@esfx/collections-hashset Package

Provides the HashSet class, a collection class that utilizes @esfx/collection-core and @esfx/equatable.

Installation

npm i @esfx/collections-hashset

Usage

• TypeScript
• JavaScript (CommonJS)

import { HashSet } from "@esfx/collections-hashset";
import { Equatable, Equaler, Comparable, Comparer } from "@esfx/equatable";

class Person {
    firstName: string;
    lastName: string;
    constructor(firstName: string, lastName: string) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    toString() {
        return `${this.firstName} ${this.lastName}`;
    }

    [Equatable.equals](other: unknown) {
        return other instanceof Person
            && this.lastName === other.lastName
            && this.firstName === other.firstName;
    }

    [Equatable.hash]() {
        return Equaler.defaultEqualer.hash(this.lastName)
            ^ Equaler.defaultEqualer.hash(this.firstName);
    }

    [Comparable.compareTo](other: unknown) {
        if (!(other instanceof Person)) throw new TypeError();
        return Comparer.defaultComparer.compare(this.lastName, other.lastName)
            || Comparer.defaultComparer.compare(this.firstName, other.firstName);
    }
}

const obj1 = new Person("Bob", "Clark");
const obj2 = new Person("Bob", "Clark");

const set = new Set<Person>(); // native ECMAScript Set
set.add(obj1);
set.add(obj2);
set.size; // 2

const hashSet = new HashSet<Person>();
hashSet.add(obj1);
hashSet.add(obj2);
hashSet.size; // 1

Classes

HashSet

Interfaces

ReadonlyHashSet<T>