Added Icefish Branchicefish_9.0.4icefish/9.0.49.0.4icefish

Meta redirects to http://old-docs.automotivelinux.org/docs/en/icefish/getting_started/

Bug-AGL: [SPEC-3633]

Signed-off-by: Shankho Boron Ghosh <shankhoghosh123@gmail.com>
Change-Id: Ie6bfbc5821b8c158fb92a076d143d8e495ac5d89
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/documentation/+/25509
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Tested-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>

1 files changed, 2485 insertions, 0 deletions

diff --git a/theme/mkdocs_windmill/js/elasticlunr.js b/theme/mkdocs_windmill/js/elasticlunr.js
new file mode 100644
index 0000000..46302e1
--- /dev/null
+++ b/theme/mkdocs_windmill/js/elasticlunr.js
@@ -0,0 +1,2485 @@
+/**
+ * elasticlunr - http://weixsong.github.io
+ * Lightweight full-text search engine in Javascript for browser search and offline search. - 0.9.5
+ *
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ * MIT Licensed
+ * @license
+ */
+
+(function(){
+
+/*!
+ * elasticlunr.js
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * Convenience function for instantiating a new elasticlunr index and configuring it
+ * with the default pipeline functions and the passed config function.
+ *
+ * When using this convenience function a new index will be created with the
+ * following functions already in the pipeline:
+ *
+ * 1. elasticlunr.trimmer - trim non-word character
+ * 2. elasticlunr.StopWordFilter - filters out any stop words before they enter the
+ * index
+ * 3. elasticlunr.stemmer - stems the tokens before entering the index.
+ *
+ *
+ * Example:
+ *
+ *     var idx = elasticlunr(function () {
+ *       this.addField('id');
+ *       this.addField('title');
+ *       this.addField('body');
+ *
+ *       //this.setRef('id'); // default ref is 'id'
+ *
+ *       this.pipeline.add(function () {
+ *         // some custom pipeline function
+ *       });
+ *     });
+ *
+ *    idx.addDoc({
+ *      id: 1,
+ *      title: 'Oracle released database 12g',
+ *      body: 'Yestaday, Oracle has released their latest database, named 12g, more robust. this product will increase Oracle profit.'
+ *    });
+ *
+ *    idx.addDoc({
+ *      id: 2,
+ *      title: 'Oracle released annual profit report',
+ *      body: 'Yestaday, Oracle has released their annual profit report of 2015, total profit is 12.5 Billion.'
+ *    });
+ *
+ *    # simple search
+ *    idx.search('oracle database');
+ *
+ *    # search with query-time boosting
+ *    idx.search('oracle database', {fields: {title: {boost: 2}, body: {boost: 1}}});
+ *
+ * @param {Function} config A function that will be called with the new instance
+ * of the elasticlunr.Index as both its context and first parameter. It can be used to
+ * customize the instance of new elasticlunr.Index.
+ * @namespace
+ * @module
+ * @return {elasticlunr.Index}
+ *
+ */
+var elasticlunr = function (config) {
+  var idx = new elasticlunr.Index;
+
+  idx.pipeline.add(
+    elasticlunr.trimmer,
+    elasticlunr.stopWordFilter,
+    elasticlunr.stemmer
+  );
+
+  if (config) config.call(idx, idx);
+
+  return idx;
+};
+
+elasticlunr.version = "0.9.5";
+
+// only used this to make elasticlunr.js compatible with lunr-languages
+// this is a trick to define a global alias of elasticlunr
+lunr = elasticlunr;
+
+/*!
+ * elasticlunr.utils
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * A namespace containing utils for the rest of the elasticlunr library
+ */
+elasticlunr.utils = {};
+
+/**
+ * Print a warning message to the console.
+ *
+ * @param {String} message The message to be printed.
+ * @memberOf Utils
+ */
+elasticlunr.utils.warn = (function (global) {
+  return function (message) {
+    if (global.console && console.warn) {
+      console.warn(message);
+    }
+  };
+})(this);
+
+/**
+ * Convert an object to string.
+ *
+ * In the case of `null` and `undefined` the function returns
+ * an empty string, in all other cases the result of calling
+ * `toString` on the passed object is returned.
+ *
+ * @param {object} obj The object to convert to a string.
+ * @return {String} string representation of the passed object.
+ * @memberOf Utils
+ */
+elasticlunr.utils.toString = function (obj) {
+  if (obj === void 0 || obj === null) {
+    return "";
+  }
+
+  return obj.toString();
+};
+/*!
+ * elasticlunr.EventEmitter
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * elasticlunr.EventEmitter is an event emitter for elasticlunr.
+ * It manages adding and removing event handlers and triggering events and their handlers.
+ *
+ * Each event could has multiple corresponding functions,
+ * these functions will be called as the sequence that they are added into the event.
+ *
+ * @constructor
+ */
+elasticlunr.EventEmitter = function () {
+  this.events = {};
+};
+
+/**
+ * Binds a handler function to a specific event(s).
+ *
+ * Can bind a single function to many different events in one call.
+ *
+ * @param {String} [eventName] The name(s) of events to bind this function to.
+ * @param {Function} fn The function to call when an event is fired.
+ * @memberOf EventEmitter
+ */
+elasticlunr.EventEmitter.prototype.addListener = function () {
+  var args = Array.prototype.slice.call(arguments),
+      fn = args.pop(),
+      names = args;
+
+  if (typeof fn !== "function") throw new TypeError ("last argument must be a function");
+
+  names.forEach(function (name) {
+    if (!this.hasHandler(name)) this.events[name] = [];
+    this.events[name].push(fn);
+  }, this);
+};
+
+/**
+ * Removes a handler function from a specific event.
+ *
+ * @param {String} eventName The name of the event to remove this function from.
+ * @param {Function} fn The function to remove from an event.
+ * @memberOf EventEmitter
+ */
+elasticlunr.EventEmitter.prototype.removeListener = function (name, fn) {
+  if (!this.hasHandler(name)) return;
+
+  var fnIndex = this.events[name].indexOf(fn);
+  if (fnIndex === -1) return;
+
+  this.events[name].splice(fnIndex, 1);
+
+  if (this.events[name].length == 0) delete this.events[name];
+};
+
+/**
+ * Call all functions that bounded to the given event.
+ *
+ * Additional data can be passed to the event handler as arguments to `emit`
+ * after the event name.
+ *
+ * @param {String} eventName The name of the event to emit.
+ * @memberOf EventEmitter
+ */
+elasticlunr.EventEmitter.prototype.emit = function (name) {
+  if (!this.hasHandler(name)) return;
+
+  var args = Array.prototype.slice.call(arguments, 1);
+
+  this.events[name].forEach(function (fn) {
+    fn.apply(undefined, args);
+  }, this);
+};
+
+/**
+ * Checks whether a handler has ever been stored against an event.
+ *
+ * @param {String} eventName The name of the event to check.
+ * @private
+ * @memberOf EventEmitter
+ */
+elasticlunr.EventEmitter.prototype.hasHandler = function (name) {
+  return name in this.events;
+};
+/*!
+ * elasticlunr.tokenizer
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * A function for splitting a string into tokens.
+ * Currently English is supported as default.
+ * Uses `elasticlunr.tokenizer.seperator` to split strings, you could change
+ * the value of this property to set how you want strings are split into tokens.
+ * IMPORTANT: use elasticlunr.tokenizer.seperator carefully, if you are not familiar with
+ * text process, then you'd better not change it.
+ *
+ * @module
+ * @param {String} str The string that you want to tokenize.
+ * @see elasticlunr.tokenizer.seperator
+ * @return {Array}
+ */
+elasticlunr.tokenizer = function (str) {
+  if (!arguments.length || str === null || str === undefined) return [];
+  if (Array.isArray(str)) {
+    var arr = str.filter(function(token) {
+      if (token === null || token === undefined) {
+        return false;
+      }
+
+      return true;
+    });
+
+    arr = arr.map(function (t) {
+      return elasticlunr.utils.toString(t).toLowerCase();
+    });
+
+    var out = [];
+    arr.forEach(function(item) {
+      var tokens = item.split(elasticlunr.tokenizer.seperator);
+      out = out.concat(tokens);
+    }, this);
+
+    return out;
+  }
+
+  return str.toString().trim().toLowerCase().split(elasticlunr.tokenizer.seperator);
+};
+
+/**
+ * Default string seperator.
