This topic area is about the programming languages themselves, not about any specific API or tool. If you have an API question, go to the top level and look for a subtopic for that API. If you have a question about Apple developer tools, start in the Developer Tools & Services topic. For Swift questions: If your question is about the SwiftUI framework, start in UI Frameworks > SwiftUI. If your question is specific to the Swift Playground app, ask over in Developer Tools & Services > Swift Playground If you’re interested in the Swift open source effort — that includes the evolution of the language, the open source tools and libraries, and Swift on non-Apple platforms — check out Swift Forums If your question is about the Swift language, that’s on topic for Programming Languages > Swift, but you might have more luck asking it in Swift Forums > Using Swift. General: Forums topic: Programming Languages Swift: Forums subtopic: Programming Languages > Swift Forums tags: Swift Developer > Swift website Swift Programming Language website The Swift Programming Language documentation Swift Forums website, and specifically Swift Forums > Using Swift Swift Package Index website Concurrency Resources, which covers Swift concurrency How to think properly about binding memory Swift Forums thread Other: Forums subtopic: Programming Languages > Generic Forums tags: Objective-C Programming with Objective-C archived documentation Objective-C Runtime documentation Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

I find these sample projects quite valuable: https://developer.apple.com/documentation/widgetkit/emoji-rangers-supporting-live-activities-interactivity-and-animations https://developer.apple.com/documentation/coredata/sharing-core-data-objects-between-icloud-users . Both use Swift 5, and it is not trivial to adopt Swift 6 with them. Any plans to update them? What is best approach for adopting Swift 6 on such sample code?

I have a function a implemented in a protocol extension that's called millions of times per second. It in turn calls a function b which is required by the protocol which does not have an implementation in the extension. According to the Time Profiler in Instruments, function a spends a lot of time in __swift_instantiateGenericMetadata. I get a big performance bump by moving a out of the extension and re-implementing it identically in each type that conforms to the protocol. Is there any way to get the compiler to do this itself? Do I need to write a macro to do it for me? There are screenshots from Instruments illustrating the issue below. Thanks! These traces are made a tiny bit more confusing because the real names of a and b are the same: read(at:). (They take different types as their parameters.) Here's the Time Profiler trace of the protocol extension implementation: And here's the trace for the duplicated-in-each-type version:

In Swift 6.4 or later, a RegexBuilder pattern can hang when an unbounded quantifier repeats a body that can match the empty string, where that body begins with NegativeLookahead. I've opened a corresponding issue and PR to resolve the issue in swift-experimental-string-processing. See below for a reproduction and a workaround. The regression affects apps running on OS 27 built with Xcode 27, which includes Swift 6.4. Running apps built with Xcode 27 on OS 26 or earlier demonstrates the expected behavior. Links: Issue: https://github.com/swiftlang/swift-experimental-string-processing/issues/865 PR: https://github.com/swiftlang/swift-experimental-string-processing/pull/866 FB23419149 and FB23179771 https://forums.swift.org/t/regexbuilder-infinite-loop-when-nullable-capture-starts-with-negativelookahead/87713 Reproduction In the reducer below, matching "A" repeatedly invokes the capture transform with an empty substring without advancing through the input. import RegexBuilder let regex = Regex { ZeroOrMore { Capture { NegativeLookahead { "a" } ZeroOrMore(.digit) } transform: { String($0) } // invoked repeatedly with "" } } _ = "A".matches(of: regex) // never returns Reduced string form: _ = try! Regex(#"(?:(?!a)\d*)*"#).firstMatch(in: "A") // never returns The issue is in the same forward-progress class as PR #851, which skips a nullable quantification's child subtree. Lookaround groups need the same treatment. The regression first appears in Swift 6.4-dev toolchains. I observed the issue in code running on iOS 27 beta 1 (24A5355q), then traced the regression to PR #849 in swift-experimental-string-processing. Workaround In the meantime, wrap the capture contents in Optionally { }: import RegexBuilder let digits = Regex { NegativeLookahead { "a" } ZeroOrMore(.digit) } let regex = Regex { ZeroOrMore { Capture { Optionally { digits } } transform: { String($0) } } } _ = "A".matches(of: regex)

In Xcode project > Build Settings > Swift Compiler - Concurrency. When we have those settings : Approachable Concurrency - Yes Default Actor Isolation - MainActor A sendable struct without @Actor annotation will be stuck to @MainActor. But if we have a sendable struct, by principle, it should be used across Actors. To remediate the situation, we had to prefix the struct with nonisolated keyword. The setting "Default Actor Isolation - MainActor" should not add @MainActor to Sendables. Problem describe in : FB23264607

Could you tell me whether Embedded Swift is expected to remain available only as a 'Development Snapshot'? I'd also be grateful to know if there are any plans to bring it to Xcode down the line. Thanks in advance!

