Hi, I've got this view model that will do a search using a database of keywords. It worked fine when the SearchEngine wasn't an actor but a regular class and the SearchResult wasn't a Sendable. But when I changed them, it returned Type of expression is ambiguous without a type annotation error at line 21 ( searchTask = Task {). What did I do wrong here? Thanks.
protocol SearchableEngine: Actor {
func searchOrSuggest(from query: String) -> SearchResult?
func setValidTitles(_ validTitles: [String])
}
@MainActor
final class SearchViewModel: ObservableObject {
@Published var showSuggestion: Bool = false
@Published var searchedTitles: [String] = []
@Published var suggestedKeyword: String? = nil
private var searchTask: Task<Void, Never>?
private let searchEngine: SearchableEngine
init(searchEngine: SearchableEngine) {
self.searchEngine = searchEngine
}
func search(_ text: String) {
searchTask?.cancel()
searchTask = Task {
guard !Task.isCancelled else { return }
let searchResult = await searchEngine.searchOrSuggest(from: text) ?? .notFound
guard !Task.isCancelled else { return }
await MainActor.run {
switch searchResult {
case let .searchItems(_, items):
showSuggestion = false
searchedTitles = items.map(\.title)
suggestedKeyword = nil
case let .suggestion(keyword, _, items):
showSuggestion = true
searchedTitles = items.map(\.title)
suggestedKeyword = keyword
case .notFound:
showSuggestion = false
searchedTitles = []
suggestedKeyword = nil
}
}
}
}
}
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Forums tags: Swift
Developer > Swift website
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The Swift Programming Language documentation
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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
Hey all!
in my personal quest to make future proof apps moving to Swift 6, one of my app has a problem when setting an artwork image in MPNowPlayingInfoCenter
Here's what I'm using to set the metadata
func setMetadata(title: String? = nil, artist: String? = nil, artwork: String? = nil) async throws {
let defaultArtwork = UIImage(named: "logo")!
var nowPlayingInfo = [
MPMediaItemPropertyTitle: title ?? "***",
MPMediaItemPropertyArtist: artist ?? "***",
MPMediaItemPropertyArtwork: MPMediaItemArtwork(boundsSize: defaultArtwork.size) { _ in
defaultArtwork
}
] as [String: Any]
if let artwork = artwork {
guard let url = URL(string: artwork) else { return }
let (data, response) = try await URLSession.shared.data(from: url)
guard (response as? HTTPURLResponse)?.statusCode == 200 else { return }
guard let image = UIImage(data: data) else { return }
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size) { _ in
image
}
}
MPNowPlayingInfoCenter.default().nowPlayingInfo = nowPlayingInfo
}
the app crashes when hitting
MPMediaItemPropertyArtwork: MPMediaItemArtwork(boundsSize: defaultArtwork.size) { _ in
defaultArtwork
}
or
nowPlayingInfo[MPMediaItemPropertyArtwork] = MPMediaItemArtwork(boundsSize: image.size) { _ in
image
}
commenting out these two make the app work again.
Again, no clue on why.
Thanks in advance
Hello
I want to implement customisation to swift argumentparser, Here are following changes want to do it in my cli
changing default footer present in help command output
currently help command output coming like this
OVERVIEW: clisample
USAGE: clisample <subcommand>
OPTIONS:
--version show the version.
-h, --help show the help.
SUBCOMMANDS:
logs (default) Export logs for clisample processes.
See 'clisample --help' for more information.'
so instead of
See 'clisample --help' for more information.'
I want my own string
For more details, run 'clisample help <subcommand>'
customise error string getting from validation error
Error: Missing value for '-t <time>'
Help: -t <time> Time window (e.g. 10h, 30m, 2d).
Usage: clisample logs --time <time>
See 'clisample logs --help' for more information.
so I want error output with example and customised footer, like this
Error: Missing value for '-t <time>'
Help: -t <time> Time window (e.g. 10h, 30m, 2d).
Usage: clisample logs --time <time>
Example: clisample logs -t 5m
For more details, run 'clisample help <subcommand>'
Is this changes possible from anyway?
