groue

import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true

Task {
    do {
        print("Start, 1 concurrent task")
        let semaphore = Semaphore(value: 1)
        await withThrowingTaskGroup(of: Void.self) { group in
            for i in 0..<10 {
                group.addTask {

groue

import SwiftUI

struct MyCollection: RandomAccessCollection {
    let startIndex = 0
    let endIndex = 1000
    subscript(index: Int) -> Int {
        print("Access \(index)")
        return index
    }
}

groue

Explicit Protocol Fulfillment

Introduction

This pitch introduces of a new keyword in front of declarations: conformance.

The conformance keyword means: "this declaration is intended by the programmer to fulfill a protocol requirement". Its presence is never required. However, when present, the program is ill-formed unless the declaration does match a protocol requirement.

For example:

groue

import GRDB

extension Database {
    /// Executes the provided closure with deferred unique indexes
    func withDeferredUniqueIndexes(_ execute: () throws -> Void) throws {
        try inSavepoint {
            // Fetch all unique indexes, but primary keys.
            let uniqueConstraints: [(table: String, index: IndexInfo)] = try String
                .fetchAll(self, sql: "SELECT name FROM sqlite_master WHERE type = 'table'")
                .filter { !Database.isGRDBInternalTable($0) }

groue

import SwiftUI

/// A Container view which uses various techniques
/// for controlling RequestView.
struct ContainerView: View {
    @State var parameter = 0
    
    var body: some View {
        List {
            Section {

groue

Pitch: Scoped Functions

Introduction

Scoped Functions are functions that enhance the leading dot syntax inside their body, so that it gives short-hand access to the members of a specific value. Such functions exist so that API designers and their consumers can collaborate towards a way to write focused code where an agreed implicit and obvious context does not have to be spelled out.

Motivation

This pitch considers that developers often want to use short-hand identifier resolution in particular contexts, and api designers often want to make it possible.

groue

import Combine
import Foundation

// MARK: - SinglePublisher

/// The protocol for "single publishers", which publish exactly one element, or
/// an error.
///
/// `Just`, `Future` and `URLSession.DataTaskPublisher` are examples of
/// publishers that conform to `SinglePublisher`.

groue

extension Collection {
    /// Returns an array of subsequences of maximum size `chunkSize`.
    ///
    /// For example:
    ///
    ///     // ["ABCD", "EFGH", "IJ"]
    ///     "ABCDEFGHIJ".split(chunkSize: 4)
    ///
    /// - parameter chunkSize: the maximum size of the returned subsequences.
    /// - precondition: chunkSize > 0

groue

import Combine

extension Publisher where Failure == Never {
    /// Same as assign(to:on:), but root object is not retained.
    func assignWeakly<Root: AnyObject>(
        to keyPath: ReferenceWritableKeyPath<Root, Self.Output>,
        on object: Root)
        -> AnyCancellable
    {
        var cancellable: AnyCancellable?

groue

import GRDB

extension QueryInterfaceRequest where RowDecoder: MutablePersistableRecord {
    /// Deletes all records in the database, but the ones selected by the request.
    ///
    /// For example:
    ///
    ///     // Delete all players whose score is below 1000
    ///     let bestPlayers = Player.filter(Column("score") > 1000)
    ///     try dbQueue.write(bestPlayers.deleteAllOther)