'use strict';

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

var he = require('he');

/*  */

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

/**
 * Convert a input value to a number for persistence.
 * If the conversion fails, return original string.
 */
function toNumber (val) {
  var n = parseFloat(val, 10);
  return (n || n === 0) ? n : val
}

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

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

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

/**
 * Check whether the object has the property.
 */
var hasOwnProperty = Object.prototype.hasOwnProperty;
function hasOwn (obj, key) {
  return hasOwnProperty.call(obj, key)
}

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

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

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

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

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

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

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

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

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

/**
 * Strict object type check. Only returns true
 * for plain JavaScript objects.
 */
var toString = Object.prototype.toString;
var OBJECT_STRING = '[object Object]';
function isPlainObject (obj) {
  return toString.call(obj) === OBJECT_STRING
}

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

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

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

/**
 * Generate a static keys string from compiler modules.
 */
function genStaticKeys (modules) {
  return modules.reduce(function (keys, m) {
    return keys.concat(m.staticKeys || [])
  }, []).join(',')
}

/**
 * Check if two values are loosely equal - that is,
 * if they are plain objects, do they have the same shape?
 */
function looseEqual (a, b) {
  /* eslint-disable eqeqeq */
  return a == b || (
    isObject(a) && isObject(b)
      ? JSON.stringify(a) === JSON.stringify(b)
      : false
  )
  /* eslint-enable eqeqeq */
}

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

/*  */

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

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

  /**
   * Whether to enable devtools
   */
  devtools: process.env.NODE_ENV !== 'production',

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

  /**
   * Ignore certain custom elements
   */
  ignoredElements: null,

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

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

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

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

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

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

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

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

var warn = noop;
var formatComponentName;

if (process.env.NODE_ENV !== 'production') {
  var hasConsole = typeof console !== 'undefined';

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

  formatComponentName = function (vm) {
    if (vm.$root === vm) {
      return 'root instance'
    }
    var name = vm._isVue
      ? vm.$options.name || vm.$options._componentTag
      : vm.name;
    return (
      (name ? ("component <" + name + ">") : "anonymous component") +
      (vm._isVue && vm.$options.__file ? (" at " + (vm.$options.__file)) : '')
    )
  };

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

/*  */

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

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

/**
 * Parse simple path.
 */
var bailRE = /[^\w.$]/;
function parsePath (path) {
  if (bailRE.test(path)) {
    return
  } else {
    var segments = path.split('.');
    return function (obj) {
      for (var i = 0; i < segments.length; i++) {
        if (!obj) { return }
        obj = obj[segments[i]];
      }
      return obj
    }
  }
}

/*  */
/* globals MutationObserver */

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

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

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

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

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

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

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

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

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

var _Set;
/* istanbul ignore if */
if (typeof Set !== 'undefined' && isNative(Set)) {
  // use native Set when available.
  _Set = Set;
} else {
  // a non-standard Set polyfill that only works with primitive keys.
  _Set = (function () {
    function Set () {
      this.set = Object.create(null);
    }
    Set.prototype.has = function has (key) {
      return this.set[key] !== undefined
    };
    Set.prototype.add = function add (key) {
      this.set[key] = 1;
    };
    Set.prototype.clear = function clear () {
      this.set = Object.create(null);
    };

    return Set;
  }());
}

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

var initProxy;

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

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

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

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

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

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

/*  */


var uid$2 = 0;

/**
 * A dep is an observable that can have multiple
 * directives subscribing to it.
 */
var Dep = function Dep () {
  this.id = uid$2++;
  this.subs = [];
};

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

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

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

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

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

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

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

/*  */


var queue = [];
var has$1 = {};
var circular = {};
var waiting = false;
var flushing = false;
var index = 0;

/**
 * Reset the scheduler's state.
 */
function resetSchedulerState () {
  queue.length = 0;
  has$1 = {};
  if (process.env.NODE_ENV !== 'production') {
    circular = {};
  }
  waiting = flushing = false;
}

/**
 * Flush both queues and run the watchers.
 */
function flushSchedulerQueue () {
  flushing = true;

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

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

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

  resetSchedulerState();
}

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

/*  */

var uid$1 = 0;

/**
 * A watcher parses an expression, collects dependencies,
 * and fires callback when the expression value changes.
 * This is used for both the $watch() api and directives.
 */
var Watcher = function Watcher (
  vm,
  expOrFn,
  cb,
  options
) {
  if ( options === void 0 ) options = {};

  this.vm = vm;
  vm._watchers.push(this);
  // options
  this.deep = !!options.deep;
  this.user = !!options.user;
  this.lazy = !!options.lazy;
  this.sync = !!options.sync;
  this.expression = expOrFn.toString();
  this.cb = cb;
  this.id = ++uid$1; // uid for batching
  this.active = true;
  this.dirty = this.lazy; // for lazy watchers
  this.deps = [];
  this.newDeps = [];
  this.depIds = new _Set();
  this.newDepIds = new _Set();
  // parse expression for getter
  if (typeof expOrFn === 'function') {
    this.getter = expOrFn;
  } else {
    this.getter = parsePath(expOrFn);
    if (!this.getter) {
      this.getter = function () {};
      process.env.NODE_ENV !== 'production' && warn(
        "Failed watching path: \"" + expOrFn + "\" " +
        'Watcher only accepts simple dot-delimited paths. ' +
        'For full control, use a function instead.',
        vm
      );
    }
  }
  this.value = this.lazy
    ? undefined
    : this.get();
};

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

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

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

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

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

/**
 * Scheduler job interface.
 * Will be called by the scheduler.
 */
Watcher.prototype.run = function run () {
  if (this.active) {
    var value = this.get();
      if (
        value !== this.value ||
      // Deep watchers and watchers on Object/Arrays should fire even
      // when the value is the same, because the value may
      // have mutated.
      isObject(value) ||
      this.deep
    ) {
      // set new value
      var oldValue = this.value;
      this.value = value;
      if (this.user) {
        try {
          this.cb.call(this.vm, value, oldValue);
        } catch (e) {
          /* istanbul ignore else */
          if (config.errorHandler) {
            config.errorHandler.call(null, e, this.vm);
          } else {
            process.env.NODE_ENV !== 'production' && warn(
              ("Error in watcher \"" + (this.expression) + "\""),
              this.vm
            );
            throw e
          }
        }
      } else {
        this.cb.call(this.vm, value, oldValue);
      }
    }
  }
};

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

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

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

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

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

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

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

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

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

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

/*  */

var arrayKeys = Object.getOwnPropertyNames(arrayMethods);

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

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

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

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

// helpers

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

/**
 * Augment an target Object or Array by defining
 * hidden properties.
 *
 * istanbul ignore next
 */
function copyAugment (target, src, keys) {
  for (var i = 0, l = keys.length; i < l; i++) {
    var key = keys[i];
    def(target, key, src[key]);
  }
}

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

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

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

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

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

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

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

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

/*  */

function initState (vm) {
  vm._watchers = [];
  initProps(vm);
  initMethods(vm);
  initData(vm);
  initComputed(vm);
  initWatch(vm);
}

var isReservedProp = makeMap('key,ref,slot');

function initProps (vm) {
  var props = vm.$options.props;
  if (props) {
    var propsData = vm.$options.propsData || {};
    var keys = vm.$options._propKeys = Object.keys(props);
    var isRoot = !vm.$parent;
    // root instance props should be converted
    observerState.shouldConvert = isRoot;
    var loop = function ( i ) {
      var key = keys[i];
      /* istanbul ignore else */
      if (process.env.NODE_ENV !== 'production') {
        if (isReservedProp(key)) {
          warn(
            ("\"" + key + "\" is a reserved attribute and cannot be used as component prop."),
            vm
          );
        }
        defineReactive$$1(vm, key, validateProp(key, props, propsData, vm), function () {
          if (vm.$parent && !observerState.isSettingProps) {
            warn(
              "Avoid mutating a prop directly since the value will be " +
              "overwritten whenever the parent component re-renders. " +
              "Instead, use a data or computed property based on the prop's " +
              "value. Prop being mutated: \"" + key + "\"",
              vm
            );
          }
        });
      } else {
        defineReactive$$1(vm, key, validateProp(key, props, propsData, vm));
      }
    };

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

function initData (vm) {
  var data = vm.$options.data;
  data = vm._data = typeof data === 'function'
    ? data.call(vm)
    : data || {};
  if (!isPlainObject(data)) {
    data = {};
    process.env.NODE_ENV !== 'production' && warn(
      'data functions should return an object.',
      vm
    );
  }
  // proxy data on instance
  var keys = Object.keys(data);
  var props = vm.$options.props;
  var i = keys.length;
  while (i--) {
    if (props && hasOwn(props, keys[i])) {
      process.env.NODE_ENV !== 'production' && warn(
        "The data property \"" + (keys[i]) + "\" is already declared as a prop. " +
        "Use prop default value instead.",
        vm
      );
    } else {
      proxy(vm, keys[i]);
    }
  }
  // observe data
  observe(data);
  data.__ob__ && data.__ob__.vmCount++;
}

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

function initComputed (vm) {
  var computed = vm.$options.computed;
  if (computed) {
    for (var key in computed) {
      var userDef = computed[key];
      if (typeof userDef === 'function') {
        computedSharedDefinition.get = makeComputedGetter(userDef, vm);
        computedSharedDefinition.set = noop;
      } else {
        computedSharedDefinition.get = userDef.get
          ? userDef.cache !== false
            ? makeComputedGetter(userDef.get, vm)
            : bind(userDef.get, vm)
          : noop;
        computedSharedDefinition.set = userDef.set
          ? bind(userDef.set, vm)
          : noop;
      }
      Object.defineProperty(vm, key, computedSharedDefinition);
    }
  }
}

function makeComputedGetter (getter, owner) {
  var watcher = new Watcher(owner, getter, noop, {
    lazy: true
  });
  return function computedGetter () {
    if (watcher.dirty) {
      watcher.evaluate();
    }
    if (Dep.target) {
      watcher.depend();
    }
    return watcher.value
  }
}

function initMethods (vm) {
  var methods = vm.$options.methods;
  if (methods) {
    for (var key in methods) {
      vm[key] = methods[key] == null ? noop : bind(methods[key], vm);
      if (process.env.NODE_ENV !== 'production' && methods[key] == null) {
        warn(
          "method \"" + key + "\" has an undefined value in the component definition. " +
          "Did you reference the function correctly?",
          vm
        );
      }
    }
  }
}

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

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

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

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

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

function proxy (vm, key) {
  if (!isReserved(key)) {
    Object.defineProperty(vm, key, {
      configurable: true,
      enumerable: true,
      get: function proxyGetter () {
        return vm._data[key]
      },
      set: function proxySetter (val) {
        vm._data[key] = val;
      }
    });
  }
}

