We continue to build our PostgreSQL wrapper. This time, we add the possibility of using queries with properly escaped parameters. To achieve this, we have to dive deep into Swift's unsafe pointer APIs.
We look at multiple ways to create variables that have a class type but also conform to a protocol.
We add the ability to map over signals and control subscriptions in a more fine-grained manner. Along the way, we improve the signal ownership model and implement the concept of disposables.
In this episode, we make a custom collection conform to Sequence. This allows us to efficiently iterate over the elements, and we gain all the useful functionality of Sequence.
We show how to make an extension on array available to other collections: first, we implement it for array slices, then we implement it as a protocol extension for all collections.
In this episode, we implement search functionality for our Ledger GUI app. In the process, we leverage several aspects we've talked about before, such as connecting view controllers, managing application state, and parsing user input.
We build a tree structure beginning with a flat array of Ledger account names. We first implement the tree using a class, and then we refactor it to a struct and discuss the differences and tradeoffs involved.
We extend the networking code from the first episode to support POST requests. Besides using Swift's enums with associated values and generics, we get to implement a map function on a custom data type.