The second code example ("if you were doing this before ARC") is completely wrong. "alloc" is a class method that allocates memory for an instance, on which "init" is then called. Calling it on an instance returned by a factory method is nonsensical.

The error is made consistently all three times, so it's clear that the author is genuinely confused about Objective-C. Maybe he's better at Swift, but it doesn't look good.

The author is Ash Furrow, who has written numerous Obj-C books and apps. I highly doubt he's confused about Obj-C; he'll probably turn up in this thread at some point though, so it may be worth asking.

Ha, yeah. Just a typo – it's been so long since I've had to write retain/release, and thank goodness!

Yeah, it looks like he meant to use `retain` rather than `alloc` (assuming he means to use them outside of the next autorelease pool drain).

The code samples were weird. Why injected property has to be optional, we can inject it using the constructor.

I think the DI was for a view controller in this case. In normal usage I would agree. DI -> use the constructor. Even in languages like Java and C# I would advocate constructor injection. View controllers and where they get instantiated with storyboards, xibs, etc? Not so much.

Yup.

* Lazy init for non-unit-test use.

* No need to have 20 parameters in your init method signature.

* Imitates Cocoa standard practices re: delegates.

* Swift's optional binding makes it safe if you don't force-unwrap objects (and makes your code more robust to boot).

I stopped reading the article there. :)

I'm a bit curious as to why people talk about "protocol oriented" as something new. It seems to me to be just a way of doing interface-oriented programming, like people coding in java have been doing for the last ten years, as well as golang dev, and many other languages... Am i missing a difference, or is it just not to confuse people that only develop in objective-c ?

Is the currying example even currying? It looks like it's just a function returning a function to me. I thought currying it's some thing like func contains(subString: String, string: String) -> Bool, and calling contains("a") would automatically return a func(x: String) -> Bool.

Currying refers to the process of taking a function that accepts multiple arguments, and turning it into a sequence of functions, each accepting a single argument. The example you provide would be more aptly described as partial application, which is the process of fixing a number of arguments to a function, producing a function of smaller arity.

Yeah, sorry for the typos in the slides – I missed them while proofreading and unfortunately can't correct them now.

I think the people in this thread discussing how my stylistic choices are "wrong" may have missed my point. Too bad.

Why is this explicitly testing for false:

  if defaults.boolForKey("launchBefore") == false {

rather than:

  if !defaults.boolForKey("launchBefore") {

I use this style myself. It is way easier to read than `!condition`. If you are scanning the code, a single `!` at the beginning of the condition won't stand out that much.

Probably a style thing. I think I recall reading about this in one of his Swift or Objective-C books? Can't quite remember.

EDIT: Or maybe even just a hastily typed example code

Unrelated: Is there a plugin syncing speaker deck and the video? Or something custom?

Its based on http://presentz.org, which sadly appears to no longer be maintained.