getter 函数，根据不同类型生成对应的 getter
        let getter;
        let forceTrigger = false;
        // 2.1 source is ref
        if (isRef(source)) {
            getter = () => source.value;
            forceTrigger = !!source._shallow;
        }
        // 2.2 source is reactive
        else if (isReactive(source)) {
            getter = () => source;
            deep = true;
        }
        // 2.3 source is array
        else if (isArray(source)) {
            getter = () => source.map(s => {
                if (isRef(s)) {
                    return s.value;
                }
                else if (isReactive(s)) {
                    return traverse(s);
                }
                else if (isFunction(s)) {
                    return callWithErrorHandling(s, instance, 2 /* WATCH_GETTER */);
                }
                else {
                     warnInvalidSource(s);
                }
            });
        }
        // 2.4 source is function
        else if (isFunction(source)) {
            // 如果是函数，直接执行取得函数执行结果
            if (cb) {
                // getter with cb
                getter = () => callWithErrorHandling(source, instance, 2 /* WATCH_GETTER */);
            }
            else {
                // no cb -> simple effect
                getter = () => {
                    if (instance && instance.isUnmounted) {
                        // 组件已经卸载了
                        return;
                    }
                    if (cleanup)
                        cleanup();
                    return callWithErrorHandling(source, instance, 3 /* WATCH_CALLBACK */, [onInvalidate]);
                };
            }
        }
        // 2.5 其他情况
        else {
            getter = NOOP;
             warnInvalidSource(source);
        }
        //
        // 3. cb + deep: true
        if (cb && deep) {
            const baseGetter = getter;
            // a. deep: true
            // b. source is reactive
            getter = () => traverse(baseGetter());
        }
        let cleanup;
        const onInvalidate = (fn) => {
            cleanup = runner.options.onStop = () => {
                callWithErrorHandling(fn, instance, 4 /* WATCH_CLEANUP */);
            };
        };
        let oldValue = isArray(source) ? [] : INITIAL_WATCHER_VALUE;
        const job = () => {
            if (!runner.active) {
                return;
            }
            if (cb) {
                // watch(source, cb)
                const newValue = runner();
                if (deep || forceTrigger || hasChanged(newValue, oldValue)) {
                    // cleanup
                    if (cleanup)
                        cleanup();
                    callWithAsyncErrorHandling(cb, instance, 3 /* WATCH_CALLBACK */, [
                        newValue,
                        // pass undefined as the old value when it's changed for the first time
                        // 第一次的时候 oldValue 为 undefined
                        oldValue === INITIAL_WATCHER_VALUE ? undefined : oldValue,
                        onInvalidate
                    ]);
                    oldValue = newValue;
                }
            }
            else {
                // watchEffect, no cb
                runner();
            }
        };
        //
        // 6. scheduler 设置
        // it is allowed to self-trigger (#1727)
        job.allowRecurse = !!cb;
        let scheduler;
        // 6.1 flush is 'sync'，让依赖同步执行，即当值发生改变之后
        // 立即就会体现出来，因为依赖在赋值之后被立即执行了
        if (flush === 'sync') {
            scheduler = job;
        }
        // 6.2 flush is 'post'
        else if (flush === 'post') {
            scheduler = () => queuePostRenderEffect(job, instance && instance.suspense);
        }
        // 6.3 flush is 'pre'(default)
        else {
            // default: 'pre'
            scheduler = () => {
                if (!instance || instance.isMounted) {
                    queuePreFlushCb(job);
                }
                else {
                    // 带 { pre: true } 选项，第一次调用必须发生在组件 mounted 之前
                    // 从而使他被同步调用，立即执行一次
                    job();
                }
            };
        }
        //
        // 7. get runner
        const runner = effect(getter, {
            lazy: true,
            onTrack,
            onTrigger,
            scheduler
        });
        // 将 effect->runner 加入到 instance.effects 中
        // 以致于在组件 unmount 时他们可以被 stop
        recordInstanceBoundEffect(runner, instance);
        // 8. runner 如何执行？
        if (cb) {
            if (immediate) {
                job();
            }
            else {
                oldValue = runner();
            }
        }
        else if (flush === 'post') {
            queuePostRenderEffect(runner, instance && instance.suspense);
        }
        else {
            runner();
        }
        //
        // 9. return runner->stop, remove runner from instance.effects
        return () => {
            stop(runner);
            if (instance) {
                remove(instance.effects, runner);
            }
        };
    }
    // this.$watch
    function instanceWatch(source, cb, options) {
        const publicThis = this.proxy;
        const getter = isString(source)
            ? () => publicThis[source]
            : source.bind(publicThis);
        return doWatch(getter, cb.bind(publicThis), options, this);
    }
    function traverse(value, seen = new Set()) {
        if (!isObject(value) || seen.has(value)) {
            return value;
        }
        seen.add(value);
        if (isRef(value)) {
            traverse(value.value, seen);
        }
        else if (isArray(value)) {
            for (let i = 0; i < value.length; i++) {
                traverse(value[i], seen);
            }
        }
        else if (isSet(value) || isMap(value)) {
            value.forEach((v) => {
                traverse(v, seen);
            });
        }
        else {
            for (const key in value) {
                traverse(value[key], seen);
            }
        }
        return value;
    }
  
    function provide(key, value) {
        if (!currentInstance) {
            {
                warn(`provide() can only be used inside setup().`);
            }
        }
        else {
            let provides = currentInstance.provides;
            // 默认情况实例会继承它父亲的 provides 对象
            // 但是当它需要 provide 自己的 values 时候，那么使用它
            // 父亲的 provides 作为原型创建一个新的对象出来变成自己的 provides
            // 这样在 `inject` 里面可以简便的从原型链中查找 injections
            // 简单说就是：
            // 1. 需要自己的就创建个新的对象继承自 Parent provides
            // 2. 这样在查找的时候就可以含方便的通过原型链查找 injections
            const parentProvides = currentInstance.parent && currentInstance.parent.provides;
            // 当父组件和当前实例相同的时候，从父组件的 provides 创建一个备份出来
            if (parentProvides === provides) {
                provides = currentInstance.provides = Object.create(parentProvides);
            }
            // TS doesn't allow symbol as index type
            provides[key] = value;
        }
    }
    function inject(key, defaultValue, treatDefaultAsFactory = false) {
        // currentRenderingInstance 兼容函数式组件
        const instance = currentInstance || currentRenderingInstance;
        if (instance) {
            // #2400
            // to support `app.use` plugins,
            // fallback to appContext's `provides` if the intance is at root
            const provides = instance.parent == null // root
                ? instance.vnode.appContext && instance.vnode.appContext.provides
                : instance.parent.provides;
            if (provides && key in provides) {
                // TS doesn't allow symbol as index type
                return provides[key];
            }
            else if (arguments.length > 1) {
                return treatDefaultAsFactory && isFunction(defaultValue)
                    ? defaultValue()
                    : defaultValue;
            }
            else {
                warn(`injection "${String(key)}" not found.`);
            }
        }
        else {
            warn(`inject() can only be used inside setup() or functional components.`);
        }
    }
  