+ */
+elasticlunr.tokenizer.defaultSeperator = /[\s\-]+/;
+
+/**
+ * The sperator used to split a string into tokens. Override this property to change the behaviour of
+ * `elasticlunr.tokenizer` behaviour when tokenizing strings. By default this splits on whitespace and hyphens.
+ *
+ * @static
+ * @see elasticlunr.tokenizer
+ */
+elasticlunr.tokenizer.seperator = elasticlunr.tokenizer.defaultSeperator;
+
+/**
+ * Set up customized string seperator
+ *
+ * @param {Object} sep The customized seperator that you want to use to tokenize a string.
+ */
+elasticlunr.tokenizer.setSeperator = function(sep) {
+    if (sep !== null && sep !== undefined && typeof(sep) === 'object') {
+        elasticlunr.tokenizer.seperator = sep;
+    }
+}
+
+/**
+ * Reset string seperator
+ *
+ */
+elasticlunr.tokenizer.resetSeperator = function() {
+    elasticlunr.tokenizer.seperator = elasticlunr.tokenizer.defaultSeperator;
+}
+
+/**
+ * Get string seperator
+ *
+ */
+elasticlunr.tokenizer.getSeperator = function() {
+    return elasticlunr.tokenizer.seperator;
+}
+/*!
+ * elasticlunr.Pipeline
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * elasticlunr.Pipelines maintain an ordered list of functions to be applied to
+ * both documents tokens and query tokens.
+ *
+ * An instance of elasticlunr.Index will contain a pipeline
+ * with a trimmer, a stop word filter, an English stemmer. Extra
+ * functions can be added before or after either of these functions or these
+ * default functions can be removed.
+ *
+ * When run the pipeline, it will call each function in turn.
+ *
+ * The output of the 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 elasticlunr.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
+ */
+elasticlunr.Pipeline = function () {
+  this._queue = [];
+};
+
+elasticlunr.Pipeline.registeredFunctions = {};
+
+/**
+ * Register a function in 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 {Function} fn The function to register.
+ * @param {String} label The label to register this function with
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.registerFunction = function (fn, label) {
+  if (label in elasticlunr.Pipeline.registeredFunctions) {
+    elasticlunr.utils.warn('Overwriting existing registered function: ' + label);
+  }
+
+  fn.label = label;
+  elasticlunr.Pipeline.registeredFunctions[label] = fn;
+};
+
+/**
+ * Get a registered function in the pipeline.
+ *
+ * @param {String} label The label of registered function.
+ * @return {Function}
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.getRegisteredFunction = function (label) {
+  if ((label in elasticlunr.Pipeline.registeredFunctions) !== true) {
+    return null;
+  }
+
+  return elasticlunr.Pipeline.registeredFunctions[label];
+};
+
+/**
+ * Warns if the function is not registered as a Pipeline function.
+ *
+ * @param {Function} fn The function to check for.
+ * @private
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.warnIfFunctionNotRegistered = function (fn) {
+  var isRegistered = fn.label && (fn.label in this.registeredFunctions);
+
+  if (!isRegistered) {
+    elasticlunr.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 elasticlunr.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.
+ * @return {elasticlunr.Pipeline}
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.load = function (serialised) {
+  var pipeline = new elasticlunr.Pipeline;
+
+  serialised.forEach(function (fnName) {
+    var fn = elasticlunr.Pipeline.getRegisteredFunction(fnName);
+
+    if (fn) {
+      pipeline.add(fn);
+    } else {
+      throw new Error('Cannot load un-registered function: ' + fnName);
+    }
+  });
+
+  return pipeline;
+};
+
+/**
+ * Adds new functions to the end of the pipeline.
+ *
+ * Logs a warning if the function has not been registered.
+ *
+ * @param {Function} functions Any number of functions to add to the pipeline.
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.prototype.add = function () {
+  var fns = Array.prototype.slice.call(arguments);
+
+  fns.forEach(function (fn) {
+    elasticlunr.Pipeline.warnIfFunctionNotRegistered(fn);
+    this._queue.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.
+ * If existingFn is not found, throw an Exception.
+ *
+ * @param {Function} existingFn A function that already exists in the pipeline.
+ * @param {Function} newFn The new function to add to the pipeline.
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.prototype.after = function (existingFn, newFn) {
+  elasticlunr.Pipeline.warnIfFunctionNotRegistered(newFn);
+
+  var pos = this._queue.indexOf(existingFn);
+  if (pos === -1) {
+    throw new Error('Cannot find existingFn');
+  }
+
+  this._queue.splice(pos + 1, 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.
+ * If existingFn is not found, throw an Exception.
+ *
+ * @param {Function} existingFn A function that already exists in the pipeline.
+ * @param {Function} newFn The new function to add to the pipeline.
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.prototype.before = function (existingFn, newFn) {
+  elasticlunr.Pipeline.warnIfFunctionNotRegistered(newFn);
+
+  var pos = this._queue.indexOf(existingFn);
+  if (pos === -1) {
+    throw new Error('Cannot find existingFn');
+  }
+
+  this._queue.splice(pos, 0, newFn);
+};
+
+/**
+ * Removes a function from the pipeline.
+ *
+ * @param {Function} fn The function to remove from the pipeline.
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.prototype.remove = function (fn) {
+  var pos = this._queue.indexOf(fn);
+  if (pos === -1) {
+    return;
+  }
+
+  this._queue.splice(pos, 1);
+};
+
+/**
+ * Runs the current list of functions that registered in the pipeline against the
+ * input tokens.
+ *
+ * @param {Array} tokens The tokens to run through the pipeline.
+ * @return {Array}
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.prototype.run = function (tokens) {
+  var out = [],
+      tokenLength = tokens.length,
+      pipelineLength = this._queue.length;
+
+  for (var i = 0; i < tokenLength; i++) {
+    var token = tokens[i];
+
+    for (var j = 0; j < pipelineLength; j++) {
+      token = this._queue[j](token, i, tokens);
+      if (token === void 0 || token === null) break;
+    };
+
+    if (token !== void 0 && token !== null) out.push(token);
+  };
+
+  return out;
+};
+
+/**
+ * Resets the pipeline by removing any existing processors.
+ *
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.prototype.reset = function () {
+  this._queue = [];
+};
+
+ /**
+  * Get the pipeline if user want to check the pipeline.
+  *
+  * @memberOf Pipeline
+  */
+ elasticlunr.Pipeline.prototype.get = function () {
+   return this._queue;
+ };
+
+/**
+ * Returns a representation of the pipeline ready for serialisation.
+ * Only serialize pipeline function's name. Not storing function, so when
+ * loading the archived JSON index file, corresponding pipeline function is
+ * added by registered function of elasticlunr.Pipeline.registeredFunctions
+ *
+ * Logs a warning if the function has not been registered.
+ *
+ * @return {Array}
+ * @memberOf Pipeline
+ */
+elasticlunr.Pipeline.prototype.toJSON = function () {
+  return this._queue.map(function (fn) {
+    elasticlunr.Pipeline.warnIfFunctionNotRegistered(fn);
+    return fn.label;
+  });
+};
+/*!
+ * elasticlunr.Index
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * elasticlunr.Index is object that manages a search index.  It contains the indexes
+ * and stores all the tokens and document lookups.  It also provides the main
+ * user facing API for the library.
+ *
+ * @constructor
+ */
+elasticlunr.Index = function () {
+  this._fields = [];
+  this._ref = 'id';
+  this.pipeline = new elasticlunr.Pipeline;
+  this.documentStore = new elasticlunr.DocumentStore;
+  this.index = {};
+  this.eventEmitter = new elasticlunr.EventEmitter;
+  this._idfCache = {};
+
+  this.on('add', 'remove', 'update', (function () {
+    this._idfCache = {};
+  }).bind(this));
+};
+
+/**
+ * Bind a handler to events being emitted by the index.
