worker.js

var MyBundle = (function (exports) {
  "use strict";

  /**
   * @license
   * Copyright 2019 Google LLC
   * SPDX-License-Identifier: Apache-2.0
   */
  const proxyMarker = Symbol("Comlink.proxy");
  const createEndpoint = Symbol("Comlink.endpoint");
  const releaseProxy = Symbol("Comlink.releaseProxy");
  const finalizer = Symbol("Comlink.finalizer");
  const throwMarker = Symbol("Comlink.thrown");
  const isObject = (val) =>
    (typeof val === "object" && val !== null) || typeof val === "function";
  /**
   * Internal transfer handle to handle objects marked to proxy.
   */
  const proxyTransferHandler = {
    canHandle: (val) => isObject(val) && val[proxyMarker],
    serialize(obj) {
      const { port1, port2 } = new MessageChannel();
      expose(obj, port1);
      return [port2, [port2]];
    },
    deserialize(port) {
      port.start();
      return wrap(port);
    },
  };
  /**
   * Internal transfer handler to handle thrown exceptions.
   */
  const throwTransferHandler = {
    canHandle: (value) => isObject(value) && throwMarker in value,
    serialize({ value }) {
      let serialized;
      if (value instanceof Error) {
        serialized = {
          isError: true,
          value: {
            message: value.message,
            name: value.name,
            stack: value.stack,
          },
        };
      } else {
        serialized = { isError: false, value };
      }
      return [serialized, []];
    },
    deserialize(serialized) {
      if (serialized.isError) {
        throw Object.assign(
          new Error(serialized.value.message),
          serialized.value
        );
      }
      throw serialized.value;
    },
  };
  /**
   * Allows customizing the serialization of certain values.
   */
  const transferHandlers = new Map([
    ["proxy", proxyTransferHandler],
    ["throw", throwTransferHandler],
  ]);
  function isAllowedOrigin(allowedOrigins, origin) {
    for (const allowedOrigin of allowedOrigins) {
      if (origin === allowedOrigin || allowedOrigin === "*") {
        return true;
      }
      if (allowedOrigin instanceof RegExp && allowedOrigin.test(origin)) {
        return true;
      }
    }
    return false;
  }
  function expose(obj, ep = globalThis, allowedOrigins = ["*"]) {
    ep.addEventListener("message", function callback(ev) {
      if (!ev || !ev.data) {
        return;
      }
      if (!isAllowedOrigin(allowedOrigins, ev.origin)) {
        console.warn(`Invalid origin '${ev.origin}' for comlink proxy`);
        return;
      }
      const { id, type, path } = Object.assign({ path: [] }, ev.data);
      const argumentList = (ev.data.argumentList || []).map(fromWireValue);
      let returnValue;
      try {
        const parent = path.slice(0, -1).reduce((obj, prop) => obj[prop], obj);
        const rawValue = path.reduce((obj, prop) => obj[prop], obj);
        switch (type) {
          case "GET" /* MessageType.GET */:
            {
              returnValue = rawValue;
            }
            break;
          case "SET" /* MessageType.SET */:
            {
              parent[path.slice(-1)[0]] = fromWireValue(ev.data.value);
              returnValue = true;
            }
            break;
          case "APPLY" /* MessageType.APPLY */:
            {
              returnValue = rawValue.apply(parent, argumentList);
            }
            break;
          case "CONSTRUCT" /* MessageType.CONSTRUCT */:
            {
              const value = new rawValue(...argumentList);
              returnValue = proxy(value);
            }
            break;
          case "ENDPOINT" /* MessageType.ENDPOINT */:
            {
              const { port1, port2 } = new MessageChannel();
              expose(obj, port2);
              returnValue = transfer(port1, [port1]);
            }
            break;
          case "RELEASE" /* MessageType.RELEASE */:
            {
              returnValue = undefined;
            }
            break;
          default:
            return;
        }
      } catch (value) {
        returnValue = { value, [throwMarker]: 0 };
      }
      Promise.resolve(returnValue)
        .catch((value) => {
          return { value, [throwMarker]: 0 };
        })
        .then((returnValue) => {
          const [wireValue, transferables] = toWireValue(returnValue);
          ep.postMessage(
            Object.assign(Object.assign({}, wireValue), { id }),
            transferables
          );
          if (type === "RELEASE" /* MessageType.RELEASE */) {
            // detach and deactive after sending release response above.
            ep.removeEventListener("message", callback);
            closeEndPoint(ep);
            if (finalizer in obj && typeof obj[finalizer] === "function") {
              obj[finalizer]();
            }
          }
        })
        .catch((error) => {
          // Send Serialization Error To Caller
          const [wireValue, transferables] = toWireValue({
            value: new TypeError("Unserializable return value"),
            [throwMarker]: 0,
          });
          ep.postMessage(
            Object.assign(Object.assign({}, wireValue), { id }),
            transferables
          );
        });
    });
    if (ep.start) {
      ep.start();
    }
  }
  function isMessagePort(endpoint) {
    return endpoint.constructor.name === "MessagePort";
  }
  function closeEndPoint(endpoint) {
    if (isMessagePort(endpoint)) endpoint.close();
  }
  function wrap(ep, target) {
    const pendingListeners = new Map();
    ep.addEventListener("message", function handleMessage(ev) {
      const { data } = ev;
      if (!data || !data.id) {
        return;
      }
      const resolver = pendingListeners.get(data.id);
      if (!resolver) {
        return;
      }
      try {
        resolver(data);
      } finally {
        pendingListeners.delete(data.id);
      }
    });
    return createProxy(ep, pendingListeners, [], target);
  }
  function throwIfProxyReleased(isReleased) {
    if (isReleased) {
      throw new Error("Proxy has been released and is not useable");
    }
  }
  function releaseEndpoint(ep) {
    return requestResponseMessage(ep, new Map(), {
      type: "RELEASE" /* MessageType.RELEASE */,
    }).then(() => {
      closeEndPoint(ep);
    });
  }
  const proxyCounter = new WeakMap();
  const proxyFinalizers =
    "FinalizationRegistry" in globalThis &&
    new FinalizationRegistry((ep) => {
      const newCount = (proxyCounter.get(ep) || 0) - 1;
      proxyCounter.set(ep, newCount);
      if (newCount === 0) {
        releaseEndpoint(ep);
      }
    });
  function registerProxy(proxy, ep) {
    const newCount = (proxyCounter.get(ep) || 0) + 1;
    proxyCounter.set(ep, newCount);
    if (proxyFinalizers) {
      proxyFinalizers.register(proxy, ep, proxy);
    }
  }
  function unregisterProxy(proxy) {
    if (proxyFinalizers) {
      proxyFinalizers.unregister(proxy);
    }
  }
  function createProxy(
    ep,
    pendingListeners,
    path = [],
    target = function () {}
  ) {
    let isProxyReleased = false;
    const proxy = new Proxy(target, {
      get(_target, prop) {
        throwIfProxyReleased(isProxyReleased);
        if (prop === releaseProxy) {
          return () => {
            unregisterProxy(proxy);
            releaseEndpoint(ep);
            pendingListeners.clear();
            isProxyReleased = true;
          };
        }
        if (prop === "then") {
          if (path.length === 0) {
            return { then: () => proxy };
          }
          const r = requestResponseMessage(ep, pendingListeners, {
            type: "GET" /* MessageType.GET */,
            path: path.map((p) => p.toString()),
          }).then(fromWireValue);
          return r.then.bind(r);
        }
        return createProxy(ep, pendingListeners, [...path, prop]);
      },
      set(_target, prop, rawValue) {
        throwIfProxyReleased(isProxyReleased);
        // FIXME: ES6 Proxy Handler `set` methods are supposed to return a
        // boolean. To show good will, we return true asynchronously ¯\_(ツ)_/¯
        const [value, transferables] = toWireValue(rawValue);
        return requestResponseMessage(
          ep,
          pendingListeners,
          {
            type: "SET" /* MessageType.SET */,
            path: [...path, prop].map((p) => p.toString()),
            value,
          },
          transferables
        ).then(fromWireValue);
      },
      apply(_target, _thisArg, rawArgumentList) {
        throwIfProxyReleased(isProxyReleased);
        const last = path[path.length - 1];
        if (last === createEndpoint) {
          return requestResponseMessage(ep, pendingListeners, {
            type: "ENDPOINT" /* MessageType.ENDPOINT */,
          }).then(fromWireValue);
        }
        // We just pretend that `bind()` didn’t happen.
        if (last === "bind") {
          return createProxy(ep, pendingListeners, path.slice(0, -1));
        }
        const [argumentList, transferables] = processArguments(rawArgumentList);
        return requestResponseMessage(
          ep,
          pendingListeners,
          {
            type: "APPLY" /* MessageType.APPLY */,
            path: path.map((p) => p.toString()),
            argumentList,
          },
          transferables
        ).then(fromWireValue);
      },
      construct(_target, rawArgumentList) {
        throwIfProxyReleased(isProxyReleased);
        const [argumentList, transferables] = processArguments(rawArgumentList);
        return requestResponseMessage(
          ep,
          pendingListeners,
          {
            type: "CONSTRUCT" /* MessageType.CONSTRUCT */,
            path: path.map((p) => p.toString()),
            argumentList,
          },
          transferables
        ).then(fromWireValue);
      },
    });
    registerProxy(proxy, ep);
    return proxy;
  }
  function myFlat(arr) {
    return Array.prototype.concat.apply([], arr);
  }
  function processArguments(argumentList) {
    const processed = argumentList.map(toWireValue);
    return [processed.map((v) => v[0]), myFlat(processed.map((v) => v[1]))];
  }
  const transferCache = new WeakMap();
  function transfer(obj, transfers) {
    transferCache.set(obj, transfers);
    return obj;
  }
  function proxy(obj) {
    return Object.assign(obj, { [proxyMarker]: true });
  }
  function toWireValue(value) {
    for (const [name, handler] of transferHandlers) {
      if (handler.canHandle(value)) {
        const [serializedValue, transferables] = handler.serialize(value);
        return [
          {
            type: "HANDLER" /* WireValueType.HANDLER */,
            name,
            value: serializedValue,
          },
          transferables,
        ];
      }
    }
    return [
      {
        type: "RAW" /* WireValueType.RAW */,
        value,
      },
      transferCache.get(value) || [],
    ];
  }
  function fromWireValue(value) {
    switch (value.type) {
      case "HANDLER" /* WireValueType.HANDLER */:
        return transferHandlers.get(value.name).deserialize(value.value);
      case "RAW" /* WireValueType.RAW */:
        return value.value;
    }
  }
  function requestResponseMessage(ep, pendingListeners, msg, transfers) {
    return new Promise((resolve) => {
      const id = generateUUID();
      pendingListeners.set(id, resolve);
      if (ep.start) {
        ep.start();
      }
      ep.postMessage(Object.assign({ id }, msg), transfers);
    });
  }
  function generateUUID() {
    return new Array(4)
      .fill(0)
      .map(() =>
        Math.floor(Math.random() * Number.MAX_SAFE_INTEGER).toString(16)
      )
      .join("-");
  }

  function getDefaultExportFromCjs(x) {
    return x &&
      x.__esModule &&
      Object.prototype.hasOwnProperty.call(x, "default")
      ? x["default"]
      : x;
  }

  var lunr$1 = { exports: {} };

  /**
   * lunr - http://lunrjs.com - A bit like Solr, but much smaller and not as bright - 2.3.9
   * Copyright (C) 2020 Oliver Nightingale
   * @license MIT
   */
  lunr$1.exports;

  var hasRequiredLunr;

  function requireLunr() {
    if (hasRequiredLunr) return lunr$1.exports;
    hasRequiredLunr = 1;
    (function (module, exports) {
      (function () {
        /**
         * A convenience function for configuring and constructing
         * a new lunr Index.
         *
         * A lunr.Builder instance is created and the pipeline setup
         * with a trimmer, stop word filter and stemmer.
         *
         * This builder object is yielded to the configuration function
         * that is passed as a parameter, allowing the list of fields
         * and other builder parameters to be customised.
         *
         * All documents _must_ be added within the passed config function.
         *
         * @example
         * var idx = lunr(function () {
         *   this.field('title')
         *   this.field('body')
         *   this.ref('id')
         *
         *   documents.forEach(function (doc) {
         *     this.add(doc)
         *   }, this)
         * })
         *
         * @see {@link lunr.Builder}
         * @see {@link lunr.Pipeline}
         * @see {@link lunr.trimmer}
         * @see {@link lunr.stopWordFilter}
         * @see {@link lunr.stemmer}
         * @namespace {function} lunr
         */
        var lunr = function (config) {
          var builder = new lunr.Builder();

          builder.pipeline.add(lunr.trimmer, lunr.stopWordFilter, lunr.stemmer);

          builder.searchPipeline.add(lunr.stemmer);

          config.call(builder, builder);
          return builder.build();
        };

        lunr.version = "2.3.9";
        /*!
         * lunr.utils
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * A namespace containing utils for the rest of the lunr library
         * @namespace lunr.utils
         */
        lunr.utils = {};

        /**
         * Print a warning message to the console.
         *
         * @param {String} message The message to be printed.
         * @memberOf lunr.utils
         * @function
         */
        lunr.utils.warn = (function (global) {
          /* eslint-disable no-console */
          return function (message) {
            console?.warn(message);
          };
          /* eslint-enable no-console */
        })(this);

        /**
         * Convert an object to a string.
         *
         * In the case of `null` and `undefined` the function returns
         * the empty string, in all other cases the result of calling
         * `toString` on the passed object is returned.
         *
         * @param {Any} obj The object to convert to a string.
         * @return {String} string representation of the passed object.
         * @memberOf lunr.utils
         */
        lunr.utils.asString = function (obj) {
          if (obj === void 0 || obj === null) {
            return "";
          } else {
            return obj.toString();
          }
        };

        /**
         * Clones an object.
         *
         * Will create a copy of an existing object such that any mutations
         * on the copy cannot affect the original.
         *
         * Only shallow objects are supported, passing a nested object to this
         * function will cause a TypeError.
         *
         * Objects with primitives, and arrays of primitives are supported.
         *
         * @param {Object} obj The object to clone.
         * @return {Object} a clone of the passed object.
         * @throws {TypeError} when a nested object is passed.
         * @memberOf Utils
         */
        lunr.utils.clone = function (obj) {
          if (obj === null || obj === undefined) {
            return obj;
          }

          var clone = Object.create(null),
            keys = Object.keys(obj);

          for (var i = 0; i < keys.length; i++) {
            var key = keys[i],
              val = obj[key];

            if (Array.isArray(val)) {
              clone[key] = val.slice();
              continue;
            }

            if (
              typeof val === "string" ||
              typeof val === "number" ||
              typeof val === "boolean"
            ) {
              clone[key] = val;
              continue;
            }

            throw new TypeError(
              "clone is not deep and does not support nested objects"
            );
          }

          return clone;
        };
        lunr.FieldRef = function (docRef, fieldName, stringValue) {
          this.docRef = docRef;
          this.fieldName = fieldName;
          this._stringValue = stringValue;
        };

        lunr.FieldRef.joiner = "/";

        lunr.FieldRef.fromString = function (s) {
          var n = s.indexOf(lunr.FieldRef.joiner);

          if (n === -1) {
            throw "malformed field ref string";
          }

          var fieldRef = s.slice(0, n),
            docRef = s.slice(n + 1);

          return new lunr.FieldRef(docRef, fieldRef, s);
        };

        lunr.FieldRef.prototype.toString = function () {
          if (this._stringValue == undefined) {
            this._stringValue =
              this.fieldName + lunr.FieldRef.joiner + this.docRef;
          }

          return this._stringValue;
        };
        /*!
         * lunr.Set
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * A lunr set.
         *
         * @constructor
         */
        lunr.Set = function (elements) {
          this.elements = Object.create(null);

          if (elements) {
            this.length = elements.length;

            for (var i = 0; i < this.length; i++) {
              this.elements[elements[i]] = true;
            }
          } else {
            this.length = 0;
          }
        };

        /**
         * A complete set that contains all elements.
         *
         * @static
         * @readonly
         * @type {lunr.Set}
         */
        lunr.Set.complete = {
          intersect: function (other) {
            return other;
          },

          union: function () {
            return this;
          },

          contains: function () {
            return true;
          },
        };

        /**
         * An empty set that contains no elements.
         *
         * @static
         * @readonly
         * @type {lunr.Set}
         */
        lunr.Set.empty = {
          intersect: function () {
            return this;
          },

          union: function (other) {
            return other;
          },

          contains: function () {
            return false;
          },
        };

        /**
         * Returns true if this set contains the specified object.
         *
         * @param {object} object - Object whose presence in this set is to be tested.
         * @returns {boolean} - True if this set contains the specified object.
         */
        lunr.Set.prototype.contains = function (object) {
          return !!this.elements[object];
        };

        /**
         * Returns a new set containing only the elements that are present in both
         * this set and the specified set.
         *
         * @param {lunr.Set} other - set to intersect with this set.
         * @returns {lunr.Set} a new set that is the intersection of this and the specified set.
         */

        lunr.Set.prototype.intersect = function (other) {
          var a,
            b,
            elements,
            intersection = [];

          if (other === lunr.Set.complete) {
            return this;
          }

          if (other === lunr.Set.empty) {
            return other;
          }

          if (this.length < other.length) {
            a = this;
            b = other;
          } else {
            a = other;
            b = this;
          }

          elements = Object.keys(a.elements);

          for (var i = 0; i < elements.length; i++) {
            var element = elements[i];
            if (element in b.elements) {
              intersection.push(element);
            }
          }

          return new lunr.Set(intersection);
        };

