github.com/shyftnetwork/go-empyrean@v1.8.3-0.20191127201940-fbfca9338f04/shyft_documentation/source/javascripts/lib/_lunr.js

/**
 * lunr - http://lunrjs.com - A bit like Solr, but much smaller and not as bright - 0.5.7
 * Copyright (C) 2014 Oliver Nightingale
 * MIT Licensed
 * @license
 */

(function(){

  /**
   * Convenience function for instantiating a new lunr 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:
   *
   * lunr.StopWordFilter - filters out any stop words before they enter the
   * index
   *
   * lunr.stemmer - stems the tokens before entering the index.
   *
   * Example:
   *
   *     var idx = lunr(function () {
 *       this.field('title', 10)
 *       this.field('tags', 100)
 *       this.field('body')
 *
 *       this.ref('cid')
 *
 *       this.pipeline.add(function () {
 *         // some custom pipeline function
 *       })
 *
 *     })
   *
   * @param {Function} config A function that will be called with the new instance
   * of the lunr.Index as both its context and first parameter. It can be used to
   * customize the instance of new lunr.Index.
   * @namespace
   * @module
   * @returns {lunr.Index}
   *
   */
  var lunr = function (config) {
    var idx = new lunr.Index

    idx.pipeline.add(
        lunr.trimmer,
        lunr.stopWordFilter,
        lunr.stemmer
    )

    if (config) config.call(idx, idx)

    return idx
  }

  lunr.version = "0.5.7"
  /*!
   * lunr.utils
   * Copyright (C) 2014 Oliver Nightingale
   */

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

  /**
   * Print a warning message to the console.
   *
   * @param {String} message The message to be printed.
   * @memberOf Utils
   */
  lunr.utils.warn = (function (global) {
    return function (message) {
      if (global.console && console.warn) {
        console.warn(message)
      }
    }
  })(this)

  /*!
   * lunr.EventEmitter
   * Copyright (C) 2014 Oliver Nightingale
   */

  /**
   * lunr.EventEmitter is an event emitter for lunr. It manages adding and removing event handlers and triggering events and their handlers.
   *
   * @constructor
   */
  lunr.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} handler The function to call when an event is fired.
   * @memberOf EventEmitter
   */
  lunr.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} handler The function to remove from an event.
   * @memberOf EventEmitter
   */
  lunr.EventEmitter.prototype.removeListener = function (name, fn) {
    if (!this.hasHandler(name)) return

    var fnIndex = this.events[name].indexOf(fn)
    this.events[name].splice(fnIndex, 1)

    if (!this.events[name].length) delete this.events[name]
  }

  /**
   * Calls all functions bound 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
   */
  lunr.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)
    })
  }

  /**
   * Checks whether a handler has ever been stored against an event.
   *
   * @param {String} eventName The name of the event to check.
   * @private
   * @memberOf EventEmitter
   */
  lunr.EventEmitter.prototype.hasHandler = function (name) {
    return name in this.events
  }

  /*!
   * lunr.tokenizer
   * Copyright (C) 2014 Oliver Nightingale
   */

  /**
   * A function for splitting a string into tokens ready to be inserted into
   * the search index.
   *
   * @module
   * @param {String} obj The string to convert into tokens
   * @returns {Array}
   */
  lunr.tokenizer = function (obj) {
    if (!arguments.length || obj == null || obj == undefined) return []
    if (Array.isArray(obj)) return obj.map(function (t) { return t.toLowerCase() })

    var str = obj.toString().replace(/^\s+/, '')

    for (var i = str.length - 1; i >= 0; i--) {
      if (/\S/.test(str.charAt(i))) {
        str = str.substring(0, i + 1)
        break
      }
    }

    return str
        .split(/(?:\s+|\-)/)
        .filter(function (token) {
          return !!token
        })
        .map(function (token) {
          return token.toLowerCase()
        })
  }
  /*!
   * lunr.Pipeline
   * Copyright (C) 2014 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 = {}

