ole

// SwiftUI question: How do you put a continuous background behind a GridRow?
//
// I would have thought:
//
//     GridRow { … }
//         .background { … }
//
// But this puts the background behind each cell individually (behaves like Group),
// which is not what I want.

ole

import SwiftUI

/// A wrapper view that provides a mutable Binding to its content closure.
///
/// Useful in Xcode Previews for interactive previews of views that take a Binding.
struct Stateful<Value, Content: View>: View {
    var content: (Binding<Value>) -> Content
    @State private var state: Value

    init(initialState: Value, @ViewBuilder content: @escaping (Binding<Value>) -> Content) {

ole

// Structure of _StackLayoutCache and related types.
// Used by SwiftUI as the Cache type for VStackLayout and HStackLayout.
//
// As of: iOS 16.0 simulator in Xcode 14.0b6

import SwiftUI

struct _StackLayoutCache {
    var stack: StackLayout
}

ole

// Excerpt from `SwiftUI.framework/Modules/SwiftUI.swiftmodule/arm64-apple-ios.swiftinterface`
// in Xcode 14.0b1
//
// This is how any `Layout`-conforming type becomes a container view
// when it's used with a `@ViewBuilder` closure.
@available(iOS 16.0, macOS 13.0, tvOS 16.0, watchOS 9.0, *)
extension SwiftUI.Layout {
  @_alwaysEmitIntoClient public func callAsFunction<V>(@SwiftUI.ViewBuilder _ content: () -> V) -> some SwiftUI.View where V : SwiftUI.View {
        return _VariadicView.Tree(
            root: _LayoutRoot(self), content: content())

ole

// I learned about `#if canImport(module, _version: x.y)` from Tony Allevato:
// https://forums.swift.org/t/pitch-sdk-conditional-code/52642/4
//
// Does this work reliably? I have no idea!
// I have only done some quick experiments in a playground.
//
// The Foundation version in Xcode 14.0b1 is:
// - in iOS's Foundation.swiftinterface: 1932.104
// - in macOS's Foundation.swiftinterface: 1932.401
//

ole

import SwiftUI

extension LocalizedStringKey.StringInterpolation {
    /// String interpolation support for links in Text.
    ///
    /// Usage:
    ///
    ///     let url: URL = …
    ///     Text("\("Link title", url: url)")
    mutating func appendInterpolation(_ linkTitle: String, link url: URL) {

ole

import Dispatch

@globalActor
final actor MyMainActor {
  // Don’t allow others to create instances
  private init() {}

  // Requirements from the implicit GlobalActor conformance
  typealias ActorType = MyMainActor

ole

// A heterogeneous dictionary with strong types in Swift, https://oleb.net/2022/heterogeneous-dictionary/
// Ole Begemann, April 2022

/// A key in a `HeterogeneousDictionary`.
public protocol HeterogeneousDictionaryKey {
  /// The "namespace" the key belongs to. Every `HeterogeneousDictionary` has its associated domain,
  /// and only keys belonging to that domain can be stored in the dictionary.
  associatedtype Domain
  /// The type of the values that can be stored under this key in the dictionary.
  associatedtype Value

ole

// This is the code for https://forums.swift.org/t/communicating-between-two-concurrent-tasks/54240

import _Concurrency

actor Buffer {
  var elements: [Int] = []
  private var isNotEmpty: CheckedContinuation<Void, Never>? = nil

  deinit {
    // TODO: If the continuation is not nil,

ole

import _Concurrency

actor Channel<Output> {
  private var conditionVar: CheckedContinuation<Output, Never>? = nil

  deinit {
    // TODO: if conditionVar != nil, resume it by throwing `CancellationError()`?
  }

  /// If there's no receiver, the sent value will be lost.