    function createDuplicateChecker() {
        const cache = Object.create(null);
        return (type, key) => {
            if (cache[key]) {
                warn(`${type} property "${key}" is already defined in ${cache[key]}.`);
            }
            else {
                cache[key] = type;
            }
        };
    }
    let isInBeforeCreate = false;
    function applyOptions(instance, options, deferredData = [], deferredWatch = [], deferredProvide = [], asMixin = false) {
        const { 
        // composition
        mixins, extends: extendsOptions, 
        // state
        data: dataOptions, computed: computedOptions, methods, watch: watchOptions, provide: provideOptions, inject: injectOptions, 
        // assets
        components, directives, 
        // lifecycle
        beforeMount, mounted, beforeUpdate, updated, activated, deactivated, beforeDestroy, beforeUnmount, destroyed, unmounted, render, renderTracked, renderTriggered, errorCaptured, 
        // public API
        expose } = options;
        const publicThis = instance.proxy;
        const ctx = instance.ctx;
        const globalMixins = instance.appContext.mixins;
        if (asMixin && render && instance.render === NOOP) {
            instance.render = render;
        }
        // applyOptions is called non-as-mixin once per instance
        if (!asMixin) {
            isInBeforeCreate = true;
            callSyncHook('beforeCreate', "bc" /* BEFORE_CREATE */, options, instance, globalMixins);
            isInBeforeCreate = false;
            // global mixins are applied first
            applyMixins(instance, globalMixins, deferredData, deferredWatch, deferredProvide);
        }
        // extending a base component...
        if (extendsOptions) {
            applyOptions(instance, extendsOptions, deferredData, deferredWatch, deferredProvide, true);
        }
        // local mixins
        if (mixins) {
            applyMixins(instance, mixins, deferredData, deferredWatch, deferredProvide);
        }
        const checkDuplicateProperties =  createDuplicateChecker() ;
        {
            const [propsOptions] = instance.propsOptions;
            if (propsOptions) {
                for (const key in propsOptions) {
                    checkDuplicateProperties("Props" /* PROPS */, key);
                }
            }
        }
        // options initialization order (to be consistent with Vue 2):
        // - props (already done outside of this function)
        // - inject
        // - methods
        // - data (deferred since it relies on `this` access)
        // - computed
        // - watch (deferred since it relies on `this` access)
        if (injectOptions) {
            if (isArray(injectOptions)) {
                for (let i = 0; i < injectOptions.length; i++) {
                    const key = injectOptions[i];
                    ctx[key] = inject(key);
                    {
                        checkDuplicateProperties("Inject" /* INJECT */, key);
                    }
                }
            }
            else {
                for (const key in injectOptions) {
                    const opt = injectOptions[key];
                    if (isObject(opt)) {
                        ctx[key] = inject(opt.from || key, opt.default, true /* treat default function as factory */);
                    }
                    else {
                        ctx[key] = inject(opt);
                    }
                    {
                        checkDuplicateProperties("Inject" /* INJECT */, key);
                    }
                }
            }
        }
        if (methods) {
            for (const key in methods) {
                const methodHandler = methods[key];
                if (isFunction(methodHandler)) {
                    ctx[key] = methodHandler.bind(publicThis);
                    {
                        checkDuplicateProperties("Methods" /* METHODS */, key);
                    }
                }
                else {
                    warn(`Method "${key}" has type "${typeof methodHandler}" in the component definition. ` +
                        `Did you reference the function correctly?`);
                }
            }
        }
        if (!asMixin) {
            if (deferredData.length) {
                deferredData.forEach(dataFn => resolveData(instance, dataFn, publicThis));
            }
            if (dataOptions) {
                // @ts-ignore dataOptions is not fully type safe
                resolveData(instance, dataOptions, publicThis);
            }
            {
                const rawData = toRaw(instance.data);
                for (const key in rawData) {
                    checkDuplicateProperties("Data" /* DATA */, key);
                    // expose data on ctx during dev
                    if (key[0] !== '$' && key[0] !== '_') {
                        Object.defineProperty(ctx, key, {
                            configurable: true,
                            enumerable: true,
                            get: () => rawData[key],
                            set: NOOP
                        });
                    }
                }
            }
        }
        else if (dataOptions) {
            deferredData.push(dataOptions);
        }
        if (computedOptions) {
            for (const key in computedOptions) {
                const opt = computedOptions[key];
                const get = isFunction(opt)
                    ? opt.bind(publicThis, publicThis)
                    : isFunction(opt.get)
                        ? opt.get.bind(publicThis, publicThis)
                        : NOOP;
                if ( get === NOOP) {
                    warn(`Computed property "${key}" has no getter.`);
                }
                const set = !isFunction(opt) && isFunction(opt.set)
                    ? opt.set.bind(publicThis)
                    :  () => {
                            warn(`Write operation failed: computed property "${key}" is readonly.`);
                        }
                        ;
                const c = computed$1({
                    get,
                    set
                });
                Object.defineProperty(ctx, key, {
                    enumerable: true,
                    configurable: true,
                    get: () => c.value,
                    set: v => (c.value = v)
                });
                {
                    checkDuplicateProperties("Computed" /* COMPUTED */, key);
                }
            }
        }
        if (watchOptions) {
            deferredWatch.push(watchOptions);
        }
        if (!asMixin && deferredWatch.length) {
            deferredWatch.forEach(watchOptions => {
                for (const key in watchOptions) {
                    createWatcher(watchOptions[key], ctx, publicThis, key);
                }
            });
        }
        if (provideOptions) {
            deferredProvide.push(provideOptions);
        }
        if (!asMixin && deferredProvide.length) {
            deferredProvide.forEach(provideOptions => {
                const provides = isFunction(provideOptions)
                    ? provideOptions.call(publicThis)
                    : provideOptions;
                Reflect.ownKeys(provides).forEach(key => {
                    provide(key, provides[key]);
                });
            });
        }
        // asset options.
        // To reduce memory usage, only components with mixins or extends will have
        // resolved asset registry attached to instance.
        if (asMixin) {
            if (components) {
                extend(instance.components ||
                    (instance.components = extend({}, instance.type.components)), components);
            }
            if (directives) {
                extend(instance.directives ||
                    (instance.directives = extend({}, instance.type.directives)), directives);
            }
        }
        // lifecycle options
        if (!asMixin) {
            callSyncHook('created', "c" /* CREATED */, options, instance, globalMixins);
        }
        if (beforeMount) {
            onBeforeMount(beforeMount.bind(publicThis));
        }
        if (mounted) {
            onMounted(mounted.bind(publicThis));
        }
        if (beforeUpdate) {
            onBeforeUpdate(beforeUpdate.bind(publicThis));
        }
        if (updated) {
            onUpdated(updated.bind(publicThis));
        }
        if (activated) {
            onActivated(activated.bind(publicThis));
        }
        if (deactivated) {
            onDeactivated(deactivated.bind(publicThis));
        }
        if (errorCaptured) {
            onErrorCaptured(errorCaptured.bind(publicThis));
        }
        if (renderTracked) {
            onRenderTracked(renderTracked.bind(publicThis));
        }
        if (renderTriggered) {
            onRenderTriggered(renderTriggered.bind(publicThis));
        }
        if ( beforeDestroy) {
            warn(`\`beforeDestroy\` has been renamed to \`beforeUnmount\`.`);
        }
        if (beforeUnmount) {
            onBeforeUnmount(beforeUnmount.bind(publicThis));
        }
        if ( destroyed) {
            warn(`\`destroyed\` has been renamed to \`unmounted\`.`);
        }
        if (unmounted) {
            onUnmounted(unmounted.bind(publicThis));
        }
        if (isArray(expose)) {
            if (!asMixin) {
                if (expose.length) {
                    const exposed = instance.exposed || (instance.exposed = proxyRefs({}));
                    expose.forEach(key => {
                        exposed[key] = toRef(publicThis, key);
                    });
                }
                else if (!instance.exposed) {
                    instance.exposed = EMPTY_OBJ;
                }
            }
            else {
                warn(`The \`expose\` option is ignored when used in mixins.`);
            }
        }
    }
    function callSyncHook(name, type, options, instance, globalMixins) {
        callHookFromMixins(name, type, globalMixins, instance);
        const { extends: base, mixins } = options;
        if (base) {
            callHookFromExtends(name, type, base, instance);
        }
        if (mixins) {
            callHookFromMixins(name, type, mixins, instance);
        }
        const selfHook = options[name];
        if (selfHook) {
            callWithAsyncErrorHandling(selfHook.bind(instance.proxy), instance, type);
        }
    }
    function callHookFromExtends(name, type, base, instance) {
        if (base.extends) {
            callHookFromExtends(name, type, base.extends, instance);
        }
        const baseHook = base[name];
        if (baseHook) {
            callWithAsyncErrorHandling(baseHook.bind(instance.proxy), instance, type);
        }
    }
    function callHookFromMixins(name, type, mixins, instance) {
        for (let i = 0; i < mixins.length; i++) {
            const chainedMixins = mixins[i].mixins;
            if (chainedMixins) {
                callHookFromMixins(name, type, chainedMixins, instance);
            }
            const fn = mixins[i][name];
            if (fn) {
                callWithAsyncErrorHandling(fn.bind(instance.proxy), instance, type);
            }
        }
    }
    function applyMixins(instance, mixins, deferredData, deferredWatch, deferredProvide) {
        for (let i = 0; i < mixins.length; i++) {
            applyOptions(instance, mixins[i], deferredData, deferredWatch, deferredProvide, true);
        }
    }
    function resolveData(instance, dataFn, publicThis) {
        if ( !isFunction(dataFn)) {
            warn(`The data option must be a function. ` +
                `Plain object usage is no longer supported.`);
        }
        const data = dataFn.call(publicThis, publicThis);
        if ( isPromise(data)) {
            warn(`data() returned a Promise - note data() cannot be async; If you ` +
                `intend to perform data fetching before component renders, use ` +
                `async setup() + <Suspense>.`);
        }
        if (!isObject(data)) {
             warn(`data() should return an object.`);
        }
        else if (instance.data === EMPTY_OBJ) {
            instance.data = reactive(data);
        }
        else {
            // existing data: this is a mixin or extends.
            extend(instance.data, data);
        }
    }
    function createWatcher(raw, ctx, publicThis, key) {
        const getter = key.includes('.')
            ? createPathGetter(publicThis, key)
            : () => publicThis[key];
        if (isString(raw)) {
            const handler = ctx[raw];
            if (isFunction(handler)) {
                watch(getter, handler);
            }
            else {
                warn(`Invalid watch handler specified by key "${raw}"`, handler);
            }
        }
        else if (isFunction(raw)) {
            watch(getter, raw.bind(publicThis));
        }
        else if (isObject(raw)) {
            if (isArray(raw)) {
                raw.forEach(r => createWatcher(r, ctx, publicThis, key));
            }
            else {
                const handler = isFunction(raw.handler)
                    ? raw.handler.bind(publicThis)
                    : ctx[raw.handler];
                if (isFunction(handler)) {
                    watch(getter, handler, raw);
                }
                else {
                    warn(`Invalid watch handler specified by key "${raw.handler}"`, handler);
                }
            }
        }
        else {
            warn(`Invalid watch option: "${key}"`, raw);
        }
    }
    function createPathGetter(ctx, path) {
        const segments = path.split('.');
        return () => {
            let cur = ctx;
            for (let i = 0; i < segments.length && cur; i++) {
                cur = cur[segments[i]];
            }
            return cur;
        };
    }
    function resolveMergedOptions(instance) {
        const raw = instance.type;
        const { __merged, mixins, extends: extendsOptions } = raw;
        if (__merged)
            return __merged;
        const globalMixins = instance.appContext.mixins;
        if (!globalMixins.length && !mixins && !extendsOptions)
            return raw;
        const options = {};
        globalMixins.forEach(m => mergeOptions(options, m, instance));
        mergeOptions(options, raw, instance);
        return (raw.__merged = options);
    }
    function mergeOptions(to, from, instance) {
        const strats = instance.appContext.config.optionMergeStrategies;
        const { mixins, extends: extendsOptions } = from;
        extendsOptions && mergeOptions(to, extendsOptions, instance);
        mixins &&
            mixins.forEach((m) => mergeOptions(to, m, instance));
        for (const key in from) {
            if (strats && hasOwn(strats, key)) {
                to[key] = strats[key](to[key], from[key], instance.proxy, key);
            }
            else {
                to[key] = from[key];
            }
        }
    }
  
