A Swift Approach

A quick lightning talk I given at NSLondon on some new concepts and features in Apple's new Language, Swift.

https://twitter.com/kylefuller

Transcript

1. A SWIFT APPROACH
2. NEW CONCEPTS
3. RUNTIME
4. @objc / NSObject
5. RUNTIME
6. WWDC 2015
7. OPTIONALS?
8. func compute() -> Bool?
9. true false neither
10. LACK OF A VALUE
11. NOT AN EMPTY VALUE
12. CAN'T WE DO THIS IN OBJECTIVE-C?
13. nil Nil NULL CGRectNull -1 0 NSNotFound NSNull ...
14. EXPRESS YOU DON'T ACCEPT NIL
15. EXPRESS YOU WILL NOT RETURN NIL
16. /// You **MUST** pass in a URL - (instancetype)initWithURL:(NSURL *)URL { NSParameterAssert(URL != nil); }
17. - (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)path { return nil; }
19. RUNTIME ERROR
20. RUNTIME ERROR
21. COMPILE ERROR
22. TUPLES
23. PYTHON
24. func get(username:String) -> (Person?, NSError?)
25. let person, error = get("Kyle")
26. OBJECTIVE-C
27. NSError *error; Person *person = [Person getPerson:@"Kyle" error:&error];
28. NAMED TUPLES
29. func get(username:String) -> (person:Person?, error:NSError?)
30. let result = get("Kyle") result.person result.error
31. - (NSArray *)getPerson:(NSString *)username; - (NSDictionary *)getPerson:(NSString *)username;
32. NSDictionary *components = [Person getPerson:@"kyle"]; Person *person = components["person"]; NSError *error = components["error"];
33. TYPE SAFETY?
34. FRAGILE
35. CLOSURES
36. EVERYTHING IS A CLOSURE
37. class TestObject { func testA() -> () { println("first test") } var testB:(() -> ()) = { println("second test") } }
38. let testing = TestObject() testing.testA() testing.testB()
39. testing.testB = testing.testA
40. testing.testB() // Actually calls testA
41. CONSISTENCY
42. GENERICS
43. func max<T : Comparable>(a:T, b:T) -> T { return a > b ? a : b }
44. max(anInteger, anotherInteger) max(aFloat, anotherFloat) max(aString, anotherString)
45. PATTERN MATCHING
46. let point = (1