It seems I can declare variables like below in a source file: private let var1 = 1234 fileprivate let var2 = "abcd" class MyClass { // ... } So what's the difference between the 2 vars here?

Usage of multiple async lets crashes the app in a nondeterministic fashion. We are experiencing this crash in production, but it is rare. 0 libswift_Concurrency.dylib 0x20a8b89b4 swift_task_create_commonImpl(unsigned long, swift::TaskOptionRecord*, swift::TargetMetadata<swift::InProcess> const*, void (swift::AsyncContext* swift_async_context) swiftasynccall*, void*, unsigned long) + 384 1 libswift_Concurrency.dylib 0x20a8b6970 swift_asyncLet_begin + 36 We managed to isolate the issue, and we submitted a technical incident (Case-ID: 8007727). However, we were completely ignored, and referred to the developer forums. To reproduce the bug you need to run the code on a physical device and under instruments (we used swift concurrency). This bug is present on iOS 17 and 18, Xcode 15.1, 15.4 and 16 beta, swift 5 and 6, including strict concurrency. Here's the code for Swift 6 / Xcode 16 / strict concurrency: (I wanted to attach the project but for some reason I am unable to) typealias VoidHandler = () -> Void enum Fetching { case inProgress, idle } protocol PersonProviding: Sendable { func getPerson() async throws -> Person } actor PersonProvider: PersonProviding { func getPerson() async throws -> Person { async let first = getFirstName() async let last = getLastName() async let age = getAge() async let role = getRole() return try await Person(firstName: first, lastName: last, age: age, familyMemberRole: role) } private func getFirstName() async throws -> String { try await Task.sleep(nanoseconds: 1_000_000_000) return ["John", "Kate", "Alex"].randomElement()! } private func getLastName() async throws -> String { try await Task.sleep(nanoseconds: 1_400_000_000) return ["Kowalski", "McMurphy", "Grimm"].randomElement()! } private func getAge() async throws -> Int { try await Task.sleep(nanoseconds: 2_100_000_000) return [56, 24, 11].randomElement()! } private func getRole() async throws -> Person.Role { try await Task.sleep(nanoseconds: 500_000_000) return Person.Role.allCases.randomElement()! } } @MainActor final class ViewModel { private let provider: PersonProviding = PersonProvider() private var fetchingTask: Task<Void, Never>? let onFetchingChanged: (Fetching) -> Void let onPersonFetched: (Person) -> Void init(onFetchingChanged: @escaping (Fetching) -> Void, onPersonFetched: @escaping (Person) -> Void) { self.onFetchingChanged = onFetchingChanged self.onPersonFetched = onPersonFetched } func fetchData() { fetchingTask?.cancel() fetchingTask = Task { do { onFetchingChanged(.inProgress) let person = try await provider.getPerson() guard !Task.isCancelled else { return } onPersonFetched(person) onFetchingChanged(.idle) } catch { print(error) } } } } struct Person { enum Role: String, CaseIterable { case mum, dad, brother, sister } let firstName: String let lastName: String let age: Int let familyMemberRole: Role init(firstName: String, lastName: String, age: Int, familyMemberRole: Person.Role) { self.firstName = firstName self.lastName = lastName self.age = age self.familyMemberRole = familyMemberRole } } import UIKit class ViewController: UIViewController { @IBOutlet private var first: UILabel! @IBOutlet private var last: UILabel! @IBOutlet private var age: UILabel! @IBOutlet private var role: UILabel! @IBOutlet private var spinner: UIActivityIndicatorView! private lazy var viewModel = ViewModel(onFetchingChanged: { [weak self] state in switch state { case .idle: self?.spinner.stopAnimating() case .inProgress: self?.spinner.startAnimating() } }, onPersonFetched: { [weak self] person in guard let self else { return } first.text = person.firstName last.text = person.lastName age.text = "\(person.age)" role.text = person.familyMemberRole.rawValue }) @IBAction private func onTap() { viewModel.fetchData() } }