    /**
     * #2437 In Vue 3, functional components do not have a public instance proxy but
     * they exist in the internal parent chain. For code that relies on traversing
     * public $parent chains, skip functional ones and go to the parent instead.
     */
    const getPublicInstance = (i) => i && (i.proxy ? i.proxy : getPublicInstance(i.parent));
    const publicPropertiesMap = extend(Object.create(null), {
        $: i => i,
        $el: i => i.vnode.el,
        $data: i => i.data,
        $props: i => ( shallowReadonly(i.props) ),
        $attrs: i => ( shallowReadonly(i.attrs) ),
        $slots: i => ( shallowReadonly(i.slots) ),
        $refs: i => ( shallowReadonly(i.refs) ),
        $parent: i => getPublicInstance(i.parent),
        $root: i => i.root && i.root.proxy,
        $emit: i => i.emit,
        $options: i => ( resolveMergedOptions(i) ),
        $forceUpdate: i => () => queueJob(i.update),
        $nextTick: i => nextTick.bind(i.proxy),
        $watch: i => ( instanceWatch.bind(i) )
    });
    const PublicInstanceProxyHandlers = {
        get({ _: instance }, key) {
            const { ctx, setupState, data, props, accessCache, type, appContext } = instance;
            // let @vue/reactivity know it should never observe Vue public instances.
            if (key === "__v_skip" /* SKIP */) {
                return true;
            }
            // for internal formatters to know that this is a Vue instance
            if ( key === '__isVue') {
                return true;
            }
            // data / props / ctx
            // This getter gets called for every property access on the render context
            // during render and is a major hotspot. The most expensive part of this
            // is the multiple hasOwn() calls. It's much faster to do a simple property
            // access on a plain object, so we use an accessCache object (with null
            // prototype) to memoize what access type a key corresponds to.
            let normalizedProps;
            if (key[0] !== '$') {
                const n = accessCache[key];
                if (n !== undefined) {
                    switch (n) {
                        case 0 /* SETUP */:
                            return setupState[key];
                        case 1 /* DATA */:
                            return data[key];
                        case 3 /* CONTEXT */:
                            return ctx[key];
                        case 2 /* PROPS */:
                            return props[key];
                        // default: just fallthrough
                    }
                }
                else if (setupState !== EMPTY_OBJ && hasOwn(setupState, key)) {
                    accessCache[key] = 0 /* SETUP */;
                    return setupState[key];
                }
                else if (data !== EMPTY_OBJ && hasOwn(data, key)) {
                    accessCache[key] = 1 /* DATA */;
                    return data[key];
                }
                else if (
                // only cache other properties when instance has declared (thus stable)
                // props
                (normalizedProps = instance.propsOptions[0]) &&
                    hasOwn(normalizedProps, key)) {
                    accessCache[key] = 2 /* PROPS */;
                    return props[key];
                }
                else if (ctx !== EMPTY_OBJ && hasOwn(ctx, key)) {
                    accessCache[key] = 3 /* CONTEXT */;
                    return ctx[key];
                }
                else if ( !isInBeforeCreate) {
                    accessCache[key] = 4 /* OTHER */;
                }
            }
            const publicGetter = publicPropertiesMap[key];
            let cssModule, globalProperties;
            // public $xxx properties
            if (publicGetter) {
                if (key === '$attrs') {
                    track(instance, "get" /* GET */, key);
                     markAttrsAccessed();
                }
                return publicGetter(instance);
            }
            else if (
            // css module (injected by vue-loader)
            (cssModule = type.__cssModules) &&
                (cssModule = cssModule[key])) {
                return cssModule;
            }
            else if (ctx !== EMPTY_OBJ && hasOwn(ctx, key)) {
                // user may set custom properties to `this` that start with `$`
                accessCache[key] = 3 /* CONTEXT */;
                return ctx[key];
            }
            else if (
            // global properties
            ((globalProperties = appContext.config.globalProperties),
                hasOwn(globalProperties, key))) {
                return globalProperties[key];
            }
            else if (
                currentRenderingInstance &&
                (!isString(key) ||
                    // #1091 avoid internal isRef/isVNode checks on component instance leading
                    // to infinite warning loop
                    key.indexOf('__v') !== 0)) {
                if (data !== EMPTY_OBJ &&
                    (key[0] === '$' || key[0] === '_') &&
                    hasOwn(data, key)) {
                    warn(`Property ${JSON.stringify(key)} must be accessed via $data because it starts with a reserved ` +
                        `character ("$" or "_") and is not proxied on the render context.`);
                }
                else {
                    warn(`Property ${JSON.stringify(key)} was accessed during render ` +
                        `but is not defined on instance.`);
                }
            }
        },
        set({ _: instance }, key, value) {
            const { data, setupState, ctx } = instance;
            if (setupState !== EMPTY_OBJ && hasOwn(setupState, key)) {
                setupState[key] = value;
            }
            else if (data !== EMPTY_OBJ && hasOwn(data, key)) {
                data[key] = value;
            }
            else if (key in instance.props) {
                