/*  */

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

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

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

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

/*  */

/*  */

function updateListeners (
  on,
  oldOn,
  add,
  remove$$1,
  vm
) {
  var name, cur, old, fn, event, capture;
  for (name in on) {
    cur = on[name];
    old = oldOn[name];
    if (!cur) {
      process.env.NODE_ENV !== 'production' && warn(
        "Invalid handler for event \"" + name + "\": got " + String(cur),
        vm
      );
    } else if (!old) {
      capture = name.charAt(0) === '!';
      event = capture ? name.slice(1) : name;
      if (Array.isArray(cur)) {
        add(event, (cur.invoker = arrInvoker(cur)), capture);
      } else {
        if (!cur.invoker) {
          fn = cur;
          cur = on[name] = {};
          cur.fn = fn;
          cur.invoker = fnInvoker(cur);
        }
        add(event, cur.invoker, capture);
      }
    } else if (cur !== old) {
      if (Array.isArray(old)) {
        old.length = cur.length;
        for (var i = 0; i < old.length; i++) { old[i] = cur[i]; }
        on[name] = old;
      } else {
        old.fn = cur;
        on[name] = old;
      }
    }
  }
  for (name in oldOn) {
    if (!on[name]) {
      event = name.charAt(0) === '!' ? name.slice(1) : name;
      remove$$1(event, oldOn[name].invoker);
    }
  }
}

function arrInvoker (arr) {
  return function (ev) {
    var arguments$1 = arguments;

    var single = arguments.length === 1;
    for (var i = 0; i < arr.length; i++) {
      single ? arr[i](ev) : arr[i].apply(null, arguments$1);
    }
  }
}

function fnInvoker (o) {
  return function (ev) {
    var single = arguments.length === 1;
    single ? o.fn(ev) : o.fn.apply(null, arguments);
  }
}

/*  */

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

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

function applyNS (vnode, ns) {
  if (vnode.tag && !vnode.ns) {
    vnode.ns = ns;
    if (vnode.children) {
      for (var i = 0, l = vnode.children.length; i < l; i++) {
        applyNS(vnode.children[i], ns);
      }
    }
  }
}

/*  */

/*  */

var activeInstance = null;

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

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

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

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

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

function lifecycleMixin (Vue) {
  Vue.prototype._mount = function (
    el,
    hydrating
  ) {
    var vm = this;
    vm.$el = el;
    if (!vm.$options.render) {
      vm.$options.render = emptyVNode;
      if (process.env.NODE_ENV !== 'production') {
        /* istanbul ignore if */
        if (vm.$options.template && vm.$options.template.charAt(0) !== '#') {
          warn(
            'You are using the runtime-only build of Vue where the template ' +
            'option is not available. Either pre-compile the templates into ' +
            'render functions, or use the compiler-included build.',
            vm
          );
        } else {
          warn(
            'Failed to mount component: template or render function not defined.',
            vm
          );
        }
      }
    }
    callHook(vm, 'beforeMount');
    vm._watcher = new Watcher(vm, function () {
      vm._update(vm._render(), hydrating);
    }, noop);
    hydrating = false;
    // manually mounted instance, call mounted on self
    // mounted is called for render-created child components in its inserted hook
    if (vm.$vnode == null) {
      vm._isMounted = true;
      callHook(vm, 'mounted');
    }
    return vm
  };

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

  Vue.prototype._updateFromParent = function (
    propsData,
    listeners,
    parentVnode,
    renderChildren
  ) {
    var vm = this;
    var hasChildren = !!(vm.$options._renderChildren || renderChildren);
    vm.$options._parentVnode = parentVnode;
    vm.$vnode = parentVnode; // update vm's placeholder node without re-render
    if (vm._vnode) { // update child tree's parent
      vm._vnode.parent = parentVnode;
    }
    vm.$options._renderChildren = renderChildren;
    // update props
    if (propsData && vm.$options.props) {
      observerState.shouldConvert = false;
      if (process.env.NODE_ENV !== 'production') {
        observerState.isSettingProps = true;
      }
      var propKeys = vm.$options._propKeys || [];
      for (var i = 0; i < propKeys.length; i++) {
        var key = propKeys[i];
        vm[key] = validateProp(key, vm.$options.props, propsData, vm);
      }
      observerState.shouldConvert = true;
      if (process.env.NODE_ENV !== 'production') {
        observerState.isSettingProps = false;
      }
      vm.$options.propsData = propsData;
    }
    // update listeners
    if (listeners) {
      var oldListeners = vm.$options._parentListeners;
      vm.$options._parentListeners = listeners;
      vm._updateListeners(listeners, oldListeners);
    }
    // resolve slots + force update if has children
    if (hasChildren) {
      vm.$slots = resolveSlots(renderChildren, parentVnode.context);
      vm.$forceUpdate();
    }
  };

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

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

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

/*  */

var hooks = { init: init, prepatch: prepatch, insert: insert, destroy: destroy };
var hooksToMerge = Object.keys(hooks);

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

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

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

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

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

  data = data || {};

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

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

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

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

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

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

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

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

function init (
  vnode,
  hydrating,
  parentElm,
  refElm
) {
  if (!vnode.child || vnode.child._isDestroyed) {
    var child = vnode.child = createComponentInstanceForVnode(
      vnode,
      activeInstance,
      parentElm,
      refElm
    );
    child.$mount(hydrating ? vnode.elm : undefined, hydrating);
  } else if (vnode.data.keepAlive) {
    // kept-alive components, treat as a patch
    var mountedNode = vnode; // work around flow
    prepatch(mountedNode, mountedNode);
    return true // let the patcher know this is a reactivated component
  }
}

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

function insert (vnode) {
  if (!vnode.child._isMounted) {
    vnode.child._isMounted = true;
    callHook(vnode.child, 'mounted');
  }
  if (vnode.data.keepAlive) {
    vnode.child._inactive = false;
    callHook(vnode.child, 'activated');
  }
}

function destroy (vnode) {
  if (!vnode.child._isDestroyed) {
    if (!vnode.data.keepAlive) {
      vnode.child.$destroy();
    } else {
      vnode.child._inactive = true;
      callHook(vnode.child, 'deactivated');
    }
  }
}

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

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

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

    var res = factory(resolve, reject);

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

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

function extractProps (data, Ctor) {
  // we are only extracting raw values here.
  // validation and default values are handled in the child
  // component itself.
  var propOptions = Ctor.options.props;
  if (!propOptions) {
    return
  }
  var res = {};
  var attrs = data.attrs;
  var props = data.props;
  var domProps = data.domProps;
  if (attrs || props || domProps) {
    for (var key in propOptions) {
      var altKey = hyphenate(key);
      checkProp(res, props, key, altKey, true) ||
      checkProp(res, attrs, key, altKey) ||
      checkProp(res, domProps, key, altKey);
    }
  }
  return res
}

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

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

function mergeHook$1 (a, b) {
  // since all hooks have at most two args, use fixed args
  // to avoid having to use fn.apply().
  return function (_, __) {
    a(_, __);
    b(_, __);
  }
}

/*  */

// wrapper function for providing a more flexible interface
// without getting yelled at by flow
function createElement (
  tag,
  data,
  children
) {
  if (data && (Array.isArray(data) || typeof data !== 'object')) {
    children = data;
    data = undefined;
  }
  // make sure to use real instance instead of proxy as context
  return _createElement(this._self, tag, data, children)
}

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

/*  */

function initRender (vm) {
  vm.$vnode = null; // the placeholder node in parent tree
  vm._vnode = null; // the root of the child tree
  vm._staticTrees = null;
  var parentVnode = vm.$options._parentVnode;
  var renderContext = parentVnode && parentVnode.context;
  vm.$slots = resolveSlots(vm.$options._renderChildren, renderContext);
  vm.$scopedSlots = {};
  // bind the public createElement fn to this instance
  // so that we get proper render context inside it.
  vm.$createElement = bind(createElement, vm);
  if (vm.$options.el) {
    vm.$mount(vm.$options.el);
  }
}

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

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

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

    if (_parentVnode && _parentVnode.data.scopedSlots) {
      vm.$scopedSlots = _parentVnode.data.scopedSlots;
    }

    if (staticRenderFns && !vm._staticTrees) {
      vm._staticTrees = [];
    }
    // set parent vnode. this allows render functions to have access
    // to the data on the placeholder node.
    vm.$vnode = _parentVnode;
    // render self
    var vnode;
    try {
      vnode = render.call(vm._renderProxy, vm.$createElement);
    } catch (e) {
      /* istanbul ignore else */
      if (config.errorHandler) {
        config.errorHandler.call(null, e, vm);
      } else {
        if (process.env.NODE_ENV !== 'production') {
          warn(("Error when rendering " + (formatComponentName(vm)) + ":"));
        }
        throw e
      }
      // return previous vnode to prevent render error causing blank component
      vnode = vm._vnode;
    }
    // return empty vnode in case the render function errored out
    if (!(vnode instanceof VNode)) {
      if (process.env.NODE_ENV !== 'production' && Array.isArray(vnode)) {
        warn(
          'Multiple root nodes returned from render function. Render function ' +
          'should return a single root node.',
          vm
        );
      }
      vnode = emptyVNode();
    }
    // set parent
    vnode.parent = _parentVnode;
    return vnode
  };

  // shorthands used in render functions
  Vue.prototype._h = createElement;
  // toString for mustaches
  Vue.prototype._s = _toString;
  // number conversion
  Vue.prototype._n = toNumber;
  // empty vnode
  Vue.prototype._e = emptyVNode;
  // loose equal
  Vue.prototype._q = looseEqual;
  // loose indexOf
  Vue.prototype._i = looseIndexOf;

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

  // mark node as static (v-once)
  Vue.prototype._o = function markOnce (
    tree,
    index,
    key
  ) {
    markStatic(tree, ("__once__" + index + (key ? ("_" + key) : "")), true);
    return tree
  };

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

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

  // filter resolution helper
  var identity = function (_) { return _; };
  Vue.prototype._f = function resolveFilter (id) {
    return resolveAsset(this.$options, 'filters', id, true) || identity
  };

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

  // renderSlot
  Vue.prototype._t = function (
    name,
    fallback,
    props
  ) {
    var scopedSlotFn = this.$scopedSlots[name];
    if (scopedSlotFn) { // scoped slot
      return scopedSlotFn(props || {}) || fallback
    } else {
      var slotNodes = this.$slots[name];
      // warn duplicate slot usage
      if (slotNodes && process.env.NODE_ENV !== 'production') {
        slotNodes._rendered && warn(
          "Duplicate presence of slot \"" + name + "\" found in the same render tree " +
          "- this will likely cause render errors.",
          this
        );
        slotNodes._rendered = true;
      }
      return slotNodes || fallback
    }
  };

  // apply v-bind object
  Vue.prototype._b = function bindProps (
    data,
    tag,
    value,
    asProp
  ) {
    if (value) {
      if (!isObject(value)) {
        process.env.NODE_ENV !== 'production' && warn(
          'v-bind without argument expects an Object or Array value',
          this
        );
      } else {
        if (Array.isArray(value)) {
          value = toObject(value);
        }
        for (var key in value) {
          if (key === 'class' || key === 'style') {
            data[key] = value[key];
          } else {
            var hash = asProp || config.mustUseProp(tag, key)
              ? data.domProps || (data.domProps = {})
              : data.attrs || (data.attrs = {});
            hash[key] = value[key];
          }
        }
      }
    }
    return data
  };

