/*!
 * vue-i18n v8.9.0 
 * (c) 2019 kazuya kawaguchi
 * Released under the MIT License.
 */
(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global.VueI18n = factory());
}(this, (function () { 'use strict';

  /*  */

  /**
   * utilities
   */

  function warn (msg, err) {
    if (typeof console !== 'undefined') {
      console.warn('[vue-i18n] ' + msg);
      /* istanbul ignore if */
      if (err) {
        console.warn(err.stack);
      }
    }
  }

  function isObject (obj) {
    return obj !== null && typeof obj === 'object'
  }

  var toString = Object.prototype.toString;
  var OBJECT_STRING = '[object Object]';
  function isPlainObject (obj) {
    return toString.call(obj) === OBJECT_STRING
  }

  function isNull (val) {
    return val === null || val === undefined
  }

  function parseArgs () {
    var args = [], len = arguments.length;
    while ( len-- ) args[ len ] = arguments[ len ];

    var locale = null;
    var params = null;
    if (args.length === 1) {
      if (isObject(args[0]) || Array.isArray(args[0])) {
        params = args[0];
      } else if (typeof args[0] === 'string') {
        locale = args[0];
      }
    } else if (args.length === 2) {
      if (typeof args[0] === 'string') {
        locale = args[0];
      }
      /* istanbul ignore if */
      if (isObject(args[1]) || Array.isArray(args[1])) {
        params = args[1];
      }
    }

    return { locale: locale, params: params }
  }

  function looseClone (obj) {
    return JSON.parse(JSON.stringify(obj))
  }

  function remove (arr, item) {
    if (arr.length) {
      var index = arr.indexOf(item);
      if (index > -1) {
        return arr.splice(index, 1)
      }
    }
  }

  var hasOwnProperty = Object.prototype.hasOwnProperty;
  function hasOwn (obj, key) {
    return hasOwnProperty.call(obj, key)
  }

  function merge (target) {
    var arguments$1 = arguments;

    var output = Object(target);
    for (var i = 1; i < arguments.length; i++) {
      var source = arguments$1[i];
      if (source !== undefined && source !== null) {
        var key = (void 0);
        for (key in source) {
          if (hasOwn(source, key)) {
            if (isObject(source[key])) {
              output[key] = merge(output[key], source[key]);
            } else {
              output[key] = source[key];
            }
          }
        }
      }
    }
    return output
  }

  function looseEqual (a, b) {
    if (a === b) { return true }
    var isObjectA = isObject(a);
    var isObjectB = isObject(b);
    if (isObjectA && isObjectB) {
      try {
        var isArrayA = Array.isArray(a);
        var isArrayB = Array.isArray(b);
        if (isArrayA && isArrayB) {
          return a.length === b.length && a.every(function (e, i) {
            return looseEqual(e, b[i])
          })
        } else if (!isArrayA && !isArrayB) {
          var keysA = Object.keys(a);
          var keysB = Object.keys(b);
          return keysA.length === keysB.length && keysA.every(function (key) {
            return looseEqual(a[key], b[key])
          })
        } else {
          /* istanbul ignore next */
          return false
        }
      } catch (e) {
        /* istanbul ignore next */
        return false
      }
    } else if (!isObjectA && !isObjectB) {
      return String(a) === String(b)
    } else {
      return false
    }
  }

  /*  */

  function extend (Vue) {
    if (!Vue.prototype.hasOwnProperty('$i18n')) {
      // $FlowFixMe
      Object.defineProperty(Vue.prototype, '$i18n', {
        get: function get () { return this._i18n }
      });
    }

    Vue.prototype.$t = function (key) {
      var values = [], len = arguments.length - 1;
      while ( len-- > 0 ) values[ len ] = arguments[ len + 1 ];

      var i18n = this.$i18n;
      return i18n._t.apply(i18n, [ key, i18n.locale, i18n._getMessages(), this ].concat( values ))
    };

    Vue.prototype.$tc = function (key, choice) {
      var values = [], len = arguments.length - 2;
      while ( len-- > 0 ) values[ len ] = arguments[ len + 2 ];

      var i18n = this.$i18n;
      return i18n._tc.apply(i18n, [ key, i18n.locale, i18n._getMessages(), this, choice ].concat( values ))
    };

    Vue.prototype.$te = function (key, locale) {
      var i18n = this.$i18n;
      return i18n._te(key, i18n.locale, i18n._getMessages(), locale)
    };

    Vue.prototype.$d = function (value) {
      var ref;

      var args = [], len = arguments.length - 1;
      while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];
      return (ref = this.$i18n).d.apply(ref, [ value ].concat( args ))
    };

    Vue.prototype.$n = function (value) {
      var ref;

      var args = [], len = arguments.length - 1;
      while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];
      return (ref = this.$i18n).n.apply(ref, [ value ].concat( args ))
    };
  }

  /*  */

  var mixin = {
    beforeCreate: function beforeCreate () {
      var options = this.$options;
      options.i18n = options.i18n || (options.__i18n ? {} : null);

      if (options.i18n) {
        if (options.i18n instanceof VueI18n) {
          // init locale messages via custom blocks
          if (options.__i18n) {
            try {
              var localeMessages = {};
              options.__i18n.forEach(function (resource) {
                localeMessages = merge(localeMessages, JSON.parse(resource));
              });
              Object.keys(localeMessages).forEach(function (locale) {
                options.i18n.mergeLocaleMessage(locale, localeMessages[locale]);
              });
            } catch (e) {
              {
                warn("Cannot parse locale messages via custom blocks.", e);
              }
            }
          }
          this._i18n = options.i18n;
          this._i18nWatcher = this._i18n.watchI18nData();
          this._i18n.subscribeDataChanging(this);
          this._subscribing = true;
        } else if (isPlainObject(options.i18n)) {
          // component local i18n
          if (this.$root && this.$root.$i18n && this.$root.$i18n instanceof VueI18n) {
            options.i18n.root = this.$root;
            options.i18n.formatter = this.$root.$i18n.formatter;
            options.i18n.fallbackLocale = this.$root.$i18n.fallbackLocale;
            options.i18n.silentTranslationWarn = this.$root.$i18n.silentTranslationWarn;
            options.i18n.silentFallbackWarn = this.$root.$i18n.silentFallbackWarn;
            options.i18n.pluralizationRules = this.$root.$i18n.pluralizationRules;
            options.i18n.preserveDirectiveContent = this.$root.$i18n.preserveDirectiveContent;
          }

