4. Current State
• TIOBE Index of language popularity
• Swift #27, increasing
• Objective-C #4, declining
• Github number of active repositories
• Swift #18, growing
• Objective-C #11, flat
Data as of February 2015
http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html
http://githut.info/
5. Swift 1.2
• Xcode 6.3 Beta
• Faster builds & executables
• Better compiler diagnostics
• Stability
• and changes to the language!
13. Duolingo Test Center
• New App written in Swift
• 3 month
(1 dev, design/backend inplace)
+ Value types, custom operators
+ Stronger, static type system, with
type inference
+ Generics especially for typesafe
collections
14. Duolingo Test Center
- Tooling: Xcode, crashes, very slow code
completion, basically no debugger, unstable/
unreliable syntax highlighting (got better)
- Swift language changes.
Known from the beginning, in retrospect only
little time spent on keeping source up to date
- Incomprehensible compiler errors
15. Duolingo Test Center
• Crash rate ~0.2% (crashes/downloads)
mostly in Objective-C third party library
• Swift eased process of building a solid
architecture. Eliminating classes of bugs by
design (e.g. Swift’s type system)
17. @brentsimmons
• Harder on 2nd look
• optionals, generics, and tuples, value vs reference
• functional design patterns
• strict type safety
• issue interoperation with Objective-C
• “Swift is happening.”
18. Random Thoughts from
Developers
• Common internal libraries, not rewriting just to
be Swift
• Sometimes interacting with Cocoa API’s harder
than thought
• Strict typing is a killer feature (finds bugs during
compile time)
21. Our take aways
• Future of iOS will be Swift
• New code written in Swift
• Rewriting only were it makes sense (lot of code changes,
restructuring)
• Know Swift AND Objective-C
• Swift uses different patterns
• Hard to follow good patterns when interfacing with
Objective-C
23. Experience
• Compiler bugs: crashes instead of error
• Renew Certificate, otherwise it crashes submitted
build
• At first slower when writing code, but learning fast
• Choice between Objective-C vs Swift patterns
• Cocoapods support is still beta
• cocoapods --pre installs 1.0.36(beta)
24. pod 'Alamofire', :git => 'https://github.com/Alamofire/
Alamofire.git', :branch => ‘xcode-6.3'
pod 'SwiftyJSON', :git => 'https://github.com/
SwiftyJSON/SwiftyJSON.git', :branch => 'xcode6.3'
25. Favourite Swift Way
enum Router: URLStringConvertible {
static let baseURLString = "http://example.com"
case Root
case User(String)
case Post(Int, Int, String)
// MARK: URLStringConvertible
var URLString: String {
let path: String = {
switch self {
case .Root:
return "/"
case .User(let username):
return "/users/(username)"
case .Post(let year, let month, let title):
let slug = title.stringByReplacingOccurrencesOfString(" ", withString: "-").lowercaseString
return "/(year)/(month)/(slug)"
}
}()
return Router.baseURLString + path
}
}
Enum with associated value and computed property
26. Learn Swift
• Read “The Swift Programming Language” by Apple
• thatthinginswift.com
• swiftdoc.org
• learnswift.tips
• Start coding in Swift!
• github.com/raywenderlich/swift-style-guide
27. My experience learning
Swift
• Functional Programming is different
• Force yourself to using good practices. Make
use of strict types. Which is hard.
• Harder to define public interface (no header).
Standard access modifier is internal. Also makes
testing harder.