+ *
+ * The handler can be bound to many events at the same time.
+ *
+ * @param {String} [eventName] The name(s) of events to bind the function to.
+ * @param {Function} fn The serialised set to load.
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.on = function () {
+  var args = Array.prototype.slice.call(arguments);
+  return this.eventEmitter.addListener.apply(this.eventEmitter, args);
+};
+
+/**
+ * Removes a handler from an event being emitted by the index.
+ *
+ * @param {String} eventName The name of events to remove the function from.
+ * @param {Function} fn The serialised set to load.
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.off = function (name, fn) {
+  return this.eventEmitter.removeListener(name, fn);
+};
+
+/**
+ * Loads a previously serialised index.
+ *
+ * Issues a warning if the index being imported was serialised
+ * by a different version of elasticlunr.
+ *
+ * @param {Object} serialisedData The serialised set to load.
+ * @return {elasticlunr.Index}
+ * @memberOf Index
+ */
+elasticlunr.Index.load = function (serialisedData) {
+  if (serialisedData.version !== elasticlunr.version) {
+    elasticlunr.utils.warn('version mismatch: current '
+                    + elasticlunr.version + ' importing ' + serialisedData.version);
+  }
+
+  var idx = new this;
+
+  idx._fields = serialisedData.fields;
+  idx._ref = serialisedData.ref;
+  idx.documentStore = elasticlunr.DocumentStore.load(serialisedData.documentStore);
+  idx.pipeline = elasticlunr.Pipeline.load(serialisedData.pipeline);
+  idx.index = {};
+  for (var field in serialisedData.index) {
+    idx.index[field] = elasticlunr.InvertedIndex.load(serialisedData.index[field]);
+  }
+
+  return idx;
+};
+
+/**
+ * Adds a field to the list of fields that will be searchable within documents in the index.
+ *
+ * Remember that inner index is build based on field, which means each field has one inverted index.
+ *
+ * Fields should be added before any documents are added to the index, fields
+ * that are added after documents are added to the index will only apply to new
+ * documents added to the index.
+ *
+ * @param {String} fieldName The name of the field within the document that should be indexed
+ * @return {elasticlunr.Index}
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.addField = function (fieldName) {
+  this._fields.push(fieldName);
+  this.index[fieldName] = new elasticlunr.InvertedIndex;
+  return this;
+};
+
+/**
+ * Sets the property used to uniquely identify documents added to the index,
+ * by default this property is 'id'.
+ *
+ * This should only be changed before adding documents to the index, changing
+ * the ref property without resetting the index can lead to unexpected results.
+ *
+ * @param {String} refName The property to use to uniquely identify the
+ * documents in the index.
+ * @param {Boolean} emitEvent Whether to emit add events, defaults to true
+ * @return {elasticlunr.Index}
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.setRef = function (refName) {
+  this._ref = refName;
+  return this;
+};
+
+/**
+ *
+ * Set if the JSON format original documents are save into elasticlunr.DocumentStore
+ *
+ * Defaultly save all the original JSON documents.
+ *
+ * @param {Boolean} save Whether to save the original JSON documents.
+ * @return {elasticlunr.Index}
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.saveDocument = function (save) {
+  this.documentStore = new elasticlunr.DocumentStore(save);
+  return this;
+};
+
+/**
+ * Add a JSON format document to the index.
+ *
+ * This is the way new documents enter the index, this function will run the
+ * fields from the document through the index's pipeline and then add it to
+ * the index, it will then show up in search results.
+ *
+ * An 'add' event is emitted with the document that has been added and the index
+ * the document has been added to. This event can be silenced by passing false
+ * as the second argument to add.
+ *
+ * @param {Object} doc The JSON format document to add to the index.
+ * @param {Boolean} emitEvent Whether or not to emit events, default true.
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.addDoc = function (doc, emitEvent) {
+  if (!doc) return;
+  var emitEvent = emitEvent === undefined ? true : emitEvent;
+
+  var docRef = doc[this._ref];
+
+  this.documentStore.addDoc(docRef, doc);
+  this._fields.forEach(function (field) {
+    var fieldTokens = this.pipeline.run(elasticlunr.tokenizer(doc[field]));
+    this.documentStore.addFieldLength(docRef, field, fieldTokens.length);
+
+    var tokenCount = {};
+    fieldTokens.forEach(function (token) {
+      if (token in tokenCount) tokenCount[token] += 1;
+      else tokenCount[token] = 1;
+    }, this);
+
+    for (var token in tokenCount) {
+      var termFrequency = tokenCount[token];
+      termFrequency = Math.sqrt(termFrequency);
+      this.index[field].addToken(token, { ref: docRef, tf: termFrequency });
+    }
+  }, this);
+
+  if (emitEvent) this.eventEmitter.emit('add', doc, this);
+};
+
+/**
+ * Removes a document from the index by doc ref.
+ *
+ * To make sure documents no longer show up in search results they can be
+ * removed from the index using this method.
+ *
+ * A 'remove' event is emitted with the document that has been removed and the index
+ * the document has been removed from. This event can be silenced by passing false
+ * as the second argument to remove.
+ *
+ * If user setting DocumentStore not storing the documents, then remove doc by docRef is not allowed.
+ *
+ * @param {String|Integer} docRef The document ref to remove from the index.
+ * @param {Boolean} emitEvent Whether to emit remove events, defaults to true
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.removeDocByRef = function (docRef, emitEvent) {
+  if (!docRef) return;
+  if (this.documentStore.isDocStored() === false) {
+    return;
+  }
+
+  if (!this.documentStore.hasDoc(docRef)) return;
+  var doc = this.documentStore.getDoc(docRef);
+  this.removeDoc(doc, false);
+};
+
+/**
+ * Removes a document from the index.
+ * This remove operation could work even the original doc is not store in the DocumentStore.
+ *
+ * To make sure documents no longer show up in search results they can be
+ * removed from the index using this method.
+ *
+ * A 'remove' event is emitted with the document that has been removed and the index
+ * the document has been removed from. This event can be silenced by passing false
+ * as the second argument to remove.
+ *
+ *
+ * @param {Object} doc The document ref to remove from the index.
+ * @param {Boolean} emitEvent Whether to emit remove events, defaults to true
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.removeDoc = function (doc, emitEvent) {
+  if (!doc) return;
+
+  var emitEvent = emitEvent === undefined ? true : emitEvent;
+
+  var docRef = doc[this._ref];
+  if (!this.documentStore.hasDoc(docRef)) return;
+
+  this.documentStore.removeDoc(docRef);
+
+  this._fields.forEach(function (field) {
+    var fieldTokens = this.pipeline.run(elasticlunr.tokenizer(doc[field]));
+    fieldTokens.forEach(function (token) {
+      this.index[field].removeToken(token, docRef);
+    }, this);
+  }, this);
+
+  if (emitEvent) this.eventEmitter.emit('remove', doc, this);
+};
+
+/**
+ * Updates a document in the index.
+ *
+ * When a document contained within the index gets updated, fields changed,
+ * added or removed, to make sure it correctly matched against search queries,
+ * it should be updated in the index.
+ *
+ * This method is just a wrapper around `remove` and `add`
+ *
+ * An 'update' event is emitted with the document that has been updated and the index.
+ * This event can be silenced by passing false as the second argument to update. Only
+ * an update event will be fired, the 'add' and 'remove' events of the underlying calls
+ * are silenced.
+ *
+ * @param {Object} doc The document to update in the index.
+ * @param {Boolean} emitEvent Whether to emit update events, defaults to true
+ * @see Index.prototype.remove
+ * @see Index.prototype.add
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.updateDoc = function (doc, emitEvent) {
+  var emitEvent = emitEvent === undefined ? true : emitEvent;
+
+  this.removeDocByRef(doc[this._ref], false);
+  this.addDoc(doc, false);
+
+  if (emitEvent) this.eventEmitter.emit('update', doc, this);
+};
+
+/**
+ * Calculates the inverse document frequency for a token within the index of a field.