I am an SDK provider working with Swift Package Manager (SPM) to deliver libraries for iOS developers. My SDK currently uses SPM targets to modularize functionality. However, SPM enforces strict resource bundling, which prevents me from efficiently offering multiple targets—each with a different set of localization files—in a single package.
Current Limitation:
When multiple SPM targets share the same source and resource directory but require distinct sets of .lproj localization folders (for app size or client requirements), SPM raises “overlapping sources” errors. The only workaround is to manually split resource directories or have clients prune localizations post-build, which is inefficient and error-prone.
Feature Request:
Please consider adding native support in Swift Package Manager for:
Defining multiple targets within a single package that can process overlapping source/resource directories,
Each target specifying a distinct subset of localization resource files via the exclude or a new designated parameter,
Enabling efficient modular delivery of SDKs to clients needing different localization payloads, without redundant resource duplication or error-prone manual pruning.
Support for this feature would greatly ease SDK distribution, lower app sizes, and improve package maintainability for iOS and all Swift platforms.
I came across a code
let myFruitBasket = ["apple":"red", "banana": "yellow", "budbeeri": "dark voilet", "chikoo": "brown"]
Can we have range for keys and values of dictionary, it will be convenient
for keys
print(myFruitBasket.keys[1...3])
// banana, budbeeri, chikoo
same for values
print(myFruitsBasket.values[1...3])
// yellow, voilet, brown
I filed the following issue on swiftlang/swift on GitHub (Aug 8th), and a followup the swift.org forums, but not getting any replies. As we near the release of Swift 6.2, I want to know if what I'm seeing below is expected, or if it's another case where the compiler needs a fix.
protocol P1: Equatable { }
struct S1: P1 { }
// Error: Conformance of 'S1' to protocol 'P1' crosses into main actor-isolated code an can cause data races
struct S1Workaround: @MainActor P1 { } // OK
// Another potential workaround if `Equatable` conformance can be moved to the conforming type.
protocol P2 { }
struct S2: Equatable, P2 { } // OK
There was a prior compiler bug fix which addressed inhereted protocols regarding @MainActor. For Equatable, one still has to use @MainActoreven when the default actor isolation is MainActor.
Also affects Hashable and any other protocol inheriting from Equatable.
Hello,
While watching WWDC25: Code-along: Elevate an app with Swift concurrency at timestamp 25:48, I noticed something in the slide/diagram that might be incorrect.
The diagram shows ExtractSticker twice, but based on the code context and spoken explanation, I think it was meant to be ExtractSticker and ExtractColor.
Reasoning:
The surrounding code and narration describe the use of async let and a Sendable Data object.
From the flow, one task extracts a sticker while the other extracts a color, so it seems like the diagram is inconsistent.
I do understand that with @concurrent, having two ExtractSticker operations on the same Data is technically possible (with two concurrent process executing their respective ExtractSticker) — but that would be a different meaning than what the talk was describing.
Since concurrency is already a subtle and error-prone topic, I thought it was worth pointing this out. If I’m mistaken, I’d love clarification. Otherwise, this could be a small correction to keep things aligned and clearer for everyone.
Minor point overall, but Swift 6’s concurrency model is doing a fantastic job at helping us write safer code—so thank you to the team for that!
(Attaching screenshots for reference)
func oneStepForward(_ input: Int) -> Int {
return input + 1
}
func oneStepBackward(_ input: Int) -> Int {
return input - 1
}
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
return backward ? oneStepBackward : oneStepForward
//Error. type of expression is ambiguous without a type annotation
}
Why am I getting this error ?
If I change this function to the following it works and will compile.
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
if backward {
return oneStepBackward
} else {
return oneStepForward
}
}
// Why am I getting the error in the previous version while it works in the second version ?
Thx in advance.
