As soon as Swift was introduced, people were adding their own extensions and patterns to the language. One of the more common patterns was the usage of a Result object. This object took on a shape similar to Swift’s Optional, and it was used to express a return type that Read more…
One of Swift 5.2’s new features is the ability to use KeyPaths as functions. This can be extremely useful in cases where you’d only return the value of a certain KeyPath in a closure. Let’s look at a pre-Swift 5.2 example where this is the case: // Swift 5.1 and Read more…
In Swift 2.0, Apple introduced the throws keyword in Swift. This addition to Swift language added the ability for developers to write code that clearly communicates that an error might occur during the execution of a code path, and it forces the caller of that code to handle, or explicitly Read more…
The ability to define custom subscripts in Swift is really powerful. It allows us to write very natural and concise code. Consider the following example of a Grid with a custom subscript: struct Grid { let items : [[GridItem]] subscript(x x: Int, y y: Int) -> GridItem? { guard !items.isEmpty, Read more…
A new Swift 5.2 feature is the ability to call instances of types as functions. Or, as the Swift Evolution proposal calls it “Callable values of user-defined nominal types”. The very short description of this feature is that it allows you to call instances of any type that has a Read more…
Xcode 11.4 is currently still in beta, keep in mind that you can’t use this version of Xcode to ship apps to the store. Read my guide on installing multiple Xcode versions alongside each other if you want to play with the Xcode 11.4 beta while keeping your copy of Read more…
So far in my Combine series I have mostly focussed on showing you how to use Combine using its built-in mechanisms. I’ve shown you how Combine’s publishers and subscribers work, how you can use Combine for networking, to drive UI updates and how you can transform a Combine publisher’s output. Read more…
When I just started my career as a developer there was a lot I didn’t know yet. There also were a lot of things I didn’t understand or had never done before. I have always been lucky enough to work in places where I was able to learn and grow Read more…
Oftentimes when you’re working with Combine, you’ll have publishers that produce a certain output. Sometimes this output is exactly what you need, but often the values that are output by a publisher need to be transformed or manipulated somehow before they are useful to their subscribers. The ability to do Read more…
So far in my series of posts about Combine, we have focussed on processing values and publishing them. In all of these posts, I used the sink method to subscribe to publishers and to handle their results. Today I would like to show you a different kind of built-in subscriber; Read more…