          // init locale messages via custom blocks
          if (options.__i18n) {
            try {
              var localeMessages$1 = {};
              options.__i18n.forEach(function (resource) {
                localeMessages$1 = merge(localeMessages$1, JSON.parse(resource));
              });
              options.i18n.messages = localeMessages$1;
            } catch (e) {
              {
                warn("Cannot parse locale messages via custom blocks.", e);
              }
            }
          }

          this._i18n = new VueI18n(options.i18n);
          this._i18nWatcher = this._i18n.watchI18nData();
          this._i18n.subscribeDataChanging(this);
          this._subscribing = true;

          if (options.i18n.sync === undefined || !!options.i18n.sync) {
            this._localeWatcher = this.$i18n.watchLocale();
          }
        } else {
          {
            warn("Cannot be interpreted 'i18n' option.");
          }
        }
      } else if (this.$root && this.$root.$i18n && this.$root.$i18n instanceof VueI18n) {
        // root i18n
        this._i18n = this.$root.$i18n;
        this._i18n.subscribeDataChanging(this);
        this._subscribing = true;
      } else if (options.parent && options.parent.$i18n && options.parent.$i18n instanceof VueI18n) {
        // parent i18n
        this._i18n = options.parent.$i18n;
        this._i18n.subscribeDataChanging(this);
        this._subscribing = true;
      }
    },

    beforeDestroy: function beforeDestroy () {
      if (!this._i18n) { return }

      var self = this;
      this.$nextTick(function () {
        if (self._subscribing) {
          self._i18n.unsubscribeDataChanging(self);
          delete self._subscribing;
        }

        if (self._i18nWatcher) {
          self._i18nWatcher();
          self._i18n.destroyVM();
          delete self._i18nWatcher;
        }

        if (self._localeWatcher) {
          self._localeWatcher();
          delete self._localeWatcher;
        }

        self._i18n = null;
      });
    }
  };

  /*  */

  var component = {
    name: 'i18n',
    functional: true,
    props: {
      tag: {
        type: String,
        default: 'span'
      },
      path: {
        type: String,
        required: true
      },
      locale: {
        type: String
      },
      places: {
        type: [Array, Object]
      }
    },
    render: function render (h, ref) {
      var props = ref.props;
      var data = ref.data;
      var children = ref.children;
      var parent = ref.parent;

      var i18n = parent.$i18n;

      children = (children || []).filter(function (child) {
        return child.tag || (child.text = child.text.trim())
      });

      if (!i18n) {
        {
          warn('Cannot find VueI18n instance!');
        }
        return children
      }

      var path = props.path;
      var locale = props.locale;

      var params = {};
      var places = props.places || {};

      var hasPlaces = Array.isArray(places)
        ? places.length > 0
        : Object.keys(places).length > 0;

      var everyPlace = children.every(function (child) {
        if (child.data && child.data.attrs) {
          var place = child.data.attrs.place;
          return (typeof place !== 'undefined') && place !== ''
        }
      });

      if (hasPlaces && children.length > 0 && !everyPlace) {
        warn('If places prop is set, all child elements must have place prop set.');
      }

      if (Array.isArray(places)) {
        places.forEach(function (el, i) {
          params[i] = el;
        });
      } else {
        Object.keys(places).forEach(function (key) {
          params[key] = places[key];
        });
      }

      children.forEach(function (child, i) {
        var key = everyPlace
          ? ("" + (child.data.attrs.place))
          : ("" + i);
        params[key] = child;
      });

      return h(props.tag, data, i18n.i(path, locale, params))
    }
  };

  /*  */

  function bind (el, binding, vnode) {
    if (!assert(el, vnode)) { return }

    t(el, binding, vnode);
  }

  function update (el, binding, vnode, oldVNode) {
    if (!assert(el, vnode)) { return }

    var i18n = vnode.context.$i18n;
    if (localeEqual(el, vnode) &&
      (looseEqual(binding.value, binding.oldValue) &&
       looseEqual(el._localeMessage, i18n.getLocaleMessage(i18n.locale)))) { return }

    t(el, binding, vnode);
  }

  function unbind (el, binding, vnode, oldVNode) {
    var vm = vnode.context;
    if (!vm) {
      warn('Vue instance does not exists in VNode context');
      return
    }

    var i18n = vnode.context.$i18n || {};
    if (!binding.modifiers.preserve && !i18n.preserveDirectiveContent) {
      el.textContent = '';
    }
    el._vt = undefined;
    delete el['_vt'];
    el._locale = undefined;
    delete el['_locale'];
    el._localeMessage = undefined;
    delete el['_localeMessage'];
  }

  function assert (el, vnode) {
    var vm = vnode.context;
    if (!vm) {
      warn('Vue instance does not exists in VNode context');
      return false
    }

    if (!vm.$i18n) {
      warn('VueI18n instance does not exists in Vue instance');
      return false
    }

    return true
  }

  function localeEqual (el, vnode) {
    var vm = vnode.context;
    return el._locale === vm.$i18n.locale
  }

  function t (el, binding, vnode) {
    var ref$1, ref$2;

    var value = binding.value;

    var ref = parseValue(value);
    var path = ref.path;
    var locale = ref.locale;
    var args = ref.args;
    var choice = ref.choice;
    if (!path && !locale && !args) {
      warn('value type not supported');
      return
    }

    if (!path) {
      warn('`path` is required in v-t directive');
      return
    }

