Map of Sets

Simple data storage that holds multiple unique values per key — a Map<K, Set<V>> with a convenient API.

Map {
  [key1]: Set[value1, value2, value3],
  [key2]: Set[value1, value2, value3],
  [key3]: Set[value1, value2, value3],
}

Installation

npm install @actualwave/map-of-sets

Usage

import MapOfSets, { createMapOfSets } from '@actualwave/map-of-sets';

const sets = new MapOfSets<string, string>();
sets.add('key', 'value 1');
sets.add('key', 'value 2');
sets.add('key', 'value 3');
sets.add('key', 'value 2'); // duplicate — ignored

console.log(sets.get('key')); // Set { 'value 1', 'value 2', 'value 3' }
console.log(sets.list('key')); // ['value 1', 'value 2', 'value 3']

API

| Method | Description | |---|---| | has(key) | Returns true if the key exists and its Set is non-empty | | hasValue(key, value) | Returns true if the value exists under the key | | get(key) | Returns the Set for the key, or undefined | | list(key) | Returns an array of values for the key, or [] | | forEach(callback) | Calls callback(value, key, map) for every value of every key | | eachValue(key, callback) | Calls callback(value, key, map) for every value of the given key | | add(key, value) | Adds a value to the key's Set (creates the Set if needed) | | set(key, values) | Replaces all values for the key with a Set or array; removes the key if empty | | remove(key) | Removes the key and all its values | | removeValue(key, value) | Removes a single value; removes the key if the Set becomes empty | | clone() | Returns a deep copy of the map |