+ *
+ * @param {String} token The token to calculate the idf of.
+ * @param {String} field The field to compute idf.
+ * @see Index.prototype.idf
+ * @private
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.idf = function (term, field) {
+  var cacheKey = "@" + field + '/' + term;
+  if (Object.prototype.hasOwnProperty.call(this._idfCache, cacheKey)) return this._idfCache[cacheKey];
+
+  var df = this.index[field].getDocFreq(term);
+  var idf = 1 + Math.log(this.documentStore.length / (df + 1));
+  this._idfCache[cacheKey] = idf;
+
+  return idf;
+};
+
+/**
+ * get fields of current index instance
+ *
+ * @return {Array}
+ */
+elasticlunr.Index.prototype.getFields = function () {
+  return this._fields.slice();
+};
+
+/**
+ * Searches the index using the passed query.
+ * Queries should be a string, multiple words are allowed.
+ *
+ * If config is null, will search all fields defaultly, and lead to OR based query.
+ * If config is specified, will search specified with query time boosting.
+ *
+ * All query tokens are passed through the same pipeline that document tokens
+ * are passed through, so any language processing involved will be run on every
+ * query term.
+ *
+ * Each query term is expanded, so that the term 'he' might be expanded to
+ * 'hello' and 'help' if those terms were already included in the index.
+ *
+ * Matching documents are returned as an array of objects, each object contains
+ * the matching document ref, as set for this index, and the similarity score
+ * for this document against the query.
+ *
+ * @param {String} query The query to search the index with.
+ * @param {JSON} userConfig The user query config, JSON format.
+ * @return {Object}
+ * @see Index.prototype.idf
+ * @see Index.prototype.documentVector
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.search = function (query, userConfig) {
+  if (!query) return [];
+
+  var configStr = null;
+  if (userConfig != null) {
+    configStr = JSON.stringify(userConfig);
+  }
+
+  var config = new elasticlunr.Configuration(configStr, this.getFields()).get();
+
+  var queryTokens = this.pipeline.run(elasticlunr.tokenizer(query));
+
+  var queryResults = {};
+
+  for (var field in config) {
+    var fieldSearchResults = this.fieldSearch(queryTokens, field, config);
+    var fieldBoost = config[field].boost;
+
+    for (var docRef in fieldSearchResults) {
+      fieldSearchResults[docRef] = fieldSearchResults[docRef] * fieldBoost;
+    }
+
+    for (var docRef in fieldSearchResults) {
+      if (docRef in queryResults) {
+        queryResults[docRef] += fieldSearchResults[docRef];
+      } else {
+        queryResults[docRef] = fieldSearchResults[docRef];
+      }
+    }
+  }
+
+  var results = [];
+  for (var docRef in queryResults) {
+    results.push({ref: docRef, score: queryResults[docRef]});
+  }
+
+  results.sort(function (a, b) { return b.score - a.score; });
+  return results;
+};
+
+/**
+ * search queryTokens in specified field.
+ *
+ * @param {Array} queryTokens The query tokens to query in this field.
+ * @param {String} field Field to query in.
+ * @param {elasticlunr.Configuration} config The user query config, JSON format.
+ * @return {Object}
+ */
+elasticlunr.Index.prototype.fieldSearch = function (queryTokens, fieldName, config) {
+  var booleanType = config[fieldName].bool;
+  var expand = config[fieldName].expand;
+  var boost = config[fieldName].boost;
+  var scores = null;
+  var docTokens = {};
+
+  // Do nothing if the boost is 0
+  if (boost === 0) {
+    return;
+  }
+
+  queryTokens.forEach(function (token) {
+    var tokens = [token];
+    if (expand == true) {
+      tokens = this.index[fieldName].expandToken(token);
+    }
+    // Consider every query token in turn. If expanded, each query token
+    // corresponds to a set of tokens, which is all tokens in the
+    // index matching the pattern queryToken* .
+    // For the set of tokens corresponding to a query token, find and score
+    // all matching documents. Store those scores in queryTokenScores,
+    // keyed by docRef.
+    // Then, depending on the value of booleanType, combine the scores
+    // for this query token with previous scores.  If booleanType is OR,
+    // then merge the scores by summing into the accumulated total, adding
+    // new document scores are required (effectively a union operator).
+    // If booleanType is AND, accumulate scores only if the document
+    // has previously been scored by another query token (an intersection
+    // operation0.
+    // Furthermore, since when booleanType is AND, additional
+    // query tokens can't add new documents to the result set, use the
+    // current document set to limit the processing of each new query
+    // token for efficiency (i.e., incremental intersection).
+
+    var queryTokenScores = {};
+    tokens.forEach(function (key) {
+      var docs = this.index[fieldName].getDocs(key);
+      var idf = this.idf(key, fieldName);
+
+      if (scores && booleanType == 'AND') {
+          // special case, we can rule out documents that have been
+          // already been filtered out because they weren't scored
+          // by previous query token passes.
+          var filteredDocs = {};
+          for (var docRef in scores) {
+              if (docRef in docs) {
+                  filteredDocs[docRef] = docs[docRef];
+              }
+          }
+          docs = filteredDocs;
+      }
+      // only record appeared token for retrieved documents for the
+      // original token, not for expaned token.
+      // beause for doing coordNorm for a retrieved document, coordNorm only care how many
+      // query token appear in that document.
+      // so expanded token should not be added into docTokens, if added, this will pollute the
+      // coordNorm
+      if (key == token) {
+        this.fieldSearchStats(docTokens, key, docs);
+      }
+
+      for (var docRef in docs) {
+        var tf = this.index[fieldName].getTermFrequency(key, docRef);
+        var fieldLength = this.documentStore.getFieldLength(docRef, fieldName);
+        var fieldLengthNorm = 1;
+        if (fieldLength != 0) {
+          fieldLengthNorm = 1 / Math.sqrt(fieldLength);
+        }
+
+        var penality = 1;
+        if (key != token) {
+          // currently I'm not sure if this penality is enough,
+          // need to do verification
+          penality = (1 - (key.length - token.length) / key.length) * 0.15;
+        }
+
+        var score = tf * idf * fieldLengthNorm * penality;
+
+        if (docRef in queryTokenScores) {
+          queryTokenScores[docRef] += score;
+        } else {
+          queryTokenScores[docRef] = score;
+        }
+      }
+    }, this);
+
+    scores = this.mergeScores(scores, queryTokenScores, booleanType);
+  }, this);
+
+  scores = this.coordNorm(scores, docTokens, queryTokens.length);
+  return scores;
+};
+
+/**
+ * Merge the scores from one set of tokens into an accumulated score table.
+ * Exact operation depends on the op parameter. If op is 'AND', then only the
+ * intersection of the two score lists is retained. Otherwise, the union of
+ * the two score lists is returned. For internal use only.
+ *
+ * @param {Object} bool accumulated scores. Should be null on first call.
+ * @param {String} scores new scores to merge into accumScores.
+ * @param {Object} op merge operation (should be 'AND' or 'OR').
+ *
+ */
+
+elasticlunr.Index.prototype.mergeScores = function (accumScores, scores, op) {
+    if (!accumScores) {
+        return scores;
+    }
+    if (op == 'AND') {
+        var intersection = {};
+        for (var docRef in scores) {
+            if (docRef in accumScores) {
+                intersection[docRef] = accumScores[docRef] + scores[docRef];
+            }
+        }
+        return intersection;
+    } else {
+        for (var docRef in scores) {
+            if (docRef in accumScores) {
+                accumScores[docRef] += scores[docRef];
+            } else {
+                accumScores[docRef] = scores[docRef];
+            }
+        }
+        return accumScores;
+    }
+};
+
+
+/**
+ * Record the occuring query token of retrieved doc specified by doc field.
+ * Only for inner user.
+ *
+ * @param {Object} docTokens a data structure stores which token appears in the retrieved doc.
+ * @param {String} token query token
+ * @param {Object} docs the retrieved documents of the query token
+ *
+ */
+elasticlunr.Index.prototype.fieldSearchStats = function (docTokens, token, docs) {
+  for (var doc in docs) {
+    if (doc in docTokens) {
+      docTokens[doc].push(token);
+    } else {
+      docTokens[doc] = [token];
+    }
+  }
+};
+
+/**
+ * coord norm the score of a doc.
+ * if a doc contain more query tokens, then the score will larger than the doc
+ * contains less query tokens.
+ *
+ * only for inner use.
+ *
+ * @param {Object} results first results
+ * @param {Object} docs field search results of a token
+ * @param {Integer} n query token number
+ * @return {Object}
+ */
+elasticlunr.Index.prototype.coordNorm = function (scores, docTokens, n) {
+  for (var doc in scores) {
+    if (!(doc in docTokens)) continue;
+    var tokens = docTokens[doc].length;
+    scores[doc] = scores[doc] * tokens / n;
+  }
+
+  return scores;
+};
+
+/**
+ * Returns a representation of the index ready for serialisation.
+ *
+ * @return {Object}
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.toJSON = function () {
+  var indexJson = {};
+  this._fields.forEach(function (field) {
+    indexJson[field] = this.index[field].toJSON();
+  }, this);
+
+  return {
+    version: elasticlunr.version,
+    fields: this._fields,
+    ref: this._ref,
+    documentStore: this.documentStore.toJSON(),
+    index: indexJson,
+    pipeline: this.pipeline.toJSON()
+  };
+};
+
+/**
+ * Applies a plugin to the current index.
+ *
+ * A plugin is a function that is called with the index as its context.
+ * Plugins can be used to customise or extend the behaviour the index
+ * in some way. A plugin is just a function, that encapsulated the custom
+ * behaviour that should be applied to the index.
+ *
+ * The plugin function will be called with the index as its argument, additional
+ * arguments can also be passed when calling use. The function will be called
+ * with the index as its context.
+ *
+ * Example:
+ *
+ *     var myPlugin = function (idx, arg1, arg2) {
+ *       // `this` is the index to be extended
+ *       // apply any extensions etc here.
+ *     }
+ *
+ *     var idx = elasticlunr(function () {
+ *       this.use(myPlugin, 'arg1', 'arg2')
+ *     })
+ *
+ * @param {Function} plugin The plugin to apply.
+ * @memberOf Index
+ */
+elasticlunr.Index.prototype.use = function (plugin) {
+  var args = Array.prototype.slice.call(arguments, 1);
+  args.unshift(this);
+  plugin.apply(this, args);
+};
+/*!
+ * elasticlunr.DocumentStore
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * elasticlunr.DocumentStore is a simple key-value document store used for storing sets of tokens for
+ * documents stored in index.
+ *
+ * elasticlunr.DocumentStore store original JSON format documents that you could build search snippet by this original JSON document.
+ *
+ * user could choose whether original JSON format document should be store, if no configuration then document will be stored defaultly.
+ * If user care more about the index size, user could select not store JSON documents, then this will has some defects, such as user
+ * could not use JSON document to generate snippets of search results.
+ *
+ * @param {Boolean} save If the original JSON document should be stored.
+ * @constructor
+ * @module
+ */
+elasticlunr.DocumentStore = function (save) {
+  if (save === null || save === undefined) {
+    this._save = true;
+  } else {
+    this._save = save;
+  }
+
+  this.docs = {};
+  this.docInfo = {};
+  this.length = 0;
+};
+
+/**
+ * Loads a previously serialised document store
+ *
+ * @param {Object} serialisedData The serialised document store to load.
+ * @return {elasticlunr.DocumentStore}
+ */
+elasticlunr.DocumentStore.load = function (serialisedData) {
+  var store = new this;
+
+  store.length = serialisedData.length;
+  store.docs = serialisedData.docs;
+  store.docInfo = serialisedData.docInfo;
+  store._save = serialisedData.save;
+
+  return store;
+};
+
+/**
+ * check if current instance store the original doc
+ *
+ * @return {Boolean}
+ */
+elasticlunr.DocumentStore.prototype.isDocStored = function () {
+  return this._save;
+};
+
+/**
+ * Stores the given doc in the document store against the given id.
+ * If docRef already exist, then update doc.
+ *
+ * Document is store by original JSON format, then you could use original document to generate search snippets.
+ *
+ * @param {Integer|String} docRef The key used to store the JSON format doc.
+ * @param {Object} doc The JSON format doc.
+ */
+elasticlunr.DocumentStore.prototype.addDoc = function (docRef, doc) {
+  if (!this.hasDoc(docRef)) this.length++;
+
+  if (this._save === true) {
+    this.docs[docRef] = clone(doc);
+  } else {
+    this.docs[docRef] = null;
+  }
+};
+
+/**
+ * Retrieves the JSON doc from the document store for a given key.
+ *
+ * If docRef not found, return null.
+ * If user set not storing the documents, return null.
+ *
+ * @param {Integer|String} docRef The key to lookup and retrieve from the document store.
+ * @return {Object}
+ * @memberOf DocumentStore
+ */
+elasticlunr.DocumentStore.prototype.getDoc = function (docRef) {
+  if (this.hasDoc(docRef) === false) return null;
+  return this.docs[docRef];
+};
+
+/**
+ * Checks whether the document store contains a key (docRef).
+ *
+ * @param {Integer|String} docRef The id to look up in the document store.
+ * @return {Boolean}
+ * @memberOf DocumentStore
+ */
+elasticlunr.DocumentStore.prototype.hasDoc = function (docRef) {
+  return docRef in this.docs;
+};
+
+/**
+ * Removes the value for a key in the document store.
+ *
+ * @param {Integer|String} docRef The id to remove from the document store.
+ * @memberOf DocumentStore
+ */
+elasticlunr.DocumentStore.prototype.removeDoc = function (docRef) {
+  if (!this.hasDoc(docRef)) return;
+
+  delete this.docs[docRef];
+  delete this.docInfo[docRef];
+  this.length--;
+};
+
+/**
+ * Add field length of a document's field tokens from pipeline results.
+ * The field length of a document is used to do field length normalization even without the original JSON document stored.
+ *
+ * @param {Integer|String} docRef document's id or reference
+ * @param {String} fieldName field name
+ * @param {Integer} length field length
+ */
+elasticlunr.DocumentStore.prototype.addFieldLength = function (docRef, fieldName, length) {
+  if (docRef === null || docRef === undefined) return;
+  if (this.hasDoc(docRef) == false) return;
+
+  if (!this.docInfo[docRef]) this.docInfo[docRef] = {};
+  this.docInfo[docRef][fieldName] = length;
+};
+
+/**
+ * Update field length of a document's field tokens from pipeline results.
+ * The field length of a document is used to do field length normalization even without the original JSON document stored.
+ *
+ * @param {Integer|String} docRef document's id or reference
+ * @param {String} fieldName field name
+ * @param {Integer} length field length
+ */
+elasticlunr.DocumentStore.prototype.updateFieldLength = function (docRef, fieldName, length) {
+  if (docRef === null || docRef === undefined) return;
+  if (this.hasDoc(docRef) == false) return;
+
+  this.addFieldLength(docRef, fieldName, length);
+};
+
+/**
+ * get field length of a document by docRef
+ *
+ * @param {Integer|String} docRef document id or reference
+ * @param {String} fieldName field name
+ * @return {Integer} field length
+ */
+elasticlunr.DocumentStore.prototype.getFieldLength = function (docRef, fieldName) {
+  if (docRef === null || docRef === undefined) return 0;
+
+  if (!(docRef in this.docs)) return 0;
+  if (!(fieldName in this.docInfo[docRef])) return 0;
+  return this.docInfo[docRef][fieldName];
+};
+
+/**
+ * Returns a JSON representation of the document store used for serialisation.
+ *
+ * @return {Object} JSON format
+ * @memberOf DocumentStore
+ */
+elasticlunr.DocumentStore.prototype.toJSON = function () {
+  return {
+    docs: this.docs,
+    docInfo: this.docInfo,
+    length: this.length,
+    save: this._save
+  };
+};
+
+/**
+ * Cloning object
+ *
+ * @param {Object} object in JSON format
+ * @return {Object} copied object
+ */
+function clone(obj) {
+  if (null === obj || "object" !== typeof obj) return obj;
+
+  var copy = obj.constructor();
+
+  for (var attr in obj) {
+    if (obj.hasOwnProperty(attr)) copy[attr] = obj[attr];
+  }
+
+  return copy;
+}
+/*!
+ * elasticlunr.stemmer
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ * Includes code from - http://tartarus.org/~martin/PorterStemmer/js.txt
+ */
+
+/**
+ * elasticlunr.stemmer is an english language stemmer, this is a JavaScript
+ * implementation of the PorterStemmer taken from http://tartarus.org/~martin
+ *
+ * @module
+ * @param {String} str The string to stem
+ * @return {String}
+ * @see elasticlunr.Pipeline
+ */
+elasticlunr.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 porterStemmer;
+})();
+
+elasticlunr.Pipeline.registerFunction(elasticlunr.stemmer, 'stemmer');
+/*!
+ * elasticlunr.stopWordFilter
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * elasticlunr.stopWordFilter is an English language stop words filter, any words
+ * contained in the stop word 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.
+ * Currently this StopwordFilter using dictionary to do O(1) time complexity stop word filtering.
+ *
+ * @module
+ * @param {String} token The token to pass through the filter
+ * @return {String}
+ * @see elasticlunr.Pipeline
+ */
+elasticlunr.stopWordFilter = function (token) {
+  if (token && elasticlunr.stopWordFilter.stopWords[token] !== true) {
+    return token;
+  }
+};
+
+/**
+ * Remove predefined stop words
+ * if user want to use customized stop words, user could use this function to delete
+ * all predefined stopwords.
+ *
+ * @return {null}
+ */
+elasticlunr.clearStopWords = function () {
+  elasticlunr.stopWordFilter.stopWords = {};
+};
+
+/**
+ * Add customized stop words
+ * user could use this function to add customized stop words
+ *
+ * @params {Array} words customized stop words
+ * @return {null}
+ */
+elasticlunr.addStopWords = function (words) {
+  if (words == null || Array.isArray(words) === false) return;
+
+  words.forEach(function (word) {
+    elasticlunr.stopWordFilter.stopWords[word] = true;
+  }, this);
+};
+
+/**
+ * Reset to default stop words
+ * user could use this function to restore default stop words
+ *
+ * @return {null}
+ */
+elasticlunr.resetStopWords = function () {
+  elasticlunr.stopWordFilter.stopWords = elasticlunr.defaultStopWords;
+};
+
+elasticlunr.defaultStopWords = {
+  "": true,
+  "a": true,
+  "able": true,
+  "about": true,
+  "across": true,
+  "after": true,
+  "all": true,
+  "almost": true,
+  "also": true,
+  "am": true,
+  "among": true,
+  "an": true,
+  "and": true,
+  "any": true,
+  "are": true,
+  "as": true,
+  "at": true,
+  "be": true,
+  "because": true,
+  "been": true,
+  "but": true,
+  "by": true,
+  "can": true,
+  "cannot": true,
+  "could": true,
+  "dear": true,
+  "did": true,
+  "do": true,
+  "does": true,
+  "either": true,
+  "else": true,
+  "ever": true,
+  "every": true,
+  "for": true,
+  "from": true,
+  "get": true,
+  "got": true,
+  "had": true,
+  "has": true,
+  "have": true,
+  "he": true,
+  "her": true,
+  "hers": true,
+  "him": true,
+  "his": true,
+  "how": true,
+  "however": true,
+  "i": true,
+  "if": true,
+  "in": true,
+  "into": true,
+  "is": true,
+  "it": true,
+  "its": true,
+  "just": true,
+  "least": true,
+  "let": true,
+  "like": true,
+  "likely": true,
+  "may": true,
+  "me": true,
+  "might": true,
+  "most": true,
+  "must": true,
+  "my": true,
+  "neither": true,
+  "no": true,
+  "nor": true,
+  "not": true,
+  "of": true,
+  "off": true,
+  "often": true,
+  "on": true,
+  "only": true,
+  "or": true,
+  "other": true,
+  "our": true,
+  "own": true,
+  "rather": true,
+  "said": true,
+  "say": true,
+  "says": true,
+  "she": true,
+  "should": true,
+  "since": true,
+  "so": true,
+  "some": true,
+  "than": true,
+  "that": true,
+  "the": true,
+  "their": true,
+  "them": true,
+  "then": true,
+  "there": true,
+  "these": true,
+  "they": true,
+  "this": true,
+  "tis": true,
+  "to": true,
+  "too": true,
+  "twas": true,
+  "us": true,
+  "wants": true,
+  "was": true,
+  "we": true,
+  "were": true,
+  "what": true,
+  "when": true,
+  "where": true,
+  "which": true,
+  "while": true,
+  "who": true,
+  "whom": true,
+  "why": true,
+  "will": true,
+  "with": true,
+  "would": true,
+  "yet": true,
+  "you": true,
+  "your": true
+};
+
+elasticlunr.stopWordFilter.stopWords = elasticlunr.defaultStopWords;
+
+elasticlunr.Pipeline.registerFunction(elasticlunr.stopWordFilter, 'stopWordFilter');
+/*!
+ * elasticlunr.trimmer
+ * Copyright (C) 2016 Oliver Nightingale
+ * Copyright (C) 2016 Wei Song
+ */
+
+/**
+ * elasticlunr.trimmer is a pipeline function for trimming non word
+ * characters from the begining 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.
+ *
+ * @module
+ * @param {String} token The token to pass through the filter
+ * @return {String}
+ * @see elasticlunr.Pipeline
+ */
+elasticlunr.trimmer = function (token) {
+  if (token === null || token === undefined) {
+    throw new Error('token should not be undefined');
+  }
+
+  return token
+    .replace(/^\W+/, '')
+    .replace(/\W+$/, '');
+};
+
+elasticlunr.Pipeline.registerFunction(elasticlunr.trimmer, 'trimmer');
+/*!
+ * elasticlunr.InvertedIndex
+ * Copyright (C) 2016 Wei Song
+ * Includes code from - http://tartarus.org/~martin/PorterStemmer/js.txt
+ */
+
+/**
+ * elasticlunr.InvertedIndex is used for efficiently storing and
+ * lookup of documents that contain a given token.
+ *
+ * @constructor
+ */
+elasticlunr.InvertedIndex = function () {
+  this.root = { docs: {}, df: 0 };
+};
+
+/**
+ * Loads a previously serialised inverted index.
+ *
+ * @param {Object} serialisedData The serialised inverted index to load.
+ * @return {elasticlunr.InvertedIndex}
+ */
+elasticlunr.InvertedIndex.load = function (serialisedData) {
+  var idx = new this;
+  idx.root = serialisedData.root;
+
+  return idx;
+};
+
+/**
+ * Adds a {token: tokenInfo} pair to the inverted index.
+ * If the token already exist, then update the tokenInfo.
+ *
+ * tokenInfo format: { ref: 1, tf: 2}
+ * tokenInfor should contains the document's ref and the tf(token frequency) of that token in
+ * the document.
+ *
+ * By default this function starts at the root of the current inverted index, however
+ * it can start at any node of the inverted index if required.
+ *
+ * @param {String} token
+ * @param {Object} tokenInfo format: { ref: 1, tf: 2}
+ * @param {Object} root An optional node at which to start looking for the
+ * correct place to enter the doc, by default the root of this elasticlunr.InvertedIndex
+ * is used.
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.addToken = function (token, tokenInfo, root) {
+  var root = root || this.root,
+      idx = 0;
+
+  while (idx <= token.length - 1) {
+    var key = token[idx];
+
+    if (!(key in root)) root[key] = {docs: {}, df: 0};
+    idx += 1;
+    root = root[key];
+  }
+
+  var docRef = tokenInfo.ref;
+  if (!root.docs[docRef]) {
+    // if this doc not exist, then add this doc
+    root.docs[docRef] = {tf: tokenInfo.tf};
+    root.df += 1;
+  } else {
+    // if this doc already exist, then update tokenInfo
+    root.docs[docRef] = {tf: tokenInfo.tf};
+  }
+};
+
+/**
+ * Checks whether a token is in this elasticlunr.InvertedIndex.
+ *
+ *
+ * @param {String} token The token to be checked
+ * @return {Boolean}
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.hasToken = function (token) {
+  if (!token) return false;
+
+  var node = this.root;
+
+  for (var i = 0; i < token.length; i++) {
+    if (!node[token[i]]) return false;
+    node = node[token[i]];
+  }
+
+  return true;
+};
+
+/**
+ * Retrieve a node from the inverted index for a given token.
+ * If token not found in this InvertedIndex, return null.
+ *
+ *
+ * @param {String} token The token to get the node for.
+ * @return {Object}
+ * @see InvertedIndex.prototype.get
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.getNode = function (token) {
+  if (!token) return null;
+
+  var node = this.root;
+
+  for (var i = 0; i < token.length; i++) {
+    if (!node[token[i]]) return null;
+    node = node[token[i]];
+  }
+
+  return node;
+};
+
+/**
+ * Retrieve the documents of a given token.
+ * If token not found, return {}.
+ *
+ *
+ * @param {String} token The token to get the documents for.
+ * @return {Object}
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.getDocs = function (token) {
+  var node = this.getNode(token);
+  if (node == null) {
+    return {};
+  }
+
+  return node.docs;
+};
+
+/**
+ * Retrieve term frequency of given token in given docRef.
+ * If token or docRef not found, return 0.
+ *
+ *
+ * @param {String} token The token to get the documents for.
+ * @param {String|Integer} docRef
+ * @return {Integer}
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.getTermFrequency = function (token, docRef) {
+  var node = this.getNode(token);
+
+  if (node == null) {
+    return 0;
+  }
+
+  if (!(docRef in node.docs)) {
+    return 0;
+  }
+
+  return node.docs[docRef].tf;
+};
+
+/**
+ * Retrieve the document frequency of given token.
+ * If token not found, return 0.
+ *
+ *
+ * @param {String} token The token to get the documents for.
+ * @return {Object}
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.getDocFreq = function (token) {
+  var node = this.getNode(token);
+
+  if (node == null) {
+    return 0;
+  }
+
+  return node.df;
+};
+
+/**
+ * Remove the document identified by document's ref from the token in the inverted index.
+ *
+ *
+ * @param {String} token Remove the document from which token.
+ * @param {String} ref The ref of the document to remove from given token.
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.removeToken = function (token, ref) {
+  if (!token) return;
+  var node = this.getNode(token);
+
+  if (node == null) return;
+
+  if (ref in node.docs) {
+    delete node.docs[ref];
+    node.df -= 1;
+  }
+};
+
+/**
+ * Find all the possible suffixes of given token using tokens currently in the inverted index.
+ * If token not found, return empty Array.
+ *
+ * @param {String} token The token to expand.
+ * @return {Array}
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.expandToken = function (token, memo, root) {
+  if (token == null || token == '') return [];
+  var memo = memo || [];
+
+  if (root == void 0) {
+    root = this.getNode(token);
+    if (root == null) return memo;
+  }
+
+  if (root.df > 0) memo.push(token);
+
+  for (var key in root) {
+    if (key === 'docs') continue;
+    if (key === 'df') continue;
+    this.expandToken(token + key, memo, root[key]);
+  }
+
+  return memo;
+};
+
+/**
+ * Returns a representation of the inverted index ready for serialisation.
+ *
+ * @return {Object}
+ * @memberOf InvertedIndex
+ */
+elasticlunr.InvertedIndex.prototype.toJSON = function () {
+  return {
+    root: this.root
+  };
+};
+
+/*!
+ * elasticlunr.Configuration
+ * Copyright (C) 2016 Wei Song
+ */
+
+ /**
+  * elasticlunr.Configuration is used to analyze the user search configuration.
+  *
+  * By elasticlunr.Configuration user could set query-time boosting, boolean model in each field.
+  *
+  * Currently configuration supports:
+  * 1. query-time boosting, user could set how to boost each field.
+  * 2. boolean model chosing, user could choose which boolean model to use for each field.
+  * 3. token expandation, user could set token expand to True to improve Recall. Default is False.
+  *
+  * Query time boosting must be configured by field category, "boolean" model could be configured
+  * by both field category or globally as the following example. Field configuration for "boolean"
+  * will overwrite global configuration.
+  * Token expand could be configured both by field category or golbally. Local field configuration will
+  * overwrite global configuration.
+  *
+  * configuration example:
+  * {
+  *   fields:{
+  *     title: {boost: 2},
+  *     body: {boost: 1}
+  *   },
+  *   bool: "OR"
+  * }
+  *
+  * "bool" field configuation overwrite global configuation example:
+  * {
+  *   fields:{
+  *     title: {boost: 2, bool: "AND"},
+  *     body: {boost: 1}
+  *   },
+  *   bool: "OR"
+  * }
+  *
+  * "expand" example:
+  * {
+  *   fields:{
+  *     title: {boost: 2, bool: "AND"},
+  *     body: {boost: 1}
+  *   },
+  *   bool: "OR",
+  *   expand: true
+  * }
+  *
+  * "expand" example for field category:
+  * {
+  *   fields:{
+  *     title: {boost: 2, bool: "AND", expand: true},
+  *     body: {boost: 1}
+  *   },
+  *   bool: "OR"
+  * }
+  *
+  * setting the boost to 0 ignores the field (this will only search the title):
+  * {
+  *   fields:{
+  *     title: {boost: 1},
+  *     body: {boost: 0}
+  *   }
+  * }
+  *
+  * then, user could search with configuration to do query-time boosting.
+  * idx.search('oracle database', {fields: {title: {boost: 2}, body: {boost: 1}}});
+  *
+  *
+  * @constructor
+  *
+  * @param {String} config user configuration
+  * @param {Array} fields fields of index instance
+  * @module
+  */
+elasticlunr.Configuration = function (config, fields) {
+  var config = config || '';
+
+  if (fields == undefined || fields == null) {
+    throw new Error('fields should not be null');
+  }
+
+  this.config = {};
+
+  var userConfig;
+  try {
+    userConfig = JSON.parse(config);
+    this.buildUserConfig(userConfig, fields);
+  } catch (error) {
+    elasticlunr.utils.warn('user configuration parse failed, will use default configuration');
+    this.buildDefaultConfig(fields);
+  }
+};
+
+/**
+ * Build default search configuration.
+ *
+ * @param {Array} fields fields of index instance
+ */
+elasticlunr.Configuration.prototype.buildDefaultConfig = function (fields) {
+  this.reset();
+  fields.forEach(function (field) {
+    this.config[field] = {
+      boost: 1,
+      bool: "OR",
+      expand: false
+    };
+  }, this);
+};
+
+/**
+ * Build user configuration.
+ *
+ * @param {JSON} config User JSON configuratoin
+ * @param {Array} fields fields of index instance
+ */
+elasticlunr.Configuration.prototype.buildUserConfig = function (config, fields) {
+  var global_bool = "OR";
+  var global_expand = false;
+
+  this.reset();
+  if ('bool' in config) {
+    global_bool = config['bool'] || global_bool;
+  }
+
+  if ('expand' in config) {
+    global_expand = config['expand'] || global_expand;
+  }
+
+  if ('fields' in config) {
+    for (var field in config['fields']) {
+      if (fields.indexOf(field) > -1) {
+        var field_config = config['fields'][field];
+        var field_expand = global_expand;
+        if (field_config.expand != undefined) {
+          field_expand = field_config.expand;
+        }
+
+        this.config[field] = {
+          boost: (field_config.boost || field_config.boost === 0) ? field_config.boost : 1,
+          bool: field_config.bool || global_bool,
+          expand: field_expand
+        };
+      } else {
+        elasticlunr.utils.warn('field name in user configuration not found in index instance fields');
+      }
+    }
+  } else {
+    this.addAllFields2UserConfig(global_bool, global_expand, fields);
+  }
+};
+
+/**
+ * Add all fields to user search configuration.
