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String functions problems on iOS18
On iOS 18 some string functions return incorrect values in some cases. Found problems on replacingOccurrences() and split() functions, but there may be others. In the results of these functions in some cases a character is left in the result string when it shouldn't. This did not happen on iOS17 and older versions. I created a very simple Test Project to reproduce the problem. If I run these tests on iOS17 or older the tests succeed. If I run these tests on iOS18 the tests fail. test_TestStr1() function shows a problem in replacingOccurrences() directly using strings. test_TestStr2() function shows a problem in split() that seems to happen only when bridging from NSString to String. import XCTest final class TestStrings18Tests: XCTestCase { override func setUpWithError() throws { // Put setup code here. This method is called before the invocation of each test method in the class. } override func tearDownWithError() throws { // Put teardown code here. This method is called after the invocation of each test method in the class. } func test_TestStr1() { let str1 = "_%\u{7}1\u{7}_"; let str2 = "%\u{7}1\u{7}"; let str3 = "X"; let str4 = str1.replacingOccurrences(of: str2, with: str3); //This should be true XCTAssertTrue(str4 == "_X_"); } func test_TestStr2() { let s1 = "TVAR(6)\u{11}201\"Ã\"\u{11}201\"A\""; let s2 = s1.components(separatedBy: "\u{11}201"); let t1 = NSString("TVAR(6)\u{11}201\"Ã\"\u{11}201\"A\"") as String; let t2 = t1.components(separatedBy: "\u{11}201"); XCTAssertTrue(s2.count == t2.count); let c = s2.count //This should be True XCTAssertTrue(s2[0] == t2[0]); } }
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507
Feb ’25
Error throws while using the speech recognition service in my app
Recently I updated to Xcode 14.0. I am building an iOS app to convert recorded audio into text. I got an exception while testing the application from the simulator(iOS 16.0). [SpeechFramework] -[SFSpeechRecognitionTask handleSpeechRecognitionDidFailWithError:]_block_invoke Ignoring subsequent recongition error: Error Domain=kAFAssistantErrorDomain Code=1101 "(null)" Error Domain=kAFAssistantErrorDomain Code=1107 "(null)" I have to know what does the error code means and why this error occurred.
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12k
Feb ’25
Best way to learn Swift
Hi I'm new here - I'm trying to learn Swift and SwiftUI. Tried on PluralSight and Udemy but they have been outdated and thus hard to follow. So after finding Apples own guides I felt relieved and happy, but now I'm stuck again. After they've updated Xcode to use #Preview instead of PreviewProvider it's hard to follow along on their tutorial. Does anyone know of good resources to study SwiftUI? Or know if apple plan to update their tutorials any time soon? I'm here now if anyone's interested or it's useful information: https://developer.apple.com/tutorials/app-dev-training/managing-state-and-life-cycle
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Feb ’25
Confusion About Objective-C's Memory Management (Cocoa)
Hello everyone, There is one thing about Objective-C's memory management that confuses me, which is a returned object's lifetime from methods with names doesn't start with "alloc", "new", "copy", or "mutableCopy". Take this as an example, when using NSBitmapImageRep's representationUsingType:properties: method, it returns an NSData object (reference: https://developer.apple.com/documentation/appkit/nsbitmapimagerep/representation(using:properties:)?language=objc). While testing this out, the NSData seemed to be an owned object (it doesn't get released until the end of the program). From what I understand, this may be an auto-released object which is released at the end of an autorelease pool block. Could someone explain this in more detail? What if I want to release that NSData object before the end of the autorelease pool block? How can I know which object is autoreleased, borrowed, or owned?
