bitmask

bitmask is a Dart package that provides a Bitmask class.

Introduction

A Bitmask object contains a collection of individual bits that may be set or not set (1 or 0). Constructors and methods are provided for setting and unsetting individual bits in a Bitmask and for applying operations such as bitwise ANDing, ORing, and XORing masks together, taking a bitwise complement, and for getting the integer value represented by the Bitmask object.

Bitmask objects are limited to representing 63 bits as this is the largest number of bits that can be contained in a Dart integer. If this class is used on the Web, the maximum number of bits should be limited to 52 as this is the largest number of bits that can be represented reliably by Javascript.

Here is a simple example showing how to use the Bitmask class with enumerations:

import 'package:bitmask/bitmask.dart';

enum Maskbits { zero, one, two, three, four, }

void main() {
  var mask1 = Bitmask.fromList([Maskbits.one.index, 
      Maskbits.three.index],
      Maskbits.values().length);
  mask1[Maskbits.four] = true;
  var mask2 = Bitmask.fromBitmask(mask1);
  mask2.unset(Maskbits.three.index);
  print(mask1.flags.toRadixString(2)); // prints 11010
  print((mask1 & mask2).flags.toRadixString(2)); // prints 10010
  print((mask1 | mask2).flags.toRadixString(2)); // prints 11010
  print((mask1 ^ mask2).flags.toRadixString(2)); // prints 1000
  print(~mask1.flags.toRadixString(2)); // prints 101
}

Installation

Add bitmask to your pubspec.yaml file.

dependencies:
  bitmask: ^1.0.0

After saving the pubspec.yaml file, run:

dart pub update