Category Archives: Links

Brent’s Swift Tension

Brent Simmons has been writing new code exclusively in Swift for a while now, and he recognizes omissions from the language that he still anticipates will be hard to overcome as Apple presumably moves toward incorporating Swift into its developer-facing frameworks. The Tension of Swift:

The Objective-C runtime allows AppKit and UIKit to provide some powerful features that I’d hate to do without: the Responder Chain, xib and storyboard loading, KVC, and the undo manager.

A key point he gets at is that however great Swift is, it’s only possible to use it to develop functional iOS and Mac apps because of the Objective C runtime still operating behind the scenes. Both AppKit and UIKit not only lean on the functionality of the runtime, but are designed with the runtime in mind.

Some major design priorities of the Swift language, namely type safety and compile time dependency binding, are at odds with the design priorities of 20 years of evolution in Apple’s frameworks. How and if that disparity will be reckoned by Apple remains to be seen.

I’m optimistic, because the Swift team has already made many concessions to make the language more compatible with the Objective C runtime. It strikes me as possibly non-optimal that a language that strikes the right compromise between Swift’s priorities and Objective C’s would start at the opposite extreme and work its way backwards, but that is what Apple seems to be doing.

Let’s hope they continue in that direction, and surprise us all with how well it all works out in the end.

A Eulogy For Objective-C

I missed Aaron Hillegass’s talk at AltConf earlier this year, but was nudged to take a look at the transcript by Caro’s tweet today linking to the talk’s video page on Realm.

Although I’m 100% sure, based on experience, that Aaron’s talk is a pure delight to watch, I also appreciate that I could jump right in and read a transcript of the talk until I get a chance to watch it. Aaron gives a thought-provoking “eulogy” for Objective-C, in which he celebrates its parentage and its life thus far.

When a guy like Aaron Hillegass gives a history of Objective-C, and speaks to its strengths and weaknesses, you should hang on every word. He covers many of the features that distinguish the language, provides a context for when they were added, and gives examples of key technologies that are enabled by them. He is also aware of the tradeoffs some of these features demand:

Loose typing made a lot of things that were difficult in other languages much easier, or possible. It also made bugs that didn’t exist in other languages possible as well. And you embrace that as an Objective-C programmer. You’re like, “This is a language for smart, pedantic, uptight people, I’m going to be very careful and do the right thing when I’m typing in names.

I love his hypothetical quote, and think it condenses the feeling a lot of us long-time Objective-C programmers have about the language. We welcome Swift in many respects, but it’s hard to let go of a language whose idiosyncrasies we’ve grown to love, hate, and ultimately make peace with.