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JavaScript/Swift Interoperability
I think that it would be helpful to have better interoperability between Swift and JavaScript. There are a lot of useful packages on NPM that don't have equivalents for Swift. It would be helpful if Apple provided easier ways to use NPM packages in a Swift project. Currently, the JavaScriptCore framework is missing many standard things used in many packages, like the fetch API. It would be helpful to be able to run sandboxed JavaScript code inside of a Swift app but allow access to specific domains, folders, etc., using a permissions system similar to Deno.
6
1
3.4k
Jan ’26
Calling a Objc method directly from C
I would like to avoid the middle man and call Objective C directly from C Currently I do this This is called from a dispatch table in a pure C file _ctx->mt_render_funcs.mtlEnd(_ctx); Which calls this routine in a obj c file .m void mtlEnd(MTRenderContext mt_ctx) { // Call the Objective-C method using Objective-C syntax [(__bridge id) mt_ctx->mt_render_funcs.mtlObj mtlEnd]; } Which ends up here... in ObjC #pragma mark mtlEnd (void)mtlEnd { // vertex buffer size_t size; size = sizeof(Vertex4ColorNormalTex) * _ctx->vert_eng.current_vertex; [_currentRenderEncoder setVertexBytes:_ctx->vert_eng.vertices length: size atIndex: VertexInputIndexVertices]; [_currentRenderEncoder drawPrimitives:(MTLPrimitiveType)_ctx->vert_eng.prim_type vertexStart:0 vertexCount:_ctx->vert_eng.current_vertex]; } It would simplify this to get rid of one call and call ObjC directly. The other idea is I want to use GCD and put a lock / unlock on the call from C to ensure thread safety so I can use GCD to dispatch a thread to do the ObjC routines. I want to stick with C as the foundation so it can be used directly from C or a FFI interface from other languages. But Metal works well in ObjC and I would prefer to use that. Thanks ahead of time.
3
0
1.5k
Mar ’26
Why is the Documentation full of Conundrums?
I'm trying to learn and focus on the task and your examples keep having hidden conundrums in them. Here is an example that got me snagged for hours last night going, Well what the F do they want me to name it? What is it you want me to learn here? Because you pose a giant riddle of name something that you should be given a name for... My friend said to me that this is a common thing you will have to do and they were right however... What are you asking me to do? Get stuck on the variable naming problem where I'm going... Yeah those are math terms from 20+ years ago and I have no idea how to classify those terms... Are you asking me that? No. So why is that in the problem. These conundrums mixed in with legitimate problems honestly make me not want to learn Swift at all.
3
0
360
Mar ’26
Undefined symbol
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
2
1
1.9k
1w
String Catalogs auto-generated symbols located in Swift Packages with default Main Actor isolation don't compile with Xcode 26.4
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.
1
0
871
1w
NotificationCenter Crash On iOS 18+ Swift6.2
After switching our iOS app project from Swift 5 to Swift 6 and publishing an update, we started seeing a large number of crashes in Firebase Crashlytics. The crashes are triggered by NotificationCenter methods (post, addObserver, removeObserver) and show the following error: BUG IN CLIENT OF LIBDISPATCH: Assertion failed: Block was expected to execute on queue [com.apple.main-thread (0x1f9dc1580)] All scopes to related calls are already explicitly marked with @MainActor. This issue never occurred with Swift 5, but appeared immediately after moving to Swift 6. Has anyone else encountered this problem? Is there a known solution or workaround? Thanks in advance!
2
1
1.7k
Nov ’25
iOS and Android
I currently have a iOS app live on the App Store but I also want to release it on Android, the whole code is in Swift so would that be possible or would I have to rewrite my whole apps code in a different coding language.
2
0
2.8k
Jan ’26
Data Disappeared
Hi, writing a database app for storing equipment details. Spent the day doing minor changes and tidying with many backups made, and always re-building to check its all working. Everything ok but then next build looses all data, what's the best thing to check to see if the data is still there, any help would be fantastic.
1
0
1.3k
Mar ’26
On iPad with Swift Playgrounds: How to open chapter as a playground?