        /**
         * Returns a new set combining the elements of this and the specified set.
         *
         * @param {lunr.Set} other - set to union with this set.
         * @return {lunr.Set} a new set that is the union of this and the specified set.
         */

        lunr.Set.prototype.union = function (other) {
          if (other === lunr.Set.complete) {
            return lunr.Set.complete;
          }

          if (other === lunr.Set.empty) {
            return this;
          }

          return new lunr.Set(
            Object.keys(this.elements).concat(Object.keys(other.elements))
          );
        };
        /**
         * A function to calculate the inverse document frequency for
         * a posting. This is shared between the builder and the index
         *
         * @private
         * @param {object} posting - The posting for a given term
         * @param {number} documentCount - The total number of documents.
         */
        lunr.idf = function (posting, documentCount) {
          var documentsWithTerm = 0;

          for (var fieldName in posting) {
            if (fieldName == "_index") continue; // Ignore the term index, its not a field
            documentsWithTerm += Object.keys(posting[fieldName]).length;
          }

          var x =
            (documentCount - documentsWithTerm + 0.5) /
            (documentsWithTerm + 0.5);

          return Math.log(1 + Math.abs(x));
        };

        /**
         * A token wraps a string representation of a token
         * as it is passed through the text processing pipeline.
         *
         * @constructor
         * @param {string} [str=''] - The string token being wrapped.
         * @param {object} [metadata={}] - Metadata associated with this token.
         */
        lunr.Token = function (str, metadata) {
          this.str = str || "";
          this.metadata = metadata || {};
        };

        /**
         * Returns the token string that is being wrapped by this object.
         *
         * @returns {string}
         */
        lunr.Token.prototype.toString = function () {
          return this.str;
        };

        /**
         * A token update function is used when updating or optionally
         * when cloning a token.
         *
         * @callback lunr.Token~updateFunction
         * @param {string} str - The string representation of the token.
         * @param {Object} metadata - All metadata associated with this token.
         */

        /**
         * Applies the given function to the wrapped string token.
         *
         * @example
         * token.update(function (str, metadata) {
         *   return str.toUpperCase()
         * })
         *
         * @param {lunr.Token~updateFunction} fn - A function to apply to the token string.
         * @returns {lunr.Token}
         */
        lunr.Token.prototype.update = function (fn) {
          this.str = fn(this.str, this.metadata);
          return this;
        };

        /**
         * Creates a clone of this token. Optionally a function can be
         * applied to the cloned token.
         *
         * @param {lunr.Token~updateFunction} [fn] - An optional function to apply to the cloned token.
         * @returns {lunr.Token}
         */
        lunr.Token.prototype.clone = function (fn) {
          fn =
            fn ||
            function (s) {
              return s;
            };
          return new lunr.Token(fn(this.str, this.metadata), this.metadata);
        };
        /*!
         * lunr.tokenizer
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * A function for splitting a string into tokens ready to be inserted into
         * the search index. Uses `lunr.tokenizer.separator` to split strings, change
         * the value of this property to change how strings are split into tokens.
         *
         * This tokenizer will convert its parameter to a string by calling `toString` and
         * then will split this string on the character in `lunr.tokenizer.separator`.
         * Arrays will have their elements converted to strings and wrapped in a lunr.Token.
         *
         * Optional metadata can be passed to the tokenizer, this metadata will be cloned and
         * added as metadata to every token that is created from the object to be tokenized.
         *
         * @static
         * @param {?(string|object|object[])} obj - The object to convert into tokens
         * @param {?object} metadata - Optional metadata to associate with every token
         * @returns {lunr.Token[]}
         * @see {@link lunr.Pipeline}
         */
        lunr.tokenizer = function (obj, metadata) {
          if (obj == null || obj == undefined) {
            return [];
          }

          if (Array.isArray(obj)) {
            return obj.map(function (t) {
              return new lunr.Token(
                lunr.utils.asString(t).toLowerCase(),
                lunr.utils.clone(metadata)
              );
            });
          }

          var str = obj.toString().toLowerCase(),
            len = str.length,
            tokens = [];

          for (var sliceEnd = 0, sliceStart = 0; sliceEnd <= len; sliceEnd++) {
            var char = str.charAt(sliceEnd),
              sliceLength = sliceEnd - sliceStart;

            if (char.match(lunr.tokenizer.separator) || sliceEnd == len) {
              if (sliceLength > 0) {
                var tokenMetadata = lunr.utils.clone(metadata) || {};
                tokenMetadata["position"] = [sliceStart, sliceLength];
                tokenMetadata["index"] = tokens.length;

                tokens.push(
                  new lunr.Token(str.slice(sliceStart, sliceEnd), tokenMetadata)
                );
              }

              sliceStart = sliceEnd + 1;
            }
          }

          return tokens;
        };

        /**
         * The separator used to split a string into tokens. Override this property to change the behaviour of
         * `lunr.tokenizer` behaviour when tokenizing strings. By default this splits on whitespace and hyphens.
         *
         * @static
         * @see lunr.tokenizer
         */
        lunr.tokenizer.separator = /[\s\-]+/;
        /*!
         * lunr.Pipeline
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * lunr.Pipelines maintain an ordered list of functions to be applied to all
         * tokens in documents entering the search index and queries being ran against
         * the index.
         *
         * An instance of lunr.Index created with the lunr shortcut will contain a
         * pipeline with a stop word filter and an English language stemmer. Extra
         * functions can be added before or after either of these functions or these
         * default functions can be removed.
         *
         * When run the pipeline will call each function in turn, passing a token, the
         * index of that token in the original list of all tokens and finally a list of
         * all the original tokens.
         *
         * The output of functions in the pipeline will be passed to the next function
         * in the pipeline. To exclude a token from entering the index the function
         * should return undefined, the rest of the pipeline will not be called with
         * this token.
         *
         * For serialisation of pipelines to work, all functions used in an instance of
         * a pipeline should be registered with lunr.Pipeline. Registered functions can
         * then be loaded. If trying to load a serialised pipeline that uses functions
         * that are not registered an error will be thrown.
         *
         * If not planning on serialising the pipeline then registering pipeline functions
         * is not necessary.
         *
         * @constructor
         */
        lunr.Pipeline = function () {
          this._stack = [];
        };

        lunr.Pipeline.registeredFunctions = Object.create(null);

        /**
         * A pipeline function maps lunr.Token to lunr.Token. A lunr.Token contains the token
         * string as well as all known metadata. A pipeline function can mutate the token string
         * or mutate (or add) metadata for a given token.
         *
         * A pipeline function can indicate that the passed token should be discarded by returning
         * null, undefined or an empty string. This token will not be passed to any downstream pipeline
         * functions and will not be added to the index.
         *
         * Multiple tokens can be returned by returning an array of tokens. Each token will be passed
         * to any downstream pipeline functions and all will returned tokens will be added to the index.
         *
         * Any number of pipeline functions may be chained together using a lunr.Pipeline.
         *
         * @interface lunr.PipelineFunction
         * @param {lunr.Token} token - A token from the document being processed.
         * @param {number} i - The index of this token in the complete list of tokens for this document/field.
         * @param {lunr.Token[]} tokens - All tokens for this document/field.
         * @returns {(?lunr.Token|lunr.Token[])}
         */

        /**
         * Register a function with the pipeline.
         *
         * Functions that are used in the pipeline should be registered if the pipeline
         * needs to be serialised, or a serialised pipeline needs to be loaded.
         *
         * Registering a function does not add it to a pipeline, functions must still be
         * added to instances of the pipeline for them to be used when running a pipeline.
         *
         * @param {lunr.PipelineFunction} fn - The function to check for.
         * @param {String} label - The label to register this function with
         */
        lunr.Pipeline.registerFunction = function (fn, label) {
          if (label in this.registeredFunctions) {
            lunr.utils.warn(
              "Overwriting existing registered function: " + label
            );
          }

          fn.label = label;
          lunr.Pipeline.registeredFunctions[fn.label] = fn;
        };

        /**
         * Warns if the function is not registered as a Pipeline function.
         *
         * @param {lunr.PipelineFunction} fn - The function to check for.
         * @private
         */
        lunr.Pipeline.warnIfFunctionNotRegistered = function (fn) {
          var isRegistered = fn.label && fn.label in this.registeredFunctions;

          if (!isRegistered) {
            lunr.utils.warn(
              "Function is not registered with pipeline. This may cause problems when serialising the index.\n",
              fn
            );
          }
        };

        /**
         * Loads a previously serialised pipeline.
         *
         * All functions to be loaded must already be registered with lunr.Pipeline.
         * If any function from the serialised data has not been registered then an
         * error will be thrown.
         *
         * @param {Object} serialised - The serialised pipeline to load.
         * @returns {lunr.Pipeline}
         */
        lunr.Pipeline.load = function (serialised) {
          var pipeline = new lunr.Pipeline();

          serialised.forEach(function (fnName) {
            var fn = lunr.Pipeline.registeredFunctions[fnName];

            if (fn) {
              pipeline.add(fn);
            } else {
              throw new Error("Cannot load unregistered function: " + fnName);
            }
          });

          return pipeline;
        };

        /**
         * Adds new functions to the end of the pipeline.
         *
         * Logs a warning if the function has not been registered.
         *
         * @param {lunr.PipelineFunction[]} functions - Any number of functions to add to the pipeline.
         */
        lunr.Pipeline.prototype.add = function () {
          var fns = Array.prototype.slice.call(arguments);

          fns.forEach(function (fn) {
            lunr.Pipeline.warnIfFunctionNotRegistered(fn);
            this._stack.push(fn);
          }, this);
        };

        /**
         * Adds a single function after a function that already exists in the
         * pipeline.
         *
         * Logs a warning if the function has not been registered.
         *
         * @param {lunr.PipelineFunction} existingFn - A function that already exists in the pipeline.
         * @param {lunr.PipelineFunction} newFn - The new function to add to the pipeline.
         */
        lunr.Pipeline.prototype.after = function (existingFn, newFn) {
          lunr.Pipeline.warnIfFunctionNotRegistered(newFn);

          var pos = this._stack.indexOf(existingFn);
          if (pos == -1) {
            throw new Error("Cannot find existingFn");
          }

          pos = pos + 1;
          this._stack.splice(pos, 0, newFn);
        };

        /**
         * Adds a single function before a function that already exists in the
         * pipeline.
         *
         * Logs a warning if the function has not been registered.
         *
         * @param {lunr.PipelineFunction} existingFn - A function that already exists in the pipeline.
         * @param {lunr.PipelineFunction} newFn - The new function to add to the pipeline.
         */
        lunr.Pipeline.prototype.before = function (existingFn, newFn) {
          lunr.Pipeline.warnIfFunctionNotRegistered(newFn);

          var pos = this._stack.indexOf(existingFn);
          if (pos == -1) {
            throw new Error("Cannot find existingFn");
          }

          this._stack.splice(pos, 0, newFn);
        };

        /**
         * Removes a function from the pipeline.
         *
         * @param {lunr.PipelineFunction} fn The function to remove from the pipeline.
         */
        lunr.Pipeline.prototype.remove = function (fn) {
          var pos = this._stack.indexOf(fn);
          if (pos == -1) {
            return;
          }

          this._stack.splice(pos, 1);
        };

        /**
         * Runs the current list of functions that make up the pipeline against the
         * passed tokens.
         *
         * @param {Array} tokens The tokens to run through the pipeline.
         * @returns {Array}
         */
        lunr.Pipeline.prototype.run = function (tokens) {
          var stackLength = this._stack.length;

          for (var i = 0; i < stackLength; i++) {
            var fn = this._stack[i];
            var memo = [];

            for (var j = 0; j < tokens.length; j++) {
              var result = fn(tokens[j], j, tokens);

              if (result === null || result === void 0 || result === "")
                continue;

              if (Array.isArray(result)) {
                for (var k = 0; k < result.length; k++) {
                  memo.push(result[k]);
                }
              } else {
                memo.push(result);
              }
            }

            tokens = memo;
          }

          return tokens;
        };

        /**
         * Convenience method for passing a string through a pipeline and getting
         * strings out. This method takes care of wrapping the passed string in a
         * token and mapping the resulting tokens back to strings.
         *
         * @param {string} str - The string to pass through the pipeline.
         * @param {?object} metadata - Optional metadata to associate with the token
         * passed to the pipeline.
         * @returns {string[]}
         */
        lunr.Pipeline.prototype.runString = function (str, metadata) {
          var token = new lunr.Token(str, metadata);

          return this.run([token]).map(function (t) {
            return t.toString();
          });
        };

        /**
         * Resets the pipeline by removing any existing processors.
         *
         */
        lunr.Pipeline.prototype.reset = function () {
          this._stack = [];
        };

        /**
         * Returns a representation of the pipeline ready for serialisation.
         *
         * Logs a warning if the function has not been registered.
         *
         * @returns {Array}
         */
        lunr.Pipeline.prototype.toJSON = function () {
          return this._stack.map(function (fn) {
            lunr.Pipeline.warnIfFunctionNotRegistered(fn);

            return fn.label;
          });
        };
        /*!
         * lunr.Vector
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * A vector is used to construct the vector space of documents and queries. These
         * vectors support operations to determine the similarity between two documents or
         * a document and a query.
         *
         * Normally no parameters are required for initializing a vector, but in the case of
         * loading a previously dumped vector the raw elements can be provided to the constructor.
         *
         * For performance reasons vectors are implemented with a flat array, where an elements
         * index is immediately followed by its value. E.g. [index, value, index, value]. This
         * allows the underlying array to be as sparse as possible and still offer decent
         * performance when being used for vector calculations.
         *
         * @constructor
         * @param {Number[]} [elements] - The flat list of element index and element value pairs.
         */
        lunr.Vector = function (elements) {
          this._magnitude = 0;
          this.elements = elements || [];
        };

        /**
         * Calculates the position within the vector to insert a given index.
         *
         * This is used internally by insert and upsert. If there are duplicate indexes then
         * the position is returned as if the value for that index were to be updated, but it
         * is the callers responsibility to check whether there is a duplicate at that index
         *
         * @param {Number} insertIdx - The index at which the element should be inserted.
         * @returns {Number}
         */
        lunr.Vector.prototype.positionForIndex = function (index) {
          // For an empty vector the tuple can be inserted at the beginning
          if (this.elements.length == 0) {
            return 0;
          }

          var start = 0,
            end = this.elements.length / 2,
            sliceLength = end - start,
            pivotPoint = Math.floor(sliceLength / 2),
            pivotIndex = this.elements[pivotPoint * 2];

          while (sliceLength > 1) {
            if (pivotIndex < index) {
              start = pivotPoint;
            }

            if (pivotIndex > index) {
              end = pivotPoint;
            }

            if (pivotIndex == index) {
              break;
            }

            sliceLength = end - start;
            pivotPoint = start + Math.floor(sliceLength / 2);
            pivotIndex = this.elements[pivotPoint * 2];
          }

          if (pivotIndex == index) {
            return pivotPoint * 2;
          }

          if (pivotIndex > index) {
            return pivotPoint * 2;
          }

          if (pivotIndex < index) {
            return (pivotPoint + 1) * 2;
          }
        };

        /**
         * Inserts an element at an index within the vector.
         *
         * Does not allow duplicates, will throw an error if there is already an entry
         * for this index.
         *
         * @param {Number} insertIdx - The index at which the element should be inserted.
         * @param {Number} val - The value to be inserted into the vector.
         */
        lunr.Vector.prototype.insert = function (insertIdx, val) {
          this.upsert(insertIdx, val, function () {
            throw "duplicate index";
          });
        };

        /**
         * Inserts or updates an existing index within the vector.
         *
         * @param {Number} insertIdx - The index at which the element should be inserted.
         * @param {Number} val - The value to be inserted into the vector.
         * @param {function} fn - A function that is called for updates, the existing value and the
         * requested value are passed as arguments
         */
        lunr.Vector.prototype.upsert = function (insertIdx, val, fn) {
          this._magnitude = 0;
          var position = this.positionForIndex(insertIdx);

          if (this.elements[position] == insertIdx) {
            this.elements[position + 1] = fn(this.elements[position + 1], val);
          } else {
            this.elements.splice(position, 0, insertIdx, val);
          }
        };

        /**
         * Calculates the magnitude of this vector.
         *
         * @returns {Number}
         */
        lunr.Vector.prototype.magnitude = function () {
          if (this._magnitude) return this._magnitude;

          var sumOfSquares = 0,
            elementsLength = this.elements.length;

          for (var i = 1; i < elementsLength; i += 2) {
            var val = this.elements[i];
            sumOfSquares += val * val;
          }

          return (this._magnitude = Math.sqrt(sumOfSquares));
        };

        /**
         * Calculates the dot product of this vector and another vector.
         *
         * @param {lunr.Vector} otherVector - The vector to compute the dot product with.
         * @returns {Number}
         */
        lunr.Vector.prototype.dot = function (otherVector) {
          var dotProduct = 0,
            a = this.elements,
            b = otherVector.elements,
            aLen = a.length,
            bLen = b.length,
            aVal = 0,
            bVal = 0,
            i = 0,
            j = 0;

          while (i < aLen && j < bLen) {
            (aVal = a[i]), (bVal = b[j]);
            if (aVal < bVal) {
              i += 2;
            } else if (aVal > bVal) {
              j += 2;
            } else if (aVal == bVal) {
              dotProduct += a[i + 1] * b[j + 1];
              i += 2;
              j += 2;
            }
          }

          return dotProduct;
        };