    var vm = vnode.context;
    if (choice) {
      el._vt = el.textContent = (ref$1 = vm.$i18n).tc.apply(ref$1, [ path, choice ].concat( makeParams(locale, args) ));
    } else {
      el._vt = el.textContent = (ref$2 = vm.$i18n).t.apply(ref$2, [ path ].concat( makeParams(locale, args) ));
    }
    el._locale = vm.$i18n.locale;
    el._localeMessage = vm.$i18n.getLocaleMessage(vm.$i18n.locale);
  }

  function parseValue (value) {
    var path;
    var locale;
    var args;
    var choice;

    if (typeof value === 'string') {
      path = value;
    } else if (isPlainObject(value)) {
      path = value.path;
      locale = value.locale;
      args = value.args;
      choice = value.choice;
    }

    return { path: path, locale: locale, args: args, choice: choice }
  }

  function makeParams (locale, args) {
    var params = [];

    locale && params.push(locale);
    if (args && (Array.isArray(args) || isPlainObject(args))) {
      params.push(args);
    }

    return params
  }

  var Vue;

  function install (_Vue) {
    /* istanbul ignore if */
    if (install.installed && _Vue === Vue) {
      warn('already installed.');
      return
    }
    install.installed = true;

    Vue = _Vue;

    var version = (Vue.version && Number(Vue.version.split('.')[0])) || -1;
    /* istanbul ignore if */
    if (version < 2) {
      warn(("vue-i18n (" + (install.version) + ") need to use Vue 2.0 or later (Vue: " + (Vue.version) + ")."));
      return
    }

    extend(Vue);
    Vue.mixin(mixin);
    Vue.directive('t', { bind: bind, update: update, unbind: unbind });
    Vue.component(component.name, component);

    // use simple mergeStrategies to prevent i18n instance lose '__proto__'
    var strats = Vue.config.optionMergeStrategies;
    strats.i18n = function (parentVal, childVal) {
      return childVal === undefined
        ? parentVal
        : childVal
    };
  }

  /*  */

  var BaseFormatter = function BaseFormatter () {
    this._caches = Object.create(null);
  };

  BaseFormatter.prototype.interpolate = function interpolate (message, values) {
    if (!values) {
      return [message]
    }
    var tokens = this._caches[message];
    if (!tokens) {
      tokens = parse(message);
      this._caches[message] = tokens;
    }
    return compile(tokens, values)
  };



  var RE_TOKEN_LIST_VALUE = /^(?:\d)+/;
  var RE_TOKEN_NAMED_VALUE = /^(?:\w)+/;

  function parse (format) {
    var tokens = [];
    var position = 0;

    var text = '';
    while (position < format.length) {
      var char = format[position++];
      if (char === '{') {
        if (text) {
          tokens.push({ type: 'text', value: text });
        }

        text = '';
        var sub = '';
        char = format[position++];
        while (char !== undefined && char !== '}') {
          sub += char;
          char = format[position++];
        }
        var isClosed = char === '}';

        var type = RE_TOKEN_LIST_VALUE.test(sub)
          ? 'list'
          : isClosed && RE_TOKEN_NAMED_VALUE.test(sub)
            ? 'named'
            : 'unknown';
        tokens.push({ value: sub, type: type });
      } else if (char === '%') {
        // when found rails i18n syntax, skip text capture
        if (format[(position)] !== '{') {
          text += char;
        }
      } else {
        text += char;
      }
    }

    text && tokens.push({ type: 'text', value: text });

    return tokens
  }

  function compile (tokens, values) {
    var compiled = [];
    var index = 0;

    var mode = Array.isArray(values)
      ? 'list'
      : isObject(values)
        ? 'named'
        : 'unknown';
    if (mode === 'unknown') { return compiled }

    while (index < tokens.length) {
      var token = tokens[index];
      switch (token.type) {
        case 'text':
          compiled.push(token.value);
          break
        case 'list':
          compiled.push(values[parseInt(token.value, 10)]);
          break
        case 'named':
          if (mode === 'named') {
            compiled.push((values)[token.value]);
          } else {
            {
              warn(("Type of token '" + (token.type) + "' and format of value '" + mode + "' don't match!"));
            }
          }
          break
        case 'unknown':
          {
            warn("Detect 'unknown' type of token!");
          }
          break
      }
      index++;
    }

    return compiled
  }

  /*  */

  /**
   *  Path parser
   *  - Inspired:
   *    Vue.js Path parser
   */

  // actions
  var APPEND = 0;
  var PUSH = 1;
  var INC_SUB_PATH_DEPTH = 2;
  var PUSH_SUB_PATH = 3;

  // states
  var BEFORE_PATH = 0;
  var IN_PATH = 1;
  var BEFORE_IDENT = 2;
  var IN_IDENT = 3;
  var IN_SUB_PATH = 4;
  var IN_SINGLE_QUOTE = 5;
  var IN_DOUBLE_QUOTE = 6;
  var AFTER_PATH = 7;
  var ERROR = 8;

  var pathStateMachine = [];

  pathStateMachine[BEFORE_PATH] = {
    'ws': [BEFORE_PATH],
    'ident': [IN_IDENT, APPEND],
    '[': [IN_SUB_PATH],
    'eof': [AFTER_PATH]
  };

  pathStateMachine[IN_PATH] = {
    'ws': [IN_PATH],
    '.': [BEFORE_IDENT],
    '[': [IN_SUB_PATH],
    'eof': [AFTER_PATH]
  };

  pathStateMachine[BEFORE_IDENT] = {
    'ws': [BEFORE_IDENT],
    'ident': [IN_IDENT, APPEND],
    '0': [IN_IDENT, APPEND],
    'number': [IN_IDENT, APPEND]
  };

  pathStateMachine[IN_IDENT] = {
    'ident': [IN_IDENT, APPEND],
    '0': [IN_IDENT, APPEND],
    'number': [IN_IDENT, APPEND],
    'ws': [IN_PATH, PUSH],
    '.': [BEFORE_IDENT, PUSH],
    '[': [IN_SUB_PATH, PUSH],
    'eof': [AFTER_PATH, PUSH]
  };

  pathStateMachine[IN_SUB_PATH] = {
    "'": [IN_SINGLE_QUOTE, APPEND],
    '"': [IN_DOUBLE_QUOTE, APPEND],
    '[': [IN_SUB_PATH, INC_SUB_PATH_DEPTH],
    ']': [IN_PATH, PUSH_SUB_PATH],
    'eof': ERROR,
    'else': [IN_SUB_PATH, APPEND]
  };

  pathStateMachine[IN_SINGLE_QUOTE] = {
    "'": [IN_SUB_PATH, APPEND],
    'eof': ERROR,
    'else': [IN_SINGLE_QUOTE, APPEND]
  };

  pathStateMachine[IN_DOUBLE_QUOTE] = {
    '"': [IN_SUB_PATH, APPEND],
    'eof': ERROR,
    'else': [IN_DOUBLE_QUOTE, APPEND]
  };