                    warn(`Attempting to mutate prop "${key}". Props are readonly.`, instance);
                return false;
            }
            if (key[0] === '$' && key.slice(1) in instance) {
                
                    warn(`Attempting to mutate public property "${key}". ` +
                        `Properties starting with $ are reserved and readonly.`, instance);
                return false;
            }
            else {
                if ( key in instance.appContext.config.globalProperties) {
                    Object.defineProperty(ctx, key, {
                        enumerable: true,
                        configurable: true,
                        value
                    });
                }
                else {
                    ctx[key] = value;
                }
            }
            return true;
        },
        has({ _: { data, setupState, accessCache, ctx, appContext, propsOptions } }, key) {
            let normalizedProps;
            return (accessCache[key] !== undefined ||
                (data !== EMPTY_OBJ && hasOwn(data, key)) ||
                (setupState !== EMPTY_OBJ && hasOwn(setupState, key)) ||
                ((normalizedProps = propsOptions[0]) && hasOwn(normalizedProps, key)) ||
                hasOwn(ctx, key) ||
                hasOwn(publicPropertiesMap, key) ||
                hasOwn(appContext.config.globalProperties, key));
        }
    };
    {
        PublicInstanceProxyHandlers.ownKeys = (target) => {
            warn(`Avoid app logic that relies on enumerating keys on a component instance. ` +
                `The keys will be empty in production mode to avoid performance overhead.`);
            return Reflect.ownKeys(target);
        };
    }
    const RuntimeCompiledPublicInstanceProxyHandlers = extend({}, PublicInstanceProxyHandlers, {
        get(target, key) {
            // fast path for unscopables when using `with` block
            if (key === Symbol.unscopables) {
                return;
            }
            return PublicInstanceProxyHandlers.get(target, key, target);
        },
        has(_, key) {
            const has = key[0] !== '_' && !isGloballyWhitelisted(key);
            if ( !has && PublicInstanceProxyHandlers.has(_, key)) {
                warn(`Property ${JSON.stringify(key)} should not start with _ which is a reserved prefix for Vue internals.`);
            }
            return has;
        }
    });
    // In dev mode, the proxy target exposes the same properties as seen on `this`
    // for easier console inspection. In prod mode it will be an empty object so
    // these properties definitions can be skipped.
    function createRenderContext(instance) {
        const target = {};
        // expose internal instance for proxy handlers
        Object.defineProperty(target, `_`, {
            configurable: true,
            enumerable: false,
            get: () => instance
        });
        // expose public properties
        Object.keys(publicPropertiesMap).forEach(key => {
            Object.defineProperty(target, key, {
                configurable: true,
                enumerable: false,
                get: () => publicPropertiesMap[key](instance),
                // intercepted by the proxy so no need for implementation,
                // but needed to prevent set errors
                set: NOOP
            });
        });
        // expose global properties
        const { globalProperties } = instance.appContext.config;
        Object.keys(globalProperties).forEach(key => {
            Object.defineProperty(target, key, {
                configurable: true,
                enumerable: false,
                get: () => globalProperties[key],
                set: NOOP
            });
        });
        return target;
    }
  