I got the error and I don’t how can I fix it help please struct MovieDetail: View { var movie: Movie let screen = UIScreen.main.bounds @State private var showSeasonPicker = true @State private var selectedSeason = 0 var body: some View { ZStack { Color.black .ignoresSafeArea() ZStack { VStack { HStack { Spacer() Button() { // Closing Button }label: { Image(systemName: "xmark.circle") .font(.system(size: 28)) } } .padding(.horizontal, 22) ScrollView (.vertical, showsIndicators: false){ VStack { StandardHomeMovie(movie: movie) .frame(width: screen.width / 2.5) MovieInfoSubheadline(movie: movie) if movie.promotionHeadline != nil { Text(movie.promotionHeadline!) .bold() .font(.headline) } PlayButton(text: "Play", imagename: "play.fill", backgroundColor: .red) { // } CurrentEpisodeInformation(movie: movie) CastInfo(movie: movie) HStack(spacing: 60){ SmallVerticalButton(text: "My List", isOnImage: "checkmark", isOffImage: "plus", isOn: true) { // } SmallVerticalButton(text: "Rate", isOnImage: "hand.thumbsup.fill", isOffImage: "hand.thumbsup", isOn: true) { // } SmallVerticalButton(text: "Share", isOnImage: "square.and.arrow.up", isOffImage: "square.and.arrow.up", isOn: true) { // } Spacer() } .padding(.leading, 20) CustomTabSwitcher(tabs: [.episodes, .trailers, .more], movie: movie, showSeasonPicker: $showSeasonPicker, selectedSeason: $selectedSeason) } .padding(.horizontal, 10) } Spacer() } .foregroundStyle(.white) if showSeasonPicker { Group { Color.black.opacity(0.9) VStack(spacing: 40){ Spacer() ForEach(0..<(movie.numberOfSeasons ?? 0)) { season in Button(action: { self.selectedSeason = (season != 0) self.showSeasonPicker = false }, label: { Text("Season: \(season + 1)") .foregroundStyle(selectedSeason == season + 1 ? .white : .gray) .bold() .font(.title2) }) } Spacer() Button(action: { self.showSeasonPicker = false }, label: { Image(systemName: "xmark.circle.fill") .foregroundStyle(.white) .font(.system(size: 40)) .scaleEffect(x: 1.1) }) .padding(.bottom, 30) } } .ignoresSafeArea() } } } } } #Preview { MovieDetail(movie: exampleMovie2) } struct MovieInfoSubheadline: View { var movie: Movie var body: some View { HStack(spacing: 20){ Image(systemName: "hand.thumbsup.fill") .foregroundStyle(.white) Text(String(movie.year)) RatingView(rating: movie.rating) Text(movie.numberOfSeasonsDisplay) ZStack{ Text("HD") .foregroundStyle(.white) .font(.system(size: 12)) .bold() Rectangle() .stroke(.gray, lineWidth: 2) .frame(width: 30, height: 20) } } .foregroundStyle(.gray) .padding(.vertical, 6) } } struct RatingView: View { var rating: String var body: some View { ZStack { Rectangle() .foregroundStyle(.gray) Text(rating) .foregroundStyle(.white) .font(.system(size: 12)) .bold() } .frame(width: 50, height: 20) } } struct CastInfo: View { var movie: Movie var body: some View { VStack(spacing: 3) { HStack { Text("Cast: \(movie.cast)") Spacer() } HStack { Text("Creaters: \(movie.creaters)") Spacer() } } .font(.caption) .foregroundStyle(.gray) .padding(.vertical, 10) } } struct CurrentEpisodeInformation: View { var movie: Movie var body: some View { Group { HStack { Text(movie.episodeInfoDisplay) .bold() Spacer() } .padding(.vertical, 4) HStack { Text(movie.episodeDescriptionDisplay) .font(.subheadline) Spacer() } } } }

I need to decode JSON into a class. The JSON has a field called "Type", and I cannot declare a property with that name in my class since Type is a reserved word. I tried declaring CodingKeys, but that doesn't work unless I declare EVERY property in the CodingKeys. This class has about a hundred properties and I have others like it, I do not want to do this. Is there a better solution?

'consume' applied to value that the compiler does not support. This is a compiler bug. Please file a bug with a small example of the bug. public func requestTopicsAndSubTopics() async throws -> (topics: [Topic], subTopics: [String: [SubTopic]]) { var subTopics = [String: [SubTopic]]() let topics = try await getTopics().sorted { $0.index < $1.index } try await withThrowingTaskGroup(of: ([SubTopic], String).self) { [weak self] group in guard let self else { return } for topic in topics { guard let topicId = topic.id else { throw Error.missingId } group.addTask { let subTopics = try await self.getSubtopics(topicId: topicId).sorted { $0.name < $1.name } return (consume subTopics, topicId) } } for try await (resultedSubTopics, topicId) in group { subTopics.updateValue(resultedSubTopics, forKey: topicId) } } return (consume topics, consume subTopics) }

I'm the developer of 8th (https://8th-dev.com), which compiles the program at run-time, on the device. There used to be an iOS version which worked, but it seems things have changed since then. I'm trying to distribute an iOS version of an app written in 8th, and am encountering "SIGKILL - CODESIGNING" when trying to execute freshly compiled code. I am doing the 'sys_icache_invalidate' thing after writing into a mmap'ed bit of memory (rwx). I'm not writing into memory that was codesigned, so I don't know why the error is that. Anyway, the question is: is it possible any more to do what I used to be able to do?