  /**
   * Check if an expression is a literal value.
   */

  var literalValueRE = /^\s?(?:true|false|-?[\d.]+|'[^']*'|"[^"]*")\s?$/;
  function isLiteral (exp) {
    return literalValueRE.test(exp)
  }

  /**
   * Strip quotes from a string
   */

  function stripQuotes (str) {
    var a = str.charCodeAt(0);
    var b = str.charCodeAt(str.length - 1);
    return a === b && (a === 0x22 || a === 0x27)
      ? str.slice(1, -1)
      : str
  }

  /**
   * Determine the type of a character in a keypath.
   */

  function getPathCharType (ch) {
    if (ch === undefined || ch === null) { return 'eof' }

    var code = ch.charCodeAt(0);

    switch (code) {
      case 0x5B: // [
      case 0x5D: // ]
      case 0x2E: // .
      case 0x22: // "
      case 0x27: // '
        return ch

      case 0x5F: // _
      case 0x24: // $
      case 0x2D: // -
        return 'ident'

      case 0x20: // Space
      case 0x09: // Tab
      case 0x0A: // Newline
      case 0x0D: // Return
      case 0xA0:  // No-break space
      case 0xFEFF:  // Byte Order Mark
      case 0x2028:  // Line Separator
      case 0x2029:  // Paragraph Separator
        return 'ws'
    }

    return 'ident'
  }

  /**
   * Format a subPath, return its plain form if it is
   * a literal string or number. Otherwise prepend the
   * dynamic indicator (*).
   */

  function formatSubPath (path) {
    var trimmed = path.trim();
    // invalid leading 0
    if (path.charAt(0) === '0' && isNaN(path)) { return false }

    return isLiteral(trimmed) ? stripQuotes(trimmed) : '*' + trimmed
  }

  /**
   * Parse a string path into an array of segments
   */

  function parse$1 (path) {
    var keys = [];
    var index = -1;
    var mode = BEFORE_PATH;
    var subPathDepth = 0;
    var c;
    var key;
    var newChar;
    var type;
    var transition;
    var action;
    var typeMap;
    var actions = [];

    actions[PUSH] = function () {
      if (key !== undefined) {
        keys.push(key);
        key = undefined;
      }
    };

    actions[APPEND] = function () {
      if (key === undefined) {
        key = newChar;
      } else {
        key += newChar;
      }
    };

    actions[INC_SUB_PATH_DEPTH] = function () {
      actions[APPEND]();
      subPathDepth++;
    };

    actions[PUSH_SUB_PATH] = function () {
      if (subPathDepth > 0) {
        subPathDepth--;
        mode = IN_SUB_PATH;
        actions[APPEND]();
      } else {
        subPathDepth = 0;
        key = formatSubPath(key);
        if (key === false) {
          return false
        } else {
          actions[PUSH]();
        }
      }
    };

    function maybeUnescapeQuote () {
      var nextChar = path[index + 1];
      if ((mode === IN_SINGLE_QUOTE && nextChar === "'") ||
        (mode === IN_DOUBLE_QUOTE && nextChar === '"')) {
        index++;
        newChar = '\\' + nextChar;
        actions[APPEND]();
        return true
      }
    }

    while (mode !== null) {
      index++;
      c = path[index];

      if (c === '\\' && maybeUnescapeQuote()) {
        continue
      }

      type = getPathCharType(c);
      typeMap = pathStateMachine[mode];
      transition = typeMap[type] || typeMap['else'] || ERROR;

      if (transition === ERROR) {
        return // parse error
      }

      mode = transition[0];
      action = actions[transition[1]];
      if (action) {
        newChar = transition[2];
        newChar = newChar === undefined
          ? c
          : newChar;
        if (action() === false) {
          return
        }
      }

      if (mode === AFTER_PATH) {
        return keys
      }
    }
  }





  var I18nPath = function I18nPath () {
    this._cache = Object.create(null);
  };

  /**
   * External parse that check for a cache hit first
   */
  I18nPath.prototype.parsePath = function parsePath (path) {
    var hit = this._cache[path];
    if (!hit) {
      hit = parse$1(path);
      if (hit) {
        this._cache[path] = hit;
      }
    }
    return hit || []
  };

  /**
   * Get path value from path string
   */
  I18nPath.prototype.getPathValue = function getPathValue (obj, path) {
    if (!isObject(obj)) { return null }

    var paths = this.parsePath(path);
    if (paths.length === 0) {
      return null
    } else {
      var length = paths.length;
      var last = obj;
      var i = 0;
      while (i < length) {
        var value = last[paths[i]];
        if (value === undefined) {
          return null
        }
        last = value;
        i++;
      }

      return last
    }
  };

  /*  */



  var numberFormatKeys = [
    'style',
    'currency',
    'currencyDisplay',
    'useGrouping',
    'minimumIntegerDigits',
    'minimumFractionDigits',
    'maximumFractionDigits',
    'minimumSignificantDigits',
    'maximumSignificantDigits',
    'localeMatcher',
    'formatMatcher'
  ];
  var linkKeyMatcher = /(?:@(?:\.[a-z]+)?:(?:[\w\-_|.]+|\([\w\-_|.]+\)))/g;
  var linkKeyPrefixMatcher = /^@(?:\.([a-z]+))?:/;
  var bracketsMatcher = /[()]/g;
  var formatters = {
    'upper': function (str) { return str.toLocaleUpperCase(); },
    'lower': function (str) { return str.toLocaleLowerCase(); }
  };

  var defaultFormatter = new BaseFormatter();

  var VueI18n = function VueI18n (options) {
    var this$1 = this;
    if ( options === void 0 ) options = {};

