bitmasker

bitmasker is a high-performance JavaScript utility library that simplifies bitmasking operations for combinatorial problems, permissions handling, and mathematical optimizations. It provides functions for setting, toggling, and querying bits, generating subsets and combinations, performing bitwise set operations, and optimizing common bitwise computations. Whether you're working with dynamic programming, combinatorics, or low-level optimizations, bitmasker makes it easier and faster to handle bit-level manipulations in JavaScript.

📦 Installation

Install via npm

npm i bitmasker

Install via yarn

yarn add bitmasker

Usage

const bm = require('bitmasker');

// Bit Manipulation Basics
console.log(bm.setBit(5, 1));        // 7 (0b101 → 0b111)
console.log(bm.clearBit(7, 1));      // 5 (0b111 → 0b101)
console.log(bm.toggleBit(5, 2));     // 1 (0b101 → 0b001)
console.log(bm.checkBit(5, 2));      // true (Bit at position 2 is set)

// Counting & Identifying Bits
console.log(bm.countSetBits(13));    // 3 (0b1101 → 3 ones)
console.log(bm.highestSetBit(18));   // 4 (0b10010 → highest set bit at pos 4)
console.log(bm.lowestSetBit(18));    // 1 (0b10010 → lowest set bit at pos 1)

// Power of Two Check
console.log(bm.isPowerOfTwo(16));    // true (16 is a power of 2)
console.log(bm.isPowerOfTwo(18));    // false (18 is not a power of 2)

console.log(bm.logBase2(16)); // 4  (2^4 = 16)
console.log(bm.hammingWeight(5)); // 2  (0b101 has 2 ones)
console.log(bm.popCountParallel(15)); // 4  (0b1111 has 4 ones)

// Subset & Combination Generation
console.log(bm.generateSubsets(3));  // ['000', '001', '010', '011', '100', '101', '110', '111']
console.log(bm.generateCombinations(4, 2)); // [ '0011', '0101', '0110', '1001', '1010', '1100' ]

// Bitmask Operations
const mapping = { a: 0, b: 1, c: 2 };

console.log(bm.toBitmask(['a', 'c'], mapping)); // 5  (0b101)
console.log(bm.fromBitmask(5, { 0: 'a', 1: 'b', 2: 'c' })); // ['a', 'c']

// Bit Manipulation
console.log(bm.binaryString(5)); // "00000000000000000000000000000101"
console.log(bm.nextBitPermutation(6)); // 9  (0b0110 -> 0b1001)
console.log(bm.grayCode(2)); // [0, 1, 3, 2]

// Bitwise Set Operations
console.log(bm.bitwiseUnion(5, 3)); // 7  (0b101 | 0b011)
console.log(bm.bitwiseIntersection(5, 3)); // 1  (0b101 & 0b011)
console.log(bm.bitwiseDifference(5, 3)); // 6  (0b101 ^ 0b011)
console.log(bm.bitwiseSubset(3, 7)); // true  (0b011 is a subset of 0b111)

// Math Using Bitwise
console.log(bm.fastModularExponentiation(2, 10, 1000)); // 24 (2^10 % 1000)
console.log(bm.fastGCD(48, 18)); // 6  (GCD of 48 and 18)

// Next Bit Permutation (Lexicographical Order)
console.log(bm.nextBitPermutation(8));  // 16 (0b1000 → 0b10000)
console.log(bm.nextBitPermutation(10)); // 12 (0b1010 → 0b1100)

📖 API Reference - Bitmasker