Repurposing my questions that weren't a good fit for the group lab to see how that goes :) I've been building a ScreenReader in Swift leveraging Structured Concurrency, actors, and recently distributed actors over XPC. https://codeberg.org/SpeakUp I have a number of questions I could ask (and would love to ask) but would start with asking for thoughts on my RunLoopExecutor project https://codeberg.org/SpeakUp/RunLoopExecutor/ All of the macOS Accessibility APIs are C/CoreFoundation/CFRunLoop based and I wanted to build something where actors would feel idiomatic for an experienced Swift developer but under the hood we're making sure that we're not contending with ourselves with all the IPC we're doing to get Accessibility data. I think so far it's been pretty successful as seen in the Controller types for the ScreenReader project: https://codeberg.org/SpeakUp/ScreenReader I'm currently using pretty naive pool implementations, one that is fixed width and one that is dynamic with a maximum width. Would love to hear different approaches to growing and shrinking the thread pool and handling things like marking a given executor as likely in a bad state (usually meaning the app it's talking to over AX API is blocking it's main thread) In the AccessibilityElement project https://codeberg.org/SpeakUp/AccessibilityElement for my HIServices Observer implementation I'm exposed to a race condition where axobserver doesn't flush it's notification queue on remove. I'm relying on pthread_specific currently to introduce thread local storage to work around this but it's quite clunky. In an ideal world the HIServices API would emit a done event to allow cleanup but so far that hasn't happened. I'll leave it there for now and do new posts with more requests for feedback if this one is well received.

Hi, Platforms state of the union shows the following code: defer { await? log.close } Note: I understand await but await? seems new. Questions Is await? (question mark seems new) a new concept? What does it mean? Or is the question mark a typo?

What resources can assist translating Objective-C to Swift? Perhaps best practices or patterns? Can a coding agent automate translating Objective-C to Swift?

I would like to learn Xcode programming on MacOS. I was wondering if anyone knows of a step by step method. Where I can learn one command at a time but also all the nuances and syntax and instances for that command (function). I see a lot of tutorials for iOS programming but I would rather start and end with MacOS, but anything helps. I would like immersive instruction like what you would find in a cad classroom.

Does anyone know if there will be a Swift 6 version of "The Swift Programming Language" book and if so, when it will be released for Apple Books?

I'm keeping most information in an actor and I would like to save also a closure in it that I get from func application( _ application: UIApplication, handleEventsForBackgroundURLSession identifier: String, completionHandler: @escaping () -> Void) Task.init{ await GeoreferenceQueue.shared.setBackgroundCompletionHandler(completionHandler) } } where GeoreferenceQueue is and actor, while the caller is a class. yet I receive error: Passing closure as a 'sending' parameter risks causing data races between code in the current task and concurrent execution of the closure and Sending task-isolated 'completionHandler' to actor-isolated instance method 'setBackgroundCompletionHandler' risks causing data races between actor-isolated and task-isolated uses

I have this simple piece of code that of course correctly ran in Swift 5: func geoRegion()-> CLRegion?{ guard let location=referenceLocation else{ return nil } return CLCircularRegion(center:location.coordinate, radius:50000, identifier:"georeferencing") } func placemarksForAddress(_ address: String) async throws -> [CLPlacemark]?{ if let placemark=placemarkCache[address]{ if placemark.location!.distance(from: referenceLocation!)<100000{ return [placemark] } } do{ guard let geoRegion=self.geoRegion() else { return nil } let placemarks = try await georeferenceQueue.geocodeAddressString( address, in: geoRegion) if placemarks.count>=0{ self.placemarkCache[address]=MKPlacemark(placemark: placemarks[0]) return placemarks } } catch { let placemarks=try await self.placemarkForLocation(referenceLocation) return placemarks } return nil } That now presents error: Sending task-isolated 'geoRegion' to actor-isolated instance method 'geocodeAddressString(_:in:)' risks causing data races between actor-isolated and task-isolated uses

I'm using that repeating timer for processing information repeatedly: actor RepeatingTimer { private var task: Task<Void, Never>? private var isPaused = false func start(duration: Double, onTick: @escaping () -> Void) { task?.cancel() // Cancel any existing timer isPaused = false task = Task { while !Task.isCancelled { // Check if paused if !isPaused { onTick() } // Sleep for the interval try? await Task.sleep(for: .seconds(duration)) } } } func pause() { isPaused = true } func resume() { isPaused = false } func stop() { task?.cancel() task = nil } }` Yet when I call it from another actor with: await timer.start(duration: interval, onTick:{ self.process() }) I get: Sending 'self'-isolated value of non-Sendable type '() -> ()' to actor-isolated instance method 'start(duration:onTick:)' risks causing races in between 'self'-isolated and actor-isolated uses Is there some more stable option for managing repeating timers, or how to solve this error?