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
2
0
1.7k
3w
Apple Silicon calling printf
What is the proper way to pass arguments to printf with multiple variables using ARM64 Apple Silicon? Example: fOutputStr: .asciz "Element[%d] = %d\n" // formated output string for an output of: Element[4] = 9 This code (see below) works on Raspberry Pi 5, on my Mac Studio, I am getting this output, Element[9] = 1871655168 What do I need to do to use printf from an assembly language call with multiple variables? I am using the following code. ` .align 2 // memory alignment model for 64-bit ARMc #if defined(APPLE) .global _main // Provide program starting address to linker Mac OS _main: #else .global main // Raspian and Linux main: #endif // stack frame work setup START stp x29, x30, [sp, -16]! str x20, [sp, -16]! mov x29, sp // stack frame work setup END // setup printf call #if defined(APPLE) adrp x0, fOutputStr@PAGE add x0, x0, fOutputStr@PAGEOFF #else ldr x0, =fOutputStr #endif mov w1, #4 mov w2, #9 print_brk: #if defined(APPLE) stp X0, X1, [SP, #-16]! stp X2, X3, [SP, #-16]! bl _printf ldp X2, X3, [SP], #16 ldp X0, X1, [SP], #16 #else bl printf #endif done: // closing stack frame work ldr x20, [sp],16 ldp x29, x30, [sp],16 // exit mov w0, wzr ret .data .align 4 // intArrayPtr: .word 3,7,5,2,4,8 // word, each value is offset by 4 fOutputStr: .asciz "Element[%d] = %d\n" // formated output string
6
1
842
Mar ’26
MPMediaItemPropertyArtwork crashes on Swift 6
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
6
0
3.2k
Sep ’25
What is the future of Objective-C?
Will Apple continue to support it, or will we wake up one day to find that Swift is the only viable language?It's a serious question. Careers depend on it. I don't accept the "No comment" approach that Apple usually takes. It's cruel.I'm willing to put the time into learning Swift if I have to. I'm not going to do it if I don't. I want to know.Frank
23
1
34k
Oct ’25
JavaScript/Swift Interoperability
I think that it would be helpful to have better interoperability between Swift and JavaScript. There are a lot of useful packages on NPM that don't have equivalents for Swift. It would be helpful if Apple provided easier ways to use NPM packages in a Swift project. Currently, the JavaScriptCore framework is missing many standard things used in many packages, like the fetch API. It would be helpful to be able to run sandboxed JavaScript code inside of a Swift app but allow access to specific domains, folders, etc., using a permissions system similar to Deno.
Replies
6
Boosts
1
Views
3.4k
Activity
Jan ’26
Calling a Objc method directly from C
I would like to avoid the middle man and call Objective C directly from C Currently I do this This is called from a dispatch table in a pure C file _ctx->mt_render_funcs.mtlEnd(_ctx); Which calls this routine in a obj c file .m void mtlEnd(MTRenderContext mt_ctx) { // Call the Objective-C method using Objective-C syntax [(__bridge id) mt_ctx->mt_render_funcs.mtlObj mtlEnd]; } Which ends up here... in ObjC #pragma mark mtlEnd (void)mtlEnd { // vertex buffer size_t size; size = sizeof(Vertex4ColorNormalTex) * _ctx->vert_eng.current_vertex; [_currentRenderEncoder setVertexBytes:_ctx->vert_eng.vertices length: size atIndex: VertexInputIndexVertices]; [_currentRenderEncoder drawPrimitives:(MTLPrimitiveType)_ctx->vert_eng.prim_type vertexStart:0 vertexCount:_ctx->vert_eng.current_vertex]; } It would simplify this to get rid of one call and call ObjC directly. The other idea is I want to use GCD and put a lock / unlock on the call from C to ensure thread safety so I can use GCD to dispatch a thread to do the ObjC routines. I want to stick with C as the foundation so it can be used directly from C or a FFI interface from other languages. But Metal works well in ObjC and I would prefer to use that. Thanks ahead of time.
Replies
3
Boosts
0
Views
1.5k
Activity
Mar ’26
Why is the Documentation full of Conundrums?
I'm trying to learn and focus on the task and your examples keep having hidden conundrums in them. Here is an example that got me snagged for hours last night going, Well what the F do they want me to name it? What is it you want me to learn here? Because you pose a giant riddle of name something that you should be given a name for... My friend said to me that this is a common thing you will have to do and they were right however... What are you asking me to do? Get stuck on the variable naming problem where I'm going... Yeah those are math terms from 20+ years ago and I have no idea how to classify those terms... Are you asking me that? No. So why is that in the problem. These conundrums mixed in with legitimate problems honestly make me not want to learn Swift at all.
Replies
3
Boosts
0
Views
360
Activity
Mar ’26
How works Experiment (Documentation) in Swift Playground?