    // Auto install if it is not done yet and `window` has `Vue`.
    // To allow users to avoid auto-installation in some cases,
    // this code should be placed here. See #290
    /* istanbul ignore if */
    if (!Vue && typeof window !== 'undefined' && window.Vue) {
      install(window.Vue);
    }

    var locale = options.locale || 'en-US';
    var fallbackLocale = options.fallbackLocale || 'en-US';
    var messages = options.messages || {};
    var dateTimeFormats = options.dateTimeFormats || {};
    var numberFormats = options.numberFormats || {};

    this._vm = null;
    this._formatter = options.formatter || defaultFormatter;
    this._missing = options.missing || null;
    this._root = options.root || null;
    this._sync = options.sync === undefined ? true : !!options.sync;
    this._fallbackRoot = options.fallbackRoot === undefined
      ? true
      : !!options.fallbackRoot;
    this._silentTranslationWarn = options.silentTranslationWarn === undefined
      ? false
      : !!options.silentTranslationWarn;
    this._silentFallbackWarn = options.silentFallbackWarn === undefined
      ? false
      : !!options.silentFallbackWarn;
    this._dateTimeFormatters = {};
    this._numberFormatters = {};
    this._path = new I18nPath();
    this._dataListeners = [];
    this._preserveDirectiveContent = options.preserveDirectiveContent === undefined
      ? false
      : !!options.preserveDirectiveContent;
    this.pluralizationRules = options.pluralizationRules || {};

    this._exist = function (message, key) {
      if (!message || !key) { return false }
      if (!isNull(this$1._path.getPathValue(message, key))) { return true }
      // fallback for flat key
      if (message[key]) { return true }
      return false
    };

    this._initVM({
      locale: locale,
      fallbackLocale: fallbackLocale,
      messages: messages,
      dateTimeFormats: dateTimeFormats,
      numberFormats: numberFormats
    });
  };

  var prototypeAccessors = { vm: { configurable: true },messages: { configurable: true },dateTimeFormats: { configurable: true },numberFormats: { configurable: true },availableLocales: { configurable: true },locale: { configurable: true },fallbackLocale: { configurable: true },missing: { configurable: true },formatter: { configurable: true },silentTranslationWarn: { configurable: true },silentFallbackWarn: { configurable: true },preserveDirectiveContent: { configurable: true } };

  VueI18n.prototype._initVM = function _initVM (data) {
    var silent = Vue.config.silent;
    Vue.config.silent = true;
    this._vm = new Vue({ data: data });
    Vue.config.silent = silent;
  };

  VueI18n.prototype.destroyVM = function destroyVM () {
    this._vm.$destroy();
  };

  VueI18n.prototype.subscribeDataChanging = function subscribeDataChanging (vm) {
    this._dataListeners.push(vm);
  };

  VueI18n.prototype.unsubscribeDataChanging = function unsubscribeDataChanging (vm) {
    remove(this._dataListeners, vm);
  };

  VueI18n.prototype.watchI18nData = function watchI18nData () {
    var self = this;
    return this._vm.$watch('$data', function () {
      var i = self._dataListeners.length;
      while (i--) {
        Vue.nextTick(function () {
          self._dataListeners[i] && self._dataListeners[i].$forceUpdate();
        });
      }
    }, { deep: true })
  };

  VueI18n.prototype.watchLocale = function watchLocale () {
    /* istanbul ignore if */
    if (!this._sync || !this._root) { return null }
    var target = this._vm;
    return this._root.$i18n.vm.$watch('locale', function (val) {
      target.$set(target, 'locale', val);
      target.$forceUpdate();
    }, { immediate: true })
  };

  prototypeAccessors.vm.get = function () { return this._vm };

  prototypeAccessors.messages.get = function () { return looseClone(this._getMessages()) };
  prototypeAccessors.dateTimeFormats.get = function () { return looseClone(this._getDateTimeFormats()) };
  prototypeAccessors.numberFormats.get = function () { return looseClone(this._getNumberFormats()) };
  prototypeAccessors.availableLocales.get = function () { return Object.keys(this.messages).sort() };

  prototypeAccessors.locale.get = function () { return this._vm.locale };
  prototypeAccessors.locale.set = function (locale) {
    this._vm.$set(this._vm, 'locale', locale);
  };

  prototypeAccessors.fallbackLocale.get = function () { return this._vm.fallbackLocale };
  prototypeAccessors.fallbackLocale.set = function (locale) {
    this._vm.$set(this._vm, 'fallbackLocale', locale);
  };

  prototypeAccessors.missing.get = function () { return this._missing };
  prototypeAccessors.missing.set = function (handler) { this._missing = handler; };

  prototypeAccessors.formatter.get = function () { return this._formatter };
  prototypeAccessors.formatter.set = function (formatter) { this._formatter = formatter; };

  prototypeAccessors.silentTranslationWarn.get = function () { return this._silentTranslationWarn };
  prototypeAccessors.silentTranslationWarn.set = function (silent) { this._silentTranslationWarn = silent; };

  prototypeAccessors.silentFallbackWarn.get = function () { return this._silentFallbackWarn };
  prototypeAccessors.silentFallbackWarn.set = function (silent) { this._silentFallbackWarn = silent; };

  prototypeAccessors.preserveDirectiveContent.get = function () { return this._preserveDirectiveContent };
  prototypeAccessors.preserveDirectiveContent.set = function (preserve) { this._preserveDirectiveContent = preserve; };

  VueI18n.prototype._getMessages = function _getMessages () { return this._vm.messages };
  VueI18n.prototype._getDateTimeFormats = function _getDateTimeFormats () { return this._vm.dateTimeFormats };
  VueI18n.prototype._getNumberFormats = function _getNumberFormats () { return this._vm.numberFormats };