During my analysis of the binary size changes after compiling Swift source code, I discovered symbols with the ".island" suffix. I couldn't find meaningful information about this suffix through my search, so I decided to reach out for assistance. While comparing the changes in binary size after modifying specific code, I noticed a significant increase (from 33MB to 520MB). Upon analyzing the symbols of the enlarged binary using the nm command, I found the following pattern: t _$s12{SomeSymbol}WOb t _$s12{SomeSymbol}WOb.island t _$s12{SomeSymbol}WOb.island2 t _$s12{SomeSymbol}WOb.island3 When I output the symbols of the binary using nm, I noticed many symbols with the same name but different ".island", ".island2", ".island3" suffixes. Disassembling the binary showed that functions with these suffixes simply delegate calls sequentially: x.island3 -> x.island2 -> x.island1 -> x. It appears that these symbols serve as delegates for function calls, but I would like to understand why such duplicated functions with these suffixes are generated. Could someone help me to provide some insights on this matter?

I came across a useful repo on GitHub: https://github.com/GianniCarlo/DirectoryWatcher/blob/master/Sources/DirectoryWatcher/DirectoryWatcher.swift self.queue = DispatchQueue.global() self.source = DispatchSource.makeFileSystemObjectSource(fileDescriptor: descriptor, eventMask: .write, queue: self.queue) self.source?.setEventHandler { [weak self] in self?.directoryDidChange() } self.source?.setCancelHandler() { close(descriptor) } self.source?.resume() How do I translate this to OC version? I have an app that was written in OC and I plan to incorporate this directory watcher into the project.

Hi @all, I get follow error: needs -Onone Swift optimization level. how can I solve this? thank you for the help greeting Fabian

When I run the code, xCode shows me this error "Expressions are not allowed at the top level" While the code is correct and runs in the main.swift file only. And also runs in online compilers. please give me solution...

We use XCode 15.2 to build our application, but we found that the app crashes on iOS 12.1.1, while it works without crashing on iOS 12.5.7. We discovered that the crash is related to ImageLoaderMachO::doModInitFunctions. We're not sure what is causing this.

Why doesn’t deinit support async? At the end of a test, I want to wipe data from HealthKit, and it’s delete function is asynchronous.

Hi all, I just wanted to ask how people were using ModelActor with the Swift 6 language mode enabled. My current implementation involves passing the ModelContainer to my ModelActor, which worked in Sonoma and previous betas of Sequoia, however in the current Beta 3, I get this error: "Sending 'self.modelContext.container' risks causing data races" I am a bit confused by this, as from what I understand, ModelContainer conforms to Sendable, so ideally this error should not be thrown. Is this a bug in Beta 3? Thanks in advance.

Just when I think I am finally starting to understand Swift I come across a gotcha like the following: I have two object, a swiftui display and one of data to be displayed. Ok, sounds easy. The data is read out of a JSON file so I have a set of arrays and dictionaries. The data is valid when read, it is definitely there, but when I go to display it, its gone. Just vanished. Wasted about a day on this so far, and I’ve seen it before, the inability to pass out of an object an array or dictionary with contents intact. If I create an array var, and not let the system do it, contents are preserved. So, in the data object I’ll have something like this: struct DataObject{ var item: [String:Any] item=JSONData serialized out of memory, and may have say, 12 fields } In my SwiftUI module I have: var item=dataObject.item dataObject.item now has 0 fields. I can allocate and initialize a dictionary in DataObject and those elements come through fine. So it seems like the stuff being serialized from JSON is being deleted out from under me.

I am getting an following error while compiling the Fortran file with "gfortran TEST_1_fortran_only_fixed.f" ld: unsupported tapi file type '!tapi-tbd' in YAML file '/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk/usr/lib/libSystem.tbd' for architecture x86_64 collect2: error: ld returned 1 exit status Please help me to solve this issue