    const emptyAppContext = createAppContext();
    let uid$2 = 0;
    function createComponentInstance(vnode, parent, suspense) {
        const type = vnode.type;
        // inherit parent app context - or - if root, adopt from root vnode
        const appContext = (parent ? parent.appContext : vnode.appContext) || emptyAppContext;
        const instance = {
            uid: uid$2++,
            vnode,
            type,
            parent,
            appContext,
            root: null,
            next: null,
            subTree: null,
            update: null,
            render: null,
            proxy: null,
            exposed: null,
            withProxy: null,
            effects: null,
            provides: parent ? parent.provides : Object.create(appContext.provides),
            accessCache: null,
            renderCache: [],
            // local resovled assets
            components: null,
            directives: null,
            // resolved props and emits options
            propsOptions: normalizePropsOptions(type, appContext),
            emitsOptions: normalizeEmitsOptions(type, appContext),
            // emit
            emit: null,
            emitted: null,
            // state
            ctx: EMPTY_OBJ,
            data: EMPTY_OBJ,
            props: EMPTY_OBJ,
            attrs: EMPTY_OBJ,
            slots: EMPTY_OBJ,
            refs: EMPTY_OBJ,
            setupState: EMPTY_OBJ,
            setupContext: null,
            // suspense related
            suspense,
            suspenseId: suspense ? suspense.pendingId : 0,
            asyncDep: null,
            asyncResolved: false,
            // lifecycle hooks
            // not using enums here because it results in computed properties
            isMounted: false,
            isUnmounted: false,
            isDeactivated: false,
            bc: null,
            c: null,
            bm: null,
            m: null,
            bu: null,
            u: null,
            um: null,
            bum: null,
            da: null,
            a: null,
            rtg: null,
            rtc: null,
            ec: null
        };
        {
            instance.ctx = createRenderContext(instance);
        }
        instance.root = parent ? parent.root : instance;
        instance.emit = emit.bind(null, instance);
        return instance;
    }
    let currentInstance = null;
    const getCurrentInstance = () => currentInstance || currentRenderingInstance;
    const setCurrentInstance = (instance) => {
        currentInstance = instance;
    };
    const isBuiltInTag = /*#__PURE__*/ makeMap('slot,component');
    function validateComponentName(name, config) {
        const appIsNativeTag = config.isNativeTag || NO;
        if (isBuiltInTag(name) || appIsNativeTag(name)) {
            warn('Do not use built-in or reserved HTML elements as component id: ' + name);
        }
    }
    let isInSSRComponentSetup = false;
    function setupComponent(instance, isSSR = false) {
        isInSSRComponentSetup = isSSR;
        const { props, children, shapeFlag } = instance.vnode;
        const isStateful = shapeFlag & 4 /* STATEFUL_COMPONENT */;
        // init props & slots
        initProps(instance, props, isStateful, isSSR);
        initSlots(instance, children);
        console.log('component stateful ? ' + isStateful);
        const setupResult = isStateful
            ? setupStatefulComponent(instance, isSSR)
            : undefined;
        isInSSRComponentSetup = false;
        return setupResult;
    }
    function setupStatefulComponent(instance, isSSR) {
        const Component = instance.type;
        // 0. create render proxy property access cache
        instance.accessCache = Object.create(null);
        // 1. create public instance / render proxy
        // also mark it raw so it's never observed
        instance.proxy = new Proxy(instance.ctx, PublicInstanceProxyHandlers);
        console.log('call setup');
        // 2. call setup()
        const { setup } = Component;
        if (setup) {
            const setupContext = (instance.setupContext =
                setup.length > 1 ? createSetupContext(instance) : null);
            currentInstance = instance;
            pauseTracking();
            const setupResult = callWithErrorHandling(setup, instance, 0 /* SETUP_FUNCTION */, [ shallowReadonly(instance.props) , setupContext]);
            resetTracking();
            currentInstance = null;
            if (isPromise(setupResult)) {
                if (isSSR) {
                    // return the promise so server-renderer can wait on it
                    return setupResult.then((resolvedResult) => {
                        handleSetupResult(instance, resolvedResult);
                    });
                }
                else {
                    // async setup returned Promise.
                    // bail here and wait for re-entry.
                    instance.asyncDep = setupResult;
                }
            }
            else {
                handleSetupResult(instance, setupResult);
            }
        }
        else {
            console.log('no setup');
            finishComponentSetup(instance);
        }
    }
    function handleSetupResult(instance, setupResult, isSSR) {
        // 1. 如果是函数当做render函数处理
        // 2. 如果是对象
        if (isFunction(setupResult)) {
            // 返回内联 render 函数
            {
                instance.render = setupResult;
            }
        }
        else if (isObject(setupResult)) {
            // 返回 bindings，这些变量可以直接在模板中使用
            instance.setupState = proxyRefs(setupResult);
        }
        else ;
        finishComponentSetup(instance);
    }
    let compile;
    /**
     * For runtime-dom to register the compiler.
     * Note the exported method uses any to avoid d.ts relying on the compiler types.
     */
    function registerRuntimeCompiler(_compile) {
        compile = _compile;
    }
    function finishComponentSetup(instance, isSSR) {
        const Component = instance.type;
        // template / render function normalization
        if (!instance.render) {
            // 没有 render 函数？
            if (compile && Component.template && !Component.render) {
                // 有 template 无 render ? 将模板编译成 render 函数
                Component.render = compile(Component.template, {
                    isCustomElement: instance.appContext.config.isCustomElement,
                    delimiters: Component.delimiters
                });
            }
            instance.render = (Component.render || NOOP);
            if (instance.render._rc) {
                instance.withProxy = new Proxy(instance.ctx, RuntimeCompiledPublicInstanceProxyHandlers);
            }
        }
        // support for 2.x options
        {
            currentInstance = instance;
            pauseTracking();
            applyOptions(instance, Component);
            resetTracking();
            currentInstance = null;
        }
        if ( !Component.render && instance.render === NOOP) {
            if (!compile && Component.template) ;
        }
    }
    const attrHandlers = {
        get: (target, key) => {
            {
                markAttrsAccessed();
            }
            return target[key];
        },
        set: () => {
            warn(`setupContext.attrs is readonly.`);
            return false;
        },
        deleteProperty: () => {
            warn(`setupContext.attrs is readonly.`);
            return false;
        }
    };
    function createSetupContext(instance) {
        const expose = exposed => {
            if ( instance.exposed) {
                warn(`expose() should be called only once per setup().`);
            }
            // ref 类型值，通过代理实现对 value 的 get/set
            instance.exposed = proxyRefs(exposed);
        };
        {
            // We use getters in dev in case libs like test-utils overwrite instance
            // properties (overwrites should not be done in prod)
            // 防止覆盖属性
            return Object.freeze({
                get props() {
                    return instance.props;
                },
                get attrs() {
                    return new Proxy(instance.attrs, attrHandlers);
                },
                get slots() {
                    return shallowReadonly(instance.slots);
                },
                get emit() {
                    return (event, ...args) => instance.emit(event, ...args);
                },
                expose
            });
        }
    }
    // record effects created during a component's setup() so that they can be
    // stopped when the component unmounts
    // 记录在组件 setup() 期间绑定了哪些 effects，方便当组件卸载的时候去停掉他们
    function recordInstanceBoundEffect(effect, instance = currentInstance) {
        if (instance) {
            (instance.effects || (instance.effects = [])).push(effect);
        }
    }
    const classifyRE = /(?:^|[-_])(\w)/g;
    const classify = (str) => str.replace(classifyRE, c => c.toUpperCase()).replace(/[-_]/g, '');
    function getComponentName(Component) {
        return isFunction(Component)
            ? Component.displayName || Component.name
            : Component.name;
    }
    /* istanbul ignore next */
    function formatComponentName(instance, Component, isRoot = false) {
        let name = getComponentName(Component);
        if (!name && Component.__file) {
            const match = Component.__file.match(/([^/\\]+)\.\w+$/);
            if (match) {
                name = match[1];
            }
        }
        if (!name && instance && instance.parent) {
            // try to infer the name based on reverse resolution
            const inferFromRegistry = (registry) => {
                for (const key in registry) {
                    if (registry[key] === Component) {
                        return key;
                    }
                }
            };
            name =
                inferFromRegistry(instance.components ||
                    instance.parent.type.components) || inferFromRegistry(instance.appContext.components);
        }
        return name ? classify(name) : isRoot ? `App` : `Anonymous`;
    }
    function isClassComponent(value) {
        return isFunction(value) && '__vccOpts' in value;
    }
  
    function computed$1(getterOrOptions) {
        const c = computed(getterOrOptions);
        recordInstanceBoundEffect(c.effect);
        return c;
    }
  
    // implementation
    function defineProps() {
        {
            warn(`defineProps() is a compiler-hint helper that is only usable inside ` +
                `<script setup> of a single file component. Its arguments should be ` +
                `compiled away and passing it at runtime has no effect.`);
        }
        return null;
    }
    // implementation
    function defineEmit() {
        {
            warn(`defineEmit() is a compiler-hint helper that is only usable inside ` +
                `<script setup> of a single file component. Its arguments should be ` +
                `compiled away and passing it at runtime has no effect.`);
        }
        return null;
    }
    function useContext() {
        const i = getCurrentInstance();
        if ( !i) {
            warn(`useContext() called without active instance.`);
        }
        return i.setupContext || (i.setupContext = createSetupContext(i));
    }
  
