source: trip-planner-front/node_modules/source-map/lib/array-set.js@ 76712b2

Last change on this file since 76712b2 was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

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1/* -*- Mode: js; js-indent-level: 2; -*- */
2/*
3 * Copyright 2011 Mozilla Foundation and contributors
4 * Licensed under the New BSD license. See LICENSE or:
5 * http://opensource.org/licenses/BSD-3-Clause
6 */
7
8/**
9 * A data structure which is a combination of an array and a set. Adding a new
10 * member is O(1), testing for membership is O(1), and finding the index of an
11 * element is O(1). Removing elements from the set is not supported. Only
12 * strings are supported for membership.
13 */
14class ArraySet {
15 constructor() {
16 this._array = [];
17 this._set = new Map();
18 }
19
20 /**
21 * Static method for creating ArraySet instances from an existing array.
22 */
23 static fromArray(aArray, aAllowDuplicates) {
24 const set = new ArraySet();
25 for (let i = 0, len = aArray.length; i < len; i++) {
26 set.add(aArray[i], aAllowDuplicates);
27 }
28 return set;
29 }
30
31 /**
32 * Return how many unique items are in this ArraySet. If duplicates have been
33 * added, than those do not count towards the size.
34 *
35 * @returns Number
36 */
37 size() {
38 return this._set.size;
39 }
40
41 /**
42 * Add the given string to this set.
43 *
44 * @param String aStr
45 */
46 add(aStr, aAllowDuplicates) {
47 const isDuplicate = this.has(aStr);
48 const idx = this._array.length;
49 if (!isDuplicate || aAllowDuplicates) {
50 this._array.push(aStr);
51 }
52 if (!isDuplicate) {
53 this._set.set(aStr, idx);
54 }
55 }
56
57 /**
58 * Is the given string a member of this set?
59 *
60 * @param String aStr
61 */
62 has(aStr) {
63 return this._set.has(aStr);
64 }
65
66 /**
67 * What is the index of the given string in the array?
68 *
69 * @param String aStr
70 */
71 indexOf(aStr) {
72 const idx = this._set.get(aStr);
73 if (idx >= 0) {
74 return idx;
75 }
76 throw new Error('"' + aStr + '" is not in the set.');
77 }
78
79 /**
80 * What is the element at the given index?
81 *
82 * @param Number aIdx
83 */
84 at(aIdx) {
85 if (aIdx >= 0 && aIdx < this._array.length) {
86 return this._array[aIdx];
87 }
88 throw new Error("No element indexed by " + aIdx);
89 }
90
91 /**
92 * Returns the array representation of this set (which has the proper indices
93 * indicated by indexOf). Note that this is a copy of the internal array used
94 * for storing the members so that no one can mess with internal state.
95 */
96 toArray() {
97 return this._array.slice();
98 }
99}
100exports.ArraySet = ArraySet;
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