  VueI18n.prototype._warnDefault = function _warnDefault (locale, key, result, vm, values) {
    if (!isNull(result)) { return result }
    if (this._missing) {
      var missingRet = this._missing.apply(null, [locale, key, vm, values]);
      if (typeof missingRet === 'string') {
        return missingRet
      }
    } else {
      if (!this._silentTranslationWarn) {
        warn(
          "Cannot translate the value of keypath '" + key + "'. " +
          'Use the value of keypath as default.'
        );
      }
    }
    return key
  };

  VueI18n.prototype._isFallbackRoot = function _isFallbackRoot (val) {
    return !val && !isNull(this._root) && this._fallbackRoot
  };

  VueI18n.prototype._isSilentFallback = function _isSilentFallback (locale) {
    return this._silentFallbackWarn && (this._isFallbackRoot() || locale !== this.fallbackLocale)
  };

  VueI18n.prototype._interpolate = function _interpolate (
    locale,
    message,
    key,
    host,
    interpolateMode,
    values,
    visitedLinkStack
  ) {
    if (!message) { return null }

    var pathRet = this._path.getPathValue(message, key);
    if (Array.isArray(pathRet) || isPlainObject(pathRet)) { return pathRet }

    var ret;
    if (isNull(pathRet)) {
      /* istanbul ignore else */
      if (isPlainObject(message)) {
        ret = message[key];
        if (typeof ret !== 'string') {
          if (!this._silentTranslationWarn && !this._isSilentFallback(locale)) {
            warn(("Value of key '" + key + "' is not a string!"));
          }
          return null
        }
      } else {
        return null
      }
    } else {
      /* istanbul ignore else */
      if (typeof pathRet === 'string') {
        ret = pathRet;
      } else {
        if (!this._silentTranslationWarn && !this._isSilentFallback(locale)) {
          warn(("Value of key '" + key + "' is not a string!"));
        }
        return null
      }
    }

    // Check for the existence of links within the translated string
    if (ret.indexOf('@:') >= 0 || ret.indexOf('@.') >= 0) {
      ret = this._link(locale, message, ret, host, 'raw', values, visitedLinkStack);
    }

    return this._render(ret, interpolateMode, values, key)
  };

  VueI18n.prototype._link = function _link (
    locale,
    message,
    str,
    host,
    interpolateMode,
    values,
    visitedLinkStack
  ) {
      var this$1 = this;

    var ret = str;

    // Match all the links within the local
    // We are going to replace each of
    // them with its translation
    var matches = ret.match(linkKeyMatcher);
    for (var idx in matches) {
      // ie compatible: filter custom array
      // prototype method
      if (!matches.hasOwnProperty(idx)) {
        continue
      }
      var link = matches[idx];
      var linkKeyPrefixMatches = link.match(linkKeyPrefixMatcher);
      var linkPrefix = linkKeyPrefixMatches[0];
        var formatterName = linkKeyPrefixMatches[1];

      // Remove the leading @:, @.case: and the brackets
      var linkPlaceholder = link.replace(linkPrefix, '').replace(bracketsMatcher, '');

      if (visitedLinkStack.includes(linkPlaceholder)) {
        {
          warn(("Circular reference found. \"" + link + "\" is already visited in the chain of " + (visitedLinkStack.reverse().join(' <- '))));
        }
        return ret
      }
      visitedLinkStack.push(linkPlaceholder);

      // Translate the link
      var translated = this$1._interpolate(
        locale, message, linkPlaceholder, host,
        interpolateMode === 'raw' ? 'string' : interpolateMode,
        interpolateMode === 'raw' ? undefined : values,
        visitedLinkStack
      );

      if (this$1._isFallbackRoot(translated)) {
        if (!this$1._silentTranslationWarn) {
          warn(("Fall back to translate the link placeholder '" + linkPlaceholder + "' with root locale."));
        }
        /* istanbul ignore if */
        if (!this$1._root) { throw Error('unexpected error') }
        var root = this$1._root.$i18n;
        translated = root._translate(
          root._getMessages(), root.locale, root.fallbackLocale,
          linkPlaceholder, host, interpolateMode, values
        );
      }
      translated = this$1._warnDefault(
        locale, linkPlaceholder, translated, host,
        Array.isArray(values) ? values : [values]
      );
      if (formatters.hasOwnProperty(formatterName)) {
        translated = formatters[formatterName](translated);
      }

      visitedLinkStack.pop();

      // Replace the link with the translated
      ret = !translated ? ret : ret.replace(link, translated);
    }

    return ret
  };

  VueI18n.prototype._render = function _render (message, interpolateMode, values, path) {
    var ret = this._formatter.interpolate(message, values, path);

    // If the custom formatter refuses to work - apply the default one
    if (!ret) {
      ret = defaultFormatter.interpolate(message, values, path);
    }

    // if interpolateMode is **not** 'string' ('row'),
    // return the compiled data (e.g. ['foo', VNode, 'bar']) with formatter
    return interpolateMode === 'string' ? ret.join('') : ret
  };

  VueI18n.prototype._translate = function _translate (
    messages,
    locale,
    fallback,
    key,
    host,
    interpolateMode,
    args
  ) {
    var res =
      this._interpolate(locale, messages[locale], key, host, interpolateMode, args, [key]);
    if (!isNull(res)) { return res }

    res = this._interpolate(fallback, messages[fallback], key, host, interpolateMode, args, [key]);
    if (!isNull(res)) {
      if (!this._silentTranslationWarn && !this._silentFallbackWarn) {
        warn(("Fall back to translate the keypath '" + key + "' with '" + fallback + "' locale."));
      }
      return res
    } else {
      return null
    }
  };

