binary-parse-fn

Painless streaming binary protocol parsers using generators.

Installation

npm install binary-parse-fn

Streaming use

This module uses the exact same generator interface as binary-parse-stream, which presents a streaming interface to a generator parser.

Usage

var BinaryParser = require('binary-parse-fn')

BinaryParser is a function that takes a buffer and passes the return value of your generator back. When your generator yields a number, it'll be fed a buffer of that length from the input. If it yields -1, it'll be given the value of the first byte instead of a single-byte buffer.

Example

The following module parses a protocol that consists of a 32-bit unsigned big-endian type parameter, an unsigned 8-bit length parameter, and a buffer of the specified length. It returns {type, buf} objects.

var BinaryParser = require('binary-parse-fn')
 
module.exports = BinaryParser(function*() {
  var type = (yield 4).readUInt32BE(0, true)
    , length = yield -1
    , buf = yield length
  return { type: type, buf: buf }
})