  // expose v-on keyCodes
  Vue.prototype._k = function getKeyCodes (key) {
    return config.keyCodes[key]
  };
}

function resolveSlots (
  renderChildren,
  context
) {
  var slots = {};
  if (!renderChildren) {
    return slots
  }
  var children = normalizeChildren(renderChildren) || [];
  var defaultSlot = [];
  var name, child;
  for (var i = 0, l = children.length; i < l; i++) {
    child = children[i];
    // named slots should only be respected if the vnode was rendered in the
    // same context.
    if ((child.context === context || child.functionalContext === context) &&
        child.data && (name = child.data.slot)) {
      var slot = (slots[name] || (slots[name] = []));
      if (child.tag === 'template') {
        slot.push.apply(slot, child.children);
      } else {
        slot.push(child);
      }
    } else {
      defaultSlot.push(child);
    }
  }
  // ignore single whitespace
  if (defaultSlot.length && !(
    defaultSlot.length === 1 &&
    (defaultSlot[0].text === ' ' || defaultSlot[0].isComment)
  )) {
    slots.default = defaultSlot;
  }
  return slots
}

/*  */

function initEvents (vm) {
  vm._events = Object.create(null);
  // init parent attached events
  var listeners = vm.$options._parentListeners;
  var on = bind(vm.$on, vm);
  var off = bind(vm.$off, vm);
  vm._updateListeners = function (listeners, oldListeners) {
    updateListeners(listeners, oldListeners || {}, on, off, vm);
  };
  if (listeners) {
    vm._updateListeners(listeners);
  }
}

function eventsMixin (Vue) {
  Vue.prototype.$on = function (event, fn) {
    var vm = this;(vm._events[event] || (vm._events[event] = [])).push(fn);
    return vm
  };

  Vue.prototype.$once = function (event, fn) {
    var vm = this;
    function on () {
      vm.$off(event, on);
      fn.apply(vm, arguments);
    }
    on.fn = fn;
    vm.$on(event, on);
    return vm
  };

  Vue.prototype.$off = function (event, fn) {
    var vm = this;
    // all
    if (!arguments.length) {
      vm._events = Object.create(null);
      return vm
    }
    // specific event
    var cbs = vm._events[event];
    if (!cbs) {
      return vm
    }
    if (arguments.length === 1) {
      vm._events[event] = null;
      return vm
    }
    // specific handler
    var cb;
    var i = cbs.length;
    while (i--) {
      cb = cbs[i];
      if (cb === fn || cb.fn === fn) {
        cbs.splice(i, 1);
        break
      }
    }
    return vm
  };

  Vue.prototype.$emit = function (event) {
    var vm = this;
    var cbs = vm._events[event];
    if (cbs) {
      cbs = cbs.length > 1 ? toArray(cbs) : cbs;
      var args = toArray(arguments, 1);
      for (var i = 0, l = cbs.length; i < l; i++) {
        cbs[i].apply(vm, args);
      }
    }
    return vm
  };
}

/*  */

var uid = 0;

function initMixin (Vue) {
  Vue.prototype._init = function (options) {
    var vm = this;
    // a uid
    vm._uid = uid++;
    // a flag to avoid this being observed
    vm._isVue = true;
    // merge options
    if (options && options._isComponent) {
      // optimize internal component instantiation
      // since dynamic options merging is pretty slow, and none of the
      // internal component options needs special treatment.
      initInternalComponent(vm, options);
    } else {
      vm.$options = mergeOptions(
        resolveConstructorOptions(vm.constructor),
        options || {},
        vm
      );
    }
    /* istanbul ignore else */
    if (process.env.NODE_ENV !== 'production') {
      initProxy(vm);
    } else {
      vm._renderProxy = vm;
    }
    // expose real self
    vm._self = vm;
    initLifecycle(vm);
    initEvents(vm);
    callHook(vm, 'beforeCreate');
    initState(vm);
    callHook(vm, 'created');
    initRender(vm);
  };
}

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

function resolveConstructorOptions (Ctor) {
  var options = Ctor.options;
  if (Ctor.super) {
    var superOptions = Ctor.super.options;
    var cachedSuperOptions = Ctor.superOptions;
    var extendOptions = Ctor.extendOptions;
    if (superOptions !== cachedSuperOptions) {
      // super option changed
      Ctor.superOptions = superOptions;
      extendOptions.render = options.render;
      extendOptions.staticRenderFns = options.staticRenderFns;
      extendOptions._scopeId = options._scopeId;
      options = Ctor.options = mergeOptions(superOptions, extendOptions);
      if (options.name) {
        options.components[options.name] = Ctor;
      }
    }
  }
  return options
}

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

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

/*  */

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

/**
 * Resolve an asset.
 * This function is used because child instances need access
 * to assets defined in its ancestor chain.
 */
function resolveAsset (
  options,
  type,
  id,
  warnMissing
) {
  /* istanbul ignore if */
  if (typeof id !== 'string') {
    return
  }
  var assets = options[type];
  var res = assets[id] ||
    // camelCase ID
    assets[camelize(id)] ||
    // Pascal Case ID
    assets[capitalize(camelize(id))];
  if (process.env.NODE_ENV !== 'production' && warnMissing && !res) {
    warn(
      'Failed to resolve ' + type.slice(0, -1) + ': ' + id,
      options
    );
  }
  return res
}

/*  */

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

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

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

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

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

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

/*  */

// attributes that should be using props for binding


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

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

var isAttr = makeMap(
  'accept,accept-charset,accesskey,action,align,alt,async,autocomplete,' +
  'autofocus,autoplay,autosave,bgcolor,border,buffered,challenge,charset,' +
  'checked,cite,class,code,codebase,color,cols,colspan,content,http-equiv,' +
  'name,contenteditable,contextmenu,controls,coords,data,datetime,default,' +
  'defer,dir,dirname,disabled,download,draggable,dropzone,enctype,method,for,' +
  'form,formaction,headers,<th>,height,hidden,high,href,hreflang,http-equiv,' +
  'icon,id,ismap,itemprop,keytype,kind,label,lang,language,list,loop,low,' +
  'manifest,max,maxlength,media,method,GET,POST,min,multiple,email,file,' +
  'muted,name,novalidate,open,optimum,pattern,ping,placeholder,poster,' +
  'preload,radiogroup,readonly,rel,required,reversed,rows,rowspan,sandbox,' +
  'scope,scoped,seamless,selected,shape,size,type,text,password,sizes,span,' +
  'spellcheck,src,srcdoc,srclang,srcset,start,step,style,summary,tabindex,' +
  'target,title,type,usemap,value,width,wrap'
);

/*  */



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

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

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

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

/*  */



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

var isUnaryTag = makeMap(
  'area,base,br,col,embed,frame,hr,img,input,isindex,keygen,' +
  'link,meta,param,source,track,wbr',
  true
);

// Elements that you can, intentionally, leave open
// (and which close themselves)
var canBeLeftOpenTag = makeMap(
  'colgroup,dd,dt,li,options,p,td,tfoot,th,thead,tr,source',
  true
);

// HTML5 tags https://html.spec.whatwg.org/multipage/indices.html#elements-3
// Phrasing Content https://html.spec.whatwg.org/multipage/dom.html#phrasing-content
var isNonPhrasingTag = makeMap(
  'address,article,aside,base,blockquote,body,caption,col,colgroup,dd,' +
  'details,dialog,div,dl,dt,fieldset,figcaption,figure,footer,form,' +
  'h1,h2,h3,h4,h5,h6,head,header,hgroup,hr,html,legend,li,menuitem,meta,' +
  'optgroup,option,param,rp,rt,source,style,summary,tbody,td,tfoot,th,thead,' +
  'title,tr,track',
  true
);

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



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



var unknownElementCache = Object.create(null);

/*  */

/**
 * Query an element selector if it's not an element already.
 */

/**
 * Not type-checking this file because it's mostly vendor code.
 */

/*!
 * HTML Parser By John Resig (ejohn.org)
 * Modified by Juriy "kangax" Zaytsev
 * Original code by Erik Arvidsson, Mozilla Public License
 * http://erik.eae.net/simplehtmlparser/simplehtmlparser.js
 */

// Regular Expressions for parsing tags and attributes
var singleAttrIdentifier = /([^\s"'<>/=]+)/;
var singleAttrAssign = /(?:=)/;
var singleAttrValues = [
  // attr value double quotes
  /"([^"]*)"+/.source,
  // attr value, single quotes
  /'([^']*)'+/.source,
  // attr value, no quotes
  /([^\s"'=<>`]+)/.source
];
var attribute = new RegExp(
  '^\\s*' + singleAttrIdentifier.source +
  '(?:\\s*(' + singleAttrAssign.source + ')' +
  '\\s*(?:' + singleAttrValues.join('|') + '))?'
);

// could use https://www.w3.org/TR/1999/REC-xml-names-19990114/#NT-QName
// but for Vue templates we can enforce a simple charset
var ncname = '[a-zA-Z_][\\w\\-\\.]*';
var qnameCapture = '((?:' + ncname + '\\:)?' + ncname + ')';
var startTagOpen = new RegExp('^<' + qnameCapture);
var startTagClose = /^\s*(\/?)>/;
var endTag = new RegExp('^<\\/' + qnameCapture + '[^>]*>');
var doctype = /^<!DOCTYPE [^>]+>/i;
var comment = /^<!--/;
var conditionalComment = /^<!\[/;

var IS_REGEX_CAPTURING_BROKEN = false;
'x'.replace(/x(.)?/g, function (m, g) {
  IS_REGEX_CAPTURING_BROKEN = g === '';
});

// Special Elements (can contain anything)
var isScriptOrStyle = makeMap('script,style', true);
var hasLang = function (attr) { return attr.name === 'lang' && attr.value !== 'html'; };
var isSpecialTag = function (tag, isSFC, stack) {
  if (isScriptOrStyle(tag)) {
    return true
  }
  if (isSFC && stack.length === 1) {
    // top-level template that has no pre-processor
    if (tag === 'template' && !stack[0].attrs.some(hasLang)) {
      return false
    } else {
      return true
    }
  }
  return false
};

var reCache = {};

var ltRE = /&lt;/g;
var gtRE = /&gt;/g;
var nlRE = /&#10;/g;
var ampRE = /&amp;/g;
var quoteRE = /&quot;/g;

function decodeAttr (value, shouldDecodeNewlines) {
  if (shouldDecodeNewlines) {
    value = value.replace(nlRE, '\n');
  }
  return value
    .replace(ltRE, '<')
    .replace(gtRE, '>')
    .replace(ampRE, '&')
    .replace(quoteRE, '"')
}

function parseHTML (html, options) {
  var stack = [];
  var expectHTML = options.expectHTML;
  var isUnaryTag$$1 = options.isUnaryTag || no;
  var index = 0;
  var last, lastTag;
  while (html) {
    last = html;
    // Make sure we're not in a script or style element
    if (!lastTag || !isSpecialTag(lastTag, options.sfc, stack)) {
      var textEnd = html.indexOf('<');
      if (textEnd === 0) {
        // Comment:
        if (comment.test(html)) {
          var commentEnd = html.indexOf('-->');

          if (commentEnd >= 0) {
            advance(commentEnd + 3);
            continue
          }
        }

