DougGregor

Initiating async work from synchronous code

Motivation

Swift async functions can only directly be called from other async functions. In synchronous code, the only mechanism provided by the Swift Concurrency model to create asynchronous work is detach. The detach operation creates a new, detached task that is completely independent of the code that initiated the detach: the closure executes concurrently, is independent of any actor unless it explicitly opts into an actor, and does not inherit certain information (such as priority).

Detached tasks are important and have their place, but they don't map well to cases where the natural "flow" of control is from the synchronous function into async code, e.g., when reacting to an event triggered in a UI:

@MainActor func saveResults() {

keith

Usage

1. swiftc main.swift -emit-module-path main.swiftmodule -emit-executable -enable-private-imports -Xfrontend -enable-implicit-dynamic
2. ./main -> prints From original bar()
3. swiftc -emit-library inject.swift -o inject.dylib -I . -Xlinker -undefined -Xlinker suppress -Xlinker -flat_namespace -Xfrontend -disable-access-control
4. DYLD_INSERT_LIBRARIES=inject.dylib ./main -> prints From replacement bar()

Notes

• Passing -Xfrontend -enable-implicit-dynamic removes you from having to add dynamic to everything you want to be replacable

DougGregor

extension Collection {
  func parallelMap<T>(
    parallelism requestedParallelism: Int? = nil,
    _ transform: @escaping (Element) async throws -> T
  ) async throws -> [T] {
    let defaultParallelism = 2
    let parallelism = requestedParallelism ?? defaultParallelism

    let n = self.count
    if n == 0 {

joevt

#!/bin/perl

# by joevt Nov 18, 2021

use 5.010;
use strict;
#use warnings;
use Data::Dumper qw(Dumper);

use JSON::PP;

truizlop

import SwiftUI

let LINE_LENGTH: Double = 500.0
let N = 720
let LINES = 18
let WAVES: Double = 18.0
let WAVE_HEIGHT: Double = 20
let SPACING: Double = 27.0
let CURL_AMOUNT: Double = 12.0

surpher

Dealing with Rust to build PactSwiftMockServer

Example of an automated script that does most of this: https://github.com/surpher/PactSwiftMockServer/blob/fb8148866bb05f49a0b1dcaae66c67bad1e7eca7/Support/build_rust_dependencies

Install Rust

curl https://sh.rustup.rs -sSf | sh

douglashill

import UIKit

class FourColumnsContainerViewController: UIViewController {
    let outerSplitViewController = UISplitViewController(style: .tripleColumn)
    let innerSplitViewController = UISplitViewController(style: .doubleColumn)

    let primary = makeContentViewController("App")
    let secondary = makeContentViewController("Files")
    let mainContent = makeContentViewController("File Content")
    let inspector = makeContentViewController("Inspector")

Gargron

Mastodon E2EE implementation guide

You need the crypto OAuth scope. Check if there is a way for you to use Olm for your programming language / platform. Using libsignal should be possible but has not been tested.

Step 1: Setting up the device/app

Use Olm to generate the device keypairs and a set of one-time keys. Decide on what the device will be called publicly (this can be changed any time). Also generate a random device ID, this can be a number or a string as long as it's securely random.

There are two device keypairs: The Curve25519 key that we call the identity key, and the Ed25519 key that we call the fingerprint key, which is used for signing and verifying that other keys belong to the same device.

pd95

#!/bin/zsh
# Shell Script to create all relevant icons from an high resolution artwork

if [ "x$1" != "x" -a -f "$1" ] ; then
    INPUT=$1
else 
    INPUT="Artwork.png"
fi

if [ ! -f "$INPUT" ]; then

RoLYroLLs

//
//  DeviceConstants.swift
//  SampleApp
//
//  Created by RoLY roLLs on 12/31/19.
//  Copyright © 2019 RoLYroLLs Enterprises, LLC. All rights reserved.
//

/// Taken from https://developer.apple.com/documentation/swiftui/securefield/3289399-previewdevice