lattner

Async/Await for Swift

• Proposal: SE-XXXX
• Authors: Chris Lattner, Joe Groff

Introduction

Modern Cocoa development involves a lot of asynchronous programming using closures and completion handlers, but these APIs are hard to use. This gets particularly problematic when many asynchronous operations are used, error handling is required, or control flow between asynchronous calls gets complicated. This proposal describes a language extension to make this a lot more natural and less error prone.

This paper introduces a first class Coroutine model to Swift. Functions can opt into to being async, allowing the programmer to compose complex logic involving asynchronous operations, leaving the compiler in charge of producing the necessary closures and state machines to implement that logic.

ddunbar

# Enable timings on build operations
defaults write com.apple.dt.Xcode ShowBuildOperationDuration -bool YES

# Enable extensive per-task timings
defaults write com.apple.dt.Xcode IDEBuildOperationTimingLogLevel -int 3

# Enable old build system logging for "implicit dependencies"
defaults write com.apple.dt.Xcode IDEBuildOperationDependenciesLogLevel -int 3

# Show logs from the "prebuild" step

ddunbar

New Build System Tricks

Command Line

alias xcbuild=$(xcode-select -p)/../SharedFrameworks/XCBuild.framework/Versions/A/Support/xcbuild
# THIS DOESNT WORK YET: xcbuild openIDEConsole  # … then switch to Xcode ➡️
xcbuild showSpecs
xcbuild build <foo.pif> [—target <target>]

louisdh

import Foundation

// Adapted from https://www.cocoanetics.com/2014/06/e-mail-validation/

extension String {
	
	var isValidEmail: Bool {
		
		guard !self.characters.isEmpty else {
			return false

chriseidhof

//
//  Operators.swift
//  FastParsing
//
//  Created by Chris Eidhof on 26/12/2016.
//  Copyright © 2016 objc.io. All rights reserved.
//

// TODO: give appropriate credit. Many parts were stolen from SwiftParsec.

mono0926

// こういう相互変換が正しそう
extension String {
    func nsRange(from range: Range<String.Index>) -> NSRange {
        let from = range.lowerBound.samePosition(in: utf16)
        let to = range.upperBound.samePosition(in: utf16)
        return NSRange(location: utf16.distance(from: utf16.startIndex, to: from),
                       length: utf16.distance(from: from, to: to))
    }
    func range(from nsRange: NSRange) -> Range<String.Index>? {
        guard

DougGregor

Implementing Recursive Protocol Constraints

Recursive protocol constraints are a small-looking feature (really, eliminating a limitation that feels arbitrary to users) that can also greatly improve the standard library. However, their implementation will require a number of changes throughout the Swift compiler. This document attempts to catalogue the kinds of changes required in the compiler to implement this feature, to provide some scoping and direction for the work.

ArchetypeBuilder

The ArchetypeBuilder is responsible for processing the requirements in a protocol, generic function, generic type, or extension of a generic type to determine whether they are consistent. It also plays a central role in producing and canonicalizing generic signatures, as well as producing archetypes for a generic signature in a given generic environment. It is where recursive protocol constraints are detected and diagnosed, and the primary place where we will need to deal with recursion.

Lazily expand nested t

dmcrodrigues

import ReactiveCocoa

let a: MutableProperty<[Int]> = MutableProperty([])

a.signal.observeNext { array in
    print("Array did change: \(array)")
}

a.value.append(1)
a.value.append(2)

dealforest

#!/usr/bin/env python

import lldb

def slack(debugger, command, result, internal_dict):
    frame = lldb.debugger.GetSelectedTarget().GetProcess().GetSelectedThread().GetSelectedFrame()
    path = command

    lldb.debugger.HandleCommand("""
    expr -l swift --

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)