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
Replies
3
Boosts
0
Views
2.2k
Activity
Mar ’26
Undefined symbol
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
Replies
2
Boosts
1
Views
1.9k
Activity
1w
String Catalogs auto-generated symbols located in Swift Packages with default Main Actor isolation don't compile with Xcode 26.4
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.
Replies
1
Boosts
0
Views
871
Activity
1w
How can I enable “Approachable Concurrency” for a Swift Package?
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?
Replies
3
Boosts
0
Views
1.1k
Activity
Jul ’25
How to retrieve the % of memory pressure using native libraries
Is there any way to retrieve the memory pressure percentage using native libraries? When I run the memory-pressure command, I can see the percentage of free memory, but I’d like to retrieve the same information using a native library.
Replies
2
Boosts
0
Views
660
Activity
Oct ’25
NotificationCenter Crash On iOS 18+ Swift6.2
After switching our iOS app project from Swift 5 to Swift 6 and publishing an update, we started seeing a large number of crashes in Firebase Crashlytics. The crashes are triggered by NotificationCenter methods (post, addObserver, removeObserver) and show the following error: BUG IN CLIENT OF LIBDISPATCH: Assertion failed: Block was expected to execute on queue [com.apple.main-thread (0x1f9dc1580)] All scopes to related calls are already explicitly marked with @MainActor. This issue never occurred with Swift 5, but appeared immediately after moving to Swift 6. Has anyone else encountered this problem? Is there a known solution or workaround? Thanks in advance!
Replies
2
Boosts
1
Views
1.7k
Activity
Nov ’25
iOS and Android
I currently have a iOS app live on the App Store but I also want to release it on Android, the whole code is in Swift so would that be possible or would I have to rewrite my whole apps code in a different coding language.
Replies
2
Boosts
0
Views
2.8k
Activity
Jan ’26
Data Disappeared
Hi, writing a database app for storing equipment details. Spent the day doing minor changes and tidying with many backups made, and always re-building to check its all working. Everything ok but then next build looses all data, what's the best thing to check to see if the data is still there, any help would be fantastic.
Replies
1
Boosts
0
Views
1.3k
Activity
Mar ’26
On iPad with Swift Playgrounds: How to open chapter as a playground?
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
Replies
2
Boosts
0
Views
1.7k
Activity
3w
Apple Silicon calling printf
What is the proper way to pass arguments to printf with multiple variables using ARM64 Apple Silicon? Example: fOutputStr: .asciz "Element[%d] = %d\n" // formated output string for an output of: Element[4] = 9 This code (see below) works on Raspberry Pi 5, on my Mac Studio, I am getting this output, Element[9] = 1871655168 What do I need to do to use printf from an assembly language call with multiple variables? I am using the following code. ` .align 2 // memory alignment model for 64-bit ARMc #if defined(APPLE) .global _main // Provide program starting address to linker Mac OS _main: #else .global main // Raspian and Linux main: #endif // stack frame work setup START stp x29, x30, [sp, -16]! str x20, [sp, -16]! mov x29, sp // stack frame work setup END // setup printf call #if defined(APPLE) adrp x0, fOutputStr@PAGE add x0, x0, fOutputStr@PAGEOFF #else ldr x0, =fOutputStr #endif mov w1, #4 mov w2, #9 print_brk: #if defined(APPLE) stp X0, X1, [SP, #-16]! stp X2, X3, [SP, #-16]! bl _printf ldp X2, X3, [SP], #16 ldp X0, X1, [SP], #16 #else bl printf #endif done: // closing stack frame work ldr x20, [sp],16 ldp x29, x30, [sp],16 // exit mov w0, wzr ret .data .align 4 // intArrayPtr: .word 3,7,5,2,4,8 // word, each value is offset by 4 fOutputStr: .asciz "Element[%d] = %d\n" // formated output string
Replies
6
Boosts
1
Views
842
Activity
Mar ’26
The Swift Programming Language Book
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?
Replies
5
Boosts
0
Views
1.4k
Activity
3w
MPMediaItemPropertyArtwork crashes on Swift 6
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
Replies
6
Boosts
0
Views
3.2k
Activity
Sep ’25
What is the future of Objective-C?
Will Apple continue to support it, or will we wake up one day to find that Swift is the only viable language?It's a serious question. Careers depend on it. I don't accept the "No comment" approach that Apple usually takes. It's cruel.I'm willing to put the time into learning Swift if I have to. I'm not going to do it if I don't. I want to know.Frank
Replies
23
Boosts
1
Views
34k
Activity
Oct ’25