For some time now Xcode has been downloading crash reports from users of my app about crashes related to arrays. One of them looks like this: ... Code Type: ARM-64 Parent Process: launchd [1] User ID: 501 Date/Time: 2024-07-18 14:59:40.4375 +0800 OS Version: macOS 15.0 (24A5289h) ... Crashed Thread: 0 Exception Type: EXC_BREAKPOINT (SIGTRAP) Exception Codes: 0x0000000000000001, 0x00000001045048b8 Termination Reason: Namespace SIGNAL, Code 5 Trace/BPT trap: 5 Terminating Process: exc handler [1771] Thread 0 Crashed: 0 MyApp 0x00000001045048b8 specialized Collection.map<A>(_:) + 596 1 MyApp 0x00000001045011e4 MyViewController.validateToolbarButtons() + 648 (MyViewController.swift:742) ... The relevant code looks like this: class MyViewController { func validateToolbarButtons() { let indexes = tableView.clickedRow == -1 || tableView.selectedRowIndexes.contains(tableView.clickedRow) ? tableView.selectedRowIndexes : IndexSet(integer: tableView.clickedRow) let items = indexes.map({ myArray[$0] }) ... } } The second crash looks like this: ... Code Type: X86-64 (Native) Parent Process: launchd [1] User ID: 502 Date/Time: 2024-07-15 15:53:35.2229 -0400 OS Version: macOS 15.0 (24A5289h) ... Crashed Thread: 0 Exception Type: EXC_BAD_INSTRUCTION (SIGILL) Exception Codes: 0x0000000000000001, 0x0000000000000000 Termination Reason: Namespace SIGNAL, Code 4 Illegal instruction: 4 Terminating Process: exc handler [13244] Thread 0 Crashed: 0 libswiftCore.dylib 0x00007ff812904fc0 _assertionFailure(_:_:flags:) + 288 1 MyApp 0x0000000101a31e04 specialized _ArrayBuffer._getElementSlowPath(_:) + 516 2 MyApp 0x00000001019d04eb MyObject.myProperty.setter + 203 (MyObject.swift:706) 3 MyApp 0x000000010192f66e MyViewController.controlTextDidChange(_:) + 190 (MyViewController.swift:166) ... And the relevant code looks like this: class MyObject { var myProperty: [MyObject] { get { ... } set { let items = newValue.map({ $0.id }) ... } } } What could cause such crashes? Could they be caused by anything other than concurrent access from multiple threads (which I'm quite sure is not the case here, as I only access these arrays from the main thread)?

Hi, everyone. I am trying to print out “Hello, world” by creating a Command Line tool project. I try to type “swiftc Hello.swift” to compile it in the terminal but instead of having a file named Hello.swift, I have a file named by default Hello.xcodeprojec. How I can solve this issue?

When i try to run break statement in default case, it doesn't run and shows 'Closure containing control flow statement cannot be used with result builder 'ViewBuilder'' error.Why it doesn't run and how to solve this trouble?

I think I found a bug in the Objective-C++ compiler, linker, or runtime. Here’s the scenario: We have a macOS app written in Swift. To control hardware from a 3rd party manufacturer, we use a couple SDKs provided by the manufacturer. The SDKs use dynamically loaded libraries and the interface is defined in C++ headers. To bridge between our Swift code and the C++ APIs we have a private Cocoapod that wraps the 3rd party interface with Objective-C++ classes. The two SDKs each provide an interface for discovering attached devices using a callback class that the programmer provides. By accident we named both callback implementations DiscoveryCallback, but this was not a compiler error because neither class was publicly declared, and each was defined in the .mm file where it was used. However, the problem we’re seeing is this: We want to discover Videohub devices, so we register a new instance of DiscoveryCallback (defined in the same .mm file as this code) with the Videohub SDK. A Videohub device is connected and the SDK calls a method on our callback. Surprise! The callback we registered in step 1 was actually the one intended for Decklink devices, defined in a completely different .mm file. This violates all sorts of assumptions and our app quickly crashes. The funny thing is, the two implementations of DiscoveryCallback have completely different method names. The Videohub SDK is supposed to be calling NewVideohubDevice, yet somehow it successfully calls DeckLinkDeviceArrived on an instance of a class it shouldn’t even know about. So the compiler has checked that our intended DiscoveryCallback matches the protocol that the SDK expects, but at runtime the compiled code instantiates a completely different implementation of DiscoveryCallback and somehow doesn’t immediately fail; we still call a method on it that doesn’t even share a name with the intended target. I imagine at this point the method names are long forgotten and are just pointers in a table. I don’t know if this is a bug in the compiler, the Objective-C++ runtime, or if this is just “working as designed” undefined behavior that I should have avoided by not giving two private classes the same name. I know it’s possible to use a private API simply by redeclaring it in my own code, and this seems related to that, but I feel like the compiler or linker should have warned me that I had two implementations of the same class, or if that is not an error, then the runtime should have instantiated the class that was privately defined in the same source file where it was used. Obviously I can’t share our entire project; I’d like to provide some sample code that replicates the issue, but I don’t have time to do that right now. I’m posting this to see if other developers have had a similar experience.

Hello! I have an application written in Objective-c/C++ and I would like it to have support for OTA updates. I implemented the logic through two executable files, one of which was responsible for launching and updating the first, but this option did not pass Apple's review. Could you tell me how this functionality can be implemented and so that it meets the requirements of the App Store.