        // http://en.wikipedia.org/wiki/Conditional_comment#Downlevel-revealed_conditional_comment
        if (conditionalComment.test(html)) {
          var conditionalEnd = html.indexOf(']>');

          if (conditionalEnd >= 0) {
            advance(conditionalEnd + 2);
            continue
          }
        }

        // Doctype:
        var doctypeMatch = html.match(doctype);
        if (doctypeMatch) {
          advance(doctypeMatch[0].length);
          continue
        }

        // End tag:
        var endTagMatch = html.match(endTag);
        if (endTagMatch) {
          var curIndex = index;
          advance(endTagMatch[0].length);
          parseEndTag(endTagMatch[0], endTagMatch[1], curIndex, index);
          continue
        }

        // Start tag:
        var startTagMatch = parseStartTag();
        if (startTagMatch) {
          handleStartTag(startTagMatch);
          continue
        }
      }

      var text = (void 0), rest$1 = (void 0), next = (void 0);
      if (textEnd > 0) {
        rest$1 = html.slice(textEnd);
        while (
          !endTag.test(rest$1) &&
          !startTagOpen.test(rest$1) &&
          !comment.test(rest$1) &&
          !conditionalComment.test(rest$1)
        ) {
          // < in plain text, be forgiving and treat it as text
          next = rest$1.indexOf('<', 1);
          if (next < 0) { break }
          textEnd += next;
          rest$1 = html.slice(textEnd);
        }
        text = html.substring(0, textEnd);
        advance(textEnd);
      }

      if (textEnd < 0) {
        text = html;
        html = '';
      }

      if (options.chars && text) {
        options.chars(text);
      }
    } else {
      var stackedTag = lastTag.toLowerCase();
      var reStackedTag = reCache[stackedTag] || (reCache[stackedTag] = new RegExp('([\\s\\S]*?)(</' + stackedTag + '[^>]*>)', 'i'));
      var endTagLength = 0;
      var rest = html.replace(reStackedTag, function (all, text, endTag) {
        endTagLength = endTag.length;
        if (stackedTag !== 'script' && stackedTag !== 'style' && stackedTag !== 'noscript') {
          text = text
            .replace(/<!--([\s\S]*?)-->/g, '$1')
            .replace(/<!\[CDATA\[([\s\S]*?)]]>/g, '$1');
        }
        if (options.chars) {
          options.chars(text);
        }
        return ''
      });
      index += html.length - rest.length;
      html = rest;
      parseEndTag('</' + stackedTag + '>', stackedTag, index - endTagLength, index);
    }

    if (html === last && options.chars) {
      options.chars(html);
      break
    }
  }

  // Clean up any remaining tags
  parseEndTag();

  function advance (n) {
    index += n;
    html = html.substring(n);
  }

  function parseStartTag () {
    var start = html.match(startTagOpen);
    if (start) {
      var match = {
        tagName: start[1],
        attrs: [],
        start: index
      };
      advance(start[0].length);
      var end, attr;
      while (!(end = html.match(startTagClose)) && (attr = html.match(attribute))) {
        advance(attr[0].length);
        match.attrs.push(attr);
      }
      if (end) {
        match.unarySlash = end[1];
        advance(end[0].length);
        match.end = index;
        return match
      }
    }
  }

  function handleStartTag (match) {
    var tagName = match.tagName;
    var unarySlash = match.unarySlash;

    if (expectHTML) {
      if (lastTag === 'p' && isNonPhrasingTag(tagName)) {
        parseEndTag('', lastTag);
      }
      if (canBeLeftOpenTag(tagName) && lastTag === tagName) {
        parseEndTag('', tagName);
      }
    }

    var unary = isUnaryTag$$1(tagName) || tagName === 'html' && lastTag === 'head' || !!unarySlash;

    var l = match.attrs.length;
    var attrs = new Array(l);
    for (var i = 0; i < l; i++) {
      var args = match.attrs[i];
      // hackish work around FF bug https://bugzilla.mozilla.org/show_bug.cgi?id=369778
      if (IS_REGEX_CAPTURING_BROKEN && args[0].indexOf('""') === -1) {
        if (args[3] === '') { delete args[3]; }
        if (args[4] === '') { delete args[4]; }
        if (args[5] === '') { delete args[5]; }
      }
      var value = args[3] || args[4] || args[5] || '';
      attrs[i] = {
        name: args[1],
        value: decodeAttr(
          value,
          options.shouldDecodeNewlines
        )
      };
    }

    if (!unary) {
      stack.push({ tag: tagName, attrs: attrs });
      lastTag = tagName;
      unarySlash = '';
    }

    if (options.start) {
      options.start(tagName, attrs, unary, match.start, match.end);
    }
  }

  function parseEndTag (tag, tagName, start, end) {
    var pos;
    if (start == null) { start = index; }
    if (end == null) { end = index; }

    // Find the closest opened tag of the same type
    if (tagName) {
      var needle = tagName.toLowerCase();
      for (pos = stack.length - 1; pos >= 0; pos--) {
        if (stack[pos].tag.toLowerCase() === needle) {
          break
        }
      }
    } else {
      // If no tag name is provided, clean shop
      pos = 0;
    }

    if (pos >= 0) {
      // Close all the open elements, up the stack
      for (var i = stack.length - 1; i >= pos; i--) {
        if (options.end) {
          options.end(stack[i].tag, start, end);
        }
      }

      // Remove the open elements from the stack
      stack.length = pos;
      lastTag = pos && stack[pos - 1].tag;
    } else if (tagName.toLowerCase() === 'br') {
      if (options.start) {
        options.start(tagName, [], true, start, end);
      }
    } else if (tagName.toLowerCase() === 'p') {
      if (options.start) {
        options.start(tagName, [], false, start, end);
      }
      if (options.end) {
        options.end(tagName, start, end);
      }
    }
  }
}

/*  */

function parseFilters (exp) {
  var inSingle = false;
  var inDouble = false;
  var inTemplateString = false;
  var inRegex = false;
  var curly = 0;
  var square = 0;
  var paren = 0;
  var lastFilterIndex = 0;
  var c, prev, i, expression, filters;

  for (i = 0; i < exp.length; i++) {
    prev = c;
    c = exp.charCodeAt(i);
    if (inSingle) {
      if (c === 0x27 && prev !== 0x5C) { inSingle = false; }
    } else if (inDouble) {
      if (c === 0x22 && prev !== 0x5C) { inDouble = false; }
    } else if (inTemplateString) {
      if (c === 0x60 && prev !== 0x5C) { inTemplateString = false; }
    } else if (inRegex) {
      if (c === 0x2f && prev !== 0x5C) { inRegex = false; }
    } else if (
      c === 0x7C && // pipe
      exp.charCodeAt(i + 1) !== 0x7C &&
      exp.charCodeAt(i - 1) !== 0x7C &&
      !curly && !square && !paren
    ) {
      if (expression === undefined) {
        // first filter, end of expression
        lastFilterIndex = i + 1;
        expression = exp.slice(0, i).trim();
      } else {
        pushFilter();
      }
    } else {
      switch (c) {
        case 0x22: inDouble = true; break         // "
        case 0x27: inSingle = true; break         // '
        case 0x60: inTemplateString = true; break // `
        case 0x2f: inRegex = true; break          // /
        case 0x28: paren++; break                 // (
        case 0x29: paren--; break                 // )
        case 0x5B: square++; break                // [
        case 0x5D: square--; break                // ]
        case 0x7B: curly++; break                 // {
        case 0x7D: curly--; break                 // }
      }
    }
  }

  if (expression === undefined) {
    expression = exp.slice(0, i).trim();
  } else if (lastFilterIndex !== 0) {
    pushFilter();
  }

  function pushFilter () {
    (filters || (filters = [])).push(exp.slice(lastFilterIndex, i).trim());
    lastFilterIndex = i + 1;
  }

  if (filters) {
    for (i = 0; i < filters.length; i++) {
      expression = wrapFilter(expression, filters[i]);
    }
  }

  return expression
}

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

/*  */

var defaultTagRE = /\{\{((?:.|\n)+?)\}\}/g;
var regexEscapeRE = /[-.*+?^${}()|[\]/\\]/g;

var buildRegex = cached(function (delimiters) {
  var open = delimiters[0].replace(regexEscapeRE, '\\$&');
  var close = delimiters[1].replace(regexEscapeRE, '\\$&');
  return new RegExp(open + '((?:.|\\n)+?)' + close, 'g')
});

function parseText (
  text,
  delimiters
) {
  var tagRE = delimiters ? buildRegex(delimiters) : defaultTagRE;
  if (!tagRE.test(text)) {
    return
  }
  var tokens = [];
  var lastIndex = tagRE.lastIndex = 0;
  var match, index;
  while ((match = tagRE.exec(text))) {
    index = match.index;
    // push text token
    if (index > lastIndex) {
      tokens.push(JSON.stringify(text.slice(lastIndex, index)));
    }
    // tag token
    var exp = parseFilters(match[1].trim());
    tokens.push(("_s(" + exp + ")"));
    lastIndex = index + match[0].length;
  }
  if (lastIndex < text.length) {
    tokens.push(JSON.stringify(text.slice(lastIndex)));
  }
  return tokens.join('+')
}