        /**
         * Calculates the similarity between this vector and another vector.
         *
         * @param {lunr.Vector} otherVector - The other vector to calculate the
         * similarity with.
         * @returns {Number}
         */
        lunr.Vector.prototype.similarity = function (otherVector) {
          return this.dot(otherVector) / this.magnitude() || 0;
        };

        /**
         * Converts the vector to an array of the elements within the vector.
         *
         * @returns {Number[]}
         */
        lunr.Vector.prototype.toArray = function () {
          var output = new Array(this.elements.length / 2);

          for (var i = 1, j = 0; i < this.elements.length; i += 2, j++) {
            output[j] = this.elements[i];
          }

          return output;
        };

        /**
         * A JSON serializable representation of the vector.
         *
         * @returns {Number[]}
         */
        lunr.Vector.prototype.toJSON = function () {
          return this.elements;
        };
        /* eslint-disable */
        /*!
         * lunr.stemmer
         * Copyright (C) 2020 Oliver Nightingale
         * Includes code from - http://tartarus.org/~martin/PorterStemmer/js.txt
         */

        /**
         * lunr.stemmer is an english language stemmer, this is a JavaScript
         * implementation of the PorterStemmer taken from http://tartarus.org/~martin
         *
         * @static
         * @implements {lunr.PipelineFunction}
         * @param {lunr.Token} token - The string to stem
         * @returns {lunr.Token}
         * @see {@link lunr.Pipeline}
         * @function
         */
        lunr.stemmer = (function () {
          var step2list = {
              ational: "ate",
              tional: "tion",
              enci: "ence",
              anci: "ance",
              izer: "ize",
              bli: "ble",
              alli: "al",
              entli: "ent",
              eli: "e",
              ousli: "ous",
              ization: "ize",
              ation: "ate",
              ator: "ate",
              alism: "al",
              iveness: "ive",
              fulness: "ful",
              ousness: "ous",
              aliti: "al",
              iviti: "ive",
              biliti: "ble",
              logi: "log",
            },
            step3list = {
              icate: "ic",
              ative: "",
              alize: "al",
              iciti: "ic",
              ical: "ic",
              ful: "",
              ness: "",
            },
            c = "[^aeiou]", // consonant
            v = "[aeiouy]", // vowel
            C = c + "[^aeiouy]*", // consonant sequence
            V = v + "[aeiou]*", // vowel sequence
            mgr0 = "^(" + C + ")?" + V + C, // [C]VC... is m>0
            meq1 = "^(" + C + ")?" + V + C + "(" + V + ")?$", // [C]VC[V] is m=1
            mgr1 = "^(" + C + ")?" + V + C + V + C, // [C]VCVC... is m>1
            s_v = "^(" + C + ")?" + v; // vowel in stem

          var re_mgr0 = new RegExp(mgr0);
          var re_mgr1 = new RegExp(mgr1);
          var re_meq1 = new RegExp(meq1);
          var re_s_v = new RegExp(s_v);

          var re_1a = /^(.+?)(ss|i)es$/;
          var re2_1a = /^(.+?)([^s])s$/;
          var re_1b = /^(.+?)eed$/;
          var re2_1b = /^(.+?)(ed|ing)$/;
          var re_1b_2 = /.$/;
          var re2_1b_2 = /(at|bl|iz)$/;
          var re3_1b_2 = new RegExp("([^aeiouylsz])\\1$");
          var re4_1b_2 = new RegExp("^" + C + v + "[^aeiouwxy]$");

          var re_1c = /^(.+?[^aeiou])y$/;
          var re_2 =
            /^(.+?)(ational|tional|enci|anci|izer|bli|alli|entli|eli|ousli|ization|ation|ator|alism|iveness|fulness|ousness|aliti|iviti|biliti|logi)$/;

          var re_3 = /^(.+?)(icate|ative|alize|iciti|ical|ful|ness)$/;

          var re_4 =
            /^(.+?)(al|ance|ence|er|ic|able|ible|ant|ement|ment|ent|ou|ism|ate|iti|ous|ive|ize)$/;
          var re2_4 = /^(.+?)(s|t)(ion)$/;

          var re_5 = /^(.+?)e$/;
          var re_5_1 = /ll$/;
          var re3_5 = new RegExp("^" + C + v + "[^aeiouwxy]$");

          var porterStemmer = function porterStemmer(w) {
            var stem, suffix, firstch, re, re2, re3, re4;

            if (w.length < 3) {
              return w;
            }

            firstch = w.substr(0, 1);
            if (firstch == "y") {
              w = firstch.toUpperCase() + w.substr(1);
            }

            // Step 1a
            re = re_1a;
            re2 = re2_1a;

            if (re.test(w)) {
              w = w.replace(re, "$1$2");
            } else if (re2.test(w)) {
              w = w.replace(re2, "$1$2");
            }

            // Step 1b
            re = re_1b;
            re2 = re2_1b;
            if (re.test(w)) {
              var fp = re.exec(w);
              re = re_mgr0;
              if (re.test(fp[1])) {
                re = re_1b_2;
                w = w.replace(re, "");
              }
            } else if (re2.test(w)) {
              var fp = re2.exec(w);
              stem = fp[1];
              re2 = re_s_v;
              if (re2.test(stem)) {
                w = stem;
                re2 = re2_1b_2;
                re3 = re3_1b_2;
                re4 = re4_1b_2;
                if (re2.test(w)) {
                  w = w + "e";
                } else if (re3.test(w)) {
                  re = re_1b_2;
                  w = w.replace(re, "");
                } else if (re4.test(w)) {
                  w = w + "e";
                }
              }
            }

            // Step 1c - replace suffix y or Y by i if preceded by a non-vowel which is not the first letter of the word (so cry -> cri, by -> by, say -> say)
            re = re_1c;
            if (re.test(w)) {
              var fp = re.exec(w);
              stem = fp[1];
              w = stem + "i";
            }

            // Step 2
            re = re_2;
            if (re.test(w)) {
              var fp = re.exec(w);
              stem = fp[1];
              suffix = fp[2];
              re = re_mgr0;
              if (re.test(stem)) {
                w = stem + step2list[suffix];
              }
            }

            // Step 3
            re = re_3;
            if (re.test(w)) {
              var fp = re.exec(w);
              stem = fp[1];
              suffix = fp[2];
              re = re_mgr0;
              if (re.test(stem)) {
                w = stem + step3list[suffix];
              }
            }

            // Step 4
            re = re_4;
            re2 = re2_4;
            if (re.test(w)) {
              var fp = re.exec(w);
              stem = fp[1];
              re = re_mgr1;
              if (re.test(stem)) {
                w = stem;
              }
            } else if (re2.test(w)) {
              var fp = re2.exec(w);
              stem = fp[1] + fp[2];
              re2 = re_mgr1;
              if (re2.test(stem)) {
                w = stem;
              }
            }

            // Step 5
            re = re_5;
            if (re.test(w)) {
              var fp = re.exec(w);
              stem = fp[1];
              re = re_mgr1;
              re2 = re_meq1;
              re3 = re3_5;
              if (re.test(stem) || (re2.test(stem) && !re3.test(stem))) {
                w = stem;
              }
            }

            re = re_5_1;
            re2 = re_mgr1;
            if (re.test(w) && re2.test(w)) {
              re = re_1b_2;
              w = w.replace(re, "");
            }

            // and turn initial Y back to y

            if (firstch == "y") {
              w = firstch.toLowerCase() + w.substr(1);
            }

            return w;
          };

          return function (token) {
            return token.update(porterStemmer);
          };
        })();

        lunr.Pipeline.registerFunction(lunr.stemmer, "stemmer");
        /*!
         * lunr.stopWordFilter
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * lunr.generateStopWordFilter builds a stopWordFilter function from the provided
         * list of stop words.
         *
         * The built in lunr.stopWordFilter is built using this generator and can be used
         * to generate custom stopWordFilters for applications or non English languages.
         *
         * @function
         * @param {Array} token The token to pass through the filter
         * @returns {lunr.PipelineFunction}
         * @see lunr.Pipeline
         * @see lunr.stopWordFilter
         */
        lunr.generateStopWordFilter = function (stopWords) {
          var words = stopWords.reduce(function (memo, stopWord) {
            memo[stopWord] = stopWord;
            return memo;
          }, {});

          return function (token) {
            if (token && words[token.toString()] !== token.toString())
              return token;
          };
        };

        /**
         * lunr.stopWordFilter is an English language stop word list filter, any words
         * contained in the list will not be passed through the filter.
         *
         * This is intended to be used in the Pipeline. If the token does not pass the
         * filter then undefined will be returned.
         *
         * @function
         * @implements {lunr.PipelineFunction}
         * @params {lunr.Token} token - A token to check for being a stop word.
         * @returns {lunr.Token}
         * @see {@link lunr.Pipeline}
         */
        lunr.stopWordFilter = lunr.generateStopWordFilter([
          "a",
          "able",
          "about",
          "across",
          "after",
          "all",
          "almost",
          "also",
          "am",
          "among",
          "an",
          "and",
          "any",
          "are",
          "as",
          "at",
          "be",
          "because",
          "been",
          "but",
          "by",
          "can",
          "cannot",
          "could",
          "dear",
          "did",
          "do",
          "does",
          "either",
          "else",
          "ever",
          "every",
          "for",
          "from",
          "get",
          "got",
          "had",
          "has",
          "have",
          "he",
          "her",
          "hers",
          "him",
          "his",
          "how",
          "however",
          "i",
          "if",
          "in",
          "into",
          "is",
          "it",
          "its",
          "just",
          "least",
          "let",
          "like",
          "likely",
          "may",
          "me",
          "might",
          "most",
          "must",
          "my",
          "neither",
          "no",
          "nor",
          "not",
          "of",
          "off",
          "often",
          "on",
          "only",
          "or",
          "other",
          "our",
          "own",
          "rather",
          "said",
          "say",
          "says",
          "she",
          "should",
          "since",
          "so",
          "some",
          "than",
          "that",
          "the",
          "their",
          "them",
          "then",
          "there",
          "these",
          "they",
          "this",
          "tis",
          "to",
          "too",
          "twas",
          "us",
          "wants",
          "was",
          "we",
          "were",
          "what",
          "when",
          "where",
          "which",
          "while",
          "who",
          "whom",
          "why",
          "will",
          "with",
          "would",
          "yet",
          "you",
          "your",
        ]);

        lunr.Pipeline.registerFunction(lunr.stopWordFilter, "stopWordFilter");
        /*!
         * lunr.trimmer
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * lunr.trimmer is a pipeline function for trimming non word
         * characters from the beginning and end of tokens before they
         * enter the index.
         *
         * This implementation may not work correctly for non latin
         * characters and should either be removed or adapted for use
         * with languages with non-latin characters.
         *
         * @static
         * @implements {lunr.PipelineFunction}
         * @param {lunr.Token} token The token to pass through the filter
         * @returns {lunr.Token}
         * @see lunr.Pipeline
         */
        lunr.trimmer = function (token) {
          return token.update(function (s) {
            return s.replace(/^\W+/, "").replace(/\W+$/, "");
          });
        };

        lunr.Pipeline.registerFunction(lunr.trimmer, "trimmer");
        /*!
         * lunr.TokenSet
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * A token set is used to store the unique list of all tokens
         * within an index. Token sets are also used to represent an
         * incoming query to the index, this query token set and index
         * token set are then intersected to find which tokens to look
         * up in the inverted index.
         *
         * A token set can hold multiple tokens, as in the case of the
         * index token set, or it can hold a single token as in the
         * case of a simple query token set.
         *
         * Additionally token sets are used to perform wildcard matching.
         * Leading, contained and trailing wildcards are supported, and
         * from this edit distance matching can also be provided.
         *
         * Token sets are implemented as a minimal finite state automata,
         * where both common prefixes and suffixes are shared between tokens.
         * This helps to reduce the space used for storing the token set.
         *
         * @constructor
         */
        lunr.TokenSet = function () {
          this.final = false;
          this.edges = {};
          this.id = lunr.TokenSet._nextId;
          lunr.TokenSet._nextId += 1;
        };

        /**
         * Keeps track of the next, auto increment, identifier to assign
         * to a new tokenSet.
         *
         * TokenSets require a unique identifier to be correctly minimised.
         *
         * @private
         */
        lunr.TokenSet._nextId = 1;

        /**
         * Creates a TokenSet instance from the given sorted array of words.
         *
         * @param {String[]} arr - A sorted array of strings to create the set from.
         * @returns {lunr.TokenSet}
         * @throws Will throw an error if the input array is not sorted.
         */
        lunr.TokenSet.fromArray = function (arr) {
          var builder = new lunr.TokenSet.Builder();

          for (var i = 0, len = arr.length; i < len; i++) {
            builder.insert(arr[i]);
          }

          builder.finish();
          return builder.root;
        };

        /**
         * Creates a token set from a query clause.
         *
         * @private
         * @param {Object} clause - A single clause from lunr.Query.
         * @param {string} clause.term - The query clause term.
         * @param {number} [clause.editDistance] - The optional edit distance for the term.
         * @returns {lunr.TokenSet}
         */
        lunr.TokenSet.fromClause = function (clause) {
          if ("editDistance" in clause) {
            return lunr.TokenSet.fromFuzzyString(
              clause.term,
              clause.editDistance
            );
          } else {
            return lunr.TokenSet.fromString(clause.term);
          }
        };

        /**
         * Creates a token set representing a single string with a specified
         * edit distance.
         *
         * Insertions, deletions, substitutions and transpositions are each
         * treated as an edit distance of 1.
         *
         * Increasing the allowed edit distance will have a dramatic impact
         * on the performance of both creating and intersecting these TokenSets.
         * It is advised to keep the edit distance less than 3.
         *
         * @param {string} str - The string to create the token set from.
         * @param {number} editDistance - The allowed edit distance to match.
         * @returns {lunr.Vector}
         */
        lunr.TokenSet.fromFuzzyString = function (str, editDistance) {
          var root = new lunr.TokenSet();

          var stack = [
            {
              node: root,
              editsRemaining: editDistance,
              str: str,
            },
          ];

          while (stack.length) {
            var frame = stack.pop();

            // no edit
            if (frame.str.length > 0) {
              var char = frame.str.charAt(0),
                noEditNode;

              if (char in frame.node.edges) {
                noEditNode = frame.node.edges[char];
              } else {
                noEditNode = new lunr.TokenSet();
                frame.node.edges[char] = noEditNode;
              }

              if (frame.str.length == 1) {
                noEditNode.final = true;
              }

              stack.push({
                node: noEditNode,
                editsRemaining: frame.editsRemaining,
                str: frame.str.slice(1),
              });
            }

            if (frame.editsRemaining == 0) {
              continue;
            }

            // insertion
            if ("*" in frame.node.edges) {
              var insertionNode = frame.node.edges["*"];
            } else {
              var insertionNode = new lunr.TokenSet();
              frame.node.edges["*"] = insertionNode;
            }

            if (frame.str.length == 0) {
              insertionNode.final = true;
            }

            stack.push({
              node: insertionNode,
              editsRemaining: frame.editsRemaining - 1,
              str: frame.str,
            });

            // deletion
            // can only do a deletion if we have enough edits remaining
            // and if there are characters left to delete in the string
            if (frame.str.length > 1) {
              stack.push({
                node: frame.node,
                editsRemaining: frame.editsRemaining - 1,
                str: frame.str.slice(1),
              });
            }

            // deletion
            // just removing the last character from the str
            if (frame.str.length == 1) {
              frame.node.final = true;
            }

            // substitution
            // can only do a substitution if we have enough edits remaining
            // and if there are characters left to substitute
            if (frame.str.length >= 1) {
              if ("*" in frame.node.edges) {
                var substitutionNode = frame.node.edges["*"];
              } else {
                var substitutionNode = new lunr.TokenSet();
                frame.node.edges["*"] = substitutionNode;
              }

              if (frame.str.length == 1) {
                substitutionNode.final = true;
              }

              stack.push({
                node: substitutionNode,
                editsRemaining: frame.editsRemaining - 1,
                str: frame.str.slice(1),
              });
            }

            // transposition
            // can only do a transposition if there are edits remaining
            // and there are enough characters to transpose
            if (frame.str.length > 1) {
              var charA = frame.str.charAt(0),
                charB = frame.str.charAt(1),
                transposeNode;

              if (charB in frame.node.edges) {
                transposeNode = frame.node.edges[charB];
              } else {
                transposeNode = new lunr.TokenSet();
                frame.node.edges[charB] = transposeNode;
              }

              if (frame.str.length == 1) {
                transposeNode.final = true;
              }

              stack.push({
                node: transposeNode,
                editsRemaining: frame.editsRemaining - 1,
                str: charA + frame.str.slice(2),
              });
            }
          }

          return root;
        };

        /**
         * Creates a TokenSet from a string.
         *
         * The string may contain one or more wildcard characters (*)
         * that will allow wildcard matching when intersecting with
         * another TokenSet.
         *
         * @param {string} str - The string to create a TokenSet from.
         * @returns {lunr.TokenSet}
         */
        lunr.TokenSet.fromString = function (str) {
          var node = new lunr.TokenSet(),
            root = node;

          /*
           * Iterates through all characters within the passed string
           * appending a node for each character.
           *
           * When a wildcard character is found then a self
           * referencing edge is introduced to continually match
           * any number of any characters.
           */
          for (var i = 0, len = str.length; i < len; i++) {
            var char = str[i],
              final = i == len - 1;

            if (char == "*") {
              node.edges[char] = node;
              node.final = final;
            } else {
              var next = new lunr.TokenSet();
              next.final = final;

              node.edges[char] = next;
              node = next;
            }
          }

          return root;
        };

