Swift: Developing iOS Applications

Putting protocols and generics to use

One cool part of Swift is generators and sequences. They provide an easy way to iterate over a list of values. Ultimately, they boil down to two different protocols: GeneratorType and SequenceType. If you implement the SequenceType protocol in your custom types, it allows you to use the for-in loop over an instance of your type. In this section, we will look at how we can do that.

Generators

The most critical part of this is the GeneratorType protocol. Essentially, a generator is an object that you can repeatedly ask for the next object in a series until there are no objects left. Most of the time you can simply use an array for this, but it is not always the best solution. For example, you can even make a generator ...