Greetings,
func stepForward(_ input: Int) -> Int {
return input + 1
}
func stepBackward(_ input: Int) -> Int {
return input - 1
}
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
return backward ? stepBackward : stepForward /* Error
type of expression is ambiguous without a type annotation */
}
Why am I getting this error. If I change the function to
func chooseStepFunction(backward: Bool) -> (Int) -> Int {
if backward {
return stepBackward
else {
return stepForward
}
}
Why is the previous chooseStepFunction giving me an error ?
Thx in advance
Is this possible while inserting a String into Set
Crashed: com.apple.root.user-initiated-qos.cooperative
0 libswiftCore.dylib 0xf4c0 _assertionFailure(_:_:flags:) + 136
1 libswiftCore.dylib 0x17f484 ELEMENT_TYPE_OF_SET_VIOLATES_HASHABLE_REQUIREMENTS(_:) + 3792
2 MyEatApp 0x44f6e8 specialized _NativeSet.insertNew(_:at:isUnique:) + 4333926120 (<compiler-generated>:4333926120)
3 MyEatApp 0x44eaec specialized Set._Variant.insert(_:) + 4333923052 (<compiler-generated>:4333923052)
4 MyEatApp 0x479f7c HomeViewModel.hanldeAnnouncementCard(from:) + 293 (HomeViewModel+PersonalizedOffer.swift:293)
5 libswift_Concurrency.dylib 0x5c134 swift::runJobInEstablishedExecutorContext(swift::Job*) + 292
6 libswift_Concurrency.dylib 0x5d5c8 swift_job_runImpl(swift::Job*, swift::SerialExecutorRef) + 156
7 libdispatch.dylib 0x13db0 _dispatch_root_queue_drain + 364
8 libdispatch.dylib 0x1454c _dispatch_worker_thread2 + 156
9 libsystem_pthread.dylib 0x9d0 _pthread_wqthread + 232
10 libsystem_pthread.dylib 0xaac start_wqthread + 8
I'm struggling to convert Swift 5 to Swift 6.
As advised in doc, I first turned strict concurrency ON. I got no error.
Then, selected swift6… and problems pop up.
I have a UIViewController with
IBOutlets: eg a TextField.
computed var eg duree
func using UNNotification: func userNotificationCenter
I get the following error in the declaration line of the func userNotificationCenter:
Main actor-isolated instance method 'userNotificationCenter(_:didReceive:withCompletionHandler:)' cannot be used to satisfy nonisolated requirement from protocol 'UNUserNotificationCenterDelegate'
So, I declared the func as non isolated.
This func calls another func func2, which I had also to declare non isolated.
Then I get error on the computed var used in func2
Main actor-isolated property 'duree' can not be referenced from a nonisolated context
So I declared duree as nonsilated(unsafe).
Now comes the tricky part.
The computed var references the IBOutlet dureeField
if dureeField.text == "X"
leading to the error
Main actor-isolated property 'dureeField' can not be referenced from a nonisolated context
So I finally declared the class as mainActor and the textField as nonisolated
@IBOutlet nonisolated(unsafe) weak var dureeField : UITextField!
That silences the error (but declaring unsafe means I get no extra robustness with swift6) just to create a new one when calling dureeField.text:
Main actor-isolated property 'text' can not be referenced from a nonisolated context
Question: how to address properties inside IBOutlets ? I do not see how to declare them non isolated and having to do it on each property of each IBOutlet would be impracticable.
The following did work, but will make code very verbose:
if MainActor.assumeIsolated({dureeField.text == "X"}) {
So I must be missing something.
As a fun project, I'm wanting to model an electronic circuit.
Components inherit from a superclass (ElectronicComponent). Each subclass (e.g. Resistor) has certain methods to return properties (e.g. resistance), but may vary by the number of outlets (leads) they have, and what they are named.
Each outlet connects to a Junction.
