Swift 5.3 released, faster and easier to use and more compatible
Swift is a general-purpose programming language built using a modern approach to safety, performance, and software design patterns.
The goal of the Swift project is to create the best available language for uses ranging from systems programming, to mobile and desktop apps, scaling up to cloud services. Most importantly, Swift is designed to make writing and maintaining correct programs easier for the developer. To achieve this goal, we believe that the most obvious way to write Swift code must also be:
Safe. The most obvious way to write code should also behave in a safe manner. Undefined behavior is the enemy of safety, and developer mistakes should be caught before software is in production. Opting for safety sometimes means Swift will feel strict, but we believe that clarity saves time in the long run.
Fast. Swift is intended as a replacement for C-based languages (C, C++, and Objective-C). As such, Swift must be comparable to those languages in performance for most tasks. Performance must also be predictable and consistent, not just fast in short bursts that require clean-up later. There are lots of languages with novel features — being fast is rare.
Expressive. Swift benefits from decades of advancement in computer science to offer syntax that is a joy to use, with modern features developers expect. But Swift is never done. We will monitor language advancements and embrace what works, continually evolving to make Swift even better.
- Closures unified with function pointers
- Tuples and multiple return values
- Fast and concise iteration over a range or collection
- Structs that support methods, extensions, and protocols
- Functional programming patterns, e.g., map and filter
- Powerful error handling built-in
- Advanced control flow with
Swift 5.3 implements the following proposals from the Swift Evolution process:
- SE-0263 – Add a
StringInitializer with Access to Uninitialized Storage
- SE-0266 – Synthesized
- SE-0267 –
whereclauses on contextually generic declarations
- SE-0268 – Refine
- SE-0269 – Increase availability of implicit
@escapingclosures when reference cycles are unlikely to occur
- SE-0276 – Multi-Pattern Catch Clauses
- SE-0277 – Float16
- SE-0279 – Multiple Trailing Closures
- SE-0280 – Enum cases as protocol witnesses
- SE-0281 –
@main: Type-Based Program Entry Points
- SE-0282 – Clarify the Swift memory consistency model ⚛︎
- SE-0285 – Ease the transition to concise magic file strings
- SE-0286 – Forward-scan matching for trailing closures