        /**
         * Converts this TokenSet into an array of strings
         * contained within the TokenSet.
         *
         * This is not intended to be used on a TokenSet that
         * contains wildcards, in these cases the results are
         * undefined and are likely to cause an infinite loop.
         *
         * @returns {string[]}
         */
        lunr.TokenSet.prototype.toArray = function () {
          var words = [];

          var stack = [
            {
              prefix: "",
              node: this,
            },
          ];

          while (stack.length) {
            var frame = stack.pop(),
              edges = Object.keys(frame.node.edges),
              len = edges.length;

            if (frame.node.final) {
              /* In Safari, at this point the prefix is sometimes corrupted, see:
               * https://github.com/olivernn/lunr.js/issues/279 Calling any
               * String.prototype method forces Safari to "cast" this string to what
               * it's supposed to be, fixing the bug. */
              frame.prefix.charAt(0);
              words.push(frame.prefix);
            }

            for (var i = 0; i < len; i++) {
              var edge = edges[i];

              stack.push({
                prefix: frame.prefix.concat(edge),
                node: frame.node.edges[edge],
              });
            }
          }

          return words;
        };

        /**
         * Generates a string representation of a TokenSet.
         *
         * This is intended to allow TokenSets to be used as keys
         * in objects, largely to aid the construction and minimisation
         * of a TokenSet. As such it is not designed to be a human
         * friendly representation of the TokenSet.
         *
         * @returns {string}
         */
        lunr.TokenSet.prototype.toString = function () {
          // NOTE: Using Object.keys here as this.edges is very likely
          // to enter 'hash-mode' with many keys being added
          //
          // avoiding a for-in loop here as it leads to the function
          // being de-optimised (at least in V8). From some simple
          // benchmarks the performance is comparable, but allowing
          // V8 to optimize may mean easy performance wins in the future.

          if (this._str) {
            return this._str;
          }

          var str = this.final ? "1" : "0",
            labels = Object.keys(this.edges).sort(),
            len = labels.length;

          for (var i = 0; i < len; i++) {
            var label = labels[i],
              node = this.edges[label];

            str = str + label + node.id;
          }

          return str;
        };

        /**
         * Returns a new TokenSet that is the intersection of
         * this TokenSet and the passed TokenSet.
         *
         * This intersection will take into account any wildcards
         * contained within the TokenSet.
         *
         * @param {lunr.TokenSet} b - An other TokenSet to intersect with.
         * @returns {lunr.TokenSet}
         */
        lunr.TokenSet.prototype.intersect = function (b) {
          var output = new lunr.TokenSet(),
            frame = undefined;

          var stack = [
            {
              qNode: b,
              output: output,
              node: this,
            },
          ];

          while (stack.length) {
            frame = stack.pop();

            // NOTE: As with the #toString method, we are using
            // Object.keys and a for loop instead of a for-in loop
            // as both of these objects enter 'hash' mode, causing
            // the function to be de-optimised in V8
            var qEdges = Object.keys(frame.qNode.edges),
              qLen = qEdges.length,
              nEdges = Object.keys(frame.node.edges),
              nLen = nEdges.length;

            for (var q = 0; q < qLen; q++) {
              var qEdge = qEdges[q];

              for (var n = 0; n < nLen; n++) {
                var nEdge = nEdges[n];

                if (nEdge == qEdge || qEdge == "*") {
                  var node = frame.node.edges[nEdge],
                    qNode = frame.qNode.edges[qEdge],
                    final = node.final && qNode.final,
                    next = undefined;

                  if (nEdge in frame.output.edges) {
                    // an edge already exists for this character
                    // no need to create a new node, just set the finality
                    // bit unless this node is already final
                    next = frame.output.edges[nEdge];
                    next.final = next.final || final;
                  } else {
                    // no edge exists yet, must create one
                    // set the finality bit and insert it
                    // into the output
                    next = new lunr.TokenSet();
                    next.final = final;
                    frame.output.edges[nEdge] = next;
                  }

                  stack.push({
                    qNode: qNode,
                    output: next,
                    node: node,
                  });
                }
              }
            }
          }

          return output;
        };
        lunr.TokenSet.Builder = function () {
          this.previousWord = "";
          this.root = new lunr.TokenSet();
          this.uncheckedNodes = [];
          this.minimizedNodes = {};
        };

        lunr.TokenSet.Builder.prototype.insert = function (word) {
          var node,
            commonPrefix = 0;

          if (word < this.previousWord) {
            throw new Error("Out of order word insertion");
          }

          for (
            var i = 0;
            i < word.length && i < this.previousWord.length;
            i++
          ) {
            if (word[i] != this.previousWord[i]) break;
            commonPrefix++;
          }

          this.minimize(commonPrefix);

          if (this.uncheckedNodes.length == 0) {
            node = this.root;
          } else {
            node = this.uncheckedNodes[this.uncheckedNodes.length - 1].child;
          }

          for (var i = commonPrefix; i < word.length; i++) {
            var nextNode = new lunr.TokenSet(),
              char = word[i];

            node.edges[char] = nextNode;

            this.uncheckedNodes.push({
              parent: node,
              char: char,
              child: nextNode,
            });

            node = nextNode;
          }

          node.final = true;
          this.previousWord = word;
        };

        lunr.TokenSet.Builder.prototype.finish = function () {
          this.minimize(0);
        };

        lunr.TokenSet.Builder.prototype.minimize = function (downTo) {
          for (var i = this.uncheckedNodes.length - 1; i >= downTo; i--) {
            var node = this.uncheckedNodes[i],
              childKey = node.child.toString();

            if (childKey in this.minimizedNodes) {
              node.parent.edges[node.char] = this.minimizedNodes[childKey];
            } else {
              // Cache the key for this node since
              // we know it can't change anymore
              node.child._str = childKey;

              this.minimizedNodes[childKey] = node.child;
            }

            this.uncheckedNodes.pop();
          }
        };
        /*!
         * lunr.Index
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * An index contains the built index of all documents and provides a query interface
         * to the index.
         *
         * Usually instances of lunr.Index will not be created using this constructor, instead
         * lunr.Builder should be used to construct new indexes, or lunr.Index.load should be
         * used to load previously built and serialized indexes.
         *
         * @constructor
         * @param {Object} attrs - The attributes of the built search index.
         * @param {Object} attrs.invertedIndex - An index of term/field to document reference.
         * @param {Object<string, lunr.Vector>} attrs.fieldVectors - Field vectors
         * @param {lunr.TokenSet} attrs.tokenSet - An set of all corpus tokens.
         * @param {string[]} attrs.fields - The names of indexed document fields.
         * @param {lunr.Pipeline} attrs.pipeline - The pipeline to use for search terms.
         */
        lunr.Index = function (attrs) {
          this.invertedIndex = attrs.invertedIndex;
          this.fieldVectors = attrs.fieldVectors;
          this.tokenSet = attrs.tokenSet;
          this.fields = attrs.fields;
          this.pipeline = attrs.pipeline;
        };

        /**
         * A result contains details of a document matching a search query.
         * @typedef {Object} lunr.Index~Result
         * @property {string} ref - The reference of the document this result represents.
         * @property {number} score - A number between 0 and 1 representing how similar this document is to the query.
         * @property {lunr.MatchData} matchData - Contains metadata about this match including which term(s) caused the match.
         */

        /**
         * Although lunr provides the ability to create queries using lunr.Query, it also provides a simple
         * query language which itself is parsed into an instance of lunr.Query.
         *
         * For programmatically building queries it is advised to directly use lunr.Query, the query language
         * is best used for human entered text rather than program generated text.
         *
         * At its simplest queries can just be a single term, e.g. `hello`, multiple terms are also supported
         * and will be combined with OR, e.g `hello world` will match documents that contain either 'hello'
         * or 'world', though those that contain both will rank higher in the results.
         *
         * Wildcards can be included in terms to match one or more unspecified characters, these wildcards can
         * be inserted anywhere within the term, and more than one wildcard can exist in a single term. Adding
         * wildcards will increase the number of documents that will be found but can also have a negative
         * impact on query performance, especially with wildcards at the beginning of a term.
         *
         * Terms can be restricted to specific fields, e.g. `title:hello`, only documents with the term
         * hello in the title field will match this query. Using a field not present in the index will lead
         * to an error being thrown.
         *
         * Modifiers can also be added to terms, lunr supports edit distance and boost modifiers on terms. A term
         * boost will make documents matching that term score higher, e.g. `foo^5`. Edit distance is also supported
         * to provide fuzzy matching, e.g. 'hello~2' will match documents with hello with an edit distance of 2.
         * Avoid large values for edit distance to improve query performance.
         *
         * Each term also supports a presence modifier. By default a term's presence in document is optional, however
         * this can be changed to either required or prohibited. For a term's presence to be required in a document the
         * term should be prefixed with a '+', e.g. `+foo bar` is a search for documents that must contain 'foo' and
         * optionally contain 'bar'. Conversely a leading '-' sets the terms presence to prohibited, i.e. it must not
         * appear in a document, e.g. `-foo bar` is a search for documents that do not contain 'foo' but may contain 'bar'.
         *
         * To escape special characters the backslash character '\' can be used, this allows searches to include
         * characters that would normally be considered modifiers, e.g. `foo\~2` will search for a term "foo~2" instead
         * of attempting to apply a boost of 2 to the search term "foo".
         *
         * @typedef {string} lunr.Index~QueryString
         * @example <caption>Simple single term query</caption>
         * hello
         * @example <caption>Multiple term query</caption>
         * hello world
         * @example <caption>term scoped to a field</caption>
         * title:hello
         * @example <caption>term with a boost of 10</caption>
         * hello^10
         * @example <caption>term with an edit distance of 2</caption>
         * hello~2
         * @example <caption>terms with presence modifiers</caption>
         * -foo +bar baz
         */

        /**
         * Performs a search against the index using lunr query syntax.
         *
         * Results will be returned sorted by their score, the most relevant results
         * will be returned first.  For details on how the score is calculated, please see
         * the {@link https://lunrjs.com/guides/searching.html#scoring|guide}.
         *
         * For more programmatic querying use lunr.Index#query.
         *
         * @param {lunr.Index~QueryString} queryString - A string containing a lunr query.
         * @throws {lunr.QueryParseError} If the passed query string cannot be parsed.
         * @returns {lunr.Index~Result[]}
         */
        lunr.Index.prototype.search = function (queryString) {
          return this.query(function (query) {
            var parser = new lunr.QueryParser(queryString, query);
            parser.parse();
          });
        };

        /**
         * A query builder callback provides a query object to be used to express
         * the query to perform on the index.
         *
         * @callback lunr.Index~queryBuilder
         * @param {lunr.Query} query - The query object to build up.
         * @this lunr.Query
         */

        /**
         * Performs a query against the index using the yielded lunr.Query object.
         *
         * If performing programmatic queries against the index, this method is preferred
         * over lunr.Index#search so as to avoid the additional query parsing overhead.
         *
         * A query object is yielded to the supplied function which should be used to
         * express the query to be run against the index.
         *
         * Note that although this function takes a callback parameter it is _not_ an
         * asynchronous operation, the callback is just yielded a query object to be
         * customized.
         *
         * @param {lunr.Index~queryBuilder} fn - A function that is used to build the query.
         * @returns {lunr.Index~Result[]}
         */
        lunr.Index.prototype.query = function (fn) {
          // for each query clause
          // * process terms
          // * expand terms from token set
          // * find matching documents and metadata
          // * get document vectors
          // * score documents

          var query = new lunr.Query(this.fields),
            matchingFields = Object.create(null),
            queryVectors = Object.create(null),
            termFieldCache = Object.create(null),
            requiredMatches = Object.create(null),
            prohibitedMatches = Object.create(null);

          /*
           * To support field level boosts a query vector is created per
           * field. An empty vector is eagerly created to support negated
           * queries.
           */
          for (var i = 0; i < this.fields.length; i++) {
            queryVectors[this.fields[i]] = new lunr.Vector();
          }

          fn.call(query, query);

          for (var i = 0; i < query.clauses.length; i++) {
            /*
             * Unless the pipeline has been disabled for this term, which is
             * the case for terms with wildcards, we need to pass the clause
             * term through the search pipeline. A pipeline returns an array
             * of processed terms. Pipeline functions may expand the passed
             * term, which means we may end up performing multiple index lookups
             * for a single query term.
             */
            var clause = query.clauses[i],
              terms = null,
              clauseMatches = lunr.Set.empty;

            if (clause.usePipeline) {
              terms = this.pipeline.runString(clause.term, {
                fields: clause.fields,
              });
            } else {
              terms = [clause.term];
            }

            for (var m = 0; m < terms.length; m++) {
              var term = terms[m];

              /*
               * Each term returned from the pipeline needs to use the same query
               * clause object, e.g. the same boost and or edit distance. The
               * simplest way to do this is to re-use the clause object but mutate
               * its term property.
               */
              clause.term = term;

              /*
               * From the term in the clause we create a token set which will then
               * be used to intersect the indexes token set to get a list of terms
               * to lookup in the inverted index
               */
              var termTokenSet = lunr.TokenSet.fromClause(clause),
                expandedTerms = this.tokenSet.intersect(termTokenSet).toArray();

              /*
               * If a term marked as required does not exist in the tokenSet it is
               * impossible for the search to return any matches. We set all the field
               * scoped required matches set to empty and stop examining any further
               * clauses.
               */
              if (
                expandedTerms.length === 0 &&
                clause.presence === lunr.Query.presence.REQUIRED
              ) {
                for (var k = 0; k < clause.fields.length; k++) {
                  var field = clause.fields[k];
                  requiredMatches[field] = lunr.Set.empty;
                }

                break;
              }

              for (var j = 0; j < expandedTerms.length; j++) {
                /*
                 * For each term get the posting and termIndex, this is required for
                 * building the query vector.
                 */
                var expandedTerm = expandedTerms[j],
                  posting = this.invertedIndex[expandedTerm],
                  termIndex = posting._index;

                for (var k = 0; k < clause.fields.length; k++) {
                  /*
                   * For each field that this query term is scoped by (by default
                   * all fields are in scope) we need to get all the document refs
                   * that have this term in that field.
                   *
                   * The posting is the entry in the invertedIndex for the matching
                   * term from above.
                   */
                  var field = clause.fields[k],
                    fieldPosting = posting[field],
                    matchingDocumentRefs = Object.keys(fieldPosting),
                    termField = expandedTerm + "/" + field,
                    matchingDocumentsSet = new lunr.Set(matchingDocumentRefs);

                  /*
                   * if the presence of this term is required ensure that the matching
                   * documents are added to the set of required matches for this clause.
                   *
                   */
                  if (clause.presence == lunr.Query.presence.REQUIRED) {
                    clauseMatches = clauseMatches.union(matchingDocumentsSet);

                    if (requiredMatches[field] === undefined) {
                      requiredMatches[field] = lunr.Set.complete;
                    }
                  }

                  /*
                   * if the presence of this term is prohibited ensure that the matching
                   * documents are added to the set of prohibited matches for this field,
                   * creating that set if it does not yet exist.
                   */
                  if (clause.presence == lunr.Query.presence.PROHIBITED) {
                    if (prohibitedMatches[field] === undefined) {
                      prohibitedMatches[field] = lunr.Set.empty;
                    }

                    prohibitedMatches[field] =
                      prohibitedMatches[field].union(matchingDocumentsSet);

                    /*
                     * Prohibited matches should not be part of the query vector used for
                     * similarity scoring and no metadata should be extracted so we continue
                     * to the next field
                     */
                    continue;
                  }

                  /*
                   * The query field vector is populated using the termIndex found for
                   * the term and a unit value with the appropriate boost applied.
                   * Using upsert because there could already be an entry in the vector
                   * for the term we are working with. In that case we just add the scores
                   * together.
                   */
                  queryVectors[field].upsert(
                    termIndex,
                    clause.boost,
                    function (a, b) {
                      return a + b;
                    }
                  );

                  /**
                   * If we've already seen this term, field combo then we've already collected
                   * the matching documents and metadata, no need to go through all that again
                   */
                  if (termFieldCache[termField]) {
                    continue;
                  }

                  for (var l = 0; l < matchingDocumentRefs.length; l++) {
                    /*
                     * All metadata for this term/field/document triple
                     * are then extracted and collected into an instance
                     * of lunr.MatchData ready to be returned in the query
                     * results
                     */
                    var matchingDocumentRef = matchingDocumentRefs[l],
                      matchingFieldRef = new lunr.FieldRef(
                        matchingDocumentRef,
                        field
                      ),
                      metadata = fieldPosting[matchingDocumentRef],
                      fieldMatch;

                    if (
                      (fieldMatch = matchingFields[matchingFieldRef]) ===
                      undefined
                    ) {
                      matchingFields[matchingFieldRef] = new lunr.MatchData(
                        expandedTerm,
                        field,
                        metadata
                      );
                    } else {
                      fieldMatch.add(expandedTerm, field, metadata);
                    }
                  }

                  termFieldCache[termField] = true;
                }
              }
            }

            /**
             * If the presence was required we need to update the requiredMatches field sets.
             * We do this after all fields for the term have collected their matches because
             * the clause terms presence is required in _any_ of the fields not _all_ of the
             * fields.
             */
            if (clause.presence === lunr.Query.presence.REQUIRED) {
              for (var k = 0; k < clause.fields.length; k++) {
                var field = clause.fields[k];
                requiredMatches[field] =
                  requiredMatches[field].intersect(clauseMatches);
              }
            }
          }

