I Don't Know Swift

I know a thing or two about Objective-C. It’s not bragging. If you’re reading my blog, there’s a decent chance that I know more about Objective-C than you do. I have opinions about it. You should take them seriously even if you disagree. They’re founded on shipping a lot of code. I’ve shipped Cocoa software solo and in big teams, OS X and iOS, year-long release cycles and 30 hours to build a demo for Steve Jobs. I’ve been writing ObjC since 10.4 was the new hotness, before ARC, before properties, before Intel. There are many developers with much more experience, but even so, I know a thing or two about Objective-C.

I have no idea how to write Swift.

Neither does anyone else.

Not even Apple.

Nobody knows Swift because it isn’t baked yet. It’s early days. We’re all still figuring it out. There are no established patterns. The syntax is still changing. The stdlib is still changing. We know even more big changes are on the horizon.1 Writing the compiler isn’t the same as shipping an app. Some things take real-world experience, and no one has that.

Tim Burks2 wrote a provocative radar recently:

…I’d like to suggest that the appropriate way to introduce a new language is for its creators to spend several months writing nontrivial applications in the language and reviewing the results with experts. This does not seem to have been done.

That’s how it’s often done. People with language design experience work on a new language, mostly in secret or obscurity. They release it to some people, maybe internally. A small community starts to form. These are the insiders, the first adopters. They try things. They tinker. They build bigger things. They at least build some large libraries (Go’s stdlib, parts of .NET for C#). They revise the languge based on what they learn. More people come. Maybe it becomes public or maybe it just gains some “critical mass” and new, uninitiated people start to use it for more serious things and maybe it even becomes “important.”

Swift has come naked into the world. Half-baked. Some parts ill-considered and changing dramatically before our eyes. Most of its libraries are still in ObjC, C, and C++. It’s just the beginning and you’re all here. You’re those early adopters, usually that tiny, almost hand-picked group. But there are thousands of you this time, here in the primordial era.

You can think this is good or bad, but it’s definitely a special opportunity. I predict with great confidence that Swift will be TIOBE’s language of the year. It entered the list at #16 and it isn’t even released yet. And here you are. Not just on the ground floor, but standing on the newly poured foundation. It seems pretty solid, but it’s not a building quite yet.

Imagine if Google had said “Go is the future for Android development” or Microsoft had recommended all C# developers move to F#. Apple has made Swift the preferred language for one of the most popular platforms in existance. I expect they’ll follow through with that. “Any evaluation of Swift starts and ends with how well it lets developers build really fantastic iOS and Mac apps.” I believe Swift meets that criteria even better than ObjC (and I love ObjC). I don’t see any reason Apple would back away from Swift now.

So there you go. You’re here at the beginning. There is no priesthood. There are no old folks sitting on rocking chairs cussing your new-fangled dot-syntax. You are the old folks. You remember before immutable arrays.

You’re a day-zero Swift expert, and if you’re not, you could be a year-zero Swift expert even if you wait for iOS 8 to ship. The niches are all still open. Read everything.3 Write something. Get involved. Try out new patterns, see if they work. Tell people what you discover.4

And most of all, if things in Swift bother you, if they don’t work for you, if they could be better, say it now. Open radars.5 Post on devforum. Write an example. Show why your way makes the code better. Swift is still changing, and it’s in beta exactly so it can change. It may be a long time before you have this chance again.

  1. Can you say access controls? We know they’re coming. We don’t know what they’ll look like. 

  2. …whose opinions I take quite seriously. He’s a smart, insightful guy. Nu is an interesting language. I even agree with some of his frustrations about Swift. We just disagree on what to do about them. 

  3. BTW, my current favorite Swift blogs are Airspeed Velocity and nomothetis (Alexandros Salazar). Highly recommended. They’re teaching me a lot. I’d love to see more people writing this way. 

  4. For example, I’ve found that if let x = x { ... } (rebinding to the same identifier) is a pretty good style for unloading an optional. I’ve also found that map() on an optional can be a handy replacement for if-let when you can’t use chaining. For example: let optY ={Y(x:$0)}. An extension on Optional to wrap map in a function called ifSet can make this a little easier to read. 

  5. Yes, radar stinks; do it anyway, it’s not that bad. And from the forums, the Swift team is clearly reading and reacting to the radars they receive.