1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
/**
* An interface for a JavaScript object that
* acts a dictionary. The keys are strings.
*/
export type IStringDictionary<V> = Record<string, V>;
/**
* An interface for a JavaScript object that
* acts a dictionary. The keys are numbers.
*/
export type INumberDictionary<V> = Record<number, V>;
/**
* Groups the collection into a dictionary based on the provided
* group function.
*/
export function groupBy<K extends string | number | symbol, V>(data: V[], groupFn: (element: V) => K): Record<K, V[]> {
const result: Record<K, V[]> = Object.create(null);
for (const element of data) {
const key = groupFn(element);
let target = result[key];
if (!target) {
target = result[key] = [];
}
target.push(element);
}
return result;
}
export function diffSets<T>(before: Set<T>, after: Set<T>): { removed: T[]; added: T[] } {
const removed: T[] = [];
const added: T[] = [];
for (const element of before) {
if (!after.has(element)) {
removed.push(element);
}
}
for (const element of after) {
if (!before.has(element)) {
added.push(element);
}
}
return { removed, added };
}
export function diffMaps<K, V>(before: Map<K, V>, after: Map<K, V>): { removed: V[]; added: V[] } {
const removed: V[] = [];
const added: V[] = [];
for (const [index, value] of before) {
if (!after.has(index)) {
removed.push(value);
}
}
for (const [index, value] of after) {
if (!before.has(index)) {
added.push(value);
}
}
return { removed, added };
}
export class SetMap<K, V> {
private map = new Map<K, Set<V>>();
add(key: K, value: V): void {
let values = this.map.get(key);
if (!values) {
values = new Set<V>();
this.map.set(key, values);
}
values.add(value);
}
delete(key: K, value: V): void {
const values = this.map.get(key);
if (!values) {
return;
}
values.delete(value);
if (values.size === 0) {
this.map.delete(key);
}
}
forEach(key: K, fn: (value: V) => void): void {
const values = this.map.get(key);
if (!values) {
return;
}
values.forEach(fn);
}
}
|
