Chris Eidhof shows some functional programming practices in Swift and explains how to use them to build tiny networking library.
The way that I work in Swift is just starting out by playing around a little bit and calling some functions. You wrap them in an autofunction and you can keep refactoring and massaging this until you end up with lots of short, small, sweet functions.
You can watch Tiny Networking: Building Micro-Libraries in Swift talk on realm.io. You could be also interested in Chris' Functional Programming in Swift talk.