          /**
           * Need to combine the field scoped required and prohibited
           * matching documents into a global set of required and prohibited
           * matches
           */
          var allRequiredMatches = lunr.Set.complete,
            allProhibitedMatches = lunr.Set.empty;

          for (var i = 0; i < this.fields.length; i++) {
            var field = this.fields[i];

            if (requiredMatches[field]) {
              allRequiredMatches = allRequiredMatches.intersect(
                requiredMatches[field]
              );
            }

            if (prohibitedMatches[field]) {
              allProhibitedMatches = allProhibitedMatches.union(
                prohibitedMatches[field]
              );
            }
          }

          var matchingFieldRefs = Object.keys(matchingFields),
            results = [],
            matches = Object.create(null);

          /*
           * If the query is negated (contains only prohibited terms)
           * we need to get _all_ fieldRefs currently existing in the
           * index. This is only done when we know that the query is
           * entirely prohibited terms to avoid any cost of getting all
           * fieldRefs unnecessarily.
           *
           * Additionally, blank MatchData must be created to correctly
           * populate the results.
           */
          if (query.isNegated()) {
            matchingFieldRefs = Object.keys(this.fieldVectors);

            for (var i = 0; i < matchingFieldRefs.length; i++) {
              var matchingFieldRef = matchingFieldRefs[i];
              var fieldRef = lunr.FieldRef.fromString(matchingFieldRef);
              matchingFields[matchingFieldRef] = new lunr.MatchData();
            }
          }

          for (var i = 0; i < matchingFieldRefs.length; i++) {
            /*
             * Currently we have document fields that match the query, but we
             * need to return documents. The matchData and scores are combined
             * from multiple fields belonging to the same document.
             *
             * Scores are calculated by field, using the query vectors created
             * above, and combined into a final document score using addition.
             */
            var fieldRef = lunr.FieldRef.fromString(matchingFieldRefs[i]),
              docRef = fieldRef.docRef;

            if (!allRequiredMatches.contains(docRef)) {
              continue;
            }

            if (allProhibitedMatches.contains(docRef)) {
              continue;
            }

            var fieldVector = this.fieldVectors[fieldRef],
              score = queryVectors[fieldRef.fieldName].similarity(fieldVector),
              docMatch;

            if ((docMatch = matches[docRef]) !== undefined) {
              docMatch.score += score;
              docMatch.matchData.combine(matchingFields[fieldRef]);
            } else {
              var match = {
                ref: docRef,
                score: score,
                matchData: matchingFields[fieldRef],
              };
              matches[docRef] = match;
              results.push(match);
            }
          }

          /*
           * Sort the results objects by score, highest first.
           */
          return results.sort(function (a, b) {
            return b.score - a.score;
          });
        };

        /**
         * Prepares the index for JSON serialization.
         *
         * The schema for this JSON blob will be described in a
         * separate JSON schema file.
         *
         * @returns {Object}
         */
        lunr.Index.prototype.toJSON = function () {
          var invertedIndex = Object.keys(this.invertedIndex)
            .sort()
            .map(function (term) {
              return [term, this.invertedIndex[term]];
            }, this);

          var fieldVectors = Object.keys(this.fieldVectors).map(function (ref) {
            return [ref, this.fieldVectors[ref].toJSON()];
          }, this);

          return {
            version: lunr.version,
            fields: this.fields,
            fieldVectors: fieldVectors,
            invertedIndex: invertedIndex,
            pipeline: this.pipeline.toJSON(),
          };
        };

        /**
         * Loads a previously serialized lunr.Index
         *
         * @param {Object} serializedIndex - A previously serialized lunr.Index
         * @returns {lunr.Index}
         */
        lunr.Index.load = function (serializedIndex) {
          var attrs = {},
            fieldVectors = {},
            serializedVectors = serializedIndex.fieldVectors,
            invertedIndex = Object.create(null),
            serializedInvertedIndex = serializedIndex.invertedIndex,
            tokenSetBuilder = new lunr.TokenSet.Builder(),
            pipeline = lunr.Pipeline.load(serializedIndex.pipeline);

          if (serializedIndex.version != lunr.version) {
            lunr.utils.warn(
              "Version mismatch when loading serialised index. Current version of lunr '" +
                lunr.version +
                "' does not match serialized index '" +
                serializedIndex.version +
                "'"
            );
          }

          for (var i = 0; i < serializedVectors.length; i++) {
            var tuple = serializedVectors[i],
              ref = tuple[0],
              elements = tuple[1];

            fieldVectors[ref] = new lunr.Vector(elements);
          }

          for (var i = 0; i < serializedInvertedIndex.length; i++) {
            var tuple = serializedInvertedIndex[i],
              term = tuple[0],
              posting = tuple[1];

            tokenSetBuilder.insert(term);
            invertedIndex[term] = posting;
          }

          tokenSetBuilder.finish();

          attrs.fields = serializedIndex.fields;

          attrs.fieldVectors = fieldVectors;
          attrs.invertedIndex = invertedIndex;
          attrs.tokenSet = tokenSetBuilder.root;
          attrs.pipeline = pipeline;

          return new lunr.Index(attrs);
        };
        /*!
         * lunr.Builder
         * Copyright (C) 2020 Oliver Nightingale
         */

        /**
         * lunr.Builder performs indexing on a set of documents and
         * returns instances of lunr.Index ready for querying.
         *
         * All configuration of the index is done via the builder, the
         * fields to index, the document reference, the text processing
         * pipeline and document scoring parameters are all set on the
         * builder before indexing.
         *
         * @constructor
         * @property {string} _ref - Internal reference to the document reference field.
         * @property {string[]} _fields - Internal reference to the document fields to index.
         * @property {object} invertedIndex - The inverted index maps terms to document fields.
         * @property {object} documentTermFrequencies - Keeps track of document term frequencies.
         * @property {object} documentLengths - Keeps track of the length of documents added to the index.
         * @property {lunr.tokenizer} tokenizer - Function for splitting strings into tokens for indexing.
         * @property {lunr.Pipeline} pipeline - The pipeline performs text processing on tokens before indexing.
         * @property {lunr.Pipeline} searchPipeline - A pipeline for processing search terms before querying the index.
         * @property {number} documentCount - Keeps track of the total number of documents indexed.
         * @property {number} _b - A parameter to control field length normalization, setting this to 0 disabled normalization, 1 fully normalizes field lengths, the default value is 0.75.
         * @property {number} _k1 - A parameter to control how quickly an increase in term frequency results in term frequency saturation, the default value is 1.2.
         * @property {number} termIndex - A counter incremented for each unique term, used to identify a terms position in the vector space.
         * @property {array} metadataWhitelist - A list of metadata keys that have been whitelisted for entry in the index.
         */
        lunr.Builder = function () {
          this._ref = "id";
          this._fields = Object.create(null);
          this._documents = Object.create(null);
          this.invertedIndex = Object.create(null);
          this.fieldTermFrequencies = {};
          this.fieldLengths = {};
          this.tokenizer = lunr.tokenizer;
          this.pipeline = new lunr.Pipeline();
          this.searchPipeline = new lunr.Pipeline();
          this.documentCount = 0;
          this._b = 0.75;
          this._k1 = 1.2;
          this.termIndex = 0;
          this.metadataWhitelist = [];
        };

        /**
         * Sets the document field used as the document reference. Every document must have this field.
         * The type of this field in the document should be a string, if it is not a string it will be
         * coerced into a string by calling toString.
         *
         * The default ref is 'id'.
         *
         * The ref should _not_ be changed during indexing, it should be set before any documents are
         * added to the index. Changing it during indexing can lead to inconsistent results.
         *
         * @param {string} ref - The name of the reference field in the document.
         */
        lunr.Builder.prototype.ref = function (ref) {
          this._ref = ref;
        };

        /**
         * A function that is used to extract a field from a document.
         *
         * Lunr expects a field to be at the top level of a document, if however the field
         * is deeply nested within a document an extractor function can be used to extract
         * the right field for indexing.
         *
         * @callback fieldExtractor
         * @param {object} doc - The document being added to the index.
         * @returns {?(string|object|object[])} obj - The object that will be indexed for this field.
         * @example <caption>Extracting a nested field</caption>
         * function (doc) { return doc.nested.field }
         */

        /**
         * Adds a field to the list of document fields that will be indexed. Every document being
         * indexed should have this field. Null values for this field in indexed documents will
         * not cause errors but will limit the chance of that document being retrieved by searches.
         *
         * All fields should be added before adding documents to the index. Adding fields after
         * a document has been indexed will have no effect on already indexed documents.
         *
         * Fields can be boosted at build time. This allows terms within that field to have more
         * importance when ranking search results. Use a field boost to specify that matches within
         * one field are more important than other fields.
         *
         * @param {string} fieldName - The name of a field to index in all documents.
         * @param {object} attributes - Optional attributes associated with this field.
         * @param {number} [attributes.boost=1] - Boost applied to all terms within this field.
         * @param {fieldExtractor} [attributes.extractor] - Function to extract a field from a document.
         * @throws {RangeError} fieldName cannot contain unsupported characters '/'
         */
        lunr.Builder.prototype.field = function (fieldName, attributes) {
          if (/\//.test(fieldName)) {
            throw new RangeError(
              "Field '" + fieldName + "' contains illegal character '/'"
            );
          }

          this._fields[fieldName] = attributes || {};
        };

        /**
         * A parameter to tune the amount of field length normalisation that is applied when
         * calculating relevance scores. A value of 0 will completely disable any normalisation
         * and a value of 1 will fully normalise field lengths. The default is 0.75. Values of b
         * will be clamped to the range 0 - 1.
         *
         * @param {number} number - The value to set for this tuning parameter.
         */
        lunr.Builder.prototype.b = function (number) {
          if (number < 0) {
            this._b = 0;
          } else if (number > 1) {
            this._b = 1;
          } else {
            this._b = number;
          }
        };

        /**
         * A parameter that controls the speed at which a rise in term frequency results in term
         * frequency saturation. The default value is 1.2. Setting this to a higher value will give
         * slower saturation levels, a lower value will result in quicker saturation.
         *
         * @param {number} number - The value to set for this tuning parameter.
         */
        lunr.Builder.prototype.k1 = function (number) {
          this._k1 = number;
        };

        /**
         * Adds a document to the index.
         *
         * Before adding fields to the index the index should have been fully setup, with the document
         * ref and all fields to index already having been specified.
         *
         * The document must have a field name as specified by the ref (by default this is 'id') and
         * it should have all fields defined for indexing, though null or undefined values will not
         * cause errors.
         *
         * Entire documents can be boosted at build time. Applying a boost to a document indicates that
         * this document should rank higher in search results than other documents.
         *
         * @param {object} doc - The document to add to the index.
         * @param {object} attributes - Optional attributes associated with this document.
         * @param {number} [attributes.boost=1] - Boost applied to all terms within this document.
         */
        lunr.Builder.prototype.add = function (doc, attributes) {
          var docRef = doc[this._ref],
            fields = Object.keys(this._fields);

          this._documents[docRef] = attributes || {};
          this.documentCount += 1;

          for (var i = 0; i < fields.length; i++) {
            var fieldName = fields[i],
              extractor = this._fields[fieldName].extractor,
              field = extractor ? extractor(doc) : doc[fieldName],
              tokens = this.tokenizer(field, {
                fields: [fieldName],
              }),
              terms = this.pipeline.run(tokens),
              fieldRef = new lunr.FieldRef(docRef, fieldName),
              fieldTerms = Object.create(null);

            this.fieldTermFrequencies[fieldRef] = fieldTerms;
            this.fieldLengths[fieldRef] = 0;

            // store the length of this field for this document
            this.fieldLengths[fieldRef] += terms.length;

            // calculate term frequencies for this field
            for (var j = 0; j < terms.length; j++) {
              var term = terms[j];

              if (fieldTerms[term] == undefined) {
                fieldTerms[term] = 0;
              }

              fieldTerms[term] += 1;

              // add to inverted index
              // create an initial posting if one doesn't exist
              if (this.invertedIndex[term] == undefined) {
                var posting = Object.create(null);
                posting["_index"] = this.termIndex;
                this.termIndex += 1;

                for (var k = 0; k < fields.length; k++) {
                  posting[fields[k]] = Object.create(null);
                }

                this.invertedIndex[term] = posting;
              }

              // add an entry for this term/fieldName/docRef to the invertedIndex
              if (this.invertedIndex[term][fieldName][docRef] == undefined) {
                this.invertedIndex[term][fieldName][docRef] =
                  Object.create(null);
              }

              // store all whitelisted metadata about this token in the
              // inverted index
              for (var l = 0; l < this.metadataWhitelist.length; l++) {
                var metadataKey = this.metadataWhitelist[l],
                  metadata = term.metadata[metadataKey];

                if (
                  this.invertedIndex[term][fieldName][docRef][metadataKey] ==
                  undefined
                ) {
                  this.invertedIndex[term][fieldName][docRef][metadataKey] = [];
                }

                this.invertedIndex[term][fieldName][docRef][metadataKey].push(
                  metadata
                );
              }
            }
          }
        };

        /**
         * Calculates the average document length for this index
         *
         * @private
         */
        lunr.Builder.prototype.calculateAverageFieldLengths = function () {
          var fieldRefs = Object.keys(this.fieldLengths),
            numberOfFields = fieldRefs.length,
            accumulator = {},
            documentsWithField = {};

          for (var i = 0; i < numberOfFields; i++) {
            var fieldRef = lunr.FieldRef.fromString(fieldRefs[i]),
              field = fieldRef.fieldName;

            documentsWithField[field] || (documentsWithField[field] = 0);
            documentsWithField[field] += 1;

            accumulator[field] || (accumulator[field] = 0);
            accumulator[field] += this.fieldLengths[fieldRef];
          }

          var fields = Object.keys(this._fields);

          for (var i = 0; i < fields.length; i++) {
            var fieldName = fields[i];
            accumulator[fieldName] =
              accumulator[fieldName] / documentsWithField[fieldName];
          }

          this.averageFieldLength = accumulator;
        };

        /**
         * Builds a vector space model of every document using lunr.Vector
         *
         * @private
         */
        lunr.Builder.prototype.createFieldVectors = function () {
          var fieldVectors = {},
            fieldRefs = Object.keys(this.fieldTermFrequencies),
            fieldRefsLength = fieldRefs.length,
            termIdfCache = Object.create(null);

          for (var i = 0; i < fieldRefsLength; i++) {
            var fieldRef = lunr.FieldRef.fromString(fieldRefs[i]),
              fieldName = fieldRef.fieldName,
              fieldLength = this.fieldLengths[fieldRef],
              fieldVector = new lunr.Vector(),
              termFrequencies = this.fieldTermFrequencies[fieldRef],
              terms = Object.keys(termFrequencies),
              termsLength = terms.length;

            var fieldBoost = this._fields[fieldName].boost || 1,
              docBoost = this._documents[fieldRef.docRef].boost || 1;

            for (var j = 0; j < termsLength; j++) {
              var term = terms[j],
                tf = termFrequencies[term],
                termIndex = this.invertedIndex[term]._index,
                idf,
                score,
                scoreWithPrecision;

              if (termIdfCache[term] === undefined) {
                idf = lunr.idf(this.invertedIndex[term], this.documentCount);
                termIdfCache[term] = idf;
              } else {
                idf = termIdfCache[term];
              }

              score =
                (idf * ((this._k1 + 1) * tf)) /
                (this._k1 *
                  (1 -
                    this._b +
                    this._b *
                      (fieldLength / this.averageFieldLength[fieldName])) +
                  tf);
              score *= fieldBoost;
              score *= docBoost;
              scoreWithPrecision = Math.round(score * 1000) / 1000;
              // Converts 1.23456789 to 1.234.
              // Reducing the precision so that the vectors take up less
              // space when serialised. Doing it now so that they behave
              // the same before and after serialisation. Also, this is
              // the fastest approach to reducing a number's precision in
              // JavaScript.

              fieldVector.insert(termIndex, scoreWithPrecision);
            }

            fieldVectors[fieldRef] = fieldVector;
          }

          this.fieldVectors = fieldVectors;
        };

        /**
         * Creates a token set of all tokens in the index using lunr.TokenSet
         *
         * @private
         */
        lunr.Builder.prototype.createTokenSet = function () {
          this.tokenSet = lunr.TokenSet.fromArray(
            Object.keys(this.invertedIndex).sort()
          );
        };

        /**
         * Builds the index, creating an instance of lunr.Index.
         *
         * This completes the indexing process and should only be called
         * once all documents have been added to the index.
         *
         * @returns {lunr.Index}
         */
        lunr.Builder.prototype.build = function () {
          this.calculateAverageFieldLengths();
          this.createFieldVectors();
          this.createTokenSet();

          return new lunr.Index({
            invertedIndex: this.invertedIndex,
            fieldVectors: this.fieldVectors,
            tokenSet: this.tokenSet,
            fields: Object.keys(this._fields),
            pipeline: this.searchPipeline,
          });
        };

        /**
         * Applies a plugin to the index builder.
         *
         * A plugin is a function that is called with the index builder as its context.
         * Plugins can be used to customise or extend the behaviour of the index
         * in some way. A plugin is just a function, that encapsulated the custom
         * behaviour that should be applied when building the index.
         *
         * The plugin function will be called with the index builder as its argument, additional
         * arguments can also be passed when calling use. The function will be called
         * with the index builder as its context.
         *
         * @param {Function} plugin The plugin to apply.
         */
        lunr.Builder.prototype.use = function (fn) {
          var args = Array.prototype.slice.call(arguments, 1);
          args.unshift(this);
          fn.apply(this, args);
        };
        /**
         * Contains and collects metadata about a matching document.
         * A single instance of lunr.MatchData is returned as part of every
         * lunr.Index~Result.
         *
         * @constructor
         * @param {string} term - The term this match data is associated with
         * @param {string} field - The field in which the term was found
         * @param {object} metadata - The metadata recorded about this term in this field
         * @property {object} metadata - A cloned collection of metadata associated with this document.
         * @see {@link lunr.Index~Result}
         */
        lunr.MatchData = function (term, field, metadata) {
          var clonedMetadata = Object.create(null),
            metadataKeys = Object.keys(metadata || {});

