@amarillion/helixgraph/lib/multimap.js

A collection of graph algorithms for game development

/**
 * Map<key, []>
 *
 * if key doesn't exist, create a single-element array with value
 * if key exists, push to the end of the array
 */
export function mmArrayPush(map, key, value) {
    const keyExists = map.has(key);
    if (keyExists) {
        map.get(key).push(value);
    }
    else {
        map.set(key, [value]);
    }
    return !keyExists;
}
/**
 * Map<key, Set()>
 *
 * if key doesn't exist, create a single-element Set with value
 * if key exists, add to the Set
 */
export function mmSetAdd(map, key, value) {
    const keyExists = map.has(key);
    if (keyExists) {
        map.get(key).add(value);
    }
    else {
        map.set(key, new Set([value]));
    }
    return !keyExists;
}