    // Actual implementation
    function h(type, propsOrChildren, children) {
        const l = arguments.length;
        if (l === 2) {
            if (isObject(propsOrChildren) && !isArray(propsOrChildren)) {
                // 没有 props 的 单节点(single vnode)
                if (isVNode(propsOrChildren)) {
                    return createVNode(type, null, [propsOrChildren]);
                }
                // 有 props 没有 children
                return createVNode(type, propsOrChildren);
            }
            else {
                // omit props
                return createVNode(type, null, propsOrChildren);
            }
        }
        else {
            // 从第三个参数开始全当做孩子节点处理
            if (l > 3) {
                children = Array.prototype.slice.call(arguments, 2);
            }
            else if (l === 3 && isVNode(children)) {
                children = [children];
            }
            return createVNode(type, propsOrChildren, children);
        }
    }
  
    const ssrContextKey = Symbol( `ssrContext` );
    const useSSRContext = () => {
        {
            warn(`useSsrContext() is not supported in the global build.`);
        }
    };
  
    function initCustomFormatter() {
        /* eslint-disable no-restricted-globals */
        if ( typeof window === 'undefined') {
            return;
        }
        const vueStyle = { style: 'color:#3ba776' };
        const numberStyle = { style: 'color:#0b1bc9' };
        const stringStyle = { style: 'color:#b62e24' };
        const keywordStyle = { style: 'color:#9d288c' };
        // custom formatter for Chrome
        // https://www.mattzeunert.com/2016/02/19/custom-chrome-devtools-object-formatters.html
        const formatter = {
            header(obj) {
                // TODO also format ComponentPublicInstance & ctx.slots/attrs in setup
                if (!isObject(obj)) {
                    return null;
                }
                if (obj.__isVue) {
                    return ['div', vueStyle, `VueInstance`];
                }
                else if (isRef(obj)) {
                    return [
                        'div',
                        {},
                        ['span', vueStyle, genRefFlag(obj)],
                        '<',
                        formatValue(obj.value),
                        `>`
                    ];
                }
                else if (isReactive(obj)) {
                    return [
                        'div',
                        {},
                        ['span', vueStyle, 'Reactive'],
                        '<',
                        formatValue(obj),
                        `>${isReadonly(obj) ? ` (readonly)` : ``}`
                    ];
                }
                else if (isReadonly(obj)) {
                    return [
                        'div',
                        {},
                        ['span', vueStyle, 'Readonly'],
                        '<',
                        formatValue(obj),
                        '>'
                    ];
                }
                return null;
            },
            hasBody(obj) {
                return obj && obj.__isVue;
            },
            body(obj) {
                if (obj && obj.__isVue) {
                    return [
                        'div',
                        {},
                        ...formatInstance(obj.$)
                    ];
                }
            }
        };
        function formatInstance(instance) {
            const blocks = [];
            if (instance.type.props && instance.props) {
                blocks.push(createInstanceBlock('props', toRaw(instance.props)));
            }
            if (instance.setupState !== EMPTY_OBJ) {
                blocks.push(createInstanceBlock('setup', instance.setupState));
            }
            if (instance.data !== EMPTY_OBJ) {
                blocks.push(createInstanceBlock('data', toRaw(instance.data)));
            }
            const computed = extractKeys(instance, 'computed');
            if (computed) {
                blocks.push(createInstanceBlock('computed', computed));
            }
            const injected = extractKeys(instance, 'inject');
            if (injected) {
                blocks.push(createInstanceBlock('injected', injected));
            }
            blocks.push([
                'div',
                {},
                [
                    'span',
                    {
                        style: keywordStyle.style + ';opacity:0.66'
                    },
                    '$ (internal): '
                ],
                ['object', { object: instance }]
            ]);
            return blocks;
        }
        function createInstanceBlock(type, target) {
            target = extend({}, target);
            if (!Object.keys(target).length) {
                return ['span', {}];
            }
            return [
                'div',
                { style: 'line-height:1.25em;margin-bottom:0.6em' },
                [
                    'div',
                    {
                        style: 'color:#476582'
                    },
                    type
                ],
                [
                    'div',
                    {
                        style: 'padding-left:1.25em'
                    },
                    ...Object.keys(target).map(key => {
                        return [
                            'div',
                            {},
                            ['span', keywordStyle, key + ': '],
                            formatValue(target[key], false)
                        ];
                    })
                ]
            ];
        }
        function formatValue(v, asRaw = true) {
            if (typeof v === 'number') {
                return ['span', numberStyle, v];
            }
            else if (typeof v === 'string') {
                return ['span', stringStyle, JSON.stringify(v)];
            }
            else if (typeof v === 'boolean') {
                return ['span', keywordStyle, v];
            }
            else if (isObject(v)) {
                return ['object', { object: asRaw ? toRaw(v) : v }];
            }
            else {
                return ['span', stringStyle, String(v)];
            }
        }
        function extractKeys(instance, type) {
            const Comp = instance.type;
            if (isFunction(Comp)) {
                return;
            }
            const extracted = {};
            for (const key in instance.ctx) {
                if (isKeyOfType(Comp, key, type)) {
                    extracted[key] = instance.ctx[key];
                }
            }
            return extracted;
        }
        function isKeyOfType(Comp, key, type) {
            const opts = Comp[type];
            if ((isArray(opts) && opts.includes(key)) ||
                (isObject(opts) && key in opts)) {
                return true;
            }
            if (Comp.extends && isKeyOfType(Comp.extends, key, type)) {
                return true;
            }
            if (Comp.mixins && Comp.mixins.some(m => isKeyOfType(m, key, type))) {
                return true;
            }
        }
        function genRefFlag(v) {
            if (v._shallow) {
                return `ShallowRef`;
            }
            if (v.effect) {
                return `ComputedRef`;
            }
            return `Ref`;
        }
        if (window.devtoolsFormatters) {
            window.devtoolsFormatters.push(formatter);
        }
        else {
            window.devtoolsFormatters = [formatter];
        }
    }
  
    /**
     * Actual implementation
     */
    function renderList(source, renderItem) {
        let ret;
        if (isArray(source) || isString(source)) {
            ret = new Array(source.length);
            for (let i = 0, l = source.length; i < l; i++) {
                ret[i] = renderItem(source[i], i);
            }
        }
        else if (typeof source === 'number') {
            if ( !Number.isInteger(source)) {
                warn(`The v-for range expect an integer value but got ${source}.`);
                return [];
            }
            ret = new Array(source);
            for (let i = 0; i < source; i++) {
                ret[i] = renderItem(i + 1, i);
            }
        }
        else if (isObject(source)) {
            if (source[Symbol.iterator]) {
                ret = Array.from(source, renderItem);
            }
            else {
                const keys = Object.keys(source);
                ret = new Array(keys.length);
                for (let i = 0, l = keys.length; i < l; i++) {
                    const key = keys[i];
                    ret[i] = renderItem(source[key], key, i);
                }
            }
        }
        else {
            ret = [];
        }
        return ret;
    }
  
    /**
     * For prefixing keys in v-on="obj" with "on"
     * @private
     */
    function toHandlers(obj) {
        const ret = {};
        if ( !isObject(obj)) {
            warn(`v-on with no argument expects an object value.`);
            return ret;
        }
        for (const key in obj) {
            ret[toHandlerKey(key)] = obj[key];
        }
        return ret;
    }
  
    /**
     * Compiler runtime helper for creating dynamic slots object
     * @private
     */
    function createSlots(slots, dynamicSlots) {
        for (let i = 0; i < dynamicSlots.length; i++) {
            const slot = dynamicSlots[i];
            // 数组动态插槽由  <template v-for="..." #[...]> 生成
            // 经过编译后的 slots: [{ name:'default', fn: ... }]
            if (isArray(slot)) {
                for (let j = 0; j < slot.length; j++) {
                    slots[slot[j].name] = slot[j].fn;
                }
            }
            else if (slot) {
                // 条件语句生成的 slot 如 <template v-if="..." #foo>
                slots[slot.name] = slot.fn;
            }
        }
        return slots;
    }
  
    // Core API ------------------------------------------------------------------
    const version = "3.0.4";
    /**
     * SSR utils for \@vue/server-renderer. Only exposed in cjs builds.
     * @internal
     */
    const ssrUtils = ( null);
  