/*  */

function baseWarn (msg) {
  console.error(("[Vue parser]: " + msg));
}

function pluckModuleFunction (
  modules,
  key
) {
  return modules
    ? modules.map(function (m) { return m[key]; }).filter(function (_) { return _; })
    : []
}

function addProp (el, name, value) {
  (el.props || (el.props = [])).push({ name: name, value: value });
}

function addAttr (el, name, value) {
  (el.attrs || (el.attrs = [])).push({ name: name, value: value });
}

function addDirective (
  el,
  name,
  rawName,
  value,
  arg,
  modifiers
) {
  (el.directives || (el.directives = [])).push({ name: name, rawName: rawName, value: value, arg: arg, modifiers: modifiers });
}

function addHandler (
  el,
  name,
  value,
  modifiers,
  important
) {
  // check capture modifier
  if (modifiers && modifiers.capture) {
    delete modifiers.capture;
    name = '!' + name; // mark the event as captured
  }
  var events;
  if (modifiers && modifiers.native) {
    delete modifiers.native;
    events = el.nativeEvents || (el.nativeEvents = {});
  } else {
    events = el.events || (el.events = {});
  }
  var newHandler = { value: value, modifiers: modifiers };
  var handlers = events[name];
  /* istanbul ignore if */
  if (Array.isArray(handlers)) {
    important ? handlers.unshift(newHandler) : handlers.push(newHandler);
  } else if (handlers) {
    events[name] = important ? [newHandler, handlers] : [handlers, newHandler];
  } else {
    events[name] = newHandler;
  }
}

function getBindingAttr (
  el,
  name,
  getStatic
) {
  var dynamicValue =
    getAndRemoveAttr(el, ':' + name) ||
    getAndRemoveAttr(el, 'v-bind:' + name);
  if (dynamicValue != null) {
    return parseFilters(dynamicValue)
  } else if (getStatic !== false) {
    var staticValue = getAndRemoveAttr(el, name);
    if (staticValue != null) {
      return JSON.stringify(staticValue)
    }
  }
}

function getAndRemoveAttr (el, name) {
  var val;
  if ((val = el.attrsMap[name]) != null) {
    var list = el.attrsList;
    for (var i = 0, l = list.length; i < l; i++) {
      if (list[i].name === name) {
        list.splice(i, 1);
        break
      }
    }
  }
  return val
}

var len;
var str;
var chr;
var index$1;
var expressionPos;
var expressionEndPos;

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

function parseModel (val) {
  str = val;
  len = str.length;
  index$1 = expressionPos = expressionEndPos = 0;

  if (val.indexOf('[') < 0 || val.lastIndexOf(']') < len - 1) {
    return {
      exp: val,
      idx: null
    }
  }

  while (!eof()) {
    chr = next();
    /* istanbul ignore if */
    if (isStringStart(chr)) {
      parseString(chr);
    } else if (chr === 0x5B) {
      parseBracket(chr);
    }
  }

  return {
    exp: val.substring(0, expressionPos),
    idx: val.substring(expressionPos + 1, expressionEndPos)
  }
}

function next () {
  return str.charCodeAt(++index$1)
}

function eof () {
  return index$1 >= len
}

function isStringStart (chr) {
  return chr === 0x22 || chr === 0x27
}

function parseBracket (chr) {
  var inBracket = 1;
  expressionPos = index$1;
  while (!eof()) {
    chr = next();
    if (isStringStart(chr)) {
      parseString(chr);
      continue
    }
    if (chr === 0x5B) { inBracket++; }
    if (chr === 0x5D) { inBracket--; }
    if (inBracket === 0) {
      expressionEndPos = index$1;
      break
    }
  }
}

function parseString (chr) {
  var stringQuote = chr;
  while (!eof()) {
    chr = next();
    if (chr === stringQuote) {
      break
    }
  }
}

/*  */

var dirRE = /^v-|^@|^:/;
var forAliasRE = /(.*?)\s+(?:in|of)\s+(.*)/;
var forIteratorRE = /\((\{[^}]*\}|[^,]*),([^,]*)(?:,([^,]*))?\)/;
var bindRE = /^:|^v-bind:/;
var onRE = /^@|^v-on:/;
var argRE = /:(.*)$/;
var modifierRE = /\.[^.]+/g;

var decodeHTMLCached = cached(he.decode);

// configurable state
var warn$1;
var platformGetTagNamespace;
var platformMustUseProp;
var platformIsPreTag;
var preTransforms;
var transforms;
var postTransforms;
var delimiters;

/**
 * Convert HTML string to AST.
 */
function parse (
  template,
  options
) {
  warn$1 = options.warn || baseWarn;
  platformGetTagNamespace = options.getTagNamespace || no;
  platformMustUseProp = options.mustUseProp || no;
  platformIsPreTag = options.isPreTag || no;
  preTransforms = pluckModuleFunction(options.modules, 'preTransformNode');
  transforms = pluckModuleFunction(options.modules, 'transformNode');
  postTransforms = pluckModuleFunction(options.modules, 'postTransformNode');
  delimiters = options.delimiters;
  var stack = [];
  var preserveWhitespace = options.preserveWhitespace !== false;
  var root;
  var currentParent;
  var inVPre = false;
  var inPre = false;
  var warned = false;
  parseHTML(template, {
    expectHTML: options.expectHTML,
    isUnaryTag: options.isUnaryTag,
    shouldDecodeNewlines: options.shouldDecodeNewlines,
    start: function start (tag, attrs, unary) {
      // check namespace.
      // inherit parent ns if there is one
      var ns = (currentParent && currentParent.ns) || platformGetTagNamespace(tag);

      // handle IE svg bug
      /* istanbul ignore if */
      if (isIE && ns === 'svg') {
        attrs = guardIESVGBug(attrs);
      }

      var element = {
        type: 1,
        tag: tag,
        attrsList: attrs,
        attrsMap: makeAttrsMap(attrs),
        parent: currentParent,
        children: []
      };
      if (ns) {
        element.ns = ns;
      }

      if (isForbiddenTag(element) && !isServerRendering()) {
        element.forbidden = true;
        process.env.NODE_ENV !== 'production' && warn$1(
          'Templates should only be responsible for mapping the state to the ' +
          'UI. Avoid placing tags with side-effects in your templates, such as ' +
          "<" + tag + ">."
        );
      }

      // apply pre-transforms
      for (var i = 0; i < preTransforms.length; i++) {
        preTransforms[i](element, options);
      }

      if (!inVPre) {
        processPre(element);
        if (element.pre) {
          inVPre = true;
        }
      }
      if (platformIsPreTag(element.tag)) {
        inPre = true;
      }
      if (inVPre) {
        processRawAttrs(element);
      } else {
        processFor(element);
        processIf(element);
        processOnce(element);
        processKey(element);

        // determine whether this is a plain element after
        // removing structural attributes
        element.plain = !element.key && !attrs.length;

        processRef(element);
        processSlot(element);
        processComponent(element);
        for (var i$1 = 0; i$1 < transforms.length; i$1++) {
          transforms[i$1](element, options);
        }
        processAttrs(element);
      }

      function checkRootConstraints (el) {
        if (process.env.NODE_ENV !== 'production' && !warned) {
          if (el.tag === 'slot' || el.tag === 'template') {
            warned = true;
            warn$1(
              "Cannot use <" + (el.tag) + "> as component root element because it may " +
              'contain multiple nodes:\n' + template
            );
          }
          if (el.attrsMap.hasOwnProperty('v-for')) {
            warned = true;
            warn$1(
              'Cannot use v-for on stateful component root element because ' +
              'it renders multiple elements:\n' + template
            );
          }
        }
      }

      // tree management
      if (!root) {
        root = element;
        checkRootConstraints(root);
      } else if (!stack.length) {
        // allow root elements with v-if, v-else-if and v-else
        if (root.if && (element.elseif || element.else)) {
          checkRootConstraints(element);
          addIfCondition(root, {
            exp: element.elseif,
            block: element
          });
        } else if (process.env.NODE_ENV !== 'production' && !warned) {
          warned = true;
          warn$1(
            "Component template should contain exactly one root element:" +
            "\n\n" + template + "\n\n" +
            "If you are using v-if on multiple elements, " +
            "use v-else-if to chain them instead."
          );
        }
      }
      if (currentParent && !element.forbidden) {
        if (element.elseif || element.else) {
          processIfConditions(element, currentParent);
        } else if (element.slotScope) { // scoped slot
          currentParent.plain = false;
          var name = element.slotTarget || 'default';(currentParent.scopedSlots || (currentParent.scopedSlots = {}))[name] = element;
        } else {
          currentParent.children.push(element);
          element.parent = currentParent;
        }
      }
      if (!unary) {
        currentParent = element;
        stack.push(element);
      }
      // apply post-transforms
      for (var i$2 = 0; i$2 < postTransforms.length; i$2++) {
        postTransforms[i$2](element, options);
      }
    },

    end: function end () {
      // remove trailing whitespace
      var element = stack[stack.length - 1];
      var lastNode = element.children[element.children.length - 1];
      if (lastNode && lastNode.type === 3 && lastNode.text === ' ') {
        element.children.pop();
      }
      // pop stack
      stack.length -= 1;
      currentParent = stack[stack.length - 1];
      // check pre state
      if (element.pre) {
        inVPre = false;
      }
      if (platformIsPreTag(element.tag)) {
        inPre = false;
      }
    },

    chars: function chars (text) {
      if (!currentParent) {
        if (process.env.NODE_ENV !== 'production' && !warned && text === template) {
          warned = true;
          warn$1(
            'Component template requires a root element, rather than just text:\n\n' + template
          );
        }
        return
      }
      // IE textarea placeholder bug
      /* istanbul ignore if */
      if (isIE &&
          currentParent.tag === 'textarea' &&
          currentParent.attrsMap.placeholder === text) {
        return
      }
      text = inPre || text.trim()
        ? decodeHTMLCached(text)
        // only preserve whitespace if its not right after a starting tag
        : preserveWhitespace && currentParent.children.length ? ' ' : '';
      if (text) {
        var expression;
        if (!inVPre && text !== ' ' && (expression = parseText(text, delimiters))) {
          currentParent.children.push({
            type: 2,
            expression: expression,
            text: text
          });
        } else {
          currentParent.children.push({
            type: 3,
            text: text
          });
        }
      }
    }
  });
  return root
}

function processPre (el) {
  if (getAndRemoveAttr(el, 'v-pre') != null) {
    el.pre = true;
  }
}

function processRawAttrs (el) {
  var l = el.attrsList.length;
  if (l) {
    var attrs = el.attrs = new Array(l);
    for (var i = 0; i < l; i++) {
      attrs[i] = {
        name: el.attrsList[i].name,
        value: JSON.stringify(el.attrsList[i].value)
      };
    }
  } else if (!el.pre) {
    // non root node in pre blocks with no attributes
    el.plain = true;
  }
}

function processKey (el) {
  var exp = getBindingAttr(el, 'key');
  if (exp) {
    if (process.env.NODE_ENV !== 'production' && el.tag === 'template') {
      warn$1("<template> cannot be keyed. Place the key on real elements instead.");
    }
    el.key = exp;
  }
}

function processRef (el) {
  var ref = getBindingAttr(el, 'ref');
  if (ref) {
    el.ref = ref;
    el.refInFor = checkInFor(el);
  }
}

function processFor (el) {
  var exp;
  if ((exp = getAndRemoveAttr(el, 'v-for'))) {
    var inMatch = exp.match(forAliasRE);
    if (!inMatch) {
      process.env.NODE_ENV !== 'production' && warn$1(
        ("Invalid v-for expression: " + exp)
      );
      return
    }
    el.for = inMatch[2].trim();
    var alias = inMatch[1].trim();
    var iteratorMatch = alias.match(forIteratorRE);
    if (iteratorMatch) {
      el.alias = iteratorMatch[1].trim();
      el.iterator1 = iteratorMatch[2].trim();
      if (iteratorMatch[3]) {
        el.iterator2 = iteratorMatch[3].trim();
      }
    } else {
      el.alias = alias;
    }
  }
}

