BinaryInitializable

Simple Swift macro for instantiating structs and classes from binary data.

Currently only supports numerical values.

Usage

Use the @BinaryInitializable macro on your structs and classes to automatically conform them to the BinaryInitialization protocol. An appropriate initializer will be generated that takes your binary data and initializes the object's properties from the binary data in source order.

Example

@BinaryInitializable
struct ScanResults {
  let distance: UInt32
  let speed: Double
}

// You will probably read your bytes from a file or external source
let bytes: [UInt8] = [0x0, 0x0, 0x9, 0xCA, 0x40, 0x3C, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCD]
let data = Data(bytes)

guard let results = try? ScanResults(binaryData: data) else {
  fatalError("In real life we should handle errors better!")
}

print("Our scan indicates you went \(results.distance) feet at an average speed of \(results.speed) MPH!")
// Output: Our scan indicates you went 2506 feet at an average speed of 28.8 MPH!
// Well, if we were less lazy with the number formatting.

If you have header data you want to ignore or only want to target a subset of bytes, Data subscripting is an easy shortcut.

// Ignore the first 4 bytes
let column = try? DataColumn(binaryData: data[4...])

What about endianness? By default, BinaryInitializable assumes your data is in little endian format. You can change this with the bigEndian flag.

@BinaryInitializable(bigEndian: true)
struct ScanResults {
  let distance: UInt32
  let speed: Double
}