bit-vector/lib/index.js

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
/**
 * Use typed arrays if we can
 */

var FastArray = typeof Uint32Array === 'undefined' ? Array : Uint32Array;

/**
 * Bit vector
 */

function createBv(sizeInBits) {
  return new FastArray(Math.ceil(sizeInBits / 32));
}

function setBit(v, idx) {
  var r = idx % 32;
  var pos = (idx - r) / 32;

  v[pos] |= 1 << r;
}

function clearBit(v, idx) {
  var r = idx % 32;
  var pos = (idx - r) / 32;

  v[pos] &= ~(1 << r);
}

function getBit(v, idx) {
  var r = idx % 32;
  var pos = (idx - r) / 32;

  return !!(v[pos] & 1 << r);
}

/**
 * Exports
 */

exports.default = {
  createBv: createBv,
  setBit: setBit,
  clearBit: clearBit,
  getBit: getBit
};