javascript integer set implemented with bitmap

intset.js

// Copyright (c) 2021, Wei Mingzhi <whistler_wmz@users.sf.net>.
// SPDX-License-Identifier: BSD-2-Clause

const IntSet = function () {
    this.data = [];
    this.size = 0;
};

IntSet.prototype.add = function (num) {
    const index = num >> 5;
    const pos = num & 31;
    if (this.data[index] === undefined) {
        this.data[index] = 0;
    }
    if (!(this.data[index] & (1 << pos))) {
        this.data[index] |= 1 << pos;
        ++this.size;
    }
};

IntSet.prototype.delete = function (num) {
    const index = num >> 5;
    const pos = num & 31;
    if (this.data[index] !== undefined && (this.data[index] & (1 << pos))) {
        this.data[index] &= ~(1 << pos);
        --this.size;
    }
};

IntSet.prototype.has = function (num) {
    const index = num >> 5;
    const pos = num & 31;

    return !!(this.data[index] && (this.data[index] & (1 << pos)));
};

IntSet.prototype.clear = function () {
    this.data = [];
    this.size = 0;
};

IntSet.prototype.fill = function (size) {
    this.size = size;
    this.data = Array((size >> 5) + 1).fill(-1);
    for (var i = 31; i > (size & 31); --i) {
        this.data[size >> 5] &= ~(1 << i);
    }
};

IntSet.prototype.forEach = function (cb) {
    this.data.forEach(function (d, idx) {
        for (var i = 0; i < 32; ++i) {
	    if (d & (1 << i)) {
                cb(idx << 5 | i);
            }
        }
    });
};