Making Swift Even More Functional (iOS Dev Camp DC)

Presented at iOS Dev Camp DC 2015

Transcript

1. Making Swift Even More Functional - IOS Dev Camp DC
2. Hello, I’m Veronica Ray!
3. Swift is great, but it could be better Time to make change is now
4. –The Recurse Center User’s Manual “Be rigorous. Understand how and why your code works. Understand your tools. If you're working with a framework (like Sinatra or Flask), learning to use it is just scratching the surface. Go deeper. Learn how it works.”
5. – Functional Programming In Swift “Functional programmers emphasize that each program can be repeatedly broken into smaller and smaller pieces; all these pieces can be assembled using function application to define a complete program.”
6. – Functional Programming In Swift “Functional programming… emphasizes the importance of programming with values, free of mutable state or other side effects.”
7. WHY FUNCTIONAL? •Helps you write clear and concise code •Makes concurrency easier •Reduces complexity
8. RECENT IMPROVEMENTS •Swift 1.2: flatmap •Swift 2.0: Recursive data structures
9. ACCESSIBILITY •How easy for first time programmers to learn? •More experienced programmers?
11. REAL CODE THE FIRST DAY
12. vs
13. BYE USELESS SYNTAX
14. •Optional makes is clear how to handle degenerate case •Code can live outside classes so easier to teach algorithmic reasoning before OOP
15. •Named parameters make it easier to translate plain English into code •ARC means coders have to think about memory management, but not too much
16. SIMPLICITY
18. COMPARED TO SCALA
20. Too many custom operators and not opinionated enough
21. FP IN SWIFT •metaprogramming •list comprehensions •tail call optimization
22. FP IN SWIFT •metaprogramming •list comprehensions •tail call optimization
23. •Allows us to do some awesome stuff •Can be implemented in a functional way
24. –RubyMonk “…the act of writing code that operates on code rather than on data. This involves inspecting and modifying a program as it runs using constructs exposed by the language.”
25. MESSAGE PASSING
26. VTABLE
27. SAFETY FIRST
28. WHY MESSAGE PASSING?
29. •Partial mocks •Method swizzling APPLICATIONS
30. PARTIAL MOCKS
31. METHOD SWIZZLING
32. WRITE STUFF LIKE CORE DATA
33. WRITE STUFF LIKE REALM
34. •Every Swift apps execute inside the Objective-C runtime •Swift-only frameworks may lead to a Swift- only runtime OBJECTIVE-C RUNTIME
35. Radar
36. A FUNCTIONAL WAY
37. TEMPLATES
38. FP IN SWIFT •metaprogramming •list comprehensions •tail call optimization
39. LIST COMPREHENSIONS
40. PYTHON
41. BYTE CODE
42. PYTHON FOR LOOP
43. BYTE CODE IS 23 LINES!
44. vs
45. ASSEMBLY IS THE SAME
46. SPELLING CORRECTOR
47. CONCISENESS Reading code Writing code
48. ADDING IT TO SWIFT
49. FP IN SWIFT •metaprogramming •list comprehensions •tail call optimization
50. RECURSION
51. TAIL CALL
52. TAIL RECURSIVE
53. STACK TRACE (fact 3) (fact-tail 3 1) (fact-tail 2 3) (fact-tail 1 6) (fact-tail 0 6) 6
54. NOT TAIL RECURSIVE
55. STACK TRACE (fact 3) (* 3 (fact 2)) (* 3 (* 2 (fact 1))) (* 3 (* 2 (* 1 (fact 0)))) (* 3 (* 2 (* 1 1))) (* 3 (* 2 1))
56. TAIL CALL OPTIMIZATION
57. NOT GUANRANTEED
58. SWIFT CODE
59. BYTE CODE jne to the label containing the conditional jump
60. BLOW OUT THE STACK
61. HOPE?
62. RECURSION KILLS
63. RADAR
64. LEARN MORE
65. •Functional Swift Conference •Open Radar •Dev Forums •Twitter •Natasha The Robot’s Blog •Other languages
66. WHEN SWIFT GOES OPEN SOURCE
67. TIME TO MAKE CHANGE IS NOW