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...
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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.
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?
'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 want to build a Swift library package that uses modified build of OpenSSL and Curl.
I have already statically compiled both and verified I can use them in an Objective-C framework on my target platform (iOS & iOS Simulator). I'm using XCFramework files that contain the static library binaries and headers:
openssl.xcframework/
ios-arm64/
openssl.framework/
Headers/
[...]
openssl
ios-arm64_x86_64-simulator/
openssl.framework/
Headers/
[...]
openssl
Info.plist
I'm not sure how I'm supposed to set up my Swift package to import these libraries.
I can use .systemLibrary but that seems to use the embedded copies of libssl and libcurl on my system, and I can't figure out how to use the path: parameter to that.
I also tried using a .binaryTarget pointing to the XCFramework files, but that didn't seem to work as there is no module generated and I'm not sure how to make one myself.
At a basic high level, this is what I'm trying to accomplish:
where libcrypto & libssl come from the provided openssl.xcframework file, and libcurl from curl.xcframework
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 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?
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()
}
}
}
}
Hello there,
we have the following crash in production (99% in background) with our latest release, but we are not able to indentify 100% the main actor.
It could be Intercom SDK.
Firebase reports:
Crash
CoreFoundation
__CFRunLoopServiceMachPort
mach_msg
__CFRunLoopServiceMachPort
Any suggestion?
I want to ask about NSDecimalNumber. is it any changes for use this function ? i test use number like this.
example:
a = "1000000.0"
var a i make number formatter use NumberFormatter
b = NSDecimalNumber(string: a with number formatter).decimalValue
i try to print b. the value return 1. Anyone can help ?
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?
@discardableResult func doSomething() -> Bool {
// does something
return true
}
This function can be called in the following ways:
doSomething()
let didSucceed = doSomething()
Is there a way to differentiate the two from inside the doSomething() function, as in, is there a way to know if the caller is using the result?
Hello everyone,
I'm encountering an issue with Swift and C++ interoperability when passing a void pointer between Swift and C++ functions. When I pass pMessageBuffer (an UnsafeMutableRawPointer) from Swift to MyCppClass.NFCompletion (a static c++ function), which expects a reference to void pointer, Swift throws an error "Cannot convert value of type 'UnsafeMutableRawPointer' to expected argument type 'Optional' ".
Here is a sample code to help in better visualization of the usecase.
Cpp Code
class MyCppClass {
public:
static void SendData(void *pMessage, TUInt16 pMessageLength) {
// Assume vSocket is my Swift object held in C++.
vSocket.Send(pMessage, pMessageLength);
}
static void NFCompletion(void * & pBuffer, TInt64 pErrorCode, VPtr pCompletionFunction) {
// Process the buffer.
}
};
Swift Code:
public class MySwiftClass {
var vConnection: NWConnection?
public init() {}
public func Send(_ pMessageBuffer: UnsafeMutableRawPointer, _ pMessageLength: TSUInt16) {
let messageData = Data(bytesNoCopy: pMessageBuffer, count: Int(pMessageLength), deallocator: .none)
self.vConnection?.send(content: messageData, completion: .contentProcessed { nw_error in
var error_code: TSInt64 = 0
if let nw_error = nw_error {
error_code = self.InternalGetNetworkErrorCode(nw_error)
}
// Here's where the issue arises:
MyCppClass.NFCompletion(pMessageBuffer, TInt64(error_code), self.uCompletionHandler)
})
}
// Example function to handle network errors
private func InternalGetNetworkErrorCode(_ error: Error) -> TSInt64 {
// Implementation to convert nw_error to TSInt64 error code
return 0 // Placeholder return value
}
}
Could someone please help me understand why this conversion error occurs? How should I correctly handle passing a void pointer between Swift and C++ functions, ensuring compatibility and proper memory management?
Note: TSInt64 is typealias for swift Int and TInt64 is alias of c++ int_64t.
Thank you in advance for your assistance!
Regards,
Harshal
Hello! I am working on a project that does some automatic code generation using SwiftSyntax and SwiftSyntaxBuilder. As part of this project, I want to put in a comment at the top of the file warning users to not modify the file and make it obvious that the code was automatically generated. I was trying to use the .lineComment(String) static member of the Trivia (or TriviaPiece) types and I expected that the comment would automatically be prefixed with the expected // and space for use in code. (For example, Trivia.lineComment("No comment") would be written as // No Comment when sent through a BasicFormat Object or similar SyntaxRewriter). I was surprised to find that this is not the case and was wondering before I write an issue on GitHub whether this behavior is intentional or a bug. If it is intentional, I'm not entirely sure if I'm missing something regarding this to more easily generate these comments.
At the moment my comment generation consists of constructing the comment in the leadingTrivia of the syntax node that appears after the comment. For example:
VariableDeclSyntax(leadingTrivia: [.newlines(2), .lineComment("// These members are always generated irrespective of the contents of the generated files. They are intended to exclusively centralize code symbols that would otherwise be repeated frequently."), .newlines(1)], modifiers: [DeclModifierSyntax(name: .keyword(.private)), DeclModifierSyntax(name: .keyword(.static))], .let, name: PatternSyntax(IdentifierPatternSyntax(identifier: "decoder")), initializer: InitializerClauseSyntax(value: ExprSyntax(stringLiteral: "\(configuration.decoderExpression)")))
outputs
// These members are always generated irrespective of the contents of the generated files. They are intended to exclusively centralize code symbols that would otherwise be repeated frequently.
private static let decoder = JSONDecoder()
in this project (with example data having been added).
I'm relatively new to Swift, and very new to concurrency via Async/Await, so please be patient. 😀
I'm having a hard time comprehending how to do complex operations asynchronously in background threads, and then in turn bring the results back to the main thread. I'm getting various errors along the lines of "Mutation of captured var 'personName' in concurrently-executing". I've paired the issue down as simply as possible as follows, and you'll see where the compiler gives the error message.
I'd appreciate any advice on how to evolve my mental model to make this work.
Thanks!
Bruce
import Foundation
actor Person {
var myName = "Thomas Jefferson"
var name: String {
get {
return myName
}
}
}
func main() {
let person = Person()
var personName: String
print("start")
let nameTask = Task {
return await person.name
}
Task {
do {
personName = try await nameTask.result.get()
// Error: Mutation of captured var 'personName' in concurrently-executing code
} catch {
print("error!!!")
}
}
print("The person's name is \(personName)")
}
RunLoop.main.run()
main()
I'm continuing with the migration towards Swift 6. Within one of our libraries, I want to check whether a parameter object: Any? confirms to Sendable.
I tried the most obvious one:
if let sendable = object as? Sendable {
}
But that results into the compiler error "Marker protocol 'Sendable' cannot be used in a conditional cast".
Is there an other way to do this?
I have a custom localisation function in my project that enforces the inclusion of the bundle parameter (specifically so that Swift packages are forced to include the Bundle.module value).
While migrating to String Catalogs, I noticed that my custom localisation function wasn't being recognised by the automatic extraction that the Swift compiler is doing, but only in my Swift package targets.
Is there a way to set something like LOCALIZED_STRING_MACRO_NAMES in Swift Packages?
Hello,
I am working on a macOS Virtualization framework project on Xcode.
Is there a way to redirect an USB device connected to the host mac, to a virtual machine.
I know this is possible with lower layers but i would like to do it with a VZVirtualMachine object. Is it possible ?
Thanks
This is the error I am continuosly receiving.
Hey, im new here. And I need to share a variable between files, settings and home. I've searched all over and found solutions, but I just don't understand what to do.