The objc.io folks — who recently closed down their excellent monthly blog/magazine to focus on book projects — just announced an upcoming book, Advanced Swift.
Advanced Swift takes you through Swift’s features, from low-level programming to high-level abstractions.
In this book, we’ll write about advanced concepts in Swift programming. If you have read the Swift Programming Guide, and want to explore more, this book is for you. Swift is a great language for systems programming, but also lends itself for very high-level programming. We’ll explore both high-level topics (for example, programming with generics and protocols), as well as low-level topics (for example, wrapping a C library and string internals).
The announcement email says:
We will release chapters one-by-one, and the first chapter on Strings is already available for those that order the early access version now. During the next months, we will keep releasing chapters, and we aim to finish the book when Swift 2 is public. The book is written by Airspeed Velocity and Chris Eidhof.
It’s $39 for the e-book, or $59 to get the print edition too.