  /**
   * 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 {Function} fn The function to check for.
   * @param {String} label The label to register this function with
   * @memberOf Pipeline
   */
  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 {Function} fn The function to check for.
   * @private
   * @memberOf Pipeline
   */
  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}
   * @memberOf 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 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
   */
  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 {Function} existingFn A function that already exists in the pipeline.
   * @param {Function} newFn The new function to add to the pipeline.
   * @memberOf Pipeline
   */
  lunr.Pipeline.prototype.after = function (existingFn, newFn) {
    lunr.Pipeline.warnIfFunctionNotRegistered(newFn)

    var pos = this._stack.indexOf(existingFn) + 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 {Function} existingFn A function that already exists in the pipeline.
   * @param {Function} newFn The new function to add to the pipeline.
   * @memberOf Pipeline
   */
  lunr.Pipeline.prototype.before = function (existingFn, newFn) {
    lunr.Pipeline.warnIfFunctionNotRegistered(newFn)

    var pos = this._stack.indexOf(existingFn)
    this._stack.splice(pos, 0, newFn)
  }

  /**
   * Removes a function from the pipeline.
   *
   * @param {Function} fn The function to remove from the pipeline.
   * @memberOf Pipeline
   */
  lunr.Pipeline.prototype.remove = function (fn) {
    var pos = this._stack.indexOf(fn)
    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}
   * @memberOf Pipeline
   */
  lunr.Pipeline.prototype.run = function (tokens) {
    var out = [],
        tokenLength = tokens.length,
        stackLength = this._stack.length

    for (var i = 0; i < tokenLength; i++) {
      var token = tokens[i]

      for (var j = 0; j < stackLength; j++) {
        token = this._stack[j](token, i, tokens)
        if (token === void 0) break
      };

      if (token !== void 0) out.push(token)
    };

    return out
  }

  /**
   * Resets the pipeline by removing any existing processors.
   *
   * @memberOf Pipeline
   */
  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}
   * @memberOf Pipeline
   */
  lunr.Pipeline.prototype.toJSON = function () {
    return this._stack.map(function (fn) {
      lunr.Pipeline.warnIfFunctionNotRegistered(fn)

      return fn.label
    })
  }
  /*!
   * lunr.Vector
   * Copyright (C) 2014 Oliver Nightingale
   */

  /**
   * lunr.Vectors implement vector related operations for
   * a series of elements.
   *
   * @constructor
   */
  lunr.Vector = function () {
    this._magnitude = null
    this.list = undefined
    this.length = 0
  }

  /**
   * lunr.Vector.Node is a simple struct for each node
   * in a lunr.Vector.
   *
   * @private
   * @param {Number} The index of the node in the vector.
   * @param {Object} The data at this node in the vector.
   * @param {lunr.Vector.Node} The node directly after this node in the vector.
   * @constructor
   * @memberOf Vector
   */
  lunr.Vector.Node = function (idx, val, next) {
    this.idx = idx
    this.val = val
    this.next = next
  }

  /**
   * Inserts a new value at a position in a vector.
   *
   * @param {Number} The index at which to insert a value.
   * @param {Object} The object to insert in the vector.
   * @memberOf Vector.
   */
  lunr.Vector.prototype.insert = function (idx, val) {
    var list = this.list

    if (!list) {
      this.list = new lunr.Vector.Node (idx, val, list)
      return this.length++
    }

    var prev = list,
        next = list.next

    while (next != undefined) {
      if (idx < next.idx) {
        prev.next = new lunr.Vector.Node (idx, val, next)
        return this.length++
      }

      prev = next, next = next.next
    }

    prev.next = new lunr.Vector.Node (idx, val, next)
    return this.length++
  }

  /**
   * Calculates the magnitude of this vector.
   *
   * @returns {Number}
   * @memberOf Vector
   */
  lunr.Vector.prototype.magnitude = function () {
    if (this._magniture) return this._magnitude
    var node = this.list,
        sumOfSquares = 0,
        val

    while (node) {
      val = node.val
      sumOfSquares += val * val
      node = node.next
    }