          // Cloning the metadata to prevent the original
          // being mutated during match data combination.
          // Metadata is kept in an array within the inverted
          // index so cloning the data can be done with
          // Array#slice
          for (var i = 0; i < metadataKeys.length; i++) {
            var key = metadataKeys[i];
            clonedMetadata[key] = metadata[key].slice();
          }

          this.metadata = Object.create(null);

          if (term !== undefined) {
            this.metadata[term] = Object.create(null);
            this.metadata[term][field] = clonedMetadata;
          }
        };

        /**
         * An instance of lunr.MatchData will be created for every term that matches a
         * document. However only one instance is required in a lunr.Index~Result. This
         * method combines metadata from another instance of lunr.MatchData with this
         * objects metadata.
         *
         * @param {lunr.MatchData} otherMatchData - Another instance of match data to merge with this one.
         * @see {@link lunr.Index~Result}
         */
        lunr.MatchData.prototype.combine = function (otherMatchData) {
          var terms = Object.keys(otherMatchData.metadata);

          for (var i = 0; i < terms.length; i++) {
            var term = terms[i],
              fields = Object.keys(otherMatchData.metadata[term]);

            if (this.metadata[term] == undefined) {
              this.metadata[term] = Object.create(null);
            }

            for (var j = 0; j < fields.length; j++) {
              var field = fields[j],
                keys = Object.keys(otherMatchData.metadata[term][field]);

              if (this.metadata[term][field] == undefined) {
                this.metadata[term][field] = Object.create(null);
              }

              for (var k = 0; k < keys.length; k++) {
                var key = keys[k];

                if (this.metadata[term][field][key] == undefined) {
                  this.metadata[term][field][key] =
                    otherMatchData.metadata[term][field][key];
                } else {
                  this.metadata[term][field][key] = this.metadata[term][field][
                    key
                  ].concat(otherMatchData.metadata[term][field][key]);
                }
              }
            }
          }
        };

        /**
         * Add metadata for a term/field pair to this instance of match data.
         *
         * @param {string} term - The term this match data is associated with
         * @param {string} field - The field in which the term was found
         * @param {object} metadata - The metadata recorded about this term in this field
         */
        lunr.MatchData.prototype.add = function (term, field, metadata) {
          if (!(term in this.metadata)) {
            this.metadata[term] = Object.create(null);
            this.metadata[term][field] = metadata;
            return;
          }

          if (!(field in this.metadata[term])) {
            this.metadata[term][field] = metadata;
            return;
          }

          var metadataKeys = Object.keys(metadata);

          for (var i = 0; i < metadataKeys.length; i++) {
            var key = metadataKeys[i];

            if (key in this.metadata[term][field]) {
              this.metadata[term][field][key] = this.metadata[term][field][
                key
              ].concat(metadata[key]);
            } else {
              this.metadata[term][field][key] = metadata[key];
            }
          }
        };
        /**
         * A lunr.Query provides a programmatic way of defining queries to be performed
         * against a {@link lunr.Index}.
         *
         * Prefer constructing a lunr.Query using the {@link lunr.Index#query} method
         * so the query object is pre-initialized with the right index fields.
         *
         * @constructor
         * @property {lunr.Query~Clause[]} clauses - An array of query clauses.
         * @property {string[]} allFields - An array of all available fields in a lunr.Index.
         */
        lunr.Query = function (allFields) {
          this.clauses = [];
          this.allFields = allFields;
        };

        /**
         * Constants for indicating what kind of automatic wildcard insertion will be used when constructing a query clause.
         *
         * This allows wildcards to be added to the beginning and end of a term without having to manually do any string
         * concatenation.
         *
         * The wildcard constants can be bitwise combined to select both leading and trailing wildcards.
         *
         * @constant
         * @default
         * @property {number} wildcard.NONE - The term will have no wildcards inserted, this is the default behaviour
         * @property {number} wildcard.LEADING - Prepend the term with a wildcard, unless a leading wildcard already exists
         * @property {number} wildcard.TRAILING - Append a wildcard to the term, unless a trailing wildcard already exists
         * @see lunr.Query~Clause
         * @see lunr.Query#clause
         * @see lunr.Query#term
         * @example <caption>query term with trailing wildcard</caption>
         * query.term('foo', { wildcard: lunr.Query.wildcard.TRAILING })
         * @example <caption>query term with leading and trailing wildcard</caption>
         * query.term('foo', {
         *   wildcard: lunr.Query.wildcard.LEADING | lunr.Query.wildcard.TRAILING
         * })
         */

        lunr.Query.wildcard = new String("*");
        lunr.Query.wildcard.NONE = 0;
        lunr.Query.wildcard.LEADING = 1;
        lunr.Query.wildcard.TRAILING = 2;

        /**
         * Constants for indicating what kind of presence a term must have in matching documents.
         *
         * @constant
         * @enum {number}
         * @see lunr.Query~Clause
         * @see lunr.Query#clause
         * @see lunr.Query#term
         * @example <caption>query term with required presence</caption>
         * query.term('foo', { presence: lunr.Query.presence.REQUIRED })
         */
        lunr.Query.presence = {
          /**
           * Term's presence in a document is optional, this is the default value.
           */
          OPTIONAL: 1,

          /**
           * Term's presence in a document is required, documents that do not contain
           * this term will not be returned.
           */
          REQUIRED: 2,

          /**
           * Term's presence in a document is prohibited, documents that do contain
           * this term will not be returned.
           */
          PROHIBITED: 3,
        };

        /**
         * A single clause in a {@link lunr.Query} contains a term and details on how to
         * match that term against a {@link lunr.Index}.
         *
         * @typedef {Object} lunr.Query~Clause
         * @property {string[]} fields - The fields in an index this clause should be matched against.
         * @property {number} [boost=1] - Any boost that should be applied when matching this clause.
         * @property {number} [editDistance] - Whether the term should have fuzzy matching applied, and how fuzzy the match should be.
         * @property {boolean} [usePipeline] - Whether the term should be passed through the search pipeline.
         * @property {number} [wildcard=lunr.Query.wildcard.NONE] - Whether the term should have wildcards appended or prepended.
         * @property {number} [presence=lunr.Query.presence.OPTIONAL] - The terms presence in any matching documents.
         */

        /**
         * Adds a {@link lunr.Query~Clause} to this query.
         *
         * Unless the clause contains the fields to be matched all fields will be matched. In addition
         * a default boost of 1 is applied to the clause.
         *
         * @param {lunr.Query~Clause} clause - The clause to add to this query.
         * @see lunr.Query~Clause
         * @returns {lunr.Query}
         */
        lunr.Query.prototype.clause = function (clause) {
          if (!("fields" in clause)) {
            clause.fields = this.allFields;
          }

          if (!("boost" in clause)) {
            clause.boost = 1;
          }

          if (!("usePipeline" in clause)) {
            clause.usePipeline = true;
          }

          if (!("wildcard" in clause)) {
            clause.wildcard = lunr.Query.wildcard.NONE;
          }

          if (
            clause.wildcard & lunr.Query.wildcard.LEADING &&
            clause.term.charAt(0) != lunr.Query.wildcard
          ) {
            clause.term = "*" + clause.term;
          }

          if (
            clause.wildcard & lunr.Query.wildcard.TRAILING &&
            clause.term.slice(-1) != lunr.Query.wildcard
          ) {
            clause.term = "" + clause.term + "*";
          }

          if (!("presence" in clause)) {
            clause.presence = lunr.Query.presence.OPTIONAL;
          }

          this.clauses.push(clause);

          return this;
        };

        /**
         * A negated query is one in which every clause has a presence of
         * prohibited. These queries require some special processing to return
         * the expected results.
         *
         * @returns boolean
         */
        lunr.Query.prototype.isNegated = function () {
          for (var i = 0; i < this.clauses.length; i++) {
            if (this.clauses[i].presence != lunr.Query.presence.PROHIBITED) {
              return false;
            }
          }

          return true;
        };

        /**
         * Adds a term to the current query, under the covers this will create a {@link lunr.Query~Clause}
         * to the list of clauses that make up this query.
         *
         * The term is used as is, i.e. no tokenization will be performed by this method. Instead conversion
         * to a token or token-like string should be done before calling this method.
         *
         * The term will be converted to a string by calling `toString`. Multiple terms can be passed as an
         * array, each term in the array will share the same options.
         *
         * @param {object|object[]} term - The term(s) to add to the query.
         * @param {object} [options] - Any additional properties to add to the query clause.
         * @returns {lunr.Query}
         * @see lunr.Query#clause
         * @see lunr.Query~Clause
         * @example <caption>adding a single term to a query</caption>
         * query.term("foo")
         * @example <caption>adding a single term to a query and specifying search fields, term boost and automatic trailing wildcard</caption>
         * query.term("foo", {
         *   fields: ["title"],
         *   boost: 10,
         *   wildcard: lunr.Query.wildcard.TRAILING
         * })
         * @example <caption>using lunr.tokenizer to convert a string to tokens before using them as terms</caption>
         * query.term(lunr.tokenizer("foo bar"))
         */
        lunr.Query.prototype.term = function (term, options) {
          if (Array.isArray(term)) {
            term.forEach(function (t) {
              this.term(t, lunr.utils.clone(options));
            }, this);
            return this;
          }

          var clause = options || {};
          clause.term = term.toString();

          this.clause(clause);

          return this;
        };
        lunr.QueryParseError = function (message, start, end) {
          this.name = "QueryParseError";
          this.message = message;
          this.start = start;
          this.end = end;
        };

        lunr.QueryParseError.prototype = new Error();
        lunr.QueryLexer = function (str) {
          this.lexemes = [];
          this.str = str;
          this.length = str.length;
          this.pos = 0;
          this.start = 0;
          this.escapeCharPositions = [];
        };

        lunr.QueryLexer.prototype.run = function () {
          var state = lunr.QueryLexer.lexText;

          while (state) {
            state = state(this);
          }
        };

        lunr.QueryLexer.prototype.sliceString = function () {
          var subSlices = [],
            sliceStart = this.start,
            sliceEnd = this.pos;

          for (var i = 0; i < this.escapeCharPositions.length; i++) {
            sliceEnd = this.escapeCharPositions[i];
            subSlices.push(this.str.slice(sliceStart, sliceEnd));
            sliceStart = sliceEnd + 1;
          }

          subSlices.push(this.str.slice(sliceStart, this.pos));
          this.escapeCharPositions.length = 0;

          return subSlices.join("");
        };

        lunr.QueryLexer.prototype.emit = function (type) {
          this.lexemes.push({
            type: type,
            str: this.sliceString(),
            start: this.start,
            end: this.pos,
          });

          this.start = this.pos;
        };

        lunr.QueryLexer.prototype.escapeCharacter = function () {
          this.escapeCharPositions.push(this.pos - 1);
          this.pos += 1;
        };

        lunr.QueryLexer.prototype.next = function () {
          if (this.pos >= this.length) {
            return lunr.QueryLexer.EOS;
          }

          var char = this.str.charAt(this.pos);
          this.pos += 1;
          return char;
        };

        lunr.QueryLexer.prototype.width = function () {
          return this.pos - this.start;
        };

        lunr.QueryLexer.prototype.ignore = function () {
          if (this.start == this.pos) {
            this.pos += 1;
          }

          this.start = this.pos;
        };

        lunr.QueryLexer.prototype.backup = function () {
          this.pos -= 1;
        };

        lunr.QueryLexer.prototype.acceptDigitRun = function () {
          var char, charCode;

          do {
            char = this.next();
            charCode = char.charCodeAt(0);
          } while (charCode > 47 && charCode < 58);

          if (char != lunr.QueryLexer.EOS) {
            this.backup();
          }
        };

        lunr.QueryLexer.prototype.more = function () {
          return this.pos < this.length;
        };

        lunr.QueryLexer.EOS = "EOS";
        lunr.QueryLexer.FIELD = "FIELD";
        lunr.QueryLexer.TERM = "TERM";
        lunr.QueryLexer.EDIT_DISTANCE = "EDIT_DISTANCE";
        lunr.QueryLexer.BOOST = "BOOST";
        lunr.QueryLexer.PRESENCE = "PRESENCE";

        lunr.QueryLexer.lexField = function (lexer) {
          lexer.backup();
          lexer.emit(lunr.QueryLexer.FIELD);
          lexer.ignore();
          return lunr.QueryLexer.lexText;
        };

        lunr.QueryLexer.lexTerm = function (lexer) {
          if (lexer.width() > 1) {
            lexer.backup();
            lexer.emit(lunr.QueryLexer.TERM);
          }

          lexer.ignore();

          if (lexer.more()) {
            return lunr.QueryLexer.lexText;
          }
        };

        lunr.QueryLexer.lexEditDistance = function (lexer) {
          lexer.ignore();
          lexer.acceptDigitRun();
          lexer.emit(lunr.QueryLexer.EDIT_DISTANCE);
          return lunr.QueryLexer.lexText;
        };

        lunr.QueryLexer.lexBoost = function (lexer) {
          lexer.ignore();
          lexer.acceptDigitRun();
          lexer.emit(lunr.QueryLexer.BOOST);
          return lunr.QueryLexer.lexText;
        };

        lunr.QueryLexer.lexEOS = function (lexer) {
          if (lexer.width() > 0) {
            lexer.emit(lunr.QueryLexer.TERM);
          }
        };

        // This matches the separator used when tokenising fields
        // within a document. These should match otherwise it is
        // not possible to search for some tokens within a document.
        //
        // It is possible for the user to change the separator on the
        // tokenizer so it _might_ clash with any other of the special
        // characters already used within the search string, e.g. :.
        //
        // This means that it is possible to change the separator in
        // such a way that makes some words unsearchable using a search
        // string.
        lunr.QueryLexer.termSeparator = lunr.tokenizer.separator;

        lunr.QueryLexer.lexText = function (lexer) {
          while (true) {
            var char = lexer.next();

            if (char == lunr.QueryLexer.EOS) {
              return lunr.QueryLexer.lexEOS;
            }

            // Escape character is '\'
            if (char.charCodeAt(0) == 92) {
              lexer.escapeCharacter();
              continue;
            }

            if (char == ":") {
              return lunr.QueryLexer.lexField;
            }

            if (char == "~") {
              lexer.backup();
              if (lexer.width() > 0) {
                lexer.emit(lunr.QueryLexer.TERM);
              }
              return lunr.QueryLexer.lexEditDistance;
            }

            if (char == "^") {
              lexer.backup();
              if (lexer.width() > 0) {
                lexer.emit(lunr.QueryLexer.TERM);
              }
              return lunr.QueryLexer.lexBoost;
            }

            // "+" indicates term presence is required
            // checking for length to ensure that only
            // leading "+" are considered
            if (char == "+" && lexer.width() === 1) {
              lexer.emit(lunr.QueryLexer.PRESENCE);
              return lunr.QueryLexer.lexText;
            }