    // 编译阶段应该将 class + :class 静态动态的绑定，编译进一个绑定
    // ['staticClass', dynamic]，其实就是合并
    function patchClass(el, value, isSVG) {
        if (value == null) {
            value = '';
        }
        if (isSVG) {
            el.setAttribute('class', value);
        }
        else {
            const transitionClasses = el /* TODO ElementWithTransition */._vtc;
            if (transitionClasses) {
                // 合并类名
                value = (value
                    ? [value, ...transitionClasses]
                    : [...transitionClasses]).join('');
            }
            el.className = value;
        }
    }
  
    function patchStyle(el, prev, next) {
        const style = el.style;
        if (!next) {
            // 删除操作
            el.removeAttribute('style');
        }
        else if (isString(next)) {
            // 更新操作，全替换操作
            if (prev !== next) {
                style.cssText = next;
            }
        }
        else {
            // 如果是对象，根据对象内的属性逐个进行更新
            for (const key in next) {
                // 更新单个值
                setStyle(style, key, next[key]);
            }
            if (prev && !isString(prev)) {
                // 删除老的不在 next 中的值
                for (const key in prev) {
                    if (next[key] == null) {
                        setStyle(style, key, '');
                    }
                }
            }
        }
    }
    const importantRE = /\s*!important$/;
    function setStyle(style, name, val) {
        if (isArray(val)) {
            // 同一个属性设置多个值？取最后一个有效值
            val.forEach(v => setStyle(style, name, v));
        }
        else {
            // 多浏览器的兼容处理，如： --webkit-...
            if (name.startsWith('--')) {
                // custom property definition
                style.setProperty(name, val);
            }
            else {
                // 自动添加前缀
                const prefixed = autoPrefix(style, name);
                if (importantRE.test(val)) {
                    // 优先级最高的处理
                    // !important
                    style.setProperty(hyphenate(prefixed), val.replace(importantRE, ''), 'important');
                }
                else {
                    style[prefixed] = val;
                }
            }
        }
    }
    const prefixes = ['Webkit', 'Moz', 'ms'];
    const prefixCache = {};
    // 自动添加前缀处理
    function autoPrefix(style, rawName) {
        const cached = prefixCache[rawName];
        if (cached) {
            return cached;
        }
        let name = camelize(rawName);
        if (name !== 'filter' && name in style) {
            return (prefixCache[rawName] = name);
        }
        name = capitalize(name);
        for (let i = 0; i < prefixes.length; i++) {
            const prefixed = prefixes[i] + name;
            if (prefixed in style) {
                return (prefixCache[rawName] = prefixed);
            }
        }
        return rawName;
    }
  
    // Async edge case fix requires storing an event listener's attach timestamp.
    // 保存事件绑定时间戳
    let _getNow = Date.now;
    // Determine what event timestamp the browser is using. Annoyingly, the
    // timestamp can either be hi-res (relative to page load) or low-res
    // (relative to UNIX epoch), so in order to compare time we have to use the
    // same timestamp type when saving the flush timestamp.
    // 兼容性处理
    if (typeof document !== 'undefined' &&
        _getNow() > document.createEvent('Event').timeStamp) {
        // if the low-res timestamp which is bigger than the event timestamp
        // (which is evaluated AFTER) it means the event is using a hi-res timestamp,
        // and we need to use the hi-res version for event listeners as well.
        _getNow = () => performance.now();
    }
    // To avoid the overhead of repeatedly calling performance.now(), we cache
    // and use the same timestamp for all event listeners attached in the same tick.
    // 缓存机制
    let cachedNow = 0;
    const p = Promise.resolve();
    const reset = () => {
        cachedNow = 0;
    };
    const getNow = () => cachedNow || (p.then(reset), (cachedNow = _getNow()));
    function addEventListener(el, event, handler, options) {
        el.addEventListener(event, handler, options);
    }
    function removeEventListener(el, event, handler, options) {
        el.removeEventListener(event, handler, options);
    }
    function patchEvent(el, rawName, prevValue, nextValue, instance = null) {
        // vue event invokers
        const invokers = el._vei || (el._vei = {});
        const existingInvoker = invokers[rawName];
        if (nextValue && existingInvoker) {
            // patch
            existingInvoker.value = nextValue;
        }
        else {
            const [name, options] = parseName(rawName);
            if (nextValue) {
                // add 添加事件
                const invoker = (invokers[rawName] = createInvoker(nextValue, instance));
                addEventListener(el, name, invoker, options);
            }
            else if (existingInvoker) {
                // remove 删除事件
                removeEventListener(el, name, existingInvoker, options);
                invokers[rawName] = undefined;
            }
        }
    }
    // 修饰符
    const optionsModifierRE = /(?:Once|Passive|Capture)$/;
    // 解析事件名 onClick -> ['click']
    // onClickOnce -> ['click', { once: true }]
    // onClickOncePassive -> ['click', { once: true, passive: true }]
    function parseName(name) {
        let options;
        if (optionsModifierRE.test(name)) {
            options = {};
            let m;
            while ((m = name.match(optionsModifierRE))) {
                name = name.slice(0, name.length - m[0].length);
                options[m[0].toLowerCase()] = true;
            }
        }
        return [name.slice(2).toLowerCase(), options];
    }
    function createInvoker(initialValue, instance) {
        const invoker = (e) => {
            // 异步边缘情况：内部点击事件触发 patch ，事件
            // 句柄在 patch 阶段绑定在 outer element 上，
            // 然后会被再次触发，这种情况的发生原因是浏览器在事件
            // 冒泡期间触发了微任务时钟(microtask ticks)
            // 解决方案：保存事件句柄被绑定瞬间的时间戳(timestamp)
            // 然后事件句柄只有在“已保存的时间戳之后触发的事件”上去执行
            const timeStamp = e.timeStamp || _getNow();
            if (timeStamp >= invoker.attached - 1) {
                callWithAsyncErrorHandling(patchStopImmediatePropagation(e, invoker.value), instance, 5 /* NATIVE_EVENT_HANDLER */, [e]);
            }
        };
        invoker.value = initialValue;
        invoker.attached = getNow();
        return invoker;
    }
    function patchStopImmediatePropagation(e, value) {
        if (isArray(value)) {
            const originalStop = e.stopImmediatePropagation;
            e.stopImmediatePropagation = () => {
                originalStop.call(e);
                e._stopped = true;
            };
            return value.map(fn => (e) => !e._stopped && fn(e));
        }
        else {
            return value;
        }
    }
  
    const xlinkNS = 'http://www.w3.org/1999/xlink';
    function patchAttr(el, key, value, isSVG) {
        if (isSVG && key.startsWith('xlink:')) {
            if (value == null) {
                el.removeAttributeNS(xlinkNS, key.slice(6, key.length));
            }
            else {
                el.setAttributeNS(xlinkNS, key, value);
            }
        }
        else {
            // note we are only checking boolean attributes that don't have a
            // corresponding dom prop of the same name here.
            const isBoolean = isSpecialBooleanAttr(key);
            if (value == null || (isBoolean && value === false)) {
                el.removeAttribute(key);
            }
            else {
                el.setAttribute(key, isBoolean ? '' : value);
            }
        }
    }
  