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606
Jan ’25
Apple Accelerate libSparse performance
I've created a Julia interface for Apple Accelerate's libSparse, via calling the library functions as if they were C (@ccall). I'm interested in using this in the context of power systems, where the sparse matrix is the Jacobian or the ABA matrix from a sparse grid network. However, I'm puzzled by the performance. I ran a sampling profiler on repeated in-place solves of Ax = b for a large sparse matrix A and random dense vectors b. (A is size 30k, positive definite so Cholesky factorization.) The 2 functions with the largest impact are _SparseConvertFromCoordinate_Double from libSparse.dylib, and BLASStateRelease from libBLAS.dylib. That strikes me as bizarre. This is an in-place solve: there should be minimal overheard from allocating/deallocating memory. Also, it seems strange that the library would repeatedly convert from coordinate form. Is this expected behavior? Thinking it might be an artifact of the Julia-C interface, I wrote up a similar program in C/Objective-C. I didn't profile it, but timing the same operation (repeated in-place solves of Ax = b for random vectors b, with the same matrix A as in the Julia) gave the same duration. I've attached the C/Objective-C below.profiling-comparison.m.txt If you're familiar with Julia, the following will give you the matrix I was working with: using PowerSystems, PowerNetworkMatrices sys = System("pglib_opf_case30000_goc.m") A = PowerNetworkMatrices.ABA_Matrix(sys).data where you can find the .m file here. (As a crude way to transfer A from Julia to C, I wrote the 3 arrays A.nzval, A.colptr, and A.rowval to .txt files as space-separated lists of numbers: the above C/objective-C reads in those files.) To duplicate my Julia profiling, do pkg> add AppleAccelerate#libSparse Profile--note the #libSparse part, these features aren't on the main branch--then run using AppleAccelerate, Profile # run previous code snippet to define A M, N = 10000, size(A)[1] bs = [rand(N) for _ in 1:M] aa_fact = AAFactorization(A) factor!(aa_fact) solve!(aa_fact, bs[1]) # pre-compile before we profile. Profile.init(n = 10^6, delay = 0.0003) @profile (for i in 1:M; solve!(aa_fact, bs[i]); end;) Profile.print(C = true, format = :flat, sortedby = :count)
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Jan ’25
Swift 6 concurrency. Apple Watch App target and -disable-dynamic-actor-isolation.
I've got a watch app, still with storyboard, WKInterfaceController and WatchConnectivity. After updating it for swift 6 concurrency I thought I'd keep it for a little while without swift 6 concurrency dynamic runtime check. So I added -disable-dynamic-actor-isolation in OTHER_SWIFT_FLAGS, but it doesn't seem to have an effect for the Apple Watch target. Without manually marking callbacks where needed with @Sendable in dynamic checks seem to be in place. swiftc invocation is as (includes -disable-dynamic-actor-isolation): swiftc -module-name GeoCameraWatchApp -Onone -enforce-exclusivity\=checked ... GeoCameraWatchApp.SwiftFileList -DDEBUG -enable-bridging-pch -disable-dynamic-actor-isolation -D DEBUG -enable-experimental-feature DebugDescriptionMacro -sdk /Applications/Xcode.app/Contents/Developer/Platforms/WatchOS.platform/Developer/SDKs/WatchOS11.2.sdk -target arm64_32-apple-watchos7.0 -g -module-cache-path /Users/stand/Library/Developer/Xcode/DerivedData/ModuleCache.noindex -Xfrontend -serialize-debugging-options -enable-testing -index-store-path /Users/stand/Library/Developer/Xcode/DerivedData/speedo-almhjmryctkitceaufvkvhkkfvdw/Index.noindex/DataStore -enable-experimental-feature OpaqueTypeErasure -Xcc -D_LIBCPP_HARDENING_MODE\=_LIBCPP_HARDENING_MODE_DEBUG -swift-version 6 ... -disable-dynamic-actor-isolation flag seems to be working for the iOS targets, I believe. The flag is described here Am I missing something? Should the flag work for both iOS and Apple Watch targets?
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616
Jan ’25
Swift 6 and 5 - Strict concurrency: complete and WKNavigationDelegate decidePolicyFor not being called.
decidePolicyFor delegate method: import WebKit @objc extension DocumentationVC { func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) Being called just alright in swift 5 minimal concurrency. Raising concurrency to complete with swift 5 or swift 6. Changing the code to avoid warnings: @preconcurrency import WebKit @objc extension DocumentationVC { func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) { The delegate method is not being called. Changing back to swift 5 concurrency minimal - it is called. Looking at WKNavigationDelegate: WK_SWIFT_UI_ACTOR @protocol WKNavigationDelegate <NSObject> - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(WK_SWIFT_UI_ACTOR void (^)(WKNavigationActionPolicy))decisionHandler WK_SWIFT_ASYNC(3); Changing the delegate method to: func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping @MainActor (WKNavigationActionPolicy) -> Void) { And it is called across swift 5 concurrency minimal to complete to swift 6. I thought, the meaning of @preconcurrency import WebKit was to keep the delegate without @MainActor before the (WKNavigationActionPolicy) still matching regardless the swift concurrency mode? My point is - this can introduce hidden breaking changes? I didn't see this documented anyhow at: https://www.swift.org/migration/documentation/migrationguide/. decidePolicyFor is an optional method - so if signature 'mismatches' - there will be no warning on not-implementing the delegate method. How do we catch or diagnose irregularities like this? Is it something @preconcurrency import WebKit should be ensuring and it is not? Is this delegate mismatch a bug on swift side or something we should be taking care of while migrating? If it is on us, how do we diagnose these potential mismatches?
