Valentin Knabel vknabel

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

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,

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	var parser = document.createElement('a');
	parser.href = "http://example.com:3000/pathname/?search=test#hash";

	parser.protocol; // => "http:"
	parser.hostname; // => "example.com"
	parser.port; // => "3000"
	parser.pathname; // => "/pathname/"
	parser.search; // => "?search=test"
	parser.hash; // => "#hash"
	parser.host; // => "example.com:3000"

	final class Loader: BindableObject {
	let didChange = PassthroughSubject<Data?, Never>()
	var task: URLSessionDataTask!
	var data: Data? = nil {
	didSet {
	didChange.send(data)
	}
	}

	init(_ url: URL) {

	func ShieldIcon(ac: Int) -> some View {
	ZStack {
	Image(systemName: "shield")
	.font(.title)
	Text("\(ac)")
	.font(.caption)
	}
	}

	import Foundation

	// Diff values for better test assertions.
	//
	// Enums and collections left as an exercise for the reader.

	// A difference between two values
	struct Difference: CustomStringConvertible {
	let path: String
	let actual: String

	// 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))

	// Licence: Robert Koch-Institut (RKI), dl-de/by-2-0

	class IncidenceWidget {

	constructor() {
	this.previousDaysToShow = 31;
	this.apiUrlDistricts = (location) => `https://services7.arcgis.com/mOBPykOjAyBO2ZKk/arcgis/rest/services/RKI_Landkreisdaten/FeatureServer/0/query?where=1%3D1&outFields=RS,GEN,cases7_bl_per_100k,cases7_per_100k,BL&geometry=${location.longitude.toFixed(3)}%2C${location.latitude.toFixed(3)}&geometryType=esriGeometryPoint&inSR=4326&spatialRel=esriSpatialRelWithin&returnGeometry=false&outSR=4326&f=json`
	this.apiUrlDistrictsHistory = (districtId) => `https://services7.arcgis.com/mOBPykOjAyBO2ZKk/ArcGIS/rest/services/Covid19_hubv/FeatureServer/0/query?where=IdLandkreis%20%3D%20%27${districtId}%27%20AND%20Meldedatum%20%3E%3D%20TIMESTAMP%20%27${this.getDateString(-this.previousDaysToShow)}%2000%3A00%3A00%27%20AND%20Meldedatum%20%3C%3D%20TIMESTAMP%20%27${this.getDateString(1)}%2000%3A00%3A00%27&outFields=Landkreis,Meldedatum,AnzahlFall&outSR=4326&f=json`
	this.stateToAbbr = {

	// Version 1.3.0
	// 27.11.2021
	//
	// Variables used by Scriptable.
	// These must be at the very top of the file. Do not edit.
	// icon-color: red; icon-glyph: notes-medical;
	// Mit Caching und Fallback
	const cacheMinutes = 60; // 60 min
	const today = new Date();
	const neededTotalVaccinations = 83200000;