    // __UNSAFE__
    // functions. The user is responsible for using them with only trusted content.
    function patchDOMProp(el, key, value, 
    // the following args are passed only due to potential innerHTML/textContent
    // overriding existing VNodes, in which case the old tree must be properly
    // unmounted.
    prevChildren, parentComponent, parentSuspense, unmountChildren) {
        if (key === 'innerHTML' || key === 'textContent') {
            if (prevChildren) {
                unmountChildren(prevChildren, parentComponent, parentSuspense);
            }
            el[key] = value == null ? '' : value;
            return;
        }
        if (key === 'value' && el.tagName !== 'PROGRESS') {
            // store value as _value as well since
            // non-string values will be stringified.
            el._value = value;
            const newValue = value == null ? '' : value;
            if (el.value !== newValue) {
                el.value = newValue;
            }
            return;
        }
        // 空值处理
        if (value === '' || value == null) {
            const type = typeof el[key];
            if (value === '' && type === 'boolean') {
                // 比如： <select multiple> 编译成： { multiple: '' }
                el[key] = true;
                return;
            }
            else if (value == null && type === 'string') {
                // 如： <div :id="null">
                el[key] = '';
                el.removeAttribute(key);
                return;
            }
            else if (type === 'number') {
                // 如： <img :width="null">
                el[key] = 0;
                el.removeAttribute(key);
                return;
            }
        }
        // some properties perform value validation and throw
        try {
            el[key] = value;
        }
        catch (e) {
            {
                warn(`Failed setting prop "${key}" on <${el.tagName.toLowerCase()}>: ` +
                    `value ${value} is invalid.`, e);
            }
        }
    }
  
    const nativeOnRE = /^on[a-z]/;
    const patchProp = (el, key, prevValue, nextValue, isSVG = false, prevChildren, parentComponent, parentSuspense, unmountChildren) => {
        switch (key) {
            // 特殊属性
            case 'class':
                patchClass(el, nextValue, isSVG);
                break;
            case 'style':
                patchStyle(el, prevValue, nextValue);
                break;
            default:
                if (isOn(key)) {
                    // 忽略 v-model 的 listeners
                    if (!isModelListener(key)) {
                        patchEvent(el, key, prevValue, nextValue, parentComponent);
                    }
                }
                else if (shouldSetAsProp(el, key, nextValue, isSVG)) {
                    patchDOMProp(el, key, nextValue, prevChildren, parentComponent, parentSuspense, unmountChildren);
                }
                else {
                    // special case for <input v-model type="checkbox"> with
                    // :true-value & :false-value
                    // store value as dom properties since non-string values will be
                    // stringified.
                    if (key === 'true-value') {
                        el._trueValue = nextValue;
                    }
                    else if (key === 'false-value') {
                        el._falseValue = nextValue;
                    }
                    patchAttr(el, key, nextValue, isSVG);
                }
                break;
        }
    };
    function shouldSetAsProp(el, key, value, isSVG) {
        if (isSVG) {
            // most keys must be set as attribute on svg elements to work
            // ...except innerHTML
            if (key === 'innerHTML') {
                return true;
            }
            // or native onclick with function values
            if (key in el && nativeOnRE.test(key) && isFunction(value)) {
                return true;
            }
            return false;
        }
        // spellcheck and draggable are numerated attrs, however their
        // corresponding DOM properties are actually booleans - this leads to
        // setting it with a string "false" value leading it to be coerced to
        // `true`, so we need to always treat them as attributes.
        // Note that `contentEditable` doesn't have this problem: its DOM
        // property is also enumerated string values.
        if (key === 'spellcheck' || key === 'draggable') {
            return false;
        }
        // #1787 form as an attribute must be a string, while it accepts an Element as
        // a prop
        if (key === 'form' && typeof value === 'string') {
            return false;
        }
        // #1526 <input list> must be set as attribute
        if (key === 'list' && el.tagName === 'INPUT') {
            return false;
        }
        // native onclick with string value, must be set as attribute
        if (nativeOnRE.test(key) && isString(value)) {
            return false;
        }
        return key in el;
    }
  
    exports.BaseTransition = BaseTransition;
    exports.Comment = Comment;
    exports.Fragment = Fragment;
    exports.KeepAlive = KeepAlive;
    exports.Static = Static;
    exports.Suspense = Suspense;
    exports.Teleport = Teleport;
    exports.Text = Text;
    exports.callWithAsyncErrorHandling = callWithAsyncErrorHandling;
    exports.callWithErrorHandling = callWithErrorHandling;
    exports.camelize = camelize;
    exports.capitalize = capitalize;
    exports.cloneVNode = cloneVNode;
    exports.computed = computed$1;
    exports.createBlock = createBlock;
    exports.createCommentVNode = createCommentVNode;
    exports.createHydrationRenderer = createHydrationRenderer;
    exports.createRenderer = createRenderer;
    exports.createSlots = createSlots;
    exports.createStaticVNode = createStaticVNode;
    exports.createTextVNode = createTextVNode;
    exports.createVNode = createVNode;
    exports.customRef = customRef;
    exports.defineAsyncComponent = defineAsyncComponent;
    exports.defineComponent = defineComponent;
    exports.defineEmit = defineEmit;
    exports.defineProps = defineProps;
    exports.getCurrentInstance = getCurrentInstance;
    exports.getTransitionRawChildren = getTransitionRawChildren;
    exports.h = h;
    exports.handleError = handleError;
    exports.initCustomFormatter = initCustomFormatter;
    exports.inject = inject;
    exports.isProxy = isProxy;
    exports.isReactive = isReactive;
    exports.isReadonly = isReadonly;
    exports.isRef = isRef;
    exports.isVNode = isVNode;
    exports.markRaw = markRaw;
    exports.mergeProps = mergeProps;
    exports.nextTick = nextTick;
    exports.onActivated = onActivated;
    exports.onBeforeMount = onBeforeMount;
    exports.onBeforeUnmount = onBeforeUnmount;
    exports.onBeforeUpdate = onBeforeUpdate;
    exports.onDeactivated = onDeactivated;
    exports.onErrorCaptured = onErrorCaptured;
    exports.onMounted = onMounted;
    exports.onRenderTracked = onRenderTracked;
    exports.onRenderTriggered = onRenderTriggered;
    exports.onUnmounted = onUnmounted;
    exports.onUpdated = onUpdated;
    exports.openBlock = openBlock;
    exports.patchProp = patchProp;
    exports.popScopeId = popScopeId;
    exports.provide = provide;
    exports.proxyRefs = proxyRefs;
    exports.pushScopeId = pushScopeId;
    exports.queuePostFlushCb = queuePostFlushCb;
    exports.reactive = reactive;
    exports.readonly = readonly;
    exports.ref = ref;
    exports.registerRuntimeCompiler = registerRuntimeCompiler;
    exports.renderList = renderList;
    exports.renderSlot = renderSlot;
    exports.resolveComponent = resolveComponent;
    exports.resolveDirective = resolveDirective;
    exports.resolveDynamicComponent = resolveDynamicComponent;
    exports.resolveTransitionHooks = resolveTransitionHooks;
    exports.setBlockTracking = setBlockTracking;
    exports.setDevtoolsHook = setDevtoolsHook;
    exports.setTransitionHooks = setTransitionHooks;
    exports.shallowReactive = shallowReactive;
    exports.shallowReadonly = shallowReadonly;
    exports.shallowRef = shallowRef;
    exports.ssrContextKey = ssrContextKey;
    exports.ssrUtils = ssrUtils;
    exports.toDisplayString = toDisplayString;
    exports.toHandlerKey = toHandlerKey;
    exports.toHandlers = toHandlers;
    exports.toRaw = toRaw;
    exports.toRef = toRef;
    exports.toRefs = toRefs;
    exports.transformVNodeArgs = transformVNodeArgs;
    exports.triggerRef = triggerRef;
    exports.unref = unref;
    exports.useContext = useContext;
    exports.useSSRContext = useSSRContext;
    exports.useTransitionState = useTransitionState;
    exports.version = version;
    exports.warn = warn;
    exports.watch = watch;
    exports.watchEffect = watchEffect;
    exports.withCtx = withCtx;
    exports.withDirectives = withDirectives;
    exports.withScopeId = withScopeId;
  
    Object.defineProperty(exports, '__esModule', { value: true });
  
    return exports;
  
  }({}));
  
  try {
    if (module) {
      module.exports = VueRuntimeDom;
    }
  } catch (e) {}
   
  