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Jan ’25
Unexpected behavior of dispatch_main on macOS
Hi! We are seeing a bit surprising behavior of dispatch_main on macOS where it seems to spawn a different thread instead of preserving the one it gets called from. Managed to reproduce it in a completely empty command-line tool project in Xcode int main(int argc, const char * argv[]) { @autoreleasepool { dispatch_main(); return 0; } } I put a breakpoint on the line with dispatch_main and see that I am on Thread 1 and inside main function. That makes sense. I resume execution and pause again. Looking at Thread output in Xcode, I can only see Thread 2. Thread 1 is gone and the executable keeps on running. So dispatch_main did what was expected (prevented the process from termination) but throws out the thread it was called from and creates a new one? Is that behavior expected or am I missing something? Just a brain teaser at this point. But we could not make sense out of it. :)
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Jan ’25
Request authorization for the notification center crash iOS app on Swift 6
Hey all! During the migration of a production app to swift 6, I've encountered a problem: when hitting the UNUserNotificationCenter.current().requestAuthorization the app crashes. If I switch back to Language Version 5 the app works as expected. The offending code is defined here class AppDelegate: NSObject, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -&gt; Bool { FirebaseApp.configure() FirebaseConfiguration.shared.setLoggerLevel(.min) UNUserNotificationCenter.current().delegate = self let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound] UNUserNotificationCenter.current().requestAuthorization(options: authOptions) { _, _ in } application.registerForRemoteNotifications() Messaging.messaging().delegate = self return true } } The error is depicted here: I have no idea how to fix this. Any help will be really appreciated thanks in advance
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5.5k
Jan ’25
Odd Shell Echo Output...
I have a simple shell script as follows: #!/bin/bash OUTPUT="network.$(date +'%d-%m-%y').info.txt" SUPPORT_ID="emailaddress" echo "---------------------------------------------------" > $OUTPUT echo "Run date and time: $(date)" >> $OUTPUT echo "---------------------------------------------------" >> $OUTPUT ifconfig >> $OUTPUT echo "---------------------------------------------------" >> $OUTPUT echo "Network info written to file: $OUTPUT." echo "Please email this file to: $SUPPORT_ID." It just dumps the network config into a file. At some point I will have the file emailed out, but right now I'm just trying to figure out why the output looks like the following? bash ./test.sh .etwork info written to file: network.26-01-25.info.txt .lease email this file to: emailaddress Why in the world does the initial character of the last couple of "echo" commands get clipped and turned into periods? The echos for the output of the commands piped into the output file are fine. Strange... Any ideas?
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512
Jan ’25
Odd Echo Output From Shell Script
I have a simple shell script as follows: #!/bin/bash OUTPUT="network.$(date +'%d-%m-%y').info.txt" SUPPORT_ID="email" echo "---------------------------------------------------" > $OUTPUT echo "Run date and time: $(date)" >> $OUTPUT echo "---------------------------------------------------" >> $OUTPUT ifconfig >> $OUTPUT echo "---------------------------------------------------" >> $OUTPUT echo "Network info written to file: $OUTPUT." echo "Please email this file to: $SUPPORT_ID." It just dumps the network config into a file. At some point I will have the file emailed out, but right now I'm just trying to figure out why the output looks like the following? bash ./test.sh .etwork info written to file: network.26-01-25.info.txt .lease email this file to: email Why in the world does the initial character of the last couple of "echo" commands get clipped and turned into periods? The echos for the output of the commands piped into the output file are fine. Strange... Any ideas?
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557
Jan ’25
Returning One Component of Struct as Encoded Value in JSON
I have a class that I want to custom encode into JSON: class Declination: Decodable, Encodable { var asString: String var asDouble: Double init(_ asString: String) { self.asString = asString self.asDouble = raToDouble(asString) } required init(from decoder: Decoder) throws { let value = try decoder.singleValueContainer() self.asString = try value.decode(String.self) self.asDouble = declinationToDouble(asString) } } As you can see, I calculate the double form of the declination when I decode a JSON file containing the data. What I want to do now is ENCODE the class back out as a single string. Currently the standard JSON encode in Swift produces the following: "declination":{"asDouble":18.26388888888889,"asString":"+18:15:50.00"} what I want to produce is: declination:"+18:15:50.00" How can I easily do that? I've read up about custom encoders and such, and I get confused about the containers and what keys are being used. I think there might be a simple answer where I could just code: extension Coordinate: Encodable { func encode(to encoder: Encoder) throws { return encoder.encode(self.asString) } } But experienced Swift developers will immediately see that won't work. Should I do JSONSerialization instead? Can I just write a toString() extension and have JSON pick that up? Any help would be appreciated. Thanks, Robert
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325
Jan ’25
Why doesn’t getAPI() show up in autocomplete despite having a default implementation in a protocol extension?
