Production Swift

In this talk, I use my recent real-world experience with Swift as a case study in an evaluation of Swift's production readiness. Take advantage of the lessons we learned to make the best decisions about Swift in your project.

Video is up here: http://www.thedotpost.com/2015/02/ash-furrow-swift-in-production

Transcript

1. Production Swift Ash Furrow
3. Objective-C
4. Agenda 1. Swift is Awesome 2. Tools are Immature 3. Be Informed
5. Swift is Different
6. How is it different? • Static vs. Dynamic • Prefers immutability • Encourages functional programming • Safe (well, safer) • Experimentation via Playgrounds
7. Optional Protocol Methods @protocol MyProtocol <NSObject> @required - (void)doSomethingNecessary; @optional - (void)doSomethingOptional; @end
8. Optional Protocol Methods protocol MyProtocol { func doSomethingNecessary() optional func doSomethingOptional() } // Compiler Error!
9. Optional Protocol Methods func doSomethingNecessary() optional func doSomethingOptional() } @objc protocol MyProtocol {
10. Objective-C Interoperability • Interoperability comes at the cost of Swift’s purity • We loose a lot of safety • Don’t just add @objc because it’ll make code compile
11. Swift is Better
12. Objective-C Hurts Me if (indexPath.section == 0) { if (indexPath.row == 0) { } else if (indexPath.row == 1) { 
 } else if ... } else if (indexPath.section == 1) { if (indexPath.row == 0) { } else if (indexPath.row == 1) { 
 } else if ... } else if ...
13. Pattern Matching switch (indexPath.section, indexPath.row) { case (0, 0): case (0, 1): case (1, 0): case (1, 1): default: // nop }
14. Pattern Matching case (let section, 0) where section % 2 == 0: case (0, let row): case let (0, row) where validate(row):
15. Self-Evaluating Lazy Closures class MySweetViewController: UIViewController { lazy var button: UIButton = { let button = UIButton.buttonWithType(.System) // configure button return button }() }
16. And many more … enums closures tuples generics compile-time awesomeness saved a kitten from a fire went to highschool prom with me function currying functions are closures array.sort(<) better terroir immutability by default type inference discovered penicillin operator overloading clear mutability syntax native collections REPL multiple return types concise pattern-matching
17. Tools are Immature
18. Apple Tools • Xcode, clang, Playgrounds, SourceKit, code signing, frameworks … • All are unstable • Causes frustrations • Causes delays • Causes hair loss
19. github.com/artsy/eidolon
20. Open Source by Default
21. Using Swift doubled our development time
22. “We don’t expect to make our deadline.”
23. Eidolon Problems • Enterprise code signing issues with Xcode 6.1 • Compiler segfaults with optimizations enabled • Constant Xcode/SourceKit crashes • Unit testing problems
25. Burnout
26. We made our deadline
27. Eidolon Awesomeness • We helped pioneer a new way of writing iOS software • Created many new libraries, tools, and resources • Used others’ new tools and contributed bug reports and fixes • Learnt a tonne, shared with others
28. Apple Tools • Someday soon, these will be ready for everyday use • But not today • You will have unanticipated problems • There will be no known solutions or workarounds • Until then, use with caution
29. 3rd Party Tools • CocoaPods 0.36 has support for Swift • Tremendous amount of open source effort • Pre-1.0, use with caution • Carthage is new but promising • Pre-1.0, use with caution
30. Be Informed
31. Making a Choice • What’s your aversion to risks? • How hard is your deadline? • Why are you building something? • How open is your team to learning a new language?
32. Why Bother?
33. Swifxpert Become a
34. Blog
35. Risks Rewards vs.
36. Be Aware • Don’t be afraid to revisit your decision • It’s OK to switch back to Objective-C
37. Recap Swift is Awesome Tools are Immature Be Informed
38. Make an informed choice. So start now. You need to know Swift to be informed.