Swift should I switch?
31
Transcript of Swift should I switch?
SwiftShould I use it for production?
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, flatData as of February 2015
http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html http://githut.info/
Swift 1.2
• Xcode 6.3 Beta
• Faster builds & executables
• Better compiler diagnostics
• Stability
• and changes to the language!
as! for failable casts
if let a = a, b = b, c = c {
Nullability Annotations
enums export to Objective-C
Deferred initialisation of let constants
Set
So is it ready for prime time?
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
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
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)
@brentsimmons ObjC: “I am laughing out loud”
Swift: "LOL"
@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.”
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)
So is it ready for prime time?
Yes it is!
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
Experience
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)
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'
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
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
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.
Single most hardest thing in Swift?
;
