krzyzanowskim

/// Wait for async operation to return value and call callback with the value
/// This class is intended to workaround/simplify async/await + actors isolation
/// https://twitter.com/krzyzanowskim/status/1523233140914876416
private class AsyncWaiter<T> {
    var didReceiveValue: Bool = false
    let value: (T) -> Void
    let operation: () async throws -> T

    init(_ value: @escaping (T) -> Void, operation: @escaping () async throws -> T) {
        self.value = value

mbrandonw

/*:
 # Seemingly Impossible Swift Programs
 */
/*:
 # 1.) Completely possible programs
 */

[1, 2, 3]
  .allSatisfy { $0 >= 2 }
[1, 2, 3]

DougGregor

import Darwin

@dynamicMemberLookup
struct Environment {
  subscript(dynamicMember name: String) -> String? {
    get {
      guard let value = getenv(name) else { return nil }

      return String(validatingUTF8: value)
    }

tclementdev

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

• You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

• Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

inamiy

React & Elm inspired frameworks in Swift

This is a curated list of iOS (Swift & ObjC) frameworks which are inspired by React and Elm.

Swift frameworks

React-inspired

• ReactSwift by @ColinEberhardt
• https://github.com/ColinEberhardt/ReactSwift

sooop

import Foundation

class StreamReader {
    let encoding: String.Encoding
    let chunkSize: Int
    let fileHandle: FileHandle
    var buffer: Data
    let delimPattern : Data
    var isAtEOF: Bool = false
    

steipete

# The trick is to link the DeviceSupport folder from the beta to the stable version.
# sudo needed if you run the Mac App Store version. Always download the dmg instead... you'll thank me later :)

# Support iOS 15 devices (Xcode 13.0) with Xcode 12.5:
sudo ln -s /Applications/Xcode-beta.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/15.0 /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport

# Then restart Xcode and reconnect your devices. You will need to do that for every beta of future iOS versions

# (A similar approach works for older versions too, just change the version number after DeviceSupport)

ericdke

func getSystemUUID() -> String? {
    let dev = IOServiceMatching("IOPlatformExpertDevice")
    let platformExpert: io_service_t = IOServiceGetMatchingService(kIOMasterPortDefault, dev)
    let serialNumberAsCFString = IORegistryEntryCreateCFProperty(platformExpert, kIOPlatformUUIDKey, kCFAllocatorDefault, 0)
    IOObjectRelease(platformExpert)
    let ser: CFTypeRef = serialNumberAsCFString.takeUnretainedValue()
    if let result = ser as? String {
        return result
    }
    return nil