Chris Novello chrisnovello

Outcome-Oriented Programming

Mike McNeil, Aug 2014

Humans are not very good at planning. We have no problem running scenarios, thinking through possibilities, and pondering "what if?" questions. I might plan to not eat my cousin's birthday cake before she gets home, for instance. If I'm very serious, I might write down my commitment; or if I'm unsure about the pros and cons, use some organizational tool like a T-chart.

But when it comes to making a decision in the moment, all bets are off. The cake is a goner.

Predictive Analysis vs. Process Design

Below, I've included a figure containing a decision tree diagram.

Author: https://www.cyanhall.com/

1. The Layer Tree

Core Animation's original name is Layer Kit

Core Animation is a compositing engine; its job is to compose different pieces of visual content on the screen, and to do so as fast as possible. The content in question is divided into individual layers stored in a hierarchy known as the layer tree. This tree forms the underpinning for all of UIKit, and for everything that you see on the screen in an iOS application.

In UIView, tasks such as rendering, layout and animation are all managed by a Core Animation class called CALayer. The only major feature of UIView that isn’t handled by CALayer is user interaction.

There are four hierarchies, each performing a different role:

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

Jelly Physics

Attempt at replicating the Jelly effect from The Floor is Jelly (http://thefloorisjelly.com/).

A Pen by Thom Chiovoloni on CodePen.

License.

	/*
	* For a more in depth look at the guard statement check out
	* http://ericcerney.com/swift-guard-statement/
	* where I build off the sample shown here.
	*/

	var x: Int? = 0

	// Lets me unwrap x and also check a condition on it
	func fooGuard() {

	/// custom unique identifier
	/// @see https://www.firebase.com/blog/2015-02-11-firebase-unique-identifiers.html
	private let ASC_CHARS = Array("-0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz")
	private let DESC_CHARS = ASC_CHARS.reverse()
	private var lastPushTime: UInt64 = 0
	private var lastRandChars = Array<Int>(count: 12, repeatedValue: 0)

	func generatePushID(ascending: Bool = true) -> String {
	let PUSH_CHARS = ascending ? ASC_CHARS: DESC_CHARS
	var timeStampChars = Array<Character>(count: 8, repeatedValue: PUSH_CHARS.first!)

	// for an updated version see https://github.com/jsdf/react-native-refreshable-listview

	var React = require('react-native')
	var {
	ListView,
	ActivityIndicatorIOS,
	StyleSheet,
	View,
	Text,
	} = React

	/**
	* Fancy ID generator that creates 20-character string identifiers with the following properties:
	*
	* 1. They're based on timestamp so that they sort after any existing ids.
	* 2. They contain 72-bits of random data after the timestamp so that IDs won't collide with other clients' IDs.
	* 3. They sort lexicographically (so the timestamp is converted to characters that will sort properly).
	* 4. They're monotonically increasing. Even if you generate more than one in the same timestamp, the
	* latter ones will sort after the former ones. We do this by using the previous random bits
	* but "incrementing" them by 1 (only in the case of a timestamp collision).
	*/