  VueI18n.prototype._t = function _t (key, _locale, messages, host) {
      var ref;

      var values = [], len = arguments.length - 4;
      while ( len-- > 0 ) values[ len ] = arguments[ len + 4 ];
    if (!key) { return '' }

    var parsedArgs = parseArgs.apply(void 0, values);
    var locale = parsedArgs.locale || _locale;

    var ret = this._translate(
      messages, locale, this.fallbackLocale, key,
      host, 'string', parsedArgs.params
    );
    if (this._isFallbackRoot(ret)) {
      if (!this._silentTranslationWarn && !this._silentFallbackWarn) {
        warn(("Fall back to translate the keypath '" + key + "' with root locale."));
      }
      /* istanbul ignore if */
      if (!this._root) { throw Error('unexpected error') }
      return (ref = this._root).$t.apply(ref, [ key ].concat( values ))
    } else {
      return this._warnDefault(locale, key, ret, host, values)
    }
  };

  VueI18n.prototype.t = function t (key) {
      var ref;

      var values = [], len = arguments.length - 1;
      while ( len-- > 0 ) values[ len ] = arguments[ len + 1 ];
    return (ref = this)._t.apply(ref, [ key, this.locale, this._getMessages(), null ].concat( values ))
  };

  VueI18n.prototype._i = function _i (key, locale, messages, host, values) {
    var ret =
      this._translate(messages, locale, this.fallbackLocale, key, host, 'raw', values);
    if (this._isFallbackRoot(ret)) {
      if (!this._silentTranslationWarn) {
        warn(("Fall back to interpolate the keypath '" + key + "' with root locale."));
      }
      if (!this._root) { throw Error('unexpected error') }
      return this._root.$i18n.i(key, locale, values)
    } else {
      return this._warnDefault(locale, key, ret, host, [values])
    }
  };

  VueI18n.prototype.i = function i (key, locale, values) {
    /* istanbul ignore if */
    if (!key) { return '' }

    if (typeof locale !== 'string') {
      locale = this.locale;
    }

    return this._i(key, locale, this._getMessages(), null, values)
  };

  VueI18n.prototype._tc = function _tc (
    key,
    _locale,
    messages,
    host,
    choice
  ) {
      var ref;

      var values = [], len = arguments.length - 5;
      while ( len-- > 0 ) values[ len ] = arguments[ len + 5 ];
    if (!key) { return '' }
    if (choice === undefined) {
      choice = 1;
    }

    var predefined = { 'count': choice, 'n': choice };
    var parsedArgs = parseArgs.apply(void 0, values);
    parsedArgs.params = Object.assign(predefined, parsedArgs.params);
    values = parsedArgs.locale === null ? [parsedArgs.params] : [parsedArgs.locale, parsedArgs.params];
    return this.fetchChoice((ref = this)._t.apply(ref, [ key, _locale, messages, host ].concat( values )), choice)
  };

  VueI18n.prototype.fetchChoice = function fetchChoice (message, choice) {
    /* istanbul ignore if */
    if (!message && typeof message !== 'string') { return null }
    var choices = message.split('|');

    choice = this.getChoiceIndex(choice, choices.length);
    if (!choices[choice]) { return message }
    return choices[choice].trim()
  };

  /**
   * @param choice {number} a choice index given by the input to $tc: `$tc('path.to.rule', choiceIndex)`
   * @param choicesLength {number} an overall amount of available choices
   * @returns a final choice index
  */
  VueI18n.prototype.getChoiceIndex = function getChoiceIndex (choice, choicesLength) {
    // Default (old) getChoiceIndex implementation - english-compatible
    var defaultImpl = function (_choice, _choicesLength) {
      _choice = Math.abs(_choice);

      if (_choicesLength === 2) {
        return _choice
          ? _choice > 1
            ? 1
            : 0
          : 1
      }

      return _choice ? Math.min(_choice, 2) : 0
    };

    if (this.locale in this.pluralizationRules) {
      return this.pluralizationRules[this.locale].apply(this, [choice, choicesLength])
    } else {
      return defaultImpl(choice, choicesLength)
    }
  };

  VueI18n.prototype.tc = function tc (key, choice) {
      var ref;

      var values = [], len = arguments.length - 2;
      while ( len-- > 0 ) values[ len ] = arguments[ len + 2 ];
    return (ref = this)._tc.apply(ref, [ key, this.locale, this._getMessages(), null, choice ].concat( values ))
  };

  VueI18n.prototype._te = function _te (key, locale, messages) {
      var args = [], len = arguments.length - 3;
      while ( len-- > 0 ) args[ len ] = arguments[ len + 3 ];

    var _locale = parseArgs.apply(void 0, args).locale || locale;
    return this._exist(messages[_locale], key)
  };

  VueI18n.prototype.te = function te (key, locale) {
    return this._te(key, this.locale, this._getMessages(), locale)
  };

  VueI18n.prototype.getLocaleMessage = function getLocaleMessage (locale) {
    return looseClone(this._vm.messages[locale] || {})
  };

  VueI18n.prototype.setLocaleMessage = function setLocaleMessage (locale, message) {
    this._vm.$set(this._vm.messages, locale, message);
  };

  VueI18n.prototype.mergeLocaleMessage = function mergeLocaleMessage (locale, message) {
    this._vm.$set(this._vm.messages, locale, merge(this._vm.messages[locale] || {}, message));
  };

  VueI18n.prototype.getDateTimeFormat = function getDateTimeFormat (locale) {
    return looseClone(this._vm.dateTimeFormats[locale] || {})
  };

  VueI18n.prototype.setDateTimeFormat = function setDateTimeFormat (locale, format) {
    this._vm.$set(this._vm.dateTimeFormats, locale, format);
  };

  VueI18n.prototype.mergeDateTimeFormat = function mergeDateTimeFormat (locale, format) {
    this._vm.$set(this._vm.dateTimeFormats, locale, merge(this._vm.dateTimeFormats[locale] || {}, format));
  };

  VueI18n.prototype._localizeDateTime = function _localizeDateTime (
    value,
    locale,
    fallback,
    dateTimeFormats,
    key
  ) {
    var _locale = locale;
    var formats = dateTimeFormats[_locale];