During refactoring of an app I made a typo which leads to a misleading error message in Xcode 26.4. I could reproduce it with a small sample code in Swift Playground. Is it a bug which should be reported? Details: I have an array containing two strings. Using a ForEach loop is fine: ForEach(appData.dataArray, id: \.self) { value in Text("\(value.subject)\t\(value.room)") } but with a typo in the Text line I got an error on the ForEach line: ForEach(appData.dataArray, id: \.self) { value in --> Cannot convert value of type '[MyArray]' to expected argument type 'Binding' Text("\(value.subject)\t\(value.subject.room)") } Complete sample code from Swift Playground (macOS 26): import SwiftUI class MyArray : Hashable, Equatable, Identifiable, ObservableObject, Codable { let id = UUID() @Published var subject: String @Published var room : String private enum CodingKeys : String, CodingKey { case subject case room } init(subject : String, room : String) { self.subject = subject self.room = room } func encode(to encoder: Encoder) throws { var container = encoder.container(keyedBy: CodingKeys.self) try container.encode(subject, forKey: .subject) try container.encode(room, forKey: .room) } required init(from decoder: Decoder) throws { let container = try decoder.container(keyedBy: CodingKeys.self) subject = try container.decode(String.self, forKey: .subject) room = try container.decode(String.self, forKey: .room) } static func == (v1: MyArray, v2: MyArray) -> Bool { let result = v1.id == v2.id return result } func hash(into hasher: inout Hasher) { hasher.combine(id) } } public class AppData : ObservableObject { @Published var dataArray : [MyArray] = [] init() { dataArray.append(MyArray(subject: "Foo", room: "Bar")) dataArray.append(MyArray(subject: "Foo", room: "Batz")) } } struct ContentView: View { @EnvironmentObject var appData : AppData var body: some View { ForEach(appData.dataArray, id: \.self) { value in Text("\(value.subject)\t\(value.subject.room)") // to fix the error replace value.subject.room with value.room } } } @main struct MyApp: App { var appData = AppData() var body: some Scene { WindowGroup { ContentView() .environmentObject(appData) } } }

Hello, I've already reported this issue via Feedback Assistant a month ago (FB22340897) but it's still open and I'd like to know whether I can expect something to be changed regarding it. Here are the details: It seems that Xcode 26.4 started specifying nonisolated for the resourceBundleDescription in the generated stringSymbols files for Swift packages: from: private let resourceBundleDescription = LocalizedStringResource.BundleDescription.atURL(resourceBundle.bundleURL) to: private nonisolated let resourceBundleDescription = LocalizedStringResource.BundleDescription.atURL(resourceBundle.bundleURL) This causes a compilation error: Main actor-isolated default value in a nonisolated context when the Package.swift for the Swift Package in which the string catalog is located specifies: swiftSettings: [.defaultIsolation(MainActor.self)] Since all tools (String Catalogs, Swift Packages and default actor isolation to be Main Actor) are recommended by Apple, I believe it should be possible to use all these together like before Xcode 26.4.

I'm almost having a heart attack with this "a DancingCreatures view" issue. I must be really dumb I've tried everything and the question just won't move forward. Someone, for the love of God, explain to me what it would be.

For a simple, resourceless cocoa apps I used to manually setup the application lifecycle (mimicking what's documented here: https://developer.apple.com/documentation/appkit/nsapplication), so my main.swift would look like: import Cocoa let delegate = SomeDelegate() _ = NSApplication.shared NSApp.delegate = delegate NSApp.run() This triggers a warning in Xcode 26.2: "Main actor-isolated conformance of SomeDelegate cannot be used in nonisolated context; this is an error in Swift 6 language mode". so what is the recommended way to refactor above so that it is Swift 6 compliant?

Is anyone have this problem on xcode 26 ? Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility50 Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility51 Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility56 Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibilityConcurrency Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibilityDynamicReplacements

Note On a Mac with Xcode installed, or on an iPad with Swift Playgrounds, you can open this chapter as a playground. Playgrounds allow you to edit the code listings and see the results immediately. (Note in page 3) (I would like to open the chapter or book: Swift Programming Language in Swift Playground on iPad) https://books.apple.com/ve/book/the-swift-programming-language-swift-5-7-beta/id1002622538?l=en-GB Best regards

Experiment Create a constant with an explicit type of Float and a value of 4. https://docs.swift.org/swift-book/documentation/the-swift-programming-language/guidedtour