The Unreasonable Effectiveness of Declarative Code and the Near Future of Programming

Writing code in a declarative style has significantly improved my effectiveness as a developer. This lightning talk will discuss how we can bring a declarative style to our Swift codebase.

Transcript

1. Benjamin Encz @benjaminencz The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 1
2. The Unreasonable Effectiveness Of Declarative Code And The Near Future of Programming The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 2
3. The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 3
4. The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 4
5. The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 5
6. The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 6
7. The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 7
8. Facts instead of Behavior usernameLabel.text <~ user.name ageLabel.text <~ user.age The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 8
9. Facts instead of Behavior usernameLabel.text <~ user.name ageLabel.text <~ user.age The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 9
10. Facts instead of Behavior usernameLabel.text <~ user.name ageLabel.text <~ user.age • Idempotent The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 9
11. Facts instead of Behavior usernameLabel.text <~ user.name ageLabel.text <~ user.age • Idempotent • Commutative The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 9
12. Facts instead of Behavior usernameLabel.text <~ user.name ageLabel.text <~ user.age • Idempotent • Commutative • Concurrent The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 9
13. Facts instead of Behavior usernameLabel.text <~ user.name ageLabel.text <~ user.age • Idempotent • Commutative • Concurrent • Reactive The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 9
14. Declarative Programming in Swift The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 10
15. public protocol DownloadSyncable { static func handleServerResponse( response: SyncResponse, request: SyncRequest, state: SyncRequestState? ) -> ( changes: [ModelChange], newState: SyncRequestState?, nextRequest: SyncRequest? ) } The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 11
16. The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 12
17. • Fact instead of behavior -> Easier to reason about The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 12
18. • Fact instead of behavior -> Easier to reason about • Interface forms DSL -> Constrained, unified implementation The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 12
19. • Fact instead of behavior -> Easier to reason about • Interface forms DSL -> Constrained, unified implementation • Separation of concerns via indirection The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 12
20. • Fact instead of behavior -> Easier to reason about • Interface forms DSL -> Constrained, unified implementation • Separation of concerns via indirection • Testability The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 12
21. The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 13
22. bit.ly/declarative-swift Further Reading: Declarative API Design in Swift (me) Defining Declarative (awelonblue) @benjaminencz The Unreasonable Effectiveness Of Declarative Code | @benjaminencz | Swift Summit, November 2016 14