            // "-" indicates term presence is prohibited
            // checking for length to ensure that only
            // leading "-" are considered
            if (char == "-" && lexer.width() === 1) {
              lexer.emit(lunr.QueryLexer.PRESENCE);
              return lunr.QueryLexer.lexText;
            }

            if (char.match(lunr.QueryLexer.termSeparator)) {
              return lunr.QueryLexer.lexTerm;
            }
          }
        };

        lunr.QueryParser = function (str, query) {
          this.lexer = new lunr.QueryLexer(str);
          this.query = query;
          this.currentClause = {};
          this.lexemeIdx = 0;
        };

        lunr.QueryParser.prototype.parse = function () {
          this.lexer.run();
          this.lexemes = this.lexer.lexemes;

          var state = lunr.QueryParser.parseClause;

          while (state) {
            state = state(this);
          }

          return this.query;
        };

        lunr.QueryParser.prototype.peekLexeme = function () {
          return this.lexemes[this.lexemeIdx];
        };

        lunr.QueryParser.prototype.consumeLexeme = function () {
          var lexeme = this.peekLexeme();
          this.lexemeIdx += 1;
          return lexeme;
        };

        lunr.QueryParser.prototype.nextClause = function () {
          var completedClause = this.currentClause;
          this.query.clause(completedClause);
          this.currentClause = {};
        };

        lunr.QueryParser.parseClause = function (parser) {
          var lexeme = parser.peekLexeme();

          if (lexeme == undefined) {
            return;
          }

          switch (lexeme.type) {
            case lunr.QueryLexer.PRESENCE:
              return lunr.QueryParser.parsePresence;
            case lunr.QueryLexer.FIELD:
              return lunr.QueryParser.parseField;
            case lunr.QueryLexer.TERM:
              return lunr.QueryParser.parseTerm;
            default:
              var errorMessage =
                "expected either a field or a term, found " + lexeme.type;

              if (lexeme.str.length >= 1) {
                errorMessage += " with value '" + lexeme.str + "'";
              }

              throw new lunr.QueryParseError(
                errorMessage,
                lexeme.start,
                lexeme.end
              );
          }
        };

        lunr.QueryParser.parsePresence = function (parser) {
          var lexeme = parser.consumeLexeme();

          if (lexeme == undefined) {
            return;
          }

          switch (lexeme.str) {
            case "-":
              parser.currentClause.presence = lunr.Query.presence.PROHIBITED;
              break;
            case "+":
              parser.currentClause.presence = lunr.Query.presence.REQUIRED;
              break;
            default:
              var errorMessage =
                "unrecognised presence operator'" + lexeme.str + "'";
              throw new lunr.QueryParseError(
                errorMessage,
                lexeme.start,
                lexeme.end
              );
          }

          var nextLexeme = parser.peekLexeme();

          if (nextLexeme == undefined) {
            var errorMessage = "expecting term or field, found nothing";
            throw new lunr.QueryParseError(
              errorMessage,
              lexeme.start,
              lexeme.end
            );
          }

          switch (nextLexeme.type) {
            case lunr.QueryLexer.FIELD:
              return lunr.QueryParser.parseField;
            case lunr.QueryLexer.TERM:
              return lunr.QueryParser.parseTerm;
            default:
              var errorMessage =
                "expecting term or field, found '" + nextLexeme.type + "'";
              throw new lunr.QueryParseError(
                errorMessage,
                nextLexeme.start,
                nextLexeme.end
              );
          }
        };

        lunr.QueryParser.parseField = function (parser) {
          var lexeme = parser.consumeLexeme();

          if (lexeme == undefined) {
            return;
          }

          if (parser.query.allFields.indexOf(lexeme.str) == -1) {
            var possibleFields = parser.query.allFields
                .map(function (f) {
                  return "'" + f + "'";
                })
                .join(", "),
              errorMessage =
                "unrecognised field '" +
                lexeme.str +
                "', possible fields: " +
                possibleFields;

            throw new lunr.QueryParseError(
              errorMessage,
              lexeme.start,
              lexeme.end
            );
          }

          parser.currentClause.fields = [lexeme.str];

          var nextLexeme = parser.peekLexeme();

          if (nextLexeme == undefined) {
            var errorMessage = "expecting term, found nothing";
            throw new lunr.QueryParseError(
              errorMessage,
              lexeme.start,
              lexeme.end
            );
          }

          switch (nextLexeme.type) {
            case lunr.QueryLexer.TERM:
              return lunr.QueryParser.parseTerm;
            default:
              var errorMessage =
                "expecting term, found '" + nextLexeme.type + "'";
              throw new lunr.QueryParseError(
                errorMessage,
                nextLexeme.start,
                nextLexeme.end
              );
          }
        };

        lunr.QueryParser.parseTerm = function (parser) {
          var lexeme = parser.consumeLexeme();

          if (lexeme == undefined) {
            return;
          }

          parser.currentClause.term = lexeme.str.toLowerCase();

          if (lexeme.str.indexOf("*") != -1) {
            parser.currentClause.usePipeline = false;
          }

          var nextLexeme = parser.peekLexeme();

          if (nextLexeme == undefined) {
            parser.nextClause();
            return;
          }

          switch (nextLexeme.type) {
            case lunr.QueryLexer.TERM:
              parser.nextClause();
              return lunr.QueryParser.parseTerm;
            case lunr.QueryLexer.FIELD:
              parser.nextClause();
              return lunr.QueryParser.parseField;
            case lunr.QueryLexer.EDIT_DISTANCE:
              return lunr.QueryParser.parseEditDistance;
            case lunr.QueryLexer.BOOST:
              return lunr.QueryParser.parseBoost;
            case lunr.QueryLexer.PRESENCE:
              parser.nextClause();
              return lunr.QueryParser.parsePresence;
            default:
              var errorMessage =
                "Unexpected lexeme type '" + nextLexeme.type + "'";
              throw new lunr.QueryParseError(
                errorMessage,
                nextLexeme.start,
                nextLexeme.end
              );
          }
        };

        lunr.QueryParser.parseEditDistance = function (parser) {
          var lexeme = parser.consumeLexeme();

          if (lexeme == undefined) {
            return;
          }

          var editDistance = parseInt(lexeme.str, 10);

          if (isNaN(editDistance)) {
            var errorMessage = "edit distance must be numeric";
            throw new lunr.QueryParseError(
              errorMessage,
              lexeme.start,
              lexeme.end
            );
          }

          parser.currentClause.editDistance = editDistance;

          var nextLexeme = parser.peekLexeme();

          if (nextLexeme == undefined) {
            parser.nextClause();
            return;
          }

          switch (nextLexeme.type) {
            case lunr.QueryLexer.TERM:
              parser.nextClause();
              return lunr.QueryParser.parseTerm;
            case lunr.QueryLexer.FIELD:
              parser.nextClause();
              return lunr.QueryParser.parseField;
            case lunr.QueryLexer.EDIT_DISTANCE:
              return lunr.QueryParser.parseEditDistance;
            case lunr.QueryLexer.BOOST:
              return lunr.QueryParser.parseBoost;
            case lunr.QueryLexer.PRESENCE:
              parser.nextClause();
              return lunr.QueryParser.parsePresence;
            default:
              var errorMessage =
                "Unexpected lexeme type '" + nextLexeme.type + "'";
              throw new lunr.QueryParseError(
                errorMessage,
                nextLexeme.start,
                nextLexeme.end
              );
          }
        };

        lunr.QueryParser.parseBoost = function (parser) {
          var lexeme = parser.consumeLexeme();

          if (lexeme == undefined) {
            return;
          }

          var boost = parseInt(lexeme.str, 10);

          if (isNaN(boost)) {
            var errorMessage = "boost must be numeric";
            throw new lunr.QueryParseError(
              errorMessage,
              lexeme.start,
              lexeme.end
            );
          }

          parser.currentClause.boost = boost;

          var nextLexeme = parser.peekLexeme();

          if (nextLexeme == undefined) {
            parser.nextClause();
            return;
          }

          switch (nextLexeme.type) {
            case lunr.QueryLexer.TERM:
              parser.nextClause();
              return lunr.QueryParser.parseTerm;
            case lunr.QueryLexer.FIELD:
              parser.nextClause();
              return lunr.QueryParser.parseField;
            case lunr.QueryLexer.EDIT_DISTANCE:
              return lunr.QueryParser.parseEditDistance;
            case lunr.QueryLexer.BOOST:
              return lunr.QueryParser.parseBoost;
            case lunr.QueryLexer.PRESENCE:
              parser.nextClause();
              return lunr.QueryParser.parsePresence;
            default:
              var errorMessage =
                "Unexpected lexeme type '" + nextLexeme.type + "'";
              throw new lunr.QueryParseError(
                errorMessage,
                nextLexeme.start,
                nextLexeme.end
              );
          }
        };

        /**
         * export the module via AMD, CommonJS or as a browser global
         * Export code from https://github.com/umdjs/umd/blob/master/returnExports.js
         */
        (function (root, factory) {
          {
            /**
             * Node. Does not work with strict CommonJS, but
             * only CommonJS-like enviroments that support module.exports,
             * like Node.
             */
            module.exports = factory();
          }
        })(this, function () {
          /**
           * Just return a value to define the module export.
           * This example returns an object, but the module
           * can return a function as the exported value.
           */
          return lunr;
        });
      })();
    })(lunr$1, lunr$1.exports);
    return lunr$1.exports;
  }

  var lunrExports = requireLunr();
  var lunr = /*@__PURE__*/ getDefaultExportFromCjs(lunrExports);

  const language = ["en", "zh"];
  const searchIndexUrl = "search-index{dir}.json?_=93562eb5";
  const searchResultLimits = 100;

  /**
   * Split a sentence to tokens, considering a sequence of consecutive Chinese words as a single token.
   *
   * @param text - Text to be tokenized.
   * @param language - Languages used.
   *
   * @returns Tokens.
   */
  function tokenize(text, language) {
    // Some languages have their own tokenizer.
    if (language.length === 1 && ["ja", "jp", "th"].includes(language[0])) {
      return lunr[language[0]].tokenizer(text).map((token) => token.toString());
    }
    let regExpMatchWords = /[^-\s]+/g;
    // Especially optimization for `zh`.
    if (language.includes("zh")) {
      // Currently only works fine with letters in Latin alphabet and Chinese.
      // https://zhuanlan.zhihu.com/p/33335629
      regExpMatchWords = /\w+|\p{Unified_Ideograph}+/gu;
      // regExpMatchWords = /\p{Unified_Ideograph}+|[^-\s\p{Unified_Ideograph}]+/gu;
      // https://mothereff.in/regexpu#input=const+regex+%3D+/%5Cp%7BUnified_Ideograph%7D/u%3B&unicodePropertyEscape=1
      // regExpMatchWords = /\w+|[\u3400-\u4DBF\u4E00-\u9FFC\uFA0E\uFA0F\uFA11\uFA13\uFA14\uFA1F\uFA21\uFA23\uFA24\uFA27-\uFA29\u{20000}-\u{2A6DD}\u{2A700}-\u{2B734}\u{2B740}-\u{2B81D}\u{2B820}-\u{2CEA1}\u{2CEB0}-\u{2EBE0}\u{30000}-\u{3134A}]+/gu
    }
    return text.toLowerCase().match(regExpMatchWords) || [];
  }

  /**
   * Get all possible terms for a string of consecutive Chinese words,
   * by a words dictionary.
   *
   * @remarks
   *
   * Terms are sorted in ascending order by the count of words.
   *
   * @param token - A string of consecutive Chinese words.
   * @param zhDictionary - A Chinese words dictionary.
   *
   * @returns A smart term list.
   */
  function cutZhWords(token, zhDictionary) {
    const wrappedTerms = [];
    function cut(subToken, carry) {
      let matchedLastIndex = 0;
      let matched = false;
      for (const words of zhDictionary) {
        if (subToken.substr(0, words.length) === words) {
          const nextCarry = {
            missed: carry.missed,
            term: carry.term.concat({
              value: words,
            }),
          };
          if (subToken.length > words.length) {
            cut(subToken.substr(words.length), nextCarry);
          } else {
            wrappedTerms.push(nextCarry);
          }
          matched = true;
        } else {
          for (
            let lastIndex = words.length - 1;
            lastIndex > matchedLastIndex;
            lastIndex -= 1
          ) {
            const subWords = words.substr(0, lastIndex);
            if (subToken.substr(0, lastIndex) === subWords) {
              matchedLastIndex = lastIndex;
              const nextCarry = {
                missed: carry.missed,
                term: carry.term.concat({
                  value: subWords,
                  trailing: true,
                }),
              };
              if (subToken.length > lastIndex) {
                cut(subToken.substr(lastIndex), nextCarry);
              } else {
                wrappedTerms.push(nextCarry);
              }
              matched = true;
              break;
            }
          }
        }
      }
      if (!matched) {
        if (subToken.length > 0) {
          cut(subToken.substr(1), {
            missed: carry.missed + 1,
            term: carry.term,
          });
        } else if (carry.term.length > 0) {
          wrappedTerms.push(carry);
        }
      }
    }
    cut(token, {
      missed: 0,
      term: [],
    });
    return wrappedTerms
      .sort((a, b) => {
        const aMissed = a.missed > 0 ? 1 : 0;
        const bMissed = b.missed > 0 ? 1 : 0;
        if (aMissed !== bMissed) {
          // Put all no-words-missed terms before words-missed terms.
          return aMissed - bMissed;
        }
        // Put terms with less words before those with more words.
        return a.term.length - b.term.length;
      })
      .map((item) => item.term);
  }

  // `lunr-languages/lunr.stemmer.support` is required.
  function generateTrimmer(wordCharacters) {
    const startRegex = new RegExp("^[^" + wordCharacters + "]+", "u");
    const endRegex = new RegExp("[^" + wordCharacters + "]+$", "u");
    return function (token) {
      return token.update(function (str) {
        return str.replace(startRegex, "").replace(endRegex, "");
      });
    };
  }

  function lunrLanguageZh(lunr, tokenizer) {
    (function (root, factory) {
      factory()(lunr);
    })(this, function () {
      /**
       * Just return a value to define the module export.
       * This example returns an object, but the module
       * can return a function as the exported value.
       */
      return function (lunr) {
        /* provides utilities for the included stemmers */
        lunr.stemmerSupport = {
          Among: function (s, substring_i, result, method) {
            this.toCharArray = function (s) {
              var sLength = s.length,
                charArr = new Array(sLength);
              for (var i = 0; i < sLength; i++) charArr[i] = s.charCodeAt(i);
              return charArr;
            };

            if (
              (!s && s != "") ||
              (!substring_i && substring_i != 0) ||
              !result
            )
              throw (
                "Bad Among initialisation: s:" +
                s +
                ", substring_i: " +
                substring_i +
                ", result: " +
                result
              );
            this.s_size = s.length;
            this.s = this.toCharArray(s);
            this.substring_i = substring_i;
            this.result = result;
            this.method = method;
          },
          SnowballProgram: function () {
            var current;
            return {
              bra: 0,
              ket: 0,
              limit: 0,
              cursor: 0,
              limit_backward: 0,
              setCurrent: function (word) {
                current = word;
                this.cursor = 0;
                this.limit = word.length;
                this.limit_backward = 0;
                this.bra = this.cursor;
                this.ket = this.limit;
              },
              getCurrent: function () {
                var result = current;
                current = null;
                return result;
              },
              in_grouping: function (s, min, max) {
                if (this.cursor < this.limit) {
                  var ch = current.charCodeAt(this.cursor);
                  if (ch <= max && ch >= min) {
                    ch -= min;
                    if (s[ch >> 3] & (0x1 << (ch & 0x7))) {
                      this.cursor++;
                      return true;
                    }
                  }
                }
                return false;
              },
              in_grouping_b: function (s, min, max) {
                if (this.cursor > this.limit_backward) {
                  var ch = current.charCodeAt(this.cursor - 1);
                  if (ch <= max && ch >= min) {
                    ch -= min;
                    if (s[ch >> 3] & (0x1 << (ch & 0x7))) {
                      this.cursor--;
                      return true;
                    }
                  }
                }
                return false;
              },
              out_grouping: function (s, min, max) {
                if (this.cursor < this.limit) {
                  var ch = current.charCodeAt(this.cursor);
                  if (ch > max || ch < min) {
                    this.cursor++;
                    return true;
                  }
                  ch -= min;
                  if (!(s[ch >> 3] & (0x1 << (ch & 0x7)))) {
                    this.cursor++;
                    return true;
                  }
                }
                return false;
              },
              out_grouping_b: function (s, min, max) {
                if (this.cursor > this.limit_backward) {
                  var ch = current.charCodeAt(this.cursor - 1);
                  if (ch > max || ch < min) {
                    this.cursor--;
                    return true;
                  }
                  ch -= min;
                  if (!(s[ch >> 3] & (0x1 << (ch & 0x7)))) {
                    this.cursor--;
                    return true;
                  }
                }
                return false;
              },
              eq_s: function (s_size, s) {
                if (this.limit - this.cursor < s_size) return false;
                for (var i = 0; i < s_size; i++)
                  if (current.charCodeAt(this.cursor + i) != s.charCodeAt(i))
                    return false;
                this.cursor += s_size;
                return true;
              },
              eq_s_b: function (s_size, s) {
                if (this.cursor - this.limit_backward < s_size) return false;
                for (var i = 0; i < s_size; i++)
                  if (
                    current.charCodeAt(this.cursor - s_size + i) !=
                    s.charCodeAt(i)
                  )
                    return false;
                this.cursor -= s_size;
                return true;
              },
              find_among: function (v, v_size) {
                var i = 0,
                  j = v_size,
                  c = this.cursor,
                  l = this.limit,
                  common_i = 0,
                  common_j = 0,
                  first_key_inspected = false;
                while (true) {
                  var k = i + ((j - i) >> 1),
                    diff = 0,
                    common = common_i < common_j ? common_i : common_j,
                    w = v[k];
                  for (var i2 = common; i2 < w.s_size; i2++) {
                    if (c + common == l) {
                      diff = -1;
                      break;
                    }
                    diff = current.charCodeAt(c + common) - w.s[i2];
                    if (diff) break;
                    common++;
                  }
                  if (diff < 0) {
                    j = k;
                    common_j = common;
                  } else {
                    i = k;
                    common_i = common;
                  }
                  if (j - i <= 1) {
                    if (i > 0 || j == i || first_key_inspected) break;
                    first_key_inspected = true;
                  }
                }
                while (true) {
                  var w = v[i];
                  if (common_i >= w.s_size) {
                    this.cursor = c + w.s_size;
                    if (!w.method) return w.result;
                    var res = w.method();
                    this.cursor = c + w.s_size;
                    if (res) return w.result;
                  }
                  i = w.substring_i;
                  if (i < 0) return 0;
                }
              },
              find_among_b: function (v, v_size) {
                var i = 0,
                  j = v_size,
                  c = this.cursor,
                  lb = this.limit_backward,
                  common_i = 0,
                  common_j = 0,
                  first_key_inspected = false;
                while (true) {
                  var k = i + ((j - i) >> 1),
                    diff = 0,
                    common = common_i < common_j ? common_i : common_j,
                    w = v[k];
                  for (var i2 = w.s_size - 1 - common; i2 >= 0; i2--) {
                    if (c - common == lb) {
                      diff = -1;
                      break;
                    }
                    diff = current.charCodeAt(c - 1 - common) - w.s[i2];
                    if (diff) break;
                    common++;
                  }
                  if (diff < 0) {
                    j = k;
                    common_j = common;
                  } else {
                    i = k;
                    common_i = common;
                  }
                  if (j - i <= 1) {
                    if (i > 0 || j == i || first_key_inspected) break;
                    first_key_inspected = true;
                  }
                }
                while (true) {
                  var w = v[i];
                  if (common_i >= w.s_size) {
                    this.cursor = c - w.s_size;
                    if (!w.method) return w.result;
                    var res = w.method();
                    this.cursor = c - w.s_size;
                    if (res) return w.result;
                  }
                  i = w.substring_i;
                  if (i < 0) return 0;
                }
              },
              replace_s: function (c_bra, c_ket, s) {
                var adjustment = s.length - (c_ket - c_bra),
                  left = current.substring(0, c_bra),
                  right = current.substring(c_ket);
                current = left + s + right;
                this.limit += adjustment;
                if (this.cursor >= c_ket) this.cursor += adjustment;
                else if (this.cursor > c_bra) this.cursor = c_bra;
                return adjustment;
              },
              slice_check: function () {
                if (
                  this.bra < 0 ||
                  this.bra > this.ket ||
                  this.ket > this.limit ||
                  this.limit > current.length
                )
                  throw "faulty slice operation";
              },
              slice_from: function (s) {
                this.slice_check();
                this.replace_s(this.bra, this.ket, s);
              },
              slice_del: function () {
                this.slice_from("");
              },
              insert: function (c_bra, c_ket, s) {
                var adjustment = this.replace_s(c_bra, c_ket, s);
                if (c_bra <= this.bra) this.bra += adjustment;
                if (c_bra <= this.ket) this.ket += adjustment;
              },
              slice_to: function () {
                this.slice_check();
                return current.substring(this.bra, this.ket);
              },
              eq_v_b: function (s) {
                return this.eq_s_b(s.length, s);
              },
            };
          },
        };

        lunr.trimmerSupport = {
          generateTrimmer: function (wordCharacters) {
            var startRegex = new RegExp("^[^" + wordCharacters + "]+");
            var endRegex = new RegExp("[^" + wordCharacters + "]+$");

            return function (token) {
              // for lunr version 2
              if (typeof token.update === "function") {
                return token.update(function (s) {
                  return s.replace(startRegex, "").replace(endRegex, "");
                });
              } else {
                // for lunr version 1
                return token.replace(startRegex, "").replace(endRegex, "");
              }
            };
          },
        };
      };
    });
    /**
     * export the module via AMD, CommonJS or as a browser global
     * Export code from https://github.com/umdjs/umd/blob/master/returnExports.js
     */
    (function (root, factory) {
      factory()(lunr);
    })(this, function () {
      /**
       * Just return a value to define the module export.
       * This example returns an object, but the module
       * can return a function as the exported value.
       */
      return function (lunr) {
        /* Set up the pipeline for indexing content in multiple languages. The
         corresponding lunr.{lang} files must be loaded before calling this
         function; English ('en') is built in.

