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.

jobliz

import redis
import threading

class Listener(threading.Thread):
    def __init__(self, r, channels):
        threading.Thread.__init__(self)
        self.redis = r
        self.pubsub = self.redis.pubsub()
        self.pubsub.subscribe(channels)
    

chriseidhof

// Run any SwiftUI view as a Mac app.

import Cocoa
import SwiftUI

NSApplication.shared.run {
    VStack {
        Text("Hello, World")
        	.padding()
            .background(Capsule().fill(Color.blue))

steipete

//
//  KeyCommand.swift
//  Adds Keyboard Shortcuts to SwiftUI on iOS 13
//  See https://steipete.com/posts/fixing-keyboardshortcut-in-swiftui/
//  License: MIT
//
// Usage: (wrap view in `KeyboardEnabledHostingController`)
// Button(action: {
//       print("Button Tapped!!")
//  }) {

Daniel-ltw

name: Build Artifacts

on: [push]

jobs:
  build:

    runs-on: ubuntu-latest

    steps:

oleganza

Async semantics proposal for Swift

Modern Cocoa development involves a lot of asynchronous programming using blocks and NSOperations. A lot of APIs are exposing blocks and they are more natural to write a lot of logic, so we'll only focus on block-based APIs.

Block-based APIs are hard to use when number of operations grows and dependencies between them become more complicated. In this paper I introduce asynchronous semantics and Promise type to Swift language (borrowing ideas from design of throw-try-catch and optionals). Functions can opt-in to become async, programmer can compose complex logic involving asynchronous operations while compiler produces necessary closures to implement that logic. This proposal does not propose new runtime model, nor "actors" or "coroutines".

Table of contents

johanneswuerbach

---
language: objective-c
before_script:
- ./scripts/travis/add-key.sh
after_script:
- ./scripts/travis/remove-key.sh
after_success:
- ./scripts/travis/testflight.sh
env:
  global:

kirpit

#! /usr/bin/env python
import threading
import subprocess
import traceback
import shlex


class Command(object):
    """
    Enables to run subprocess commands in a different thread with TIMEOUT option.

smileyborg

// UICollectionView Objective-C example

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
        
    NSIndexPath *selectedIndexPath = [[self.collectionView indexPathsForSelectedItems] firstObject];
    if (selectedIndexPath != nil) {
        id<UIViewControllerTransitionCoordinator> coordinator = self.transitionCoordinator;
        if (coordinator != nil) {
            [coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {

jhjguxin

In this article, I'll walk through a basic Rails (3.2.x) setup for creating a nested resource for two models. Nested resources work well when you want to build out URL structure between two related models, and still maintain a RESTful convention. This code assumes you are running RVM to manage Ruby/Gem versions, and Git for version control.

Creating a new Rails project

$ mkdir family # create rvm gemset 
$ echo "rvm use --create ruby-1.9.2@family" > family/.rvmrc 
$ cd family # install rails 
$ gem install rails # create new rails project 
$ rails new . # version control