    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}
   * @memberOf Vector
   */
  lunr.Vector.prototype.dot = function (otherVector) {
    var node = this.list,
        otherNode = otherVector.list,
        dotProduct = 0

    while (node && otherNode) {
      if (node.idx < otherNode.idx) {
        node = node.next
      } else if (node.idx > otherNode.idx) {
        otherNode = otherNode.next
      } else {
        dotProduct += node.val * otherNode.val
        node = node.next
        otherNode = otherNode.next
      }
    }

    return dotProduct
  }

  /**
   * Calculates the cosine similarity between this vector and another
   * vector.
   *
   * @param {lunr.Vector} otherVector The other vector to calculate the
   * similarity with.
   * @returns {Number}
   * @memberOf Vector
   */
  lunr.Vector.prototype.similarity = function (otherVector) {
    return this.dot(otherVector) / (this.magnitude() * otherVector.magnitude())
  }
  /*!
   * lunr.SortedSet
   * Copyright (C) 2014 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 () {
    Array.prototype.slice.call(arguments).forEach(function (element) {
      if (~this.indexOf(element)) return
      this.elements.splice(this.locationFor(element), 0, element)
    }, this)

    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.
   * @param {Number} start An optional index at which to start searching from
   * within the set.
   * @param {Number} end An optional index at which to stop search from within
   * the set.
   * @returns {Number}
   * @memberOf SortedSet
   */
  lunr.SortedSet.prototype.indexOf = function (elem, start, end) {
    var start = start || 0,
        end = end || this.elements.length,
        sectionLength = end - start,
        pivot = start + Math.floor(sectionLength / 2),
        pivotElem = this.elements[pivot]

    if (sectionLength <= 1) {
      if (pivotElem === elem) {
        return pivot
      } else {
        return -1
      }
    }

    if (pivotElem < elem) return this.indexOf(elem, pivot, end)
    if (pivotElem > elem) return this.indexOf(elem, start, pivot)
    if (pivotElem === elem) return pivot
  }

  /**
   * 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
   * @param {Number} start An optional index at which to start searching from
   * within the set.
   * @param {Number} end An optional index at which to stop search from within
   * the set.
   * @returns {Number}
   * @memberOf SortedSet
   */
  lunr.SortedSet.prototype.locationFor = function (elem, start, end) {
    var start = start || 0,
        end = end || this.elements.length,
        sectionLength = end - start,
        pivot = start + Math.floor(sectionLength / 2),
        pivotElem = this.elements[pivot]

    if (sectionLength <= 1) {
      if (pivotElem > elem) return pivot
      if (pivotElem < elem) return pivot + 1
    }

    if (pivotElem < elem) return this.locationFor(elem, pivot, end)
    if (pivotElem > elem) return this.locationFor(elem, start, pivot)
  }

  /**
   * 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()

    unionSet.add.apply(unionSet, shortSet.toArray())

    return unionSet
  }

  /**
   * Returns a representation of the sorted set ready for serialisation.
   *
   * @returns {Array}
   * @memberOf SortedSet
   */
  lunr.SortedSet.prototype.toJSON = function () {
    return this.toArray()
  }
  /*!
   * lunr.Index
   * Copyright (C) 2014 Oliver Nightingale
   */

  /**
   * lunr.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
   */
  lunr.Index = function () {
    this._fields = []
    this._ref = 'id'
    this.pipeline = new lunr.Pipeline
    this.documentStore = new lunr.Store
    this.tokenStore = new lunr.TokenStore
    this.corpusTokens = new lunr.SortedSet
    this.eventEmitter =  new lunr.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} handler The serialised set to load.
   * @memberOf Index
   */
  lunr.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} handler The serialised set to load.
   * @memberOf Index
   */
  lunr.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 lunr.
   *
   * @param {Object} serialisedData The serialised set to load.
   * @returns {lunr.Index}
   * @memberOf Index
   */
  lunr.Index.load = function (serialisedData) {
    if (serialisedData.version !== lunr.version) {
      lunr.utils.warn('version mismatch: current ' + lunr.version + ' importing ' + serialisedData.version)
    }

    var idx = new this

    idx._fields = serialisedData.fields
    idx._ref = serialisedData.ref

    idx.documentStore = lunr.Store.load(serialisedData.documentStore)
    idx.tokenStore = lunr.TokenStore.load(serialisedData.tokenStore)
    idx.corpusTokens = lunr.SortedSet.load(serialisedData.corpusTokens)
    idx.pipeline = lunr.Pipeline.load(serialisedData.pipeline)

    return idx
  }

  /**
   * Adds a field to the list of fields that will be searchable within documents
   * in the index.
   *
   * An optional boost param can be passed to affect how much tokens in this field
   * rank in search results, by default the boost value is 1.
   *
   * 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
   * @param {Number} boost An optional boost that can be applied to terms in this
   * field.
   * @returns {lunr.Index}
   * @memberOf Index
   */
  lunr.Index.prototype.field = function (fieldName, opts) {
    var opts = opts || {},
        field = { name: fieldName, boost: opts.boost || 1 }

    this._fields.push(field)
    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
   * @returns {lunr.Index}
   * @memberOf Index
   */
  lunr.Index.prototype.ref = function (refName) {
    this._ref = refName
    return this
  }

  /**
   * Add a 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 document to add to the index.
   * @param {Boolean} emitEvent Whether or not to emit events, default true.
   * @memberOf Index
   */
  lunr.Index.prototype.add = function (doc, emitEvent) {
    var docTokens = {},
        allDocumentTokens = new lunr.SortedSet,
        docRef = doc[this._ref],
        emitEvent = emitEvent === undefined ? true : emitEvent

    this._fields.forEach(function (field) {
      var fieldTokens = this.pipeline.run(lunr.tokenizer(doc[field.name]))

      docTokens[field.name] = fieldTokens
      lunr.SortedSet.prototype.add.apply(allDocumentTokens, fieldTokens)
    }, this)

    this.documentStore.set(docRef, allDocumentTokens)
    lunr.SortedSet.prototype.add.apply(this.corpusTokens, allDocumentTokens.toArray())

    for (var i = 0; i < allDocumentTokens.length; i++) {
      var token = allDocumentTokens.elements[i]
      var tf = this._fields.reduce(function (memo, field) {
        var fieldLength = docTokens[field.name].length

        if (!fieldLength) return memo

        var tokenCount = docTokens[field.name].filter(function (t) { return t === token }).length

        return memo + (tokenCount / fieldLength * field.boost)
      }, 0)

      this.tokenStore.add(token, { ref: docRef, tf: tf })
    };

    if (emitEvent) this.eventEmitter.emit('add', doc, this)
  }

  /**
   * Removes a document from the index.
   *
   * To make sure documents no longer show up in search results they can be
   * removed from the index using this method.
   *
   * The document passed only needs to have the same ref property value as the
   * document that was added to the index, they could be completely different
   * objects.
   *
   * 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 to remove from the index.
   * @param {Boolean} emitEvent Whether to emit remove events, defaults to true
   * @memberOf Index
   */
  lunr.Index.prototype.remove = function (doc, emitEvent) {
    var docRef = doc[this._ref],
        emitEvent = emitEvent === undefined ? true : emitEvent

    if (!this.documentStore.has(docRef)) return

    var docTokens = this.documentStore.get(docRef)

    this.documentStore.remove(docRef)

    docTokens.forEach(function (token) {
      this.tokenStore.remove(token, docRef)
    }, 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
   */
  lunr.Index.prototype.update = function (doc, emitEvent) {
    var emitEvent = emitEvent === undefined ? true : emitEvent

    this.remove(doc, false)
    this.add(doc, false)

    if (emitEvent) this.eventEmitter.emit('update', doc, this)
  }

  /**
   * Calculates the inverse document frequency for a token within the index.
   *
   * @param {String} token The token to calculate the idf of.
   * @see Index.prototype.idf
   * @private
   * @memberOf Index
   */
  lunr.Index.prototype.idf = function (term) {
    var cacheKey = "@" + term
    if (Object.prototype.hasOwnProperty.call(this._idfCache, cacheKey)) return this._idfCache[cacheKey]

    var documentFrequency = this.tokenStore.count(term),
        idf = 1

    if (documentFrequency > 0) {
      idf = 1 + Math.log(this.tokenStore.length / documentFrequency)
    }

    return this._idfCache[cacheKey] = idf
  }

  /**
   * Searches the index using the passed query.
   *
   * Queries should be a string, multiple words are allowed and will lead to an
   * AND based query, e.g. `idx.search('foo bar')` will run a search for
   * documents containing both 'foo' and 'bar'.
   *
   * 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.
   * @returns {Object}
   * @see Index.prototype.idf
   * @see Index.prototype.documentVector
   * @memberOf Index
   */
  lunr.Index.prototype.search = function (query) {
    var queryTokens = this.pipeline.run(lunr.tokenizer(query)),
        queryVector = new lunr.Vector,
        documentSets = [],
        fieldBoosts = this._fields.reduce(function (memo, f) { return memo + f.boost }, 0)

    var hasSomeToken = queryTokens.some(function (token) {
      return this.tokenStore.has(token)
    }, this)

    if (!hasSomeToken) return []

    queryTokens
        .forEach(function (token, i, tokens) {
          var tf = 1 / tokens.length * this._fields.length * fieldBoosts,
              self = this

          var set = this.tokenStore.expand(token).reduce(function (memo, key) {
            var pos = self.corpusTokens.indexOf(key),
                idf = self.idf(key),
                similarityBoost = 1,
                set = new lunr.SortedSet

            // if the expanded key is not an exact match to the token then
            // penalise the score for this key by how different the key is
            // to the token.
            if (key !== token) {
              var diff = Math.max(3, key.length - token.length)
              similarityBoost = 1 / Math.log(diff)
            }

            // calculate the query tf-idf score for this token
            // applying an similarityBoost to ensure exact matches
            // these rank higher than expanded terms
            if (pos > -1) queryVector.insert(pos, tf * idf * similarityBoost)

            // add all the documents that have this key into a set
            Object.keys(self.tokenStore.get(key)).forEach(function (ref) { set.add(ref) })

            return memo.union(set)
          }, new lunr.SortedSet)

          documentSets.push(set)
        }, this)

    var documentSet = documentSets.reduce(function (memo, set) {
      return memo.intersect(set)
    })

    return documentSet
        .map(function (ref) {
          return { ref: ref, score: queryVector.similarity(this.documentVector(ref)) }
        }, this)
        .sort(function (a, b) {
          return b.score - a.score
        })
  }

  /**
   * Generates a vector containing all the tokens in the document matching the
   * passed documentRef.
   *
   * The vector contains the tf-idf score for each token contained in the
   * document with the passed documentRef.  The vector will contain an element
   * for every token in the indexes corpus, if the document does not contain that
   * token the element will be 0.
   *
   * @param {Object} documentRef The ref to find the document with.
   * @returns {lunr.Vector}
   * @private
   * @memberOf Index
   */
  lunr.Index.prototype.documentVector = function (documentRef) {
    var documentTokens = this.documentStore.get(documentRef),
        documentTokensLength = documentTokens.length,
        documentVector = new lunr.Vector

    for (var i = 0; i < documentTokensLength; i++) {
      var token = documentTokens.elements[i],
          tf = this.tokenStore.get(token)[documentRef].tf,
          idf = this.idf(token)

      documentVector.insert(this.corpusTokens.indexOf(token), tf * idf)
    };

    return documentVector
  }

  /**
   * Returns a representation of the index ready for serialisation.
   *
   * @returns {Object}
   * @memberOf Index
   */
  lunr.Index.prototype.toJSON = function () {
    return {
      version: lunr.version,
      fields: this._fields,
      ref: this._ref,
      documentStore: this.documentStore.toJSON(),
      tokenStore: this.tokenStore.toJSON(),
      corpusTokens: this.corpusTokens.toJSON(),
      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 = lunr(function () {
 *       this.use(myPlugin, 'arg1', 'arg2')
 *     })
   *
   * @param {Function} plugin The plugin to apply.
   * @memberOf Index
   */
  lunr.Index.prototype.use = function (plugin) {
    var args = Array.prototype.slice.call(arguments, 1)
    args.unshift(this)
    plugin.apply(this, args)
  }
  /*!
   * lunr.Store
   * Copyright (C) 2014 Oliver Nightingale
   */

