Vinh Nguyen vinhnx

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

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

Types

A type is a collection of possible values. An integer can have values 0, 1, 2, 3, etc.; a boolean can have values true and false. We can imagine any type we like: for example, a HighFive type that allows the values "hi" or 5, but nothing else. It's not a string and it's not an integer; it's its own, separate type.

Statically typed languages constrain variables' types: the programming language might know, for example, that x is an Integer. In that case, the programmer isn't allowed to say x = true; that would be an invalid program. The compiler will refuse to compile it, so we can't even run it.

Videos

Introduction to Functional Programming Johannes Weiß - http://kcy.me/1ngiv
ReactiveCocoa at MobiDevDay Andrew Sardone - http://kcy.me/1nhl3
The Future Of ReactiveCocoa Justin Spahr-Summers - http://kcy.me/1nhs7
Enemy of the State Justin Spahr-Summers - http://kcy.me/1njzs
WWDC 2014 Session 229 - Advanced iOS Application Architecture and Patterns Andy Matuschak - http://kcy.me/1pyva
Functioning as a Functionalist Andy Matuschak - http://kcy.me/22o45
Controlling Complexity in Swift Andy Matuschak - http://kcy.me/23sc9
Functional and reactive programming with Swift Ash Furrow -

	/// An object that has some tear-down logic
	public protocol Disposable {
	func dispose()
	}


	/// An event provides a mechanism for raising notifications, together with some
	/// associated data. Multiple function handlers can be added, with each being invoked,
	/// with the event data, when the event is raised.
	public class Event<T> {

	//
	// CoreDataController.swift
	//
	// Created by Keith Harrison http://useyourloaf.com
	// Copyright (c) 2017 Keith Harrison. All rights reserved.
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are met:
	//
	// 1. Redistributions of source code must retain the above copyright

	import Foundation

	// MARK: - Comparable

	extension NSDecimalNumber: Comparable {}

	public func ==(lhs: NSDecimalNumber, rhs: NSDecimalNumber) -> Bool {
	return lhs.compare(rhs) == .OrderedSame
	}

	struct Regex {
	let pattern: String
	let options: NSRegularExpressionOptions!

	private var matcher: NSRegularExpression {
	return NSRegularExpression(pattern: self.pattern, options: self.options, error: nil)
	}

	init(pattern: String, options: NSRegularExpressionOptions = nil) {
	self.pattern = pattern

	protocol Calendar {
	typealias Unit: BidirectionalIndexType

	typealias Era: Unit
	typealias Year: Unit
	typealias Month: Unit
	typealias Week: Unit
	typealias Day: Unit
	typealias Weekday: Unit
	typealias Hour: Unit

	// countries, states and subdivisions were generated relying on next documents:
	// http://www.iso.org/iso/country_names_and_code_elements
	// http://www.unece.org/cefact/locode/welcome.html

	var countriesAndStates = [
	{"Country":"AD","State":"Canillo"},
	{"Country":"AD","State":"Encamp"},
	{"Country":"AD","State":"La Massana"},
	{"Country":"AD","State":"Ordino"},
	{"Country":"AD","State":"Sant Julià de Lòria"},