    // fallback locale
    if (isNull(formats) || isNull(formats[key])) {
      if (!this._silentTranslationWarn) {
        warn(("Fall back to '" + fallback + "' datetime formats from '" + locale + " datetime formats."));
      }
      _locale = fallback;
      formats = dateTimeFormats[_locale];
    }

    if (isNull(formats) || isNull(formats[key])) {
      return null
    } else {
      var format = formats[key];
      var id = _locale + "__" + key;
      var formatter = this._dateTimeFormatters[id];
      if (!formatter) {
        formatter = this._dateTimeFormatters[id] = new Intl.DateTimeFormat(_locale, format);
      }
      return formatter.format(value)
    }
  };

  VueI18n.prototype._d = function _d (value, locale, key) {
    /* istanbul ignore if */
    if (!VueI18n.availabilities.dateTimeFormat) {
      warn('Cannot format a Date value due to not supported Intl.DateTimeFormat.');
      return ''
    }

    if (!key) {
      return new Intl.DateTimeFormat(locale).format(value)
    }

    var ret =
      this._localizeDateTime(value, locale, this.fallbackLocale, this._getDateTimeFormats(), key);
    if (this._isFallbackRoot(ret)) {
      if (!this._silentTranslationWarn) {
        warn(("Fall back to datetime localization of root: key '" + key + "' ."));
      }
      /* istanbul ignore if */
      if (!this._root) { throw Error('unexpected error') }
      return this._root.$i18n.d(value, key, locale)
    } else {
      return ret || ''
    }
  };

  VueI18n.prototype.d = function d (value) {
      var args = [], len = arguments.length - 1;
      while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];

    var locale = this.locale;
    var key = null;

    if (args.length === 1) {
      if (typeof args[0] === 'string') {
        key = args[0];
      } else if (isObject(args[0])) {
        if (args[0].locale) {
          locale = args[0].locale;
        }
        if (args[0].key) {
          key = args[0].key;
        }
      }
    } else if (args.length === 2) {
      if (typeof args[0] === 'string') {
        key = args[0];
      }
      if (typeof args[1] === 'string') {
        locale = args[1];
      }
    }

    return this._d(value, locale, key)
  };

  VueI18n.prototype.getNumberFormat = function getNumberFormat (locale) {
    return looseClone(this._vm.numberFormats[locale] || {})
  };

  VueI18n.prototype.setNumberFormat = function setNumberFormat (locale, format) {
    this._vm.$set(this._vm.numberFormats, locale, format);
  };

  VueI18n.prototype.mergeNumberFormat = function mergeNumberFormat (locale, format) {
    this._vm.$set(this._vm.numberFormats, locale, merge(this._vm.numberFormats[locale] || {}, format));
  };

  VueI18n.prototype._localizeNumber = function _localizeNumber (
    value,
    locale,
    fallback,
    numberFormats,
    key,
    options
  ) {
    var _locale = locale;
    var formats = numberFormats[_locale];

    // fallback locale
    if (isNull(formats) || isNull(formats[key])) {
      if (!this._silentTranslationWarn) {
        warn(("Fall back to '" + fallback + "' number formats from '" + locale + " number formats."));
      }
      _locale = fallback;
      formats = numberFormats[_locale];
    }

    if (isNull(formats) || isNull(formats[key])) {
      return null
    } else {
      var format = formats[key];

      var formatter;
      if (options) {
        // If options specified - create one time number formatter
        formatter = new Intl.NumberFormat(_locale, Object.assign({}, format, options));
      } else {
        var id = _locale + "__" + key;
        formatter = this._numberFormatters[id];
        if (!formatter) {
          formatter = this._numberFormatters[id] = new Intl.NumberFormat(_locale, format);
        }
      }
      return formatter.format(value)
    }
  };

  VueI18n.prototype._n = function _n (value, locale, key, options) {
    /* istanbul ignore if */
    if (!VueI18n.availabilities.numberFormat) {
      {
        warn('Cannot format a Number value due to not supported Intl.NumberFormat.');
      }
      return ''
    }

    if (!key) {
      var nf = !options ? new Intl.NumberFormat(locale) : new Intl.NumberFormat(locale, options);
      return nf.format(value)
    }

    var ret =
      this._localizeNumber(value, locale, this.fallbackLocale, this._getNumberFormats(), key, options);
    if (this._isFallbackRoot(ret)) {
      if (!this._silentTranslationWarn) {
        warn(("Fall back to number localization of root: key '" + key + "' ."));
      }
      /* istanbul ignore if */
      if (!this._root) { throw Error('unexpected error') }
      return this._root.$i18n.n(value, Object.assign({}, { key: key, locale: locale }, options))
    } else {
      return ret || ''
    }
  };

  VueI18n.prototype.n = function n (value) {
      var args = [], len = arguments.length - 1;
      while ( len-- > 0 ) args[ len ] = arguments[ len + 1 ];

    var locale = this.locale;
    var key = null;
    var options = null;

    if (args.length === 1) {
      if (typeof args[0] === 'string') {
        key = args[0];
      } else if (isObject(args[0])) {
        if (args[0].locale) {
          locale = args[0].locale;
        }
        if (args[0].key) {
          key = args[0].key;
        }

        // Filter out number format options only
        options = Object.keys(args[0]).reduce(function (acc, key) {
            var obj;

          if (numberFormatKeys.includes(key)) {
            return Object.assign({}, acc, ( obj = {}, obj[key] = args[0][key], obj ))
          }
          return acc
        }, null);
      }
    } else if (args.length === 2) {
      if (typeof args[0] === 'string') {
        key = args[0];
      }
      if (typeof args[1] === 'string') {
        locale = args[1];
      }
    }

    return this._n(value, locale, key, options)
  };

  Object.defineProperties( VueI18n.prototype, prototypeAccessors );

  var availabilities;
  // $FlowFixMe
  Object.defineProperty(VueI18n, 'availabilities', {
    get: function get () {
      if (!availabilities) {
        var intlDefined = typeof Intl !== 'undefined';
        availabilities = {
          dateTimeFormat: intlDefined && typeof Intl.DateTimeFormat !== 'undefined',
          numberFormat: intlDefined && typeof Intl.NumberFormat !== 'undefined'
        };
      }

      return availabilities
    }
  });

  VueI18n.install = install;
  VueI18n.version = '8.9.0';

  return VueI18n;

})));
