Daniel Pink danielpi

Thoughts on Swift 2 Errors

When Swift was first announced, I was gratified to see that one of the (few) philosophies that it shared with Objective-C was that exceptions should not be used for control flow, only for highlighting fatal programming errors at development time.

So it came as a surprise to me when Swift 2 brought (What appeared to be) traditional exception handling to the language.

Similarly surprised were the functional Swift programmers, who had put their faith in the Haskell-style approach to error handling, where every function returns an enum (or monad, if you like) containing either a valid result or an error. This seemed like a natural fit for Swift, so why did Apple instead opt for a solution originally designed for clumsy imperative languages?

I'm going to cover three things in this post:

Learning FP the hard way: Experiences on the Elm language

by Ossi Hanhinen, @ohanhi

with the support of Futurice 💚.

Licensed under CC BY 4.0.

Editorial note

Mac OS X 10.10 Yosemite

Custom recipe to get OS X 10.10 Yosemite running from scratch, setup applications and developer environment. I use this gist to keep track of the important software and steps required to have a functioning system after a semi-annual fresh install. On average, I reinstall each computer from scratch every 6 months, and I do not perform upgrades between distros.

This keeps the system performing at top speeds, clean of trojans, spyware, and ensures that I maintain good organizational practices for my content and backups. I highly recommend this.

You are encouraged to fork this and modify it to your heart's content to match your own needs.

Install Software

Internet Scale Services Checklist

A checklist for designing and developing internet scale services, inspired by James Hamilton's 2007 paper "On Desgining and Deploying Internet-Scale Services."

http://mvdirona.com/jrh/talksandpapers/jamesrh_lisa.pdf

Basic tenets

Does the design expect failures to happen regularly and handle them gracefully?
Have we kept things as simple as possible?

	/*

	Erica Sadun, http://ericasadun.com
	GameplayKit Available 10.11, iOS 9

	*/

	import Foundation
	import GameplayKit // only available on OS X 10.11, iOS 9

	import Foundation
	import Cocoa
	import XCPlayground

	public let DropNotification = "DropNotification"

	public class DropWindow : NSWindow {
	required public init?(coder: NSCoder) {
	super.init(coder: coder)
	self.registerForDraggedTypes([NSFilenamesPboardType])

	// integerWithBytes.swift
	// as seen in http://natecook.com/blog/2015/03/a-sanatorium-for-swift-generics/
	//
	// (c) 2015 Nate Cook, licensed under the MIT license

	protocol BitshiftOperationsType {
	func <<(lhs: Self, rhs: Self) -> Self
	func >>(lhs: Self, rhs: Self) -> Self
	func <<=(inout lhs: Self, rhs: Self)
	func >>=(inout lhs: Self, rhs: Self)

	// Playground - noun: a place where people can play

	import Foundation

	typealias Byte = UInt8

	protocol GenericIntegerType: IntegerType {
	init(_ v: Int)
	init(_ v: UInt)
	init(_ v: Int8)

	enum ConsPosition {
	case Left, Right
	}

	func cons<T>(a: T, b: T) -> (ConsPosition -> T) {
	func innerCons(i: ConsPosition) -> T {
	if i == .Left {
	return a;
	} else {
	return b;

	/*
	Boyer-Moore string search

	This code is based on the article "Faster String Searches" by Costas Menico
	from Dr Dobb's magazine, July 1989. (Yes, 1989!)
	http://www.drdobbs.com/database/faster-string-searches/184408171
	*/

	extension String {
	func indexOf(pattern: String) -> String.Index? {