https://github.com/patrickroberts/struct-view
Simple DSL for defining binary structures in JavaScript
https://github.com/patrickroberts/struct-view
Last synced: about 1 month ago
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Simple DSL for defining binary structures in JavaScript
- Host: GitHub
- URL: https://github.com/patrickroberts/struct-view
- Owner: patrickroberts
- License: mit
- Created: 2022-01-19T21:01:22.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2025-05-08T02:48:48.000Z (about 2 months ago)
- Last Synced: 2025-05-08T03:23:48.537Z (about 2 months ago)
- Language: TypeScript
- Homepage: http://patrickroberts.dev/struct-view/
- Size: 426 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# struct-view
[](https://github.com/patrickroberts/struct-view/actions)
[](https://codecov.io/gh/patrickroberts/struct-view)
[](https://github.com/patrickroberts/struct-view/blob/main/LICENSE)
[](https://www.npmjs.com/package/struct-view)
## Simple DSL for defining binary structures in JavaScript
### Why struct-view?
This library enables developers to define and use packed binary structures in JavaScript without any external dependencies. It is not intended for ABI-compliance or for use with foreign function interfaces.
### Installation
```sh
npm i struct-view
yarn add struct-view
```
### Example Usage
Writing a WAV header:
```ts
// wav.ts
import { char, struct, uint16, uint32, uint8, union } from 'struct-view';
const ChunkHeader = struct(
char(4)('chunkId'),
uint32('chunkSize'),
);
const SubChunk1 = struct(
ChunkHeader,
uint16('audioFormat'),
uint16('numChannels'),
uint32('sampleRate'),
uint32('byteRate'),
uint16('blockAlign'),
uint16('bitsPerSample'),
);
const WavHeader = struct(
ChunkHeader,
char(4)('format'),
SubChunk1('subChunk1'),
ChunkHeader('subChunk2'),
);
const WavBytes = uint8(WavHeader.BYTES_PER_INSTANCE);
const WavView = union(
WavHeader('header'),
WavBytes('bytes'),
);
const view = new WavView();
const { header, bytes } = view;
const { subChunk1, subChunk2 } = header;
header.chunkId = 'RIFF';
header.chunkSize = header.byteLength - ChunkHeader.BYTES_PER_INSTANCE;
header.format = 'WAVE';
subChunk1.chunkId = 'fmt ';
subChunk1.chunkSize = subChunk1.byteLength - ChunkHeader.BYTES_PER_INSTANCE;
subChunk1.audioFormat = 1;
subChunk1.numChannels = 1;
subChunk1.sampleRate = 44100;
subChunk1.byteRate = 88200;
subChunk1.blockAlign = 2;
subChunk1.bitsPerSample = 16;
subChunk2.chunkId = 'data';
process.stdout.write(bytes);
```
Output:
```
npx ts-node examples/wav | xxd
00000000: 5249 4646 2400 0000 5741 5645 666d 7420 RIFF$...WAVEfmt
00000010: 1000 0000 0100 0100 44ac 0000 8858 0100 ........D....X..
00000020: 0200 1000 6461 7461 0000 0000 ....data....
```
### Documentation
API Reference available on [GitHub Pages](https://patrickroberts.github.io/struct-view)
### Code Coverage
Available on [Codecov](https://codecov.io/gh/patrickroberts/struct-view)
### Todo
* Bitfield Support