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Looks awesome and conveniently designed! Am I understanding that `/* pseudocode */ el = MyElement.read( 0b111010101 ) && console.log( json.dump(el) );` would

• rezonant 5y ago
  The library has both imperative and declarative mechanisms for reading bits- The BitstreamReader class provides all the read*() methods and the elements provide a way to declare fields (ie "structural"), and use BitstreamReader to accomplish that. For bitstreamReader.read(), the first parameter is the number of bits to read. So for example: import { BitstreamReader } from '@astronautlabs/bitstream'; let reader = new BitstreamReader(); reader.addBuffer(Buffer.from([0b11101010, 0b10000000])); let value = reader.readSync(9); expect(value).to.equal(0b111010101); Conversely for writing with BitstreamWriter you can do: import { BufferedWritable, WritableStream } from '@astronautlabs/bitstream'; let writable = new BufferedWritable(); let writer = new BitstreamWriter(writable); writer.write(9, 0b111010101); expect(writable.buffer.length).to.equal(1); // because the last bit isn't a full byte writer.write(7, 0); expect(writable.buffer.length).to.equal(2); expect(Array.from(writable.buffer)).to.eql([0b11101010, 0b10000000]); Using Bitstream Elements you would do import { BitstreamElement } from '@astronautlabs/bitstream'; class MyElement extends BitstreamElement { @Field(9) value : number; } expect(MyElement.deserialize(Buffer.from([0b11101010, 0b10000000])).value).to.equal(0b111010101) // with 7 bits left expect(Array.from(new MyElement().with({ value: 0b111010101 }).serialize())).to.eql([0b11101010, 0b10000000])