Andriy andreyz

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,

Following the tradition from last year, here's my complete list of all interesting features and updates I could find in Apple's OSes, SDKs and developer tools that were announced at this year's WWDC. This is based on the keynotes, the "What's New In ..." presentations and some others, Apple's release notes, and blog posts and tweets that I came across in the last few weeks.

If for some reason you haven't watched the talks yet, I really recommend watching at least the "State of the Union" and the "What's New In" intros for the platforms you're interested in. The unofficial WWDC Mac app is great way to download the videos and keep track of what you've already watched.

If you're interested, here are my WWDC 2015 notes (might be useful if you're planning to drop support for iOS 8 now and start using some iOS 9 APIs).

OSX → macOS 10.12 Sierra

Interactive Machine Learning

Taught by Brad Knox at the MIT Media Lab in 2014. Course website. Lecture and visiting speaker notes.

Power to the People: The Role of Humans in Interactive Machine Learning by Knox, Cakmak, Kulesza, Amershi, and Lau
A Few Useful Things to Know about Machine Learning by Domingos
Machine Learning that Matters by Wagstaff
Beyond Concise and Colorful: Learning Intelligible Rules by Pazzani et al.
[Designing Games with a Purpose] (https://www.cs.cmu.edu/~biglou/GWAP_CACM.pdf) by von Ahn and Dabbish
[Human Model Evaluation in Interactive Supervised

Videos

Introduction to Functional Programming Johannes Weiß - https://vimeo.com/100786088
ReactiveCocoa at MobiDevDay Andrew Sardone - https://vimeo.com/65637501
The Future Of ReactiveCocoa Justin Spahr-Summers - https://www.youtube.com/watch?v=ICNjRS2X8WM
Enemy of the State Justin Spahr-Summers - https://www.youtube.com/watch?v=7AqXBuJOJkY
WWDC 2014 Session 229 - Advanced iOS Application Architecture and Patterns Andy Matuschak - https://developer.apple.com/videos/play/wwdc2014/229/
Functioning as a Functionalist Andy Matuschak - https://www.youtube.com/watch?v=rJosPrqBqrA
Controlling Complexity in Swift Andy Matuschak - https://realm.io/news/andy-matuschak-controlling-complexity/

	#!/usr/bin/env ruby

	print "What is the URL of your Apple Downloads resource?\nURL:"
	url = gets.strip

	print "What is the ADCDownloadAuth cookie token:\nADCDownloadAuth: "
	token = gets.strip

	command = "aria2c --header \"Host: adcdownload.apple.com\" --header \"Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8\" --header \"Upgrade-Insecure-Requests: 1\" --header \"Cookie: ADCDownloadAuth=#{token}\" --header \"User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 10_1 like Mac OS X) AppleWebKit/602.2.14 (KHTML, like Gecko) Version/10.0 Mobile/14B72 Safari/602.1\" --header \"Accept-Language: en-us\" -x 16 -s 16 #{url} -d ~/Downloads"


	protocol CaseCountable { }

	extension CaseCountable where Self : RawRepresentable, Self.RawValue == Int {

	static var count: Int {
	var count = 0
	while let _ = Self(rawValue: count) { count+=1 }
	return count
	}

	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
	<plist version="1.0">
	<!-- iOS 10, macOS Sierra, and friends bring a new logging subsystem that's
	supposed to scale from the kernel, up to frameworks, and up to apps. It defaults
	to a more regimented, privacy-focused approach that large apps and complex
	systems need.

	It, along with Activity Tracing introduced in iOS 8 and macOS Yosemite and the
	Console app in macOS Sierra, hope to help you graduate from caveman debugging to

	/**
	A default implmentation that provides a few convenience methods for starting and stopping coordinators.
	*/
	extension Coordinator {

	// Default implementation, so that we don't have to do this for all coordinators.
	func startChild<T: NSObject where T: Coordinator>(coordinator coordinator: T, withIdentifier identifier: String, callback: CoordinatorCallback?) -> T {
	childCoordinators[identifier] = coordinator
	coordinator.start(withCallback: callback)
	return coordinator

	import UIKit

	// This class allows the "presentedController" to receive touches
	// https://pspdfkit.com/blog/2015/presentation-controllers/
	class PSPDFTouchForwardingView: UIView {

	var passthroughViews: [UIView] = []

	override func hitTest(point: CGPoint, withEvent event: UIEvent?) -> UIView? {
	guard let hitView = super.hitTest(point, withEvent: event) else { return nil }