+ *
+ * @param {String} bool Boolean model
+ * @param {String} expand Expand model
+ * @param {Array} fields fields of index instance
+ */
+elasticlunr.Configuration.prototype.addAllFields2UserConfig = function (bool, expand, fields) {
+  fields.forEach(function (field) {
+    this.config[field] = {
+      boost: 1,
+      bool: bool,
+      expand: expand
+    };
+  }, this);
+};
+
+/**
+ * get current user configuration
+ */
+elasticlunr.Configuration.prototype.get = function () {
+  return this.config;
+};
+
+/**
+ * reset user search configuration.
+ */
+elasticlunr.Configuration.prototype.reset = function () {
+  this.config = {};
+};
+/**
+ * sorted_set.js is added only to make elasticlunr.js compatible with lunr-languages.
+ * if elasticlunr.js support different languages by default, this will make elasticlunr.js
+ * much bigger that not good for browser usage.
+ *
+ */
+
+
+/*!
+ * lunr.SortedSet
+ * Copyright (C) 2016 Oliver Nightingale
+ */
+
+/**
+ * lunr.SortedSets are used to maintain an array of uniq values in a sorted
+ * order.
+ *
+ * @constructor
+ */
+lunr.SortedSet = function () {
+  this.length = 0
+  this.elements = []
+}
+
+/**
+ * Loads a previously serialised sorted set.
+ *
+ * @param {Array} serialisedData The serialised set to load.
+ * @returns {lunr.SortedSet}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.load = function (serialisedData) {
+  var set = new this
+
+  set.elements = serialisedData
+  set.length = serialisedData.length
+
+  return set
+}
+
+/**
+ * Inserts new items into the set in the correct position to maintain the
+ * order.
+ *
+ * @param {Object} The objects to add to this set.
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.add = function () {
+  var i, element
+
+  for (i = 0; i < arguments.length; i++) {
+    element = arguments[i]
+    if (~this.indexOf(element)) continue
+    this.elements.splice(this.locationFor(element), 0, element)
+  }
+
+  this.length = this.elements.length
+}
+
+/**
+ * Converts this sorted set into an array.
+ *
+ * @returns {Array}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.toArray = function () {
+  return this.elements.slice()
+}
+
+/**
+ * Creates a new array with the results of calling a provided function on every
+ * element in this sorted set.
+ *
+ * Delegates to Array.prototype.map and has the same signature.
+ *
+ * @param {Function} fn The function that is called on each element of the
+ * set.
+ * @param {Object} ctx An optional object that can be used as the context
+ * for the function fn.
+ * @returns {Array}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.map = function (fn, ctx) {
+  return this.elements.map(fn, ctx)
+}
+
+/**
+ * Executes a provided function once per sorted set element.
+ *
+ * Delegates to Array.prototype.forEach and has the same signature.
+ *
+ * @param {Function} fn The function that is called on each element of the
+ * set.
+ * @param {Object} ctx An optional object that can be used as the context
+ * @memberOf SortedSet
+ * for the function fn.
+ */
+lunr.SortedSet.prototype.forEach = function (fn, ctx) {
+  return this.elements.forEach(fn, ctx)
+}
+
+/**
+ * Returns the index at which a given element can be found in the
+ * sorted set, or -1 if it is not present.
+ *
+ * @param {Object} elem The object to locate in the sorted set.
+ * @returns {Number}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.indexOf = function (elem) {
+  var start = 0,
+      end = this.elements.length,
+      sectionLength = end - start,
+      pivot = start + Math.floor(sectionLength / 2),
+      pivotElem = this.elements[pivot]
+
+  while (sectionLength > 1) {
+    if (pivotElem === elem) return pivot
+
+    if (pivotElem < elem) start = pivot
+    if (pivotElem > elem) end = pivot
+
+    sectionLength = end - start
+    pivot = start + Math.floor(sectionLength / 2)
+    pivotElem = this.elements[pivot]
+  }
+
+  if (pivotElem === elem) return pivot
+
+  return -1
+}
+
+/**
+ * Returns the position within the sorted set that an element should be
+ * inserted at to maintain the current order of the set.
+ *
+ * This function assumes that the element to search for does not already exist
+ * in the sorted set.
+ *
+ * @param {Object} elem The elem to find the position for in the set
+ * @returns {Number}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.locationFor = function (elem) {
+  var start = 0,
+      end = this.elements.length,
+      sectionLength = end - start,
+      pivot = start + Math.floor(sectionLength / 2),
+      pivotElem = this.elements[pivot]
+
+  while (sectionLength > 1) {
+    if (pivotElem < elem) start = pivot
+    if (pivotElem > elem) end = pivot
+
+    sectionLength = end - start
+    pivot = start + Math.floor(sectionLength / 2)
+    pivotElem = this.elements[pivot]
+  }
+
+  if (pivotElem > elem) return pivot
+  if (pivotElem < elem) return pivot + 1
+}
+
+/**
+ * Creates a new lunr.SortedSet that contains the elements in the intersection
+ * of this set and the passed set.
+ *
+ * @param {lunr.SortedSet} otherSet The set to intersect with this set.
+ * @returns {lunr.SortedSet}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.intersect = function (otherSet) {
+  var intersectSet = new lunr.SortedSet,
+      i = 0, j = 0,
+      a_len = this.length, b_len = otherSet.length,
+      a = this.elements, b = otherSet.elements
+
+  while (true) {
+    if (i > a_len - 1 || j > b_len - 1) break
+
+    if (a[i] === b[j]) {
+      intersectSet.add(a[i])
+      i++, j++
+      continue
+    }
+
+    if (a[i] < b[j]) {
+      i++
+      continue
+    }
+
+    if (a[i] > b[j]) {
+      j++
+      continue
+    }
+  };
+
+  return intersectSet
+}
+
+/**
+ * Makes a copy of this set
+ *
+ * @returns {lunr.SortedSet}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.clone = function () {
+  var clone = new lunr.SortedSet
+
+  clone.elements = this.toArray()
+  clone.length = clone.elements.length
+
+  return clone
+}
+
+/**
+ * Creates a new lunr.SortedSet that contains the elements in the union
+ * of this set and the passed set.
+ *
+ * @param {lunr.SortedSet} otherSet The set to union with this set.
+ * @returns {lunr.SortedSet}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.union = function (otherSet) {
+  var longSet, shortSet, unionSet
+
+  if (this.length >= otherSet.length) {
+    longSet = this, shortSet = otherSet
+  } else {
+    longSet = otherSet, shortSet = this
+  }
+
+  unionSet = longSet.clone()
+
+  for(var i = 0, shortSetElements = shortSet.toArray(); i < shortSetElements.length; i++){
+    unionSet.add(shortSetElements[i])
+  }
+
+  return unionSet
+}
+
+/**
+ * Returns a representation of the sorted set ready for serialisation.
+ *
+ * @returns {Array}
+ * @memberOf SortedSet
+ */
+lunr.SortedSet.prototype.toJSON = function () {
+  return this.toArray()
+}
+  /**
+   * 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) {
+    if (typeof define === 'function' && define.amd) {
+      // AMD. Register as an anonymous module.
+      define(factory)
+    } else if (typeof exports === 'object') {
+      /**
+       * Node. Does not work with strict CommonJS, but
+       * only CommonJS-like enviroments that support module.exports,
+       * like Node.
+       */
+      module.exports = factory()
+    } else {
+      // Browser globals (root is window)
+      root.elasticlunr = 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 elasticlunr
+  }))
+})();