Nicky McCurdy nickserv

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.

async/await is just the do-notation of the Promise monad

CertSimple just wrote a blog post arguing ES2017's async/await was the best thing to happen with JavaScript. I wholeheartedly agree.

In short, one of the (few?) good things about JavaScript used to be how well it handled asynchronous requests. This was mostly thanks to its Scheme-inherited implementation of functions and closures. That, though, was also one of its worst faults, because it led to the "callback hell", an seemingly unavoidable pattern that made highly asynchronous JS code almost unreadable. Many solutions attempted to solve that, but most failed. Promises almost did it, but failed too. Finally, async/await is here and, combined with Promises, it solves the problem for good. On this post, I'll explain why that is the case and trace a link between promises, async/await, the do-notation and monads.

First, let's illustrate the 3 styles by implementing

WannaCry|WannaDecrypt0r NSA-Cyberweapon-Powered Ransomware Worm

Virus Name: WannaCrypt, WannaCry, WanaCrypt0r, WCrypt, WCRY
Vector: All Windows versions before Windows 10 are vulnerable if not patched for MS-17-010. It uses EternalBlue MS17-010 to propagate.
Ransom: between $300 to $600. There is code to 'rm' (delete) files in the virus. Seems to reset if the virus crashes.
Backdooring: The worm loops through every RDP session on a system to run the ransomware as that user. It also installs the DOUBLEPULSAR backdoor. It corrupts shadow volumes to make recovery harder. (source: malwarebytes)
Kill switch: If the website www.iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea.com is up the virus exits instead of infecting the host. (source: malwarebytes). This domain has been sinkholed, stopping the spread of the worm. Will not work if proxied (source).

update: A minor variant of the viru

[8:27 PM] cquill: @acemarke Right, so many portions of the UI will be connected. But does each connected portion typically get its own container component? Seems verbose and redundant to have the following for each CRUD resource: UserList, UserListContainer, UserView, UserViewContainer, UserEdit, UserEditContainer, UserNew, UserNewContainer. Is there a simpler way?
[9:56 PM] acemarke: @cquill : this leads into one of my favorite (?) semi-rants, and one that I apparently need to write down so I can paste it
[9:57 PM] acemarke: A "container" component is simply any component whose primary job is to fetch data from somewhere, and pass that data on to its children
[9:58 PM] acemarke: With Redux, the wrapper components generated by connect are "container" components, since their job is to extract data from the Redux store
[9:58 PM] acemarke: I generally dislike the somewhat-common approach of trying to divide everything into a "components" folder and a "containers" folder
[9:59 P

Formats

Python docstrings can be written following several formats as the other posts showed. However the default Sphinx docstring format was not mentioned and is based on reStructuredText (reST). You can get some information about the main formats in that tuto.

Note that the reST is recommended by the PEP 287

There follows the main used formats for docstrings.

- Epytext

[11:29 AM] acemarke: @user1 , @user2, @user3 : I've got articles on modals over here: https://github.com/markerikson/react-redux-links/blob/master/react-component-patterns.md#modal-dialogs . (Will have to add that "from scratch" article to the list)
GitHub
markerikson/react-redux-links
react-redux-links - Curated tutorial and resource links I've collected on React, Redux, ES6, and more
[11:29 AM] user4: What's React Fiber
[11:30 AM] user4: Whats up with these " Adverts "
[11:30 AM] user4: kinda of annoying in a way
[11:30 AM] acemarke: "adverts"?
[11:30 AM] user4: lol
[11:30 AM] user4: oh ur real

Code is clean if it can be understood easily – by everyone on the team. Clean code can be read and enhanced by a developer other than its original author. With understandability comes readability, changeability, extensibility and maintainability.

General rules

Follow standard conventions.
Keep it simple stupid. Simpler is always better. Reduce complexity as much as possible.
Boy scout rule. Leave the campground cleaner than you found it.
Always find root cause. Always look for the root cause of a problem.

	const timing = store => next => action => {
	performance.mark(`${action.type}_start`);
	let result = next(action);
	performance.mark(`${action.type}_end`);
	performance.measure(
	`${action.type}`,
	`${action.type}_start`,
	`${action.type}_end`
	);
	return result;

	console.log(1);
	(_ => console.log(2))();
	eval('console.log(3);');
	console.log.call(null, 4);
	console.log.apply(null, [5]);
	new Function('console.log(6)')();
	Reflect.apply(console.log, null, [7])
	Reflect.construct(function(){console.log(8)}, []);
	Function.prototype.apply.call(console.log, null, [9]);
	Function.prototype.call.call(console.log, null, 10);

	/*
	Let us re-create `Promise.all`

	`Promise.all` method returns a promise that resolves when all of the promises in the iterable argument have resolved,
	or rejects with the reason of the first passed promise that rejects.

	Read more about `Promise.all` on MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/all

	A basic example would be something like this: