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1/**2 * Mnemonist Fuzzy Map3 * ====================4 *5 * The fuzzy map is a map whose keys are processed by a function before6 * read/write operations. This can often result in multiple keys accessing7 * the same resource (example: a map with lowercased keys).8 */9var forEach = require('obliterator/foreach');10 11var identity = function(x) {12  return x;13};14 15/**16 * FuzzyMap.17 *18 * @constructor19 * @param {array|function} descriptor - Hash functions descriptor.20 */21function FuzzyMap(descriptor) {22  this.items = new Map();23  this.clear();24 25  if (Array.isArray(descriptor)) {26    this.writeHashFunction = descriptor[0];27    this.readHashFunction = descriptor[1];28  }29  else {30    this.writeHashFunction = descriptor;31    this.readHashFunction = descriptor;32  }33 34  if (!this.writeHashFunction)35    this.writeHashFunction = identity;36  if (!this.readHashFunction)37    this.readHashFunction = identity;38 39  if (typeof this.writeHashFunction !== 'function')40    throw new Error('mnemonist/FuzzyMap.constructor: invalid hash function given.');41 42  if (typeof this.readHashFunction !== 'function')43    throw new Error('mnemonist/FuzzyMap.constructor: invalid hash function given.');44}45 46/**47 * Method used to clear the structure.48 *49 * @return {undefined}50 */51FuzzyMap.prototype.clear = function() {52  this.items.clear();53 54  // Properties55  this.size = 0;56};57 58/**59 * Method used to add an item to the FuzzyMap.60 *61 * @param  {any} item - Item to add.62 * @return {FuzzyMap}63 */64FuzzyMap.prototype.add = function(item) {65  var key = this.writeHashFunction(item);66 67  this.items.set(key, item);68  this.size = this.items.size;69 70  return this;71};72 73/**74 * Method used to set an item in the FuzzyMap using the given key.75 *76 * @param  {any} key  - Key to use.77 * @param  {any} item - Item to add.78 * @return {FuzzyMap}79 */80FuzzyMap.prototype.set = function(key, item) {81  key = this.writeHashFunction(key);82 83  this.items.set(key, item);84  this.size = this.items.size;85 86  return this;87};88 89/**90 * Method used to retrieve an item from the FuzzyMap.91 *92 * @param  {any} key - Key to use.93 * @return {any}94 */95FuzzyMap.prototype.get = function(key) {96  key = this.readHashFunction(key);97 98  return this.items.get(key);99};100 101/**102 * Method used to test the existence of an item in the map.103 *104 * @param  {any} key - Key to check.105 * @return {boolean}106 */107FuzzyMap.prototype.has = function(key) {108  key = this.readHashFunction(key);109 110  return this.items.has(key);111};112 113/**114 * Method used to iterate over each of the FuzzyMap's values.115 *116 * @param  {function}  callback - Function to call for each item.117 * @param  {object}    scope    - Optional scope.118 * @return {undefined}119 */120FuzzyMap.prototype.forEach = function(callback, scope) {121  scope = arguments.length > 1 ? scope : this;122 123  this.items.forEach(function(value) {124    callback.call(scope, value, value);125  });126};127 128/**129 * Method returning an iterator over the FuzzyMap's values.130 *131 * @return {FuzzyMapIterator}132 */133FuzzyMap.prototype.values = function() {134  return this.items.values();135};136 137/**138 * Attaching the #.values method to Symbol.iterator if possible.139 */140if (typeof Symbol !== 'undefined')141  FuzzyMap.prototype[Symbol.iterator] = FuzzyMap.prototype.values;142 143/**144 * Convenience known method.145 */146FuzzyMap.prototype.inspect = function() {147  var array = Array.from(this.items.values());148 149  Object.defineProperty(array, 'constructor', {150    value: FuzzyMap,151    enumerable: false152  });153 154  return array;155};156 157if (typeof Symbol !== 'undefined')158  FuzzyMap.prototype[Symbol.for('nodejs.util.inspect.custom')] = FuzzyMap.prototype.inspect;159 160/**161 * Static @.from function taking an arbitrary iterable & converting it into162 * a structure.163 *164 * @param  {Iterable}       iterable   - Target iterable.165 * @param  {array|function} descriptor - Hash functions descriptor.166 * @param  {boolean}        useSet     - Whether to use #.set or #.add167 * @return {FuzzyMap}168 */169FuzzyMap.from = function(iterable, descriptor, useSet) {170  var map = new FuzzyMap(descriptor);171 172  forEach(iterable, function(value, key) {173    if (useSet)174      map.set(key, value);175    else176      map.add(value);177  });178 179  return map;180};181 182/**183 * Exporting.184 */185module.exports = FuzzyMap;186