function processIf (el) {
  var exp = getAndRemoveAttr(el, 'v-if');
  if (exp) {
    el.if = exp;
    addIfCondition(el, {
      exp: exp,
      block: el
    });
  } else {
    if (getAndRemoveAttr(el, 'v-else') != null) {
      el.else = true;
    }
    var elseif = getAndRemoveAttr(el, 'v-else-if');
    if (elseif) {
      el.elseif = elseif;
    }
  }
}

function processIfConditions (el, parent) {
  var prev = findPrevElement(parent.children);
  if (prev && prev.if) {
    addIfCondition(prev, {
      exp: el.elseif,
      block: el
    });
  } else if (process.env.NODE_ENV !== 'production') {
    warn$1(
      "v-" + (el.elseif ? ('else-if="' + el.elseif + '"') : 'else') + " " +
      "used on element <" + (el.tag) + "> without corresponding v-if."
    );
  }
}

function addIfCondition (el, condition) {
  if (!el.ifConditions) {
    el.ifConditions = [];
  }
  el.ifConditions.push(condition);
}

function processOnce (el) {
  var once = getAndRemoveAttr(el, 'v-once');
  if (once != null) {
    el.once = true;
  }
}

function processSlot (el) {
  if (el.tag === 'slot') {
    el.slotName = getBindingAttr(el, 'name');
    if (process.env.NODE_ENV !== 'production' && el.key) {
      warn$1(
        "`key` does not work on <slot> because slots are abstract outlets " +
        "and can possibly expand into multiple elements. " +
        "Use the key on a wrapping element instead."
      );
    }
  } else {
    var slotTarget = getBindingAttr(el, 'slot');
    if (slotTarget) {
      el.slotTarget = slotTarget === '""' ? '"default"' : slotTarget;
    }
    if (el.tag === 'template') {
      el.slotScope = getAndRemoveAttr(el, 'scope');
    }
  }
}

function processComponent (el) {
  var binding;
  if ((binding = getBindingAttr(el, 'is'))) {
    el.component = binding;
  }
  if (getAndRemoveAttr(el, 'inline-template') != null) {
    el.inlineTemplate = true;
  }
}

function processAttrs (el) {
  var list = el.attrsList;
  var i, l, name, rawName, value, arg, modifiers, isProp;
  for (i = 0, l = list.length; i < l; i++) {
    name = rawName = list[i].name;
    value = list[i].value;
    if (dirRE.test(name)) {
      // mark element as dynamic
      el.hasBindings = true;
      // modifiers
      modifiers = parseModifiers(name);
      if (modifiers) {
        name = name.replace(modifierRE, '');
      }
      if (bindRE.test(name)) { // v-bind
        name = name.replace(bindRE, '');
        value = parseFilters(value);
        if (modifiers) {
          if (modifiers.prop) {
            isProp = true;
            name = camelize(name);
            if (name === 'innerHtml') { name = 'innerHTML'; }
          }
          if (modifiers.camel) {
            name = camelize(name);
          }
        }
        if (isProp || platformMustUseProp(el.tag, name)) {
          addProp(el, name, value);
        } else {
          addAttr(el, name, value);
        }
      } else if (onRE.test(name)) { // v-on
        name = name.replace(onRE, '');
        addHandler(el, name, value, modifiers);
      } else { // normal directives
        name = name.replace(dirRE, '');
        // parse arg
        var argMatch = name.match(argRE);
        if (argMatch && (arg = argMatch[1])) {
          name = name.slice(0, -(arg.length + 1));
        }
        addDirective(el, name, rawName, value, arg, modifiers);
        if (process.env.NODE_ENV !== 'production' && name === 'model') {
          checkForAliasModel(el, value);
        }
      }
    } else {
      // literal attribute
      if (process.env.NODE_ENV !== 'production') {
        var expression = parseText(value, delimiters);
        if (expression) {
          warn$1(
            name + "=\"" + value + "\": " +
            'Interpolation inside attributes has been removed. ' +
            'Use v-bind or the colon shorthand instead. For example, ' +
            'instead of <div id="{{ val }}">, use <div :id="val">.'
          );
        }
      }
      addAttr(el, name, JSON.stringify(value));
    }
  }
}

function checkInFor (el) {
  var parent = el;
  while (parent) {
    if (parent.for !== undefined) {
      return true
    }
    parent = parent.parent;
  }
  return false
}

function parseModifiers (name) {
  var match = name.match(modifierRE);
  if (match) {
    var ret = {};
    match.forEach(function (m) { ret[m.slice(1)] = true; });
    return ret
  }
}

function makeAttrsMap (attrs) {
  var map = {};
  for (var i = 0, l = attrs.length; i < l; i++) {
    if (process.env.NODE_ENV !== 'production' && map[attrs[i].name] && !isIE) {
      warn$1('duplicate attribute: ' + attrs[i].name);
    }
    map[attrs[i].name] = attrs[i].value;
  }
  return map
}

function findPrevElement (children) {
  var i = children.length;
  while (i--) {
    if (children[i].tag) { return children[i] }
  }
}

function isForbiddenTag (el) {
  return (
    el.tag === 'style' ||
    (el.tag === 'script' && (
      !el.attrsMap.type ||
      el.attrsMap.type === 'text/javascript'
    ))
  )
}

var ieNSBug = /^xmlns:NS\d+/;
var ieNSPrefix = /^NS\d+:/;

/* istanbul ignore next */
function guardIESVGBug (attrs) {
  var res = [];
  for (var i = 0; i < attrs.length; i++) {
    var attr = attrs[i];
    if (!ieNSBug.test(attr.name)) {
      attr.name = attr.name.replace(ieNSPrefix, '');
      res.push(attr);
    }
  }
  return res
}

function checkForAliasModel (el, value) {
  var _el = el;
  while (_el) {
    if (_el.for && _el.alias === value) {
      warn$1(
        "<" + (el.tag) + " v-model=\"" + value + "\">: " +
        "You are binding v-model directly to a v-for iteration alias. " +
        "This will not be able to modify the v-for source array because " +
        "writing to the alias is like modifying a function local variable. " +
        "Consider using an array of objects and use v-model on an object property instead."
      );
    }
    _el = _el.parent;
  }
}

/*  */

var isStaticKey;
var isPlatformReservedTag;

var genStaticKeysCached = cached(genStaticKeys$1);

/**
 * Goal of the optimizer: walk the generated template AST tree
 * and detect sub-trees that are purely static, i.e. parts of
 * the DOM that never needs to change.
 *
 * Once we detect these sub-trees, we can:
 *
 * 1. Hoist them into constants, so that we no longer need to
 *    create fresh nodes for them on each re-render;
 * 2. Completely skip them in the patching process.
 */
function optimize (root, options) {
  if (!root) { return }
  isStaticKey = genStaticKeysCached(options.staticKeys || '');
  isPlatformReservedTag = options.isReservedTag || no;
  // first pass: mark all non-static nodes.
  markStatic(root);
  // second pass: mark static roots.
  markStaticRoots(root, false);
}

function genStaticKeys$1 (keys) {
  return makeMap(
    'type,tag,attrsList,attrsMap,plain,parent,children,attrs' +
    (keys ? ',' + keys : '')
  )
}

function markStatic (node) {
  node.static = isStatic(node);
  if (node.type === 1) {
    // do not make component slot content static. this avoids
    // 1. components not able to mutate slot nodes
    // 2. static slot content fails for hot-reloading
    if (
      !isPlatformReservedTag(node.tag) &&
      node.tag !== 'slot' &&
      node.attrsMap['inline-template'] == null
    ) {
      return
    }
    for (var i = 0, l = node.children.length; i < l; i++) {
      var child = node.children[i];
      markStatic(child);
      if (!child.static) {
        node.static = false;
      }
    }
  }
}

function markStaticRoots (node, isInFor) {
  if (node.type === 1) {
    if (node.static || node.once) {
      node.staticInFor = isInFor;
    }
    // For a node to qualify as a static root, it should have children that
    // are not just static text. Otherwise the cost of hoisting out will
    // outweigh the benefits and it's better off to just always render it fresh.
    if (node.static && node.children.length && !(
      node.children.length === 1 &&
      node.children[0].type === 3
    )) {
      node.staticRoot = true;
      return
    } else {
      node.staticRoot = false;
    }
    if (node.children) {
      for (var i = 0, l = node.children.length; i < l; i++) {
        markStaticRoots(node.children[i], isInFor || !!node.for);
      }
    }
    if (node.ifConditions) {
      walkThroughConditionsBlocks(node.ifConditions, isInFor);
    }
  }
}

function walkThroughConditionsBlocks (conditionBlocks, isInFor) {
  for (var i = 1, len = conditionBlocks.length; i < len; i++) {
    markStaticRoots(conditionBlocks[i].block, isInFor);
  }
}

function isStatic (node) {
  if (node.type === 2) { // expression
    return false
  }
  if (node.type === 3) { // text
    return true
  }
  return !!(node.pre || (
    !node.hasBindings && // no dynamic bindings
    !node.if && !node.for && // not v-if or v-for or v-else
    !isBuiltInTag(node.tag) && // not a built-in
    isPlatformReservedTag(node.tag) && // not a component
    !isDirectChildOfTemplateFor(node) &&
    Object.keys(node).every(isStaticKey)
  ))
}

function isDirectChildOfTemplateFor (node) {
  while (node.parent) {
    node = node.parent;
    if (node.tag !== 'template') {
      return false
    }
    if (node.for) {
      return true
    }
  }
  return false
}

/*  */

var fnExpRE = /^\s*([\w$_]+|\([^)]*?\))\s*=>|^function\s*\(/;
var simplePathRE = /^\s*[A-Za-z_$][\w$]*(?:\.[A-Za-z_$][\w$]*|\['.*?']|\[".*?"]|\[\d+]|\[[A-Za-z_$][\w$]*])*\s*$/;

