How a Swift property wrapper can refer to its enclosing type, and examples of how that capability could be used.
Vincent Pradeilles joins John to discuss various ways to use Swift language features like key paths and closures, how they relate to patterns typically used within functional programming, and when and how to adopt such patterns.
A roundup of some of the key ways in which Swift 5.3 enhances the overall experience of building views using SwiftUI.
An overview of the tools and directives that enable us to influence how our Swift code gets compiled, and what sort of situations that each of those tools might be particularly useful in.
A closer look at Swift’s result builders feature, and how it can give us some really valuable insights into how SwiftUI’s DSL operates under the hood.
A look at a few somewhat lesser-known ways in which enums can be used to solve various problems in Swift-based apps and libraries.
Let’s take a closer look at opaque return types, how they can be used both with and without SwiftUI, and how they compare to similar generic programming techniques, such as type erasure.
An introduction to Swift’s type inference system, how it makes the syntax of the language so lightweight, and how to work around some of its limitations.
In this Basics article, let’s take a look at a few examples of the various kinds of properties that Swift supports, and what their characteristics are.
Swift enums are really powerful, but they can often be made even more capable when mixed with other kinds of Swift types — such as protocols and structs. This week, let’s take a look at a few examples of doing just that.
What makes Swift a protocol-oriented language, and how can protocols be used to create abstractions and to enable code reuse? That’s what we’ll take a look at in this Basics article.
A summary of all Swift by Sundell content published during March 2020.
Let’s explore how optional values work in Swift, including how they’re implemented under the hood, and what sort of techniques that we can use to handle them.
This week, let’s take a look at how Swift’s property wrappers work, and explore a few examples of situations in which they could be really useful.
Welcome to Swift Clips — a new series of shorter videos showcasing interesting and useful Swift tips and techniques. In this first episode we’ll take a look at first class functions, which is a language feature that enables us to use functions in really powerful ways.
An overview of Swift’s five different levels of access control, how they work, and when each of them might be useful in practice.
This week, let’s dive deep into the world of pattern matching in Swift — to take a look at how we can construct completely custom patterns, and some of the interesting techniques that we can unlock by doing so.
How enums work in Swift, a look at some of their most prominent features, and examples of situations in which they can be incredibly useful.
Swift 5.1 has now been officially released, and despite being a minor release, it contains a substantial number of changes and improvements. This week, let’s take a look at five of those features, and what kind of situations they could be useful in.
This week, let’s take a look at how subscripting works in Swift, and a few different ways to incorporate it into the way we design APIs — including some brand new capabilities that are being added in Swift 5.1.
SwiftUI brings a new, declarative way to build UIs for Apple’s platforms, and also pushes the Swift language itself to new limits — by making heavy use of a set of key new syntax features, that are being introduced as part of Swift 5.1, in order to provide a very DSL-like API. This week, let’s take a first look at those features and how they work.
Being able to express basic values using inline literals is an essential feature in most programming languages. This week, let’s focus on string literals, by taking a take a look at the many different ways that they can be used and how we — through Swift’s highly protocol-oriented design — are able to customize the way literals are interpreted.
One really elegant aspect of Swift’s design is how it manages to hide much of its power behind much simpler programming constructs. Pattern matching is one source of that power, especially considering how it’s integrated into many different aspects of the language.
Reflection is a common programming language feature that enables us to inspect, and work with, the members of a type — dynamically, at runtime. That may seem at odds with Swift’s heavy focus on compile-time validation — but this week, let’s take a look at when reflection can come in handy, and how it can let us make our code a bit more dynamic.
When using syntactic sugar, what we ideally want is to be able to strike a nice balance between low verbosity and clarity, and this week, let’s take a look at a few different ways that type aliases can enable us to do just that.
A really elegant aspect of Swift's take on optionals is that they're largely implemented using the type system - since all optional values are actually represented using an enum under the hood. That gives us some interesting capabilities, since we can extend that enum to add our own convenience APIs and other kinds of functionality. This week, let's take a look at how to do just that.
Swift keeps gaining more and more features that are more dynamic in nature, while still retaining its focus on type safe code. This week, let’s take a look at how key paths in Swift work, and some of the cool and powerful things they can let us do.
With each new release, Swift keeps getting better and better at creating compiler-generated implementations of common boilerplate. One such new feature in Swift 4.2 is the new CaseIterable protocol - that enables us to tell the compiler to automatically synthesize an allCases collection for any RawRepresentable enum. This week, let's take a look at some examples of scenarios in which this new feature can come very much in handy.
Type inference is a key feature of the Swift type system and plays a big part in the syntax of the language - making it less verbose by eliminating the need for manual type annotations where the compiler itself can infer the types of various values.
One really interesting feature of Swift is the ability to create lightweight value containers using tuples. The concept is quite simple - tuples let us easily group together any number of objects or values without having to create a new type. But even though it's a simple concept, it opens up some really interesting opportunities, both in terms of API design and when structuring code.
Few Swift features cause as much heated debate as the use of custom operators. While some people find them really useful in order to reduce code verbosity, others think that they should be avoided completely. This week, let's take a look at a few situations that custom operators could be used in, and some of the pros and cons of using them.
Languages that support first class functions enable us to use functions and methods just like any other object or value. We can pass them as arguments, save them in properties or return them from another function. In order words, the language treats functions as "first class citizens".
Even though closures are very widely used, there's a lot of behaviors and caveats to keep in mind when using them. This week, let's take a closer look at closures, how capturing works and some techniques that can make handling them easier.
Using generic type constraints, we are able to add new APIs and behaviors to a type only under a certain set of constraints. This week, let's take a look at some techniques and patterns that are made possible because of type constraints, and how they can be used in practice.
Swift’s @autoclosure attribute enables us to define an argument that automatically gets wrapped in a closure. It’s primarily used to defer execution of a (potentially expensive) expression to when it’s actually needed, rather than doing it directly when the argument is passed.
Lazy properties allow you to create certain parts of a Swift type when needed, rather than doing it as part of its initialization process. This can be useful in order to avoid optionals, or to improve performance when certain properties might be expensive to create. This week, let’s take a look at a few ways to define lazy properties in Swift, and how different techniques are useful in different situations.
One major focus of Swift is compile time safety — enabling us as developers to easily focus on writing code that is more predictable and less prone to runtime errors. However, sometimes things do fail for various reasons — so this week, let’s take a look at how we can handle such failures appropriately, and what tools we have at our disposal for doing so.
While Swift does not yet feature a dedicated namespace keyword, it does support nesting types within others. Let’s take a look at how using such nested types can help us improve the structure of our code.