  /**
   * lunr.Store is a simple key-value store used for storing sets of tokens for
   * documents stored in index.
   *
   * @constructor
   * @module
   */
  lunr.Store = function () {
    this.store = {}
    this.length = 0
  }

  /**
   * Loads a previously serialised store
   *
   * @param {Object} serialisedData The serialised store to load.
   * @returns {lunr.Store}
   * @memberOf Store
   */
  lunr.Store.load = function (serialisedData) {
    var store = new this

    store.length = serialisedData.length
    store.store = Object.keys(serialisedData.store).reduce(function (memo, key) {
      memo[key] = lunr.SortedSet.load(serialisedData.store[key])
      return memo
    }, {})

    return store
  }

  /**
   * Stores the given tokens in the store against the given id.
   *
   * @param {Object} id The key used to store the tokens against.
   * @param {Object} tokens The tokens to store against the key.
   * @memberOf Store
   */
  lunr.Store.prototype.set = function (id, tokens) {
    if (!this.has(id)) this.length++
    this.store[id] = tokens
  }

  /**
   * Retrieves the tokens from the store for a given key.
   *
   * @param {Object} id The key to lookup and retrieve from the store.
   * @returns {Object}
   * @memberOf Store
   */
  lunr.Store.prototype.get = function (id) {
    return this.store[id]
  }

  /**
   * Checks whether the store contains a key.
   *
   * @param {Object} id The id to look up in the store.
   * @returns {Boolean}
   * @memberOf Store
   */
  lunr.Store.prototype.has = function (id) {
    return id in this.store
  }

  /**
   * Removes the value for a key in the store.
   *
   * @param {Object} id The id to remove from the store.
   * @memberOf Store
   */
  lunr.Store.prototype.remove = function (id) {
    if (!this.has(id)) return

    delete this.store[id]
    this.length--
  }

  /**
   * Returns a representation of the store ready for serialisation.
   *
   * @returns {Object}
   * @memberOf Store
   */
  lunr.Store.prototype.toJSON = function () {
    return {
      store: this.store,
      length: this.length
    }
  }

  /*!
   * lunr.stemmer
   * Copyright (C) 2014 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://tartaurs.org/~martin
   *
   * @module
   * @param {String} str The string to stem
   * @returns {String}
   * @see lunr.Pipeline
   */
  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 porterStemmer;
  })();

  lunr.Pipeline.registerFunction(lunr.stemmer, 'stemmer')
  /*!
   * lunr.stopWordFilter
   * Copyright (C) 2014 Oliver Nightingale
   */

  /**
   * 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.
   *
   * @module
   * @param {String} token The token to pass through the filter
   * @returns {String}
   * @see lunr.Pipeline
   */
  lunr.stopWordFilter = function (token) {
    if (lunr.stopWordFilter.stopWords.indexOf(token) === -1) return token
  }

  lunr.stopWordFilter.stopWords = new lunr.SortedSet
  lunr.stopWordFilter.stopWords.length = 119
  lunr.stopWordFilter.stopWords.elements = [
    "",
    "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) 2014 Oliver Nightingale
   */

  /**
   * lunr.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
   * @returns {String}
   * @see lunr.Pipeline
   */
  lunr.trimmer = function (token) {
    return token
        .replace(/^\W+/, '')
        .replace(/\W+$/, '')
  }

  lunr.Pipeline.registerFunction(lunr.trimmer, 'trimmer')
  /*!
   * lunr.stemmer
   * Copyright (C) 2014 Oliver Nightingale
   * Includes code from - http://tartarus.org/~martin/PorterStemmer/js.txt
   */

  /**
   * lunr.TokenStore is used for efficient storing and lookup of the reverse
   * index of token to document ref.
   *
   * @constructor
   */
  lunr.TokenStore = function () {
    this.root = { docs: {} }
    this.length = 0
  }