// keyCode aliases
var keyCodes = {
  esc: 27,
  tab: 9,
  enter: 13,
  space: 32,
  up: 38,
  left: 37,
  right: 39,
  down: 40,
  'delete': [8, 46]
};

var modifierCode = {
  stop: '$event.stopPropagation();',
  prevent: '$event.preventDefault();',
  self: 'if($event.target !== $event.currentTarget)return;'
};

var isMouseEventRE = /^mouse|^pointer|^(click|dblclick|contextmenu|wheel)$/;
var mouseEventModifierCode = {
  ctrl: 'if(!$event.ctrlKey)return;',
  shift: 'if(!$event.shiftKey)return;',
  alt: 'if(!$event.altKey)return;',
  meta: 'if(!$event.metaKey)return;'
};

function genHandlers (events, native) {
  var res = native ? 'nativeOn:{' : 'on:{';
  for (var name in events) {
    res += "\"" + name + "\":" + (genHandler(name, events[name])) + ",";
  }
  return res.slice(0, -1) + '}'
}

function genHandler (
  name,
  handler
) {
  if (!handler) {
    return 'function(){}'
  } else if (Array.isArray(handler)) {
    return ("[" + (handler.map(function (handler) { return genHandler(name, handler); }).join(',')) + "]")
  } else if (!handler.modifiers) {
    return fnExpRE.test(handler.value) || simplePathRE.test(handler.value)
      ? handler.value
      : ("function($event){" + (handler.value) + "}")
  } else {
    var code = '';
    var keys = [];
    var isMouseEvnet = isMouseEventRE.test(name);
    for (var key in handler.modifiers) {
      if (modifierCode[key]) {
        code += modifierCode[key];
      } else if (isMouseEvnet && mouseEventModifierCode[key]) {
        code += mouseEventModifierCode[key];
      } else {
        keys.push(key);
      }
    }
    if (keys.length) {
      code = genKeyFilter(keys) + code;
    }
    var handlerCode = simplePathRE.test(handler.value)
      ? handler.value + '($event)'
      : handler.value;
    return 'function($event){' + code + handlerCode + '}'
  }
}

function genKeyFilter (keys) {
  var code = keys.length === 1
    ? normalizeKeyCode(keys[0])
    : Array.prototype.concat.apply([], keys.map(normalizeKeyCode));
  if (Array.isArray(code)) {
    return ("if(" + (code.map(function (c) { return ("$event.keyCode!==" + c); }).join('&&')) + ")return;")
  } else {
    return ("if($event.keyCode!==" + code + ")return;")
  }
}

function normalizeKeyCode (key) {
  return (
    parseInt(key, 10) || // number keyCode
    keyCodes[key] || // built-in alias
    ("_k(" + (JSON.stringify(key)) + ")") // custom alias
  )
}

/*  */

function bind$1 (el, dir) {
  el.wrapData = function (code) {
    return ("_b(" + code + ",'" + (el.tag) + "'," + (dir.value) + (dir.modifiers && dir.modifiers.prop ? ',true' : '') + ")")
  };
}

var baseDirectives = {
  bind: bind$1,
  cloak: noop
};

/*  */

// configurable state
var warn$2;
var transforms$1;
var dataGenFns;
var platformDirectives;
var staticRenderFns;
var onceCount;
var currentOptions;

function generate (
  ast,
  options
) {
  // save previous staticRenderFns so generate calls can be nested
  var prevStaticRenderFns = staticRenderFns;
  var currentStaticRenderFns = staticRenderFns = [];
  var prevOnceCount = onceCount;
  onceCount = 0;
  currentOptions = options;
  warn$2 = options.warn || baseWarn;
  transforms$1 = pluckModuleFunction(options.modules, 'transformCode');
  dataGenFns = pluckModuleFunction(options.modules, 'genData');
  platformDirectives = options.directives || {};
  var code = ast ? genElement(ast) : '_h("div")';
  staticRenderFns = prevStaticRenderFns;
  onceCount = prevOnceCount;
  return {
    render: ("with(this){return " + code + "}"),
    staticRenderFns: currentStaticRenderFns
  }
}

function genElement (el) {
  if (el.staticRoot && !el.staticProcessed) {
    return genStatic(el)
  } else if (el.once && !el.onceProcessed) {
    return genOnce(el)
  } else if (el.for && !el.forProcessed) {
    return genFor(el)
  } else if (el.if && !el.ifProcessed) {
    return genIf(el)
  } else if (el.tag === 'template' && !el.slotTarget) {
    return genChildren(el) || 'void 0'
  } else if (el.tag === 'slot') {
    return genSlot(el)
  } else {
    // component or element
    var code;
    if (el.component) {
      code = genComponent(el.component, el);
    } else {
      var data = el.plain ? undefined : genData(el);

      var children = el.inlineTemplate ? null : genChildren(el);
      code = "_h('" + (el.tag) + "'" + (data ? ("," + data) : '') + (children ? ("," + children) : '') + ")";
    }
    // module transforms
    for (var i = 0; i < transforms$1.length; i++) {
      code = transforms$1[i](el, code);
    }
    return code
  }
}

// hoist static sub-trees out
function genStatic (el) {
  el.staticProcessed = true;
  staticRenderFns.push(("with(this){return " + (genElement(el)) + "}"));
  return ("_m(" + (staticRenderFns.length - 1) + (el.staticInFor ? ',true' : '') + ")")
}

// v-once
function genOnce (el) {
  el.onceProcessed = true;
  if (el.if && !el.ifProcessed) {
    return genIf(el)
  } else if (el.staticInFor) {
    var key = '';
    var parent = el.parent;
    while (parent) {
      if (parent.for) {
        key = parent.key;
        break
      }
      parent = parent.parent;
    }
    if (!key) {
      process.env.NODE_ENV !== 'production' && warn$2(
        "v-once can only be used inside v-for that is keyed. "
      );
      return genElement(el)
    }
    return ("_o(" + (genElement(el)) + "," + (onceCount++) + (key ? ("," + key) : "") + ")")
  } else {
    return genStatic(el)
  }
}

function genIf (el) {
  el.ifProcessed = true; // avoid recursion
  return genIfConditions(el.ifConditions.slice())
}

function genIfConditions (conditions) {
  if (!conditions.length) {
    return '_e()'
  }

  var condition = conditions.shift();
  if (condition.exp) {
    return ("(" + (condition.exp) + ")?" + (genTernaryExp(condition.block)) + ":" + (genIfConditions(conditions)))
  } else {
    return ("" + (genTernaryExp(condition.block)))
  }

  // v-if with v-once should generate code like (a)?_m(0):_m(1)
  function genTernaryExp (el) {
    return el.once ? genOnce(el) : genElement(el)
  }
}

function genFor (el) {
  var exp = el.for;
  var alias = el.alias;
  var iterator1 = el.iterator1 ? ("," + (el.iterator1)) : '';
  var iterator2 = el.iterator2 ? ("," + (el.iterator2)) : '';
  el.forProcessed = true; // avoid recursion
  return "_l((" + exp + ")," +
    "function(" + alias + iterator1 + iterator2 + "){" +
      "return " + (genElement(el)) +
    '})'
}

function genData (el) {
  var data = '{';

  // directives first.
  // directives may mutate the el's other properties before they are generated.
  var dirs = genDirectives(el);
  if (dirs) { data += dirs + ','; }

  // key
  if (el.key) {
    data += "key:" + (el.key) + ",";
  }
  // ref
  if (el.ref) {
    data += "ref:" + (el.ref) + ",";
  }
  if (el.refInFor) {
    data += "refInFor:true,";
  }
  // pre
  if (el.pre) {
    data += "pre:true,";
  }
  // record original tag name for components using "is" attribute
  if (el.component) {
    data += "tag:\"" + (el.tag) + "\",";
  }
  // module data generation functions
  for (var i = 0; i < dataGenFns.length; i++) {
    data += dataGenFns[i](el);
  }
  // attributes
  if (el.attrs) {
    data += "attrs:{" + (genProps(el.attrs)) + "},";
  }
  // DOM props
  if (el.props) {
    data += "domProps:{" + (genProps(el.props)) + "},";
  }
  // event handlers
  if (el.events) {
    data += (genHandlers(el.events)) + ",";
  }
  if (el.nativeEvents) {
    data += (genHandlers(el.nativeEvents, true)) + ",";
  }
  // slot target
  if (el.slotTarget) {
    data += "slot:" + (el.slotTarget) + ",";
  }
  // scoped slots
  if (el.scopedSlots) {
    data += (genScopedSlots(el.scopedSlots)) + ",";
  }
  // inline-template
  if (el.inlineTemplate) {
    var inlineTemplate = genInlineTemplate(el);
    if (inlineTemplate) {
      data += inlineTemplate + ",";
    }
  }
  data = data.replace(/,$/, '') + '}';
  // v-bind data wrap
  if (el.wrapData) {
    data = el.wrapData(data);
  }
  return data
}

function genDirectives (el) {
  var dirs = el.directives;
  if (!dirs) { return }
  var res = 'directives:[';
  var hasRuntime = false;
  var i, l, dir, needRuntime;
  for (i = 0, l = dirs.length; i < l; i++) {
    dir = dirs[i];
    needRuntime = true;
    var gen = platformDirectives[dir.name] || baseDirectives[dir.name];
    if (gen) {
      // compile-time directive that manipulates AST.
      // returns true if it also needs a runtime counterpart.
      needRuntime = !!gen(el, dir, warn$2);
    }
    if (needRuntime) {
      hasRuntime = true;
      res += "{name:\"" + (dir.name) + "\",rawName:\"" + (dir.rawName) + "\"" + (dir.value ? (",value:(" + (dir.value) + "),expression:" + (JSON.stringify(dir.value))) : '') + (dir.arg ? (",arg:\"" + (dir.arg) + "\"") : '') + (dir.modifiers ? (",modifiers:" + (JSON.stringify(dir.modifiers))) : '') + "},";
    }
  }
  if (hasRuntime) {
    return res.slice(0, -1) + ']'
  }
}

function genInlineTemplate (el) {
  var ast = el.children[0];
  if (process.env.NODE_ENV !== 'production' && (
    el.children.length > 1 || ast.type !== 1
  )) {
    warn$2('Inline-template components must have exactly one child element.');
  }
  if (ast.type === 1) {
    var inlineRenderFns = generate(ast, currentOptions);
    return ("inlineTemplate:{render:function(){" + (inlineRenderFns.render) + "},staticRenderFns:[" + (inlineRenderFns.staticRenderFns.map(function (code) { return ("function(){" + code + "}"); }).join(',')) + "]}")
  }
}

function genScopedSlots (slots) {
  return ("scopedSlots:{" + (Object.keys(slots).map(function (key) { return genScopedSlot(key, slots[key]); }).join(',')) + "}")
}

function genScopedSlot (key, el) {
  return key + ":function(" + (String(el.attrsMap.scope)) + "){" +
    "return " + (el.tag === 'template'
      ? genChildren(el) || 'void 0'
      : genElement(el)) + "}"
}

function genChildren (el) {
  if (el.children.length) {
    return '[' + el.children.map(genNode).join(',') + ']'
  }
}

function genNode (node) {
  if (node.type === 1) {
    return genElement(node)
  } else {
    return genText(node)
  }
}

function genText (text) {
  return text.type === 2
    ? text.expression // no need for () because already wrapped in _s()
    : transformSpecialNewlines(JSON.stringify(text.text))
}

function genSlot (el) {
  var slotName = el.slotName || '"default"';
  var children = genChildren(el);
  return ("_t(" + slotName + (children ? ("," + children) : '') + (el.attrs ? ((children ? '' : ',null') + ",{" + (el.attrs.map(function (a) { return ((camelize(a.name)) + ":" + (a.value)); }).join(',')) + "}") : '') + ")")
}