I’m working on a project in Xcode 16.2 and encountered an issue where getAPI() with a default implementation in a protocol extension doesn’t show up in autocomplete. Here’s a simplified version of the code: import Foundation public protocol Repository { func getAPI(from url: String?) } extension Repository { public func getAPI(from url: String? = "https://...") { getAPI(from: url) } } final class _Repository: Repository { func getAPI(from url: String?) { // Task... } } let repo: Repository = _Repository() repo.getAPI( // Autocomplete doesn't suggest getAPI() I’ve tried the following without success: • Clean build folder • Restart Xcode • Reindexing Is there something wrong with the code, or is this a known issue with Xcode 16.2? I’d appreciate any insights or suggestions.
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562
Jan ’25
indices(where:) Swift Playgrounds Issue: "Cannot call value of non-function type Range<Int>"
Hey there- I'm having a quite interesting bug on Swift Playgrounds. I am trying to run my app with this following code snippet which does not compile on Swift Playgrounds, yet compiles on XCode (note: this is a Swift Playground app) if #available(iOS 18.0, *) { //simple function to get the indices of other items that have the same date as the "date" variable let indices = data!.indices(where: { item in let sameMonth = Calendar.current.component(.month, from: item.time) == Calendar.current.component(.month, from: date) let sameYear = Calendar.current.component(.year, from: item.time) == Calendar.current.component(.year, from: date) let sameDay = Calendar.current.component(.day, from: item.time) == Calendar.current.component(.year, from: date) return sameDay && sameMonth && sameYear }) However, the indices(where:) codeblock seems to stop the app from compiling (ONLY on Swift Playgrounds - it works perfectly fine on XCode). I am getting the following error: Cannot call value of non-function type 'Range<Array<Int>.Index>' (aka 'Range<Int>') Please let me know if you have any insight regarding this issue. -ColoredOwl
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539
Jan ’25
Swift6 race warning
I'm trying to fix some Swift6 warnings, this one seems too strict, I'm not sure how to fix it. The variable path is a String, which should be immutable, it's a local variable and never used again inside of the function, but still Swift6 complains about it being a race condition, passing it to the task What should I do here to fix the warning?
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602
Jan ’25
Polynomial Coefficients calculation
How can I calculate polynomial coefficients for Tone Curve points: // • Red channel: (0, 0), (60, 39), (128, 128), (255, 255) // • Green channel: (0, 0), (63, 50), (128, 128), (255, 255) // • Blue channel: (0, 0), (60, 47), (119, 119), (255, 255) CIFilter: func colorCrossPolynomial(inputImage: CIImage) -> CIImage? { let colorCrossPolynomial = CIFilter.colorCrossPolynomial() let redfloatArr: [CGFloat] = [1, 1, 1, 1, 0, 0, 0, 0, 0, 0] let greenfloatArr: [CGFloat] = [0, 1, 1, 0, 0, 0, 0, 0, 0, 1] let bluefloatArr: [CGFloat] = [0, 0, 1, 0, 0, 0, 0, 1, 1, 0] colorCrossPolynomial.inputImage = inputImage colorCrossPolynomial.blueCoefficients = CIVector(values: bluefloatArr, count: bluefloatArr.count) colorCrossPolynomial.redCoefficients = CIVector(values: redfloatArr, count: redfloatArr.count) colorCrossPolynomial.greenCoefficients = CIVector(values: greenfloatArr, count: greenfloatArr.count) return colorCrossPolynomial.outputImage }
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443
Jan ’25
Can't access C/C++ basic libraries
Hello, I am a software engineer student and I have recently been getting problems on my Mac regarding the C/C++ libraries. I have used my macbook for uni work for months, but around 3 or 4 months ago my macbook could not compile my work since it couldnt find the basic libraries I was using. For example, iostream. I have been using VSCode, and what it exactly says is "cannot open source file "iostream". Please run the 'Select IntelliSense Configuration...' command to locate your system headers." I have tried researching, changing the include path, even using chatgpt, and nothing. Is anyone having this same problem, or is able to help me? If any other information is needed, please let me know!
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742
Jan ’25