| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121 | /* -*- Mode: js; js-indent-level: 2; -*- *//* * Copyright 2011 Mozilla Foundation and contributors * Licensed under the New BSD license. See LICENSE or: * http://opensource.org/licenses/BSD-3-Clause */var util = require('./util');var has = Object.prototype.hasOwnProperty;var hasNativeMap = typeof Map !== "undefined";/** * A data structure which is a combination of an array and a set. Adding a new * member is O(1), testing for membership is O(1), and finding the index of an * element is O(1). Removing elements from the set is not supported. Only * strings are supported for membership. */function ArraySet() {  this._array = [];  this._set = hasNativeMap ? new Map() : Object.create(null);}/** * Static method for creating ArraySet instances from an existing array. */ArraySet.fromArray = function ArraySet_fromArray(aArray, aAllowDuplicates) {  var set = new ArraySet();  for (var i = 0, len = aArray.length; i < len; i++) {    set.add(aArray[i], aAllowDuplicates);  }  return set;};/** * Return how many unique items are in this ArraySet. If duplicates have been * added, than those do not count towards the size. * * @returns Number */ArraySet.prototype.size = function ArraySet_size() {  return hasNativeMap ? this._set.size : Object.getOwnPropertyNames(this._set).length;};/** * Add the given string to this set. * * @param String aStr */ArraySet.prototype.add = function ArraySet_add(aStr, aAllowDuplicates) {  var sStr = hasNativeMap ? aStr : util.toSetString(aStr);  var isDuplicate = hasNativeMap ? this.has(aStr) : has.call(this._set, sStr);  var idx = this._array.length;  if (!isDuplicate || aAllowDuplicates) {    this._array.push(aStr);  }  if (!isDuplicate) {    if (hasNativeMap) {      this._set.set(aStr, idx);    } else {      this._set[sStr] = idx;    }  }};/** * Is the given string a member of this set? * * @param String aStr */ArraySet.prototype.has = function ArraySet_has(aStr) {  if (hasNativeMap) {    return this._set.has(aStr);  } else {    var sStr = util.toSetString(aStr);    return has.call(this._set, sStr);  }};/** * What is the index of the given string in the array? * * @param String aStr */ArraySet.prototype.indexOf = function ArraySet_indexOf(aStr) {  if (hasNativeMap) {    var idx = this._set.get(aStr);    if (idx >= 0) {        return idx;    }  } else {    var sStr = util.toSetString(aStr);    if (has.call(this._set, sStr)) {      return this._set[sStr];    }  }  throw new Error('"' + aStr + '" is not in the set.');};/** * What is the element at the given index? * * @param Number aIdx */ArraySet.prototype.at = function ArraySet_at(aIdx) {  if (aIdx >= 0 && aIdx < this._array.length) {    return this._array[aIdx];  }  throw new Error('No element indexed by ' + aIdx);};/** * Returns the array representation of this set (which has the proper indices * indicated by indexOf). Note that this is a copy of the internal array used * for storing the members so that no one can mess with internal state. */ArraySet.prototype.toArray = function ArraySet_toArray() {  return this._array.slice();};exports.ArraySet = ArraySet;
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