In my code to assemble a circuit, while I'm able to manually hook up the outlets to the junctions, I'd like to be able to use code similar to the following…
class Lead: Hashable // implementation omitted
{
let id = UUID()
unowned let component: ElectronicComponent
weak var connection: Junction?
init(component: ElectronicComponent, to connection: Junction? = nil)
{
self.component = component
self.connection = connection
}
}
@dynamicMemberLookup
class ElectronicComponent
{
let id = UUID()
var connections: Set<Lead> = []
let label: String?
init(label: String)
{
self.label = label
}
subscript<T>(dynamicMember keyPath: KeyPath<ElectronicComponent, T>) -> T
{
self[keyPath: keyPath]
}
func connect(lead: KeyPath<ElectronicComponent, Lead>, to junction: Junction)
{
let lead = self[keyPath: lead]
lead.connection = junction
connections.insert(lead)
}
}
class Resistor: ElectronicComponent
{
var input, output: Lead?
let resistance: Measurement<UnitElectricResistance>
init(_ label: String, resistance: Measurement<UnitElectricResistance>)
{
self.resistance = resistance
super.init(label: label)
}
}
let resistorA = Resistor("R1", resistance: .init(value: 100, unit: .ohms))
let junctionA = Junction(name: "A")
resistorA.connect(lead: \.outlet2, to: junctionA)
While I'm able to do this by implementing @dynamicMemberLookup in each subclass, I'd like to be able to do this in the superclass to save repeating the code.
subscript<T>(dynamicMember keyPath: KeyPath<ElectronicComponent, T>) -> T
{
self[keyPath: keyPath]
}
Unfortunately, the compiler is not allowing me to do this as the superclass doesn't know about the subclass properties, and at the call site, the subclass isn't seen as ElectronicComponent.
I've been doing trial and error with protocol conformance and other things, but hitting walls each time.
One possibility is replacing the set of outlets with a dictionary, and using Strings instead of key paths, but would prefer not to.
Another thing I haven't tried is creating and adopting a protocol with the method implemented in there. Another considered approach is using macros in the subclasses, but I'd like to see if there is a possibility of achieving the goal using my current approach, for learning as much as anything.
I'm developing an audio unit for use on iOS. The AUv3 worked fine with xcode 15.X and swift 5.X. I recently tried to submit an update to my plug-in but Apple refused submission because my Xcode was not the latest. Now that I'm on Xcode 16.4 I can't get my project to compile, even when following all of the same previous steps.
As one example of a change, Xcode doesn't appear to include the “C++ and Objective-C interoperability” build setting that it used to. This setting is noted in the Swift documentation and I used to need it, https://www.swift.org/documentation/cxx-interop/project-build-setup/#mixing-swift-and-c-using-xcode
Currently my C++ code can't see anything from Swift, and I get a "Use of undeclared identifier 'project_name'". I've selected Switch support for version 5.0 in an attempt to minimize changes from Apple.
My process is I generate an Xcode project file from my audio plugin support, JUCE. Then I add in the swift files, click yes to create bridging headers, but c++ doesn't see swift anymore. I'd greatly appreciate any suggestions.
Topic:
Programming Languages
SubTopic:
Swift
I want to understand what the recommended way is for string interoperability between swift and c++. Below are the 3 ways to achieve it. Approach 2 is not allowed at work due to restrictions with using std libraries.
Approach 1:
In C++:
char arr[] = "C++ String";
void * cppstring = arr;
std::cout<<"before:"<<(char*)cppstring<<std::endl; // C++ String
// calling swift function and passing the void buffer to it, so that swift can update the buffer content
Module1::SwiftClass:: ReceiveString (cppstring, length);
std::cout<<"after:"<<(char*)cppstring<<std::endl; // SwiftStr
In Swift:
func ReceiveString (pBuffer : UnsafeMutableRawPointer , pSize : UInt ) -> Void
{
// to convert cpp-str to swift-str:
let swiftStr = String (cString: pBuffer.assumingMemoryBound(to: Int8.self));
print("pBuffer content: \(bufferAsString)");
// to modify cpp-str without converting:
let swiftstr:String = "SwiftStr"
_ = swiftstr.withCString { (cString: UnsafePointer<Int8>) in
pBuffer.initializeMemory(as: Int8.self, from: cString, count: swiftstr.count+1)
}
}
Approach 2:
The ‘String’ type returned from a swift function is received as ‘swift::String’ type in cpp. This is implicitly casted to std::string type. The std::string has the method available to convert it to char *.
