LANGUAGE · 52 ARTICLES
Continue through the latest Swift language articles.
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\.name is not shorthand syntax for map, but a value of the independent KeyPath type. This article explains what it means to turn property access into a value, the three layers—read-only, value-type writable, and reference-type writable—and practical use cases.
Read articleProperty wrappers are a Swift language feature introduced in Swift 5.1 through SE-0258, not SwiftUI syntax. This article explains how the compiler translates @Clamped, what wrappedValue and projectedValue ($) really are, and where to draw the line against overuse.
Read articleFrom what Codable synthesis actually generates to standard fixes for key mismatches, date formats, nested structures, and partial failures—and DecodingError debugging.
Read articleThe five functions map·filter·compactMap·flatMap·reduce differ by what the closure returns. This guide covers when to choose them over for loops, the intermediate arrays created by chaining, and the problems lazy sequences solve.
Read articleAssociated types are type placeholders built into protocols. This article explains the infamous generic constraint error, how SE-0309 and SE-0346 removed the restrictions, and how to use primary associated types.
Read articleMethod swizzling is a technique that swaps, at runtime, the mapping table connecting selectors and IMPs. This guide covers the conventional implementation, the side effect of _cmd lying, and the boundaries of acceptable use.
Read articleIn code written since Swift 5.6, you’ll see some or any before protocol names: some View, any Error, some Collection. Protocol names used to work directly in type positions, but the compiler now warns or errors unless you add any.…
Read articleThe first time you encounter angle brackets <T> in Swift code, you pause. A capital letter appears beside a function name, and opening the documentation reveals signatures like func map<T>( transform: (Element) -> T) -> [T]. Generics are the gateway to intermediate Swift…
Read articleWhy does method-swizzling code always go in +load? Can’t we put it in the similar-looking +initialize instead?
Read articleSE-0296 and SE-0345 often appear in Swift articles and release notes. SE-0296 accompanies async/await, while SE-0345 appears in discussions of shorthand if let name syntax. What are these numbers?
Read articleThe Swift standard library reveals one striking fact: not only primitive types such as Int, Double, and Bool, but also String, Array, Dictionary, and Set are all structs. Things that are naturally classes in other languages are value types in Swift…
Read articleSwift has an unusual coexistence: beginners start with one line, print("Hello"), in Playgrounds, while the same language implements a standard library tangled with generics and macros. A coding education app for elementary students (Swift…
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