         Returns: a lunr plugin for use in your indexer.

         Known drawback: every word will be stemmed with stemmers for every
         language. This could mean that sometimes words that have the same
         stemming root will not be stemmed as such.
         */
        lunr.multiLanguage = function (/* lang1, lang2, ... */) {
          var languages = Array.prototype.slice.call(arguments);
          var nameSuffix = languages.join("-");
          var wordCharacters = "";
          var pipeline = [];
          var searchPipeline = [];
          for (var i = 0; i < languages.length; ++i) {
            if (languages[i] == "en") {
              wordCharacters += "\\w";
              pipeline.unshift(lunr.stopWordFilter);
              pipeline.push(lunr.stemmer);
              searchPipeline.push(lunr.stemmer);
            } else {
              wordCharacters += lunr[languages[i]].wordCharacters;
              if (lunr[languages[i]].stopWordFilter) {
                pipeline.unshift(lunr[languages[i]].stopWordFilter);
              }
              if (lunr[languages[i]].stemmer) {
                pipeline.push(lunr[languages[i]].stemmer);
                searchPipeline.push(lunr[languages[i]].stemmer);
              }
            }
          }
          var multiTrimmer =
            lunr.trimmerSupport.generateTrimmer(wordCharacters);
          lunr.Pipeline.registerFunction(
            multiTrimmer,
            "lunr-multi-trimmer-" + nameSuffix
          );
          pipeline.unshift(multiTrimmer);

          return function () {
            this.pipeline.reset();

            this.pipeline.add.apply(this.pipeline, pipeline);

            // for lunr version 2
            // this is necessary so that every searched word is also stemmed before
            // in lunr <= 1 this is not needed, as it is done using the normal pipeline
            if (this.searchPipeline) {
              this.searchPipeline.reset();
              this.searchPipeline.add.apply(
                this.searchPipeline,
                searchPipeline
              );
            }
          };
        };
      };
    });

    lunr.trimmerSupport.generateTrimmer = generateTrimmer;
    lunr.zh = function () {
      this.pipeline.reset();
      this.pipeline.add(lunr.zh.trimmer, lunr.zh.stopWordFilter);
      if (tokenizer) {
        this.tokenizer = tokenizer;
      }
    };
    if (tokenizer) {
      lunr.zh.tokenizer = tokenizer;
    }
    // https://zhuanlan.zhihu.com/p/33335629
    // https://mothereff.in/regexpu#input=const+regex+%3D+/%5Cp%7BUnified_Ideograph%7D/u%3B&unicodePropertyEscape=1
    lunr.zh.wordCharacters =
      "\\u3400-\\u4DBF\\u4E00-\\u9FFC\\uFA0E\\uFA0F\\uFA11\\uFA13\\uFA14\\uFA1F\\uFA21\\uFA23\\uFA24\\uFA27-\\uFA29\\u{20000}-\\u{2A6DD}\\u{2A700}-\\u{2B734}\\u{2B740}-\\u{2B81D}\\u{2B820}-\\u{2CEA1}\\u{2CEB0}-\\u{2EBE0}\\u{30000}-\\u{3134A}";
    lunr.zh.trimmer = lunr.trimmerSupport.generateTrimmer(
      lunr.zh.wordCharacters
    );
    lunr.Pipeline.registerFunction(lunr.zh.trimmer, "trimmer-zh");
    /* lunr stop word filter. see https://www.ranks.nl/stopwords/chinese-stopwords */
    lunr.zh.stopWordFilter = lunr.generateStopWordFilter(
      "的 一 不 在 人 有 是 为 以 于 上 他 而 后 之 来 及 了 因 下 可 到 由 这 与 也 此 但 并 个 其 已 无 小 我 们 起 最 再 今 去 好 只 又 或 很 亦 某 把 那 你 乃 它 吧 被 比 别 趁 当 从 到 得 打 凡 儿 尔 该 各 给 跟 和 何 还 即 几 既 看 据 距 靠 啦 了 另 么 每 们 嘛 拿 哪 那 您 凭 且 却 让 仍 啥 如 若 使 谁 虽 随 同 所 她 哇 嗡 往 哪 些 向 沿 哟 用 于 咱 则 怎 曾 至 致 着 诸 自".split(
        " "
      )
    );
    lunr.Pipeline.registerFunction(lunr.zh.stopWordFilter, "stopWordFilter-zh");
  }

  const MAX_TERMS = 12;
  const HALF_MAX_TERMS = MAX_TERMS / 2;
  /**
   * Get all possible terms for a list of tokens consists of words mixed in Chinese and non-Chinese,
   * by a Chinese words dictionary.
   *
   * @param tokens - Tokens consists of English words or strings of consecutive Chinese words.
   * @param zhDictionary - A Chinese words dictionary.
   *
   * @returns A smart term list.
   */
  function smartTerms(tokens, zhDictionary) {
    const tokenTerms = tokens
      .map((token) => {
        if (/\p{Unified_Ideograph}/u.test(token)) {
          return cutZhWords(token, zhDictionary);
        } else {
          return [{ value: token }];
        }
      })
      .slice(0, MAX_TERMS);
    const tokenTermsThatAreMultiple = tokenTerms.filter(
      (tokenTerm) => tokenTerm.length > 1
    );
    let termsProduct = 1;
    let overflowed = false;
    for (const tokenTerm of tokenTermsThatAreMultiple) {
      if (overflowed) {
        tokenTerm.splice(1, tokenTerm.length - 1);
      } else {
        if (tokenTerm.length > HALF_MAX_TERMS) {
          tokenTerm.splice(HALF_MAX_TERMS, tokenTerm.length - HALF_MAX_TERMS);
        }
        const product = termsProduct * tokenTerm.length;
        if (product >= MAX_TERMS) {
          if (product > MAX_TERMS) {
            const max = Math.floor(MAX_TERMS / termsProduct);
            tokenTerm.splice(max, tokenTerm.length - max);
            termsProduct = max * termsProduct;
          } else {
            termsProduct = product;
          }
          if (termsProduct > HALF_MAX_TERMS) {
            overflowed = true;
          }
        } else {
          termsProduct = product;
        }
      }
    }
    // Get all possible combinations of terms.
    const terms = [];
    function combine(index, carry) {
      if (index === tokenTerms.length || carry.length >= MAX_TERMS) {
        terms.push(carry.slice(0, MAX_TERMS));
        return;
      }
      for (const term of tokenTerms[index]) {
        combine(index + 1, carry.concat(term));
      }
    }
    combine(0, []);
    return terms;
  }

  /**
   * Get all possible queries for a list of tokens consists of words mixed English and Chinese,
   * by a Chinese words dictionary.
   *
   * @param tokens - Tokens consists of English words or strings of consecutive Chinese words.
   * @param zhDictionary - A Chinese words dictionary.
   *
   * @returns A smart query list.
   */
  function smartQueries(tokens, zhDictionary) {
    const terms = smartTerms(tokens, zhDictionary);
    if (terms.length === 0) {
      // There are no matched terms.
      // All tokens are considered required and with wildcard.
      return [
        {
          tokens,
          term: tokens.map((value) => ({
            value,
            presence: lunr.Query.presence.REQUIRED,
            wildcard:
              lunr.Query.wildcard.LEADING | lunr.Query.wildcard.TRAILING,
          })),
        },
      ];
    }
    // The last token of a term maybe incomplete while user is typing.
    for (const term of terms) {
      term[term.length - 1].maybeTyping = true;
    }

    lunrLanguageZh(lunr);
    // Try to append terms without stop words,
    // since they are removed in the index.
    const stopWordPipelines = [];
    for (const lang of language) {
      if (lang === "en") {
        {
          stopWordPipelines.unshift(lunr.stopWordFilter);
        }
      } else {
        const lunrLang = lunr[lang];
        if (lunrLang.stopWordFilter) {
          stopWordPipelines.unshift(lunrLang.stopWordFilter);
        }
      }
    }
    let refinedTerms;
    if (stopWordPipelines.length > 0) {
      const pipe = (term) =>
        stopWordPipelines.reduce(
          (term, p) => term.filter((item) => p(item.value)),
          term
        );
      refinedTerms = [];
      const newTerms = [];
      for (const term of terms) {
        const filteredTerm = pipe(term);
        refinedTerms.push(filteredTerm);
        // Add extra terms only if some stop words are removed,
        // and some non-stop-words exist too.
        if (filteredTerm.length < term.length && filteredTerm.length > 0) {
          newTerms.push(filteredTerm);
        }
      }
      terms.push(...newTerms);
    } else {
      refinedTerms = terms.slice();
    }
    // Also try to add extra terms which miss one of the searched tokens,
    // when the term contains 3 or more tokens,
    // to improve the search precision.
    const extraTerms = [];
    for (const term of refinedTerms) {
      if (term.length > 2) {
        for (let i = term.length - 1; i >= 0; i -= 1) {
          extraTerms.push(term.slice(0, i).concat(term.slice(i + 1)));
        }
      }
    }
    return getQueriesMaybeTyping(terms).concat(
      getQueriesMaybeTyping(extraTerms)
    );
  }
  function getQueriesMaybeTyping(terms) {
    return termsToQueries(terms).concat(
      termsToQueries(
        // Ignore terms whose last token already has a trailing wildcard,
        // or the last token is not `maybeTyping`.
        terms.filter((term) => {
          const token = term[term.length - 1];
          return !token.trailing && token.maybeTyping;
        }),
        true
      )
    );
  }
  function termsToQueries(terms, maybeTyping) {
    return terms.map((term) => ({
      tokens: term.map((item) => item.value),
      term: term.map((item) => ({
        value: item.value,
        presence: lunr.Query.presence.REQUIRED,
        // The last token of a term maybe incomplete while user is typing.
        // So append more queries with trailing wildcard added.
        wildcard: (
          maybeTyping ? item.trailing || item.maybeTyping : item.trailing
        )
          ? lunr.Query.wildcard.TRAILING
          : lunr.Query.wildcard.NONE,
      })),
    }));
  }

  var SearchDocumentType;
  (function (SearchDocumentType) {
    SearchDocumentType[(SearchDocumentType["Title"] = 0)] = "Title";
    SearchDocumentType[(SearchDocumentType["Heading"] = 1)] = "Heading";
    SearchDocumentType[(SearchDocumentType["Description"] = 2)] = "Description";
    SearchDocumentType[(SearchDocumentType["Keywords"] = 3)] = "Keywords";
    SearchDocumentType[(SearchDocumentType["Content"] = 4)] = "Content";
  })(SearchDocumentType || (SearchDocumentType = {}));

  function sortSearchResults(results) {
    results.forEach((item, index) => {
      item.index = index;
    });
    // Put search results of headings/contents/descriptions just after
    // their belonged page's title, if existed.
    results.sort((a, b) => {
      let aPageIndex =
        (a.type === SearchDocumentType.Heading ||
          a.type === SearchDocumentType.Content ||
          a.type === SearchDocumentType.Description) &&
        a.page
          ? results.findIndex((item) => item.document === a.page)
          : a.index;
      let bPageIndex =
        (b.type === SearchDocumentType.Heading ||
          b.type === SearchDocumentType.Content ||
          b.type === SearchDocumentType.Description) &&
        b.page
          ? results.findIndex((item) => item.document === b.page)
          : b.index;
      if (aPageIndex === -1) {
        aPageIndex = a.index;
      }
      if (bPageIndex === -1) {
        bPageIndex = b.index;
      }
      if (aPageIndex === bPageIndex) {
        const diff = (b.type === 0 ? 1 : 0) - (a.type === 0 ? 1 : 0);
        return diff === 0 ? a.index - b.index : diff;
      }
      return aPageIndex - bPageIndex;
    });
  }

  function processTreeStatusOfSearchResults(results) {
    results.forEach((item, i) => {
      if (
        i > 0 &&
        item.page &&
        results
          .slice(0, i)
          .some(
            (prev) =>
              (prev.type === SearchDocumentType.Keywords
                ? prev.page
                : prev.document) === item.page
          )
      ) {
        if (i < results.length - 1 && results[i + 1].page === item.page) {
          item.isInterOfTree = true;
        } else {
          item.isLastOfTree = true;
        }
      }
    });
  }

  const cache = new Map();
  class SearchWorker {
    async fetchIndexes(baseUrl, searchContext) {
      await this.lowLevelFetchIndexes(baseUrl, searchContext);
    }
    async lowLevelFetchIndexes(baseUrl, searchContext) {
      const cacheKey = `${baseUrl}${searchContext}`;
      let promise = cache.get(cacheKey);
      if (!promise) {
        promise = legacyFetchIndexes(baseUrl, searchContext);
        cache.set(cacheKey, promise);
      }
      return promise;
    }
    async search(baseUrl, searchContext, input) {
      const rawTokens = tokenize(input, language);
      if (rawTokens.length === 0) {
        return [];
      }
      const { wrappedIndexes, zhDictionary } = await this.lowLevelFetchIndexes(
        baseUrl,
        searchContext
      );
      const queries = smartQueries(rawTokens, zhDictionary);
      const results = [];
      search: for (const { term, tokens } of queries) {
        for (const { documents, index, type } of wrappedIndexes) {
          results.push(
            ...index
              .query((query) => {
                for (const item of term) {
                  query.term(item.value, {
                    wildcard: item.wildcard,
                    presence: item.presence,
                  });
                }
              })
              .slice(0, searchResultLimits)
              // Remove duplicated results.
              .filter(
                (result) =>
                  !results.some(
                    (item) => item.document.i.toString() === result.ref
                  )
              )
              .slice(0, searchResultLimits - results.length)
              .map((result) => {
                const document = documents.find(
                  (doc) => doc.i.toString() === result.ref
                );
                return {
                  document,
                  type,
                  page:
                    type !== SearchDocumentType.Title &&
                    wrappedIndexes[0].documents.find(
                      (doc) => doc.i === document.p
                    ),
                  metadata: result.matchData.metadata,
                  tokens,
                  score: result.score,
                };
              })
          );
          if (results.length >= searchResultLimits) {
            break search;
          }
        }
      }
      sortSearchResults(results);
      processTreeStatusOfSearchResults(results);
      return results;
    }
  }
  async function legacyFetchIndexes(baseUrl, searchContext) {
    const url = `${baseUrl}${searchIndexUrl.replace(
      "{dir}",
      searchContext ? `-${searchContext.replace(/\//g, "-")}` : ""
    )}`;
    // Catch potential attacks.
    const fullUrl = new URL(url, "https://cdnd.selectdb.com");
    // if (fullUrl.origin !== location.origin) {
    //     throw new Error("Unexpected version url");
    // }
    const json = await (await fetch(fullUrl)).json();
    const wrappedIndexes = json.map(({ documents, index }, type) => ({
      type: type,
      documents,
      index: lunr.Index.load(index),
    }));
    const zhDictionary = json.reduce((acc, item) => {
      for (const tuple of item.index.invertedIndex) {
        if (/\p{Unified_Ideograph}/u.test(tuple[0][0])) {
          acc.add(tuple[0]);
        }
      }
      return acc;
    }, new Set());
    return {
      wrappedIndexes,
      zhDictionary: Array.from(zhDictionary),
    };
  }
  expose(SearchWorker);

  exports.SearchWorker = SearchWorker;

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

  return exports;
})({});