IanKeen

/// Rather than using `onAppear { ... }` to update a value you can do this instead:

struct MyView: View {
    @Update(to: 1.0, after: 0.5) var opacity: Double = 0.0

    var body: some View {
        ZStack {
            Color.black.edgesIgnoringSafeArea(.all)
            VStack {
                Text("Hello World!")

keybuk

SwiftUI Custom Alignments

Moved to https://netsplit.com/swiftui/alignments/

AliSoftware

/*:
 This is a concept re-implementation of the @Binding and @State property wrappers from SwiftUI

 The only purpose of this code is to implement those wrappers myself
   just to understand how they work internally and why they are needed,

 ⚠️ This is not supposed to be a reference implementation nor cover all
      subtleties of the real Binding and State types.
    The only purpose of this playground is to show how re-implementing
      them myself has helped me understand the whole thing better

chriseidhof

final class Loader: BindableObject {
    let didChange = PassthroughSubject<Data?, Never>()
    var task: URLSessionDataTask!
    var data: Data? = nil {
        didSet {
            didChange.send(data)
        }
    }
    
    init(_ url: URL) {

Tulakshana

//
//  MovieTransitionsVC.swift
//  VideoAnimations
//
//  Created by Tula on 2018-06-14.
//  Copyright © 2018 Tula. All rights reserved.
//

import UIKit
import AVFoundation

DivineDominion

// - MARK: Example Code

/// A model 
struct User {
    let firstName: String
    let lastName: String
    let age: Int?
}

/// Initializer using a Partial<T> -- You could generate this with Sourcery

harlanhaskins

import Foundation

/// `StringScanner` is a fast scanner for Strings and String-like objects.
/// It's used to extract structured bits from unstructured strings, while
/// avoiding making extra copies of string bits until absolutely necessary.
/// You can build Scanners over Substrings, allowing you to scan
/// parts of strings and use smaller, more specialized scanners to extract bits
/// of that String without needing to reuse another scanner.
public struct StringScanner<Input: StringProtocol> {
  let input: Input

milseman

State of String: ABI, Performance, Ergonomics, and You!

Hello, I’ve been working on implementing, optimizing, and improving String in preparation for ABI stability, and I thought I’d share the current status of String in Swift 5 and some potential directions to go. This is the product of conversations with open source contributors and my colleagues on the Swift standard library team at Apple.

The primary area of focus is stabilizing String’s ABI, but we’d be remiss if we couldn’t also fit in performance and ergonomic improvements. String’s ergonomics in particular is one area where we think the status quo is woefully inadequate, and over half of this email is devoted to that topic. At the end, there’s a section about a community initiative that we hope can help users of String as well as guide future development.

(Note: I’m sending this to swift-dev because much of the contents revolve around implementation concerns. I’ll also cross-reference on swift-evolution and swift-users. See also the [StringManife

IanKeen

import PlaygroundSupport

// using constrained static members on `Style` we can create presets
extension Style where T: UIButton {
    static var global: Style<UIButton> {
        return .init { button in
            button.backgroundColor = .blue
            button.setTitleColor(.red, for: .normal)
        }
    }

loganmoseley

import Foundation
import Result

public extension Result {
    
    /// Constructs a success wrapping `value`, iff `value` is not nil and `error` is nil.
    ///
    /// Constructs a failure wrapping `error`, iff `error` is not nil and `value` is nil.
    ///
    /// Otherwise, returns nil.