// componentName is el.component, take it as argument to shun flow's pessimistic refinement
function genComponent (componentName, el) {
  var children = el.inlineTemplate ? null : genChildren(el);
  return ("_h(" + componentName + "," + (genData(el)) + (children ? ("," + children) : '') + ")")
}

function genProps (props) {
  var res = '';
  for (var i = 0; i < props.length; i++) {
    var prop = props[i];
    res += "\"" + (prop.name) + "\":" + (transformSpecialNewlines(prop.value)) + ",";
  }
  return res.slice(0, -1)
}

// #3895, #4268
function transformSpecialNewlines (text) {
  return text
    .replace(/\u2028/g, '\\u2028')
    .replace(/\u2029/g, '\\u2029')
}

/*  */

/**
 * Compile a template.
 */
function compile$2 (
  template,
  options
) {
  var ast = parse(template.trim(), options);
  optimize(ast, options);
  var code = generate(ast, options);
  return {
    ast: ast,
    render: code.render,
    staticRenderFns: code.staticRenderFns
  }
}

/*  */

// operators like typeof, instanceof and in are allowed
var prohibitedKeywordRE = new RegExp('\\b' + (
  'do,if,for,let,new,try,var,case,else,with,await,break,catch,class,const,' +
  'super,throw,while,yield,delete,export,import,return,switch,default,' +
  'extends,finally,continue,debugger,function,arguments'
).split(',').join('\\b|\\b') + '\\b');
// check valid identifier for v-for
var identRE = /[A-Za-z_$][\w$]*/;
// strip strings in expressions
var stripStringRE = /'(?:[^'\\]|\\.)*'|"(?:[^"\\]|\\.)*"|`(?:[^`\\]|\\.)*\$\{|\}(?:[^`\\]|\\.)*`|`(?:[^`\\]|\\.)*`/g;

// detect problematic expressions in a template
function detectErrors (ast) {
  var errors = [];
  if (ast) {
    checkNode(ast, errors);
  }
  return errors
}

function checkNode (node, errors) {
  if (node.type === 1) {
    for (var name in node.attrsMap) {
      if (dirRE.test(name)) {
        var value = node.attrsMap[name];
        if (value) {
          if (name === 'v-for') {
            checkFor(node, ("v-for=\"" + value + "\""), errors);
          } else {
            checkExpression(value, (name + "=\"" + value + "\""), errors);
          }
        }
      }
    }
    if (node.children) {
      for (var i = 0; i < node.children.length; i++) {
        checkNode(node.children[i], errors);
      }
    }
  } else if (node.type === 2) {
    checkExpression(node.expression, node.text, errors);
  }
}

function checkFor (node, text, errors) {
  checkExpression(node.for || '', text, errors);
  checkIdentifier(node.alias, 'v-for alias', text, errors);
  checkIdentifier(node.iterator1, 'v-for iterator', text, errors);
  checkIdentifier(node.iterator2, 'v-for iterator', text, errors);
}

function checkIdentifier (ident, type, text, errors) {
  if (typeof ident === 'string' && !identRE.test(ident)) {
    errors.push(("- invalid " + type + " \"" + ident + "\" in expression: " + text));
  }
}

function checkExpression (exp, text, errors) {
  try {
    new Function(("return " + exp));
  } catch (e) {
    var keywordMatch = exp.replace(stripStringRE, '').match(prohibitedKeywordRE);
    if (keywordMatch) {
      errors.push(
        "- avoid using JavaScript keyword as property name: " +
        "\"" + (keywordMatch[0]) + "\" in expression " + text
      );
    } else {
      errors.push(("- invalid expression: " + text));
    }
  }
}

/*  */

function transformNode (el, options) {
  var warn = options.warn || baseWarn;
  var staticClass = getAndRemoveAttr(el, 'class');
  var ref = parseStaticClass(staticClass, options);
  var dynamic = ref.dynamic;
  var classResult = ref.classResult;
  if (process.env.NODE_ENV !== 'production' && dynamic && staticClass) {
    warn(
      "class=\"" + staticClass + "\": " +
      'Interpolation inside attributes has been deprecated. ' +
      'Use v-bind or the colon shorthand instead.'
    );
  }
  if (!dynamic && classResult) {
    el.staticClass = classResult;
  }
  var classBinding = getBindingAttr(el, 'class', false /* getStatic */);
  if (classBinding) {
    el.classBinding = classBinding;
  } else if (dynamic) {
    el.classBinding = classResult;
  }
}

function genData$1 (el) {
  var data = '';
  if (el.staticClass) {
    data += "staticClass:" + (el.staticClass) + ",";
  }
  if (el.classBinding) {
    data += "class:" + (el.classBinding) + ",";
  }
  return data
}

function parseStaticClass (staticClass, options) {
  // "a b c" -> ["a", "b", "c"] => staticClass: ["a", "b", "c"]
  // "a {{x}} c" -> ["a", x, "c"] => classBinding: '["a", x, "c"]'
  var dynamic = false;
  var classResult = '';
  if (staticClass) {
    var classList = staticClass.trim().split(' ').map(function (name) {
      var result = parseText(name, options.delimiters);
      if (result) {
        dynamic = true;
        return result
      }
      return JSON.stringify(name)
    });
    if (classList.length) {
      classResult = '[' + classList.join(',') + ']';
    }
  }
  return { dynamic: dynamic, classResult: classResult }
}

var klass = {
  staticKeys: ['staticClass'],
  transformNode: transformNode,
  genData: genData$1
};

/*  */

var normalize = cached(camelize);

function transformNode$1 (el, options) {
  var warn = options.warn || baseWarn;
  var staticStyle = getAndRemoveAttr(el, 'style');
  var ref = parseStaticStyle(staticStyle, options);
  var dynamic = ref.dynamic;
  var styleResult = ref.styleResult;
  if (process.env.NODE_ENV !== 'production' && dynamic) {
    warn(
      "style=\"" + (String(staticStyle)) + "\": " +
      'Interpolation inside attributes has been deprecated. ' +
      'Use v-bind or the colon shorthand instead.'
    );
  }
  if (!dynamic && styleResult) {
    el.staticStyle = styleResult;
  }
  var styleBinding = getBindingAttr(el, 'style', false /* getStatic */);
  if (styleBinding) {
    el.styleBinding = styleBinding;
  } else if (dynamic) {
    el.styleBinding = styleResult;
  }
}

function genData$2 (el) {
  var data = '';
  if (el.staticStyle) {
    data += "staticStyle:" + (el.staticStyle) + ",";
  }
  if (el.styleBinding) {
    data += "style:" + (el.styleBinding) + ",";
  }
  return data
}

function parseStaticStyle (staticStyle, options) {
  // "width: 200px; height: 200px;" -> {width: 200, height: 200}
  // "width: 200px; height: {{y}}" -> {width: 200, height: y}
  var dynamic = false;
  var styleResult = '';
  if (staticStyle) {
    var styleList = staticStyle.trim().split(';').map(function (style) {
      var result = style.trim().split(':');
      if (result.length !== 2) {
        return
      }
      var key = normalize(result[0].trim());
      var value = result[1].trim();
      var dynamicValue = parseText(value, options.delimiters);
      if (dynamicValue) {
        dynamic = true;
        return key + ':' + dynamicValue
      }
      return key + ':' + JSON.stringify(value)
    }).filter(function (result) { return result; });
    if (styleList.length) {
      styleResult = '{' + styleList.join(',') + '}';
    }
  }
  return { dynamic: dynamic, styleResult: styleResult }
}

var style = {
  staticKeys: ['staticStyle'],
  transformNode: transformNode$1,
  genData: genData$2
};

/*  */

function transformNode$2 (el, options) {
  if (el.attrsMap.append === 'tree') {
    el.appendAsTree = true;
  }
}

function genData$3 (el) {
  return el.appendAsTree ? "appendAsTree:true," : ''
}

var append = {
  staticKeys: ['appendAsTree'],
  transformNode: transformNode$2,
  genData: genData$3
};

var modules = [
  klass,
  style,
  append
];

/*  */

function model (
  el,
  dir,
  _warn
) {
  genDefaultModel(el, dir.value, dir.modifiers);
}

function genDefaultModel (
  el,
  value,
  modifiers
) {
  var ref = modifiers || {};
  var lazy = ref.lazy;
  var trim = ref.trim;
  var event = lazy ? 'change' : 'input';
  var isNative = el.tag === 'input' || el.tag === 'textarea';
  var valueExpression = isNative
    ? ("$event.target.attr.value" + (trim ? '.trim()' : ''))
    : "$event";
  var code = genAssignmentCode(value, valueExpression);
  addAttr(el, 'value', ("(" + value + ")"));
  addHandler(el, event, code, null, true);
}

function genAssignmentCode (value, assignment) {
  var modelRs = parseModel(value);
  if (modelRs.idx === null) {
    return (value + "=" + assignment)
  } else {
    return "var $$exp = " + (modelRs.exp) + ", $$idx = " + (modelRs.idx) + ";" +
      "if (!Array.isArray($$exp)){" +
        value + "=" + assignment + "}" +
      "else{$$exp.splice($$idx, 1, " + assignment + ")}"
  }
}

var directives = {
  model: model
};

var latestNodeId = 1;

function TextNode (text) {
  this.instanceId = '';
  this.nodeId = latestNodeId++;
  this.parentNode = null;
  this.nodeType = 3;
  this.text = text;
}

var renderer = {
  TextNode: TextNode,
  instances: {},
  modules: {},
  components: {}
};

var isReservedTag$1 = makeMap(
  'div,img,image,input,switch,indicator,list,scroller,cell,template,text,slider,image'
);
function isUnaryTag$1 () { /* console.log('isUnaryTag') */ }
function mustUseProp$1 () { /* console.log('mustUseProp') */ }
function getTagNamespace$1 () { /* console.log('getTagNamespace') */ }

/*  */

var cache = Object.create(null);

var baseOptions = {
  preserveWhitespace: false,
  modules: modules,
  staticKeys: genStaticKeys(modules),
  directives: directives,
  isReservedTag: isReservedTag$1,
  isUnaryTag: isUnaryTag$1,
  mustUseProp: mustUseProp$1,
  getTagNamespace: getTagNamespace$1
};

function compile$1 (
  template,
  options
) {
  options = options
    ? extend(extend({}, baseOptions), options)
    : baseOptions;
  return compile$2(template, options)
}



function makeFunction (code) {
  try {
    return new Function(code)
  } catch (e) {
    return noop
  }
}

/*  */

function compile$$1 (
  template,
  options
) {
  options = options || {};
  var errors = [];
  // allow injecting modules/directives
  var baseModules = baseOptions.modules || [];
  var modules = options.modules
    ? baseModules.concat(options.modules)
    : baseModules;
  var directives = options.directives
    ? extend(extend({}, baseOptions.directives), options.directives)
    : baseOptions.directives;
  var compiled = compile$1(template, {
    modules: modules,
    directives: directives,
    warn: function (msg) {
      errors.push(msg);
    }
  });
  compiled.errors = errors.concat(detectErrors(compiled.ast));
  return compiled
}

exports.compile = compile$$1;