void
TWCppClass::StringConversion ()
{
// GetSwiftString() is a swift call that returns swift::String which can be received in std::string type
std::string stdstr = Module1::SwiftClass::GetSwiftString ();
char * cstr = stdstr.data ();
const char * conststr= stdstr.c_str ();
}
Approach 3:
The swift::String type that is obtained from a swift function can be received in char * by directly casting the address of the swift::String. We cannot directly receive a swift::String into a char *.
void
TWCppClass::StringConversion ()
{
// GetSwiftString() is a swift call that returns swift::String
swift::String swiftstr = Module1::SwiftClass::GetSwiftString ();
// obtaining the address of swift string and casting it into char *
char * cstr = (char*)&swiftstr;
}
I’m aware that Xcode version 26 beta 3 provides an option to enable Swift’s Approachable Concurrency feature at the project level. However, I’d like to achieve the same for a Swift Package. Could you please advise on how to enable Approachable Concurrency support specifically for a Swift Package?
I'm having trouble dealing with concurrency with the SFAuthorizationPluginView. Does anybody know how this can be solved?
https://developer.apple.com/documentation/securityinterface/sfauthorizationpluginview
The crux of it is:
If I inherit an object as part of an API, and the API is preconcurrency, and thus is nonisolated (but in reality is @MainActor), how do I return a @MainActor GUI element?
https://developer.apple.com/documentation/securityinterface/sfauthorizationpluginview/firstresponder()
The longer story:
I made my view class inherit SFAuthorizationPluginView.
The API is preconcurrency (but not marked as preconcurrency)
I started using concurrency in my plugin to retrieve data over XPC. (https://developer.apple.com/documentation/xpc/xpcsession + https://developer.apple.com/documentation/swift/withcheckedthrowingcontinuation(isolation:function:_:))
Once I retrieve the data over XPC, I need to post it on GUI, hence I've set my view class as @MainActor in order to do the thread switch.
Swift compiler keeps complaining:
override func firstResponder() -> NSResponder? {
return usernameField
}
"Main actor-isolated property 'usernameField' can not be referenced from a nonisolated context; this is an error in the Swift 6 language mode"
override func firstResponder() -> NSResponder? {
MainActor.assumeIsolated {
return usernameField
}
}
"Sending 'self' risks causing data races; this is an error in the Swift 6 language mode"
I think fundamentally, the API is forcing me to give away a @MainActor variable through a nonisolated function, and there is no way to shut up the compiler.
I've tried @preconcurrency and it has no effect as far as I can tell. I've also tried marking the function explicitly as nonisolated.
The rest of the API are less problematic, but returning a GUI variable is exceptionally difficult.
Module compiled with Swift 6.0.3 cannot be imported by the Swift 6.1 compiler: /private/var/tmp/_bazel_xx/8b7c61ad484d9da1bf94a11f12ae6ffd/rules_xcodeproj.noindex/build_output_base/execroot/main/CustomModules/BIYThred/CocoaLumberjack/framework/CocoaLumberjack.framework/Modules/CocoaLumberjack.swiftmodule/arm64-apple-ios.swiftmodule
谁能告诉我为什么?
“[正在运行] swift ”d:\vscode object\swift object\ceshi.swift”
JIT 会话错误:未找到符号:[ $ss 27_allocateUninitializedArrayySayxG_BptBwlFyp_Tg5 ]
未能具体化符号: { (main, { main, $sSa 12_endMutationyyF, $ss 5print_9separator10terminatoryypd_S2StFfA0_, $ss 5print_9separator10terminatoryypd_S2StFfA1_, $ss 27_finalizeUninitializedArrayySayxGABnlF }) }
[完成] 在 0.47 秒内退出并带有 code=4294967295”
当“Swift for Windows”在 VSCode for Windows 上运行时。
路径为 true,“Package-swift-lsp: Path”为 true。
谁能告诉我为什么?
Topic:
Programming Languages
SubTopic:
Swift