  /**
   * Loads a previously serialised token store
   *
   * @param {Object} serialisedData The serialised token store to load.
   * @returns {lunr.TokenStore}
   * @memberOf TokenStore
   */
  lunr.TokenStore.load = function (serialisedData) {
    var store = new this

    store.root = serialisedData.root
    store.length = serialisedData.length

    return store
  }

  /**
   * Adds a new token doc pair to the store.
   *
   * By default this function starts at the root of the current store, however
   * it can start at any node of any token store if required.
   *
   * @param {String} token The token to store the doc under
   * @param {Object} doc The doc to store against the token
   * @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 lunr.TokenStore
   * is used.
   * @memberOf TokenStore
   */
  lunr.TokenStore.prototype.add = function (token, doc, root) {
    var root = root || this.root,
        key = token[0],
        rest = token.slice(1)

    if (!(key in root)) root[key] = {docs: {}}

    if (rest.length === 0) {
      root[key].docs[doc.ref] = doc
      this.length += 1
      return
    } else {
      return this.add(rest, doc, root[key])
    }
  }

  /**
   * Checks whether this key is contained within this lunr.TokenStore.
   *
   * By default this function starts at the root of the current store, however
   * it can start at any node of any token store if required.
   *
   * @param {String} token The token to check for
   * @param {Object} root An optional node at which to start
   * @memberOf TokenStore
   */
  lunr.TokenStore.prototype.has = 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 token store for a given token.
   *
   * By default this function starts at the root of the current store, however
   * it can start at any node of any token store if required.
   *
   * @param {String} token The token to get the node for.
   * @param {Object} root An optional node at which to start.
   * @returns {Object}
   * @see TokenStore.prototype.get
   * @memberOf TokenStore
   */
  lunr.TokenStore.prototype.getNode = function (token) {
    if (!token) return {}

    var node = this.root

    for (var i = 0; i < token.length; i++) {
      if (!node[token[i]]) return {}

      node = node[token[i]]
    }

    return node
  }

  /**
   * Retrieve the documents for a node for the given token.
   *
   * By default this function starts at the root of the current store, however
   * it can start at any node of any token store if required.
   *
   * @param {String} token The token to get the documents for.
   * @param {Object} root An optional node at which to start.
   * @returns {Object}
   * @memberOf TokenStore
   */
  lunr.TokenStore.prototype.get = function (token, root) {
    return this.getNode(token, root).docs || {}
  }

  lunr.TokenStore.prototype.count = function (token, root) {
    return Object.keys(this.get(token, root)).length
  }

  /**
   * Remove the document identified by ref from the token in the store.
   *
   * By default this function starts at the root of the current store, however
   * it can start at any node of any token store if required.
   *
   * @param {String} token The token to get the documents for.
   * @param {String} ref The ref of the document to remove from this token.
   * @param {Object} root An optional node at which to start.
   * @returns {Object}
   * @memberOf TokenStore
   */
  lunr.TokenStore.prototype.remove = function (token, ref) {
    if (!token) return
    var node = this.root

    for (var i = 0; i < token.length; i++) {
      if (!(token[i] in node)) return
      node = node[token[i]]
    }

    delete node.docs[ref]
  }

  /**
   * Find all the possible suffixes of the passed token using tokens
   * currently in the store.
   *
   * @param {String} token The token to expand.
   * @returns {Array}
   * @memberOf TokenStore
   */
  lunr.TokenStore.prototype.expand = function (token, memo) {
    var root = this.getNode(token),
        docs = root.docs || {},
        memo = memo || []

    if (Object.keys(docs).length) memo.push(token)

    Object.keys(root)
        .forEach(function (key) {
          if (key === 'docs') return

          memo.concat(this.expand(token + key, memo))
        }, this)

    return memo
  }

  /**
   * Returns a representation of the token store ready for serialisation.
   *
   * @returns {Object}
   * @memberOf TokenStore
   */
  lunr.TokenStore.prototype.toJSON = function () {
    return {
      root: this.root,
      length: this.length
    }
  }


  /**
   * 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.lunr = 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
  }))
})()