1import { Hashable } from "./Hashable";
 2
 3export class HashableSet<T extends Hashable> extends Set<T> implements Hashable {
 4  get hashKey() {
 5    return JSON.stringify([...this.values()].map((value) => value.hashKey).sort());
 6  }
 7
 8  equals(other: unknown): boolean {
 9    return other instanceof HashableSet && this.hashKey === (other as HashableSet<T>).hashKey;
10  }
11}
12
13export class HashSet<T extends Hashable> extends HashableSet<T> {
14  static readonly EMPTY = Object.freeze(new HashSet());
15  [Symbol.toStringTag]: "Set";
16  private readonly elementMap = new Map<string, T>();
17
18  constructor(iterable?: Iterable<T>) {
19    super();
20    if (iterable) {
21      for (const value of iterable) {
22        this.add(value);
23      }
24    }
25  }
26
27  get size() {
28    return this.elementMap.size;
29  }
30
31  add(value: T): this {
32    this.elementMap.set(value.hashKey, value);
33    return this;
34  }
35
36  clear(): void {
37    this.elementMap.clear();
38  }
39
40  delete(value: T): boolean {
41    return this.elementMap.delete(value.hashKey);
42  }
43
44  forEach(callback: (value: T, value2: T, set: Set<T>) => void, thisArg?: any): void {
45    const self = this;
46    this.elementMap.forEach((value) => {
47      callback.bind(thisArg)(value, value, self);
48    });
49  }
50
51  has(value: T): boolean {
52    return this.elementMap.has(value.hashKey);
53  }
54
55  [Symbol.iterator](): IterableIterator<T> {
56    return this.values();
57  }
58
59  *entries(): IterableIterator<[T, T]> {
60    for (const value of this.elementMap.values()) {
61      yield [value, value];
62    }
63  }
64
65  keys(): IterableIterator<T> {
66    return this.elementMap.values();
67  }
68
69  values(): IterableIterator<T> {
70    return this.elementMap.values();
71  }
72}