SwiftyBinaryFormatter

This framework is an assistant in generating binary files. Makes it a lot easier, at least for me.

What it is

Its philosophy is essentially to make compiling binary data easier to comprehend, as most of the functionality is already available directly in basic Swift types. Through a combination of typealiases to help mentally bridge the concept of Byte to UInt8, etc and conveniences to append larger types, automatically breaking them down into their smaller components (like taking a Word/UInt32 and breaking it into 4 Byte/UInt8s to be successively appended to the blob). Additionally, it's meant to be as unobtrusive as possible, mimicing existing method naming styles so as to naturally slip into your code. There's more info on my blog.

Note that, while semantically, the terms may not be entirely correct as they are technically relative to the platform they are on, they should should line up with what their typically understood to be. I think. I don't know everything.

So if you have a need to conform to a file spec that outputs binary data, this should help assist in making that easier.

Basics

It provides methods to easily convert bidirectionallty between of the following types:

Type	Alias
UInt8	Byte
UInt16	TwoByte
UInt32	Word
UInt64	LongWord

All of the following can be converted to any of the above types easily:

• UInt
• Int
• Int8
• Int16
• Int32
• Int64

And finally, the following can be converted to an array of Byte:

• Float
• Double

The integer types all gain the following properties and methods (which enable the above mentioned functionality) through the BinaryFormattingProtocol:

• var byteCount: Int
• static var typeByteCount: Int
• var longWords: [LongWord]
• var longWord: LongWord
• var wordsArray: [Word] (words is already part of vanilla Swift)
• var word: Word
• var twoBytes: [TwoByte]
• var twoByte: TwoByte
• var bytes: [Byte]
• var byte: Byte
• var hexString: String
• var binaryString: String
• init(hexString: String)
• init(character: Character)
• subscript(_ index: Int) -> UInt8 (returns the value of the bit in the requested index)
• subscript(padded index: Int) -> UInt8 (returns the value of the bit in the requested index, padding if you escape the bitWidth of the type)

And both integer AND float types gain the BitRepper protocol, allowing easy retrieval of the underlying bit representation of the value. (Yes, float types come with this, but with the protcol, you can pass either type into a function and get the underlying bitPattern regardless)

So this is great and everything, but what can you do with it? Well, Data is a great type. The thing is, it's a bit strict. Its main interaction is with UInt8s, or Bytes. It only likes appending Bytes, initializing from Bytes, and pretty much nothing else. But that doesn't make much sense, does it? I mean, all these other types are really just UInt8/Bytess underneath it all, aren't they? (Yes, they are) Well, the real magic of SwiftyBinaryFormatter is that you now can use all these types with Data and it will magically just break them down into their source Bytes for you.

So, have an Int you need to store in a Data blob? Easy!

let myInt = 1234

let myFirstData = Data(myInt.bytes)

Wait, now I need to smash a magic number on the front, and follow it up with a Double value of today's date and then pi.:

var compiledData = Data(magicNumber)
compiledData.append(myFirstData)
compiledData.append(Date().timeIntervalSince1970)
compiledData.append(Double.pi)

And finally add a Byte, Word, TwoByte, Word, LongWord sequence because reasons.

compiledData.append(contentsOf: [Byte(3), Word(42), TwoByte(1238), Word(123456789), LongWord(9999999999)])

I think you get the picture.

Installation

Carthage

1. Add github "mredig/SwiftyBinaryFormatter" ~> 1.0.0 to your cartfile
2. carthage update
3. Add import SwiftyBinaryFormatter to the top of any file you with to use it in

SPM

1. Add the line .package(url: "https://github.com/mredig/SwiftyBinaryFormatter.git", from: "1.0.0") to the appropriate section of your Package.swift
   • The Package Name is SwiftyBinaryFormatter - add that as a dependency to any targets you want to use it in.
2. swift package update or use Xcode
3. Add import SwiftyBinaryFormatter to the top of any file you with to use it in

CocoaPods

1. Run brew install carthage
2. Create a file in your project called Cartfile and add the line github "mredig/SwiftyBinaryFormatter" ~> 1.0.0
3. Run carthage update
4. ...Basically, just use Carthage. It's better.