binary 1.2.1

Utilities for accessing binary data and bit manipulation in Dart and Flutter

Binary

Utilities for accessing binary data and bit manipulation in Dart and Flutter.

Getting started

Using package:binary is easy, we have almost no dependencies:

# Add a new dependency to "pubspec.yaml".
dependencies:
  binary:

import 'package:binary/binary.dart';

// Start using package:binary.

If you are not familiar with extension methods in Dart, it is worth reading the documentation before using this package, which has heavy use of extensions for most functionality. A small primer is instead of writing something like:

void main() {
  // Old API in version <= 0.1.3:
  print(toBinaryPadded(0x0C, 8)); // 00001100
}

You now use toBinaryPadded (and other methods) as an extension method:

void main() {
  // New API.
  print(0x0C.toBinaryPadded(8)); // 00001100
}

Usage

This package provides a few sets of APIs extension methods and boxed classes.

See the API docs for complete documentation.

Most users will use the extension methods on int or String:

// Uses "parseBits" (on String) and "shiftRight" (on int).
void main() {
  test('shiftRight should work identical to >>> in JavaScript', () {
    expect(
      '0111' '1111'.parseBits().shiftRight(5, 8),
      '0000' '0011'.parseBits(),
    );
  });
}

For convenience, extension methods are also present on List<int>:

// Uses "rotateRight" (on List<int>).
void main() {
  test('rotateRight should work similarly to int.rotateRight', () {
    final list = ['0110' '0000'.parseBits()];
    expect(
      list.rotateRight(0, 1).toBinaryPadded(8),
      '0011' '0000',
    );
  });
}

There are also some specialized extension methods on the typed_data types:

• Uint8List, Int8List
• Uint16List, Int16List
• Uint32List, Int32List

Boxed Types

It is possible to sacrifice performance in order to get more type safety and range checking. For apps or libraries where this is a suitable tradeoff, we provide these boxed types/classes:

• Bit
• Int4 and Uint4
• Int8 and Uint8
• Int16 and Uint16
• Int32 and Uint32

Bit Patterns

There is also builder-type API for generating patterns to match against bits. The easiest way to explain this API is it is like RegExp, except for matching and capturing components of bits:

void main() {
  // Create a BitPattern.
  final $01V = BitPatternBuilder([
    BitPart(0),
    BitPart(1),
    BitPart.v(1),
  ]).build();

  // Match it against bits.
  print($01V.matches('011'.parseBits())); // true

  // Capture variables (if any), similar to a RegExp.
  print($01V.capture('011'.parseBits())); // [1]
}

Compatibility

This package is intended to work identically and well in both the standalone Dart VM, Flutter, and web builds of Dart and Flutter (both in DDC and Dart2JS). As a result, there are no built-in ways to access integers > 32-bit provided (as web integers are limited).

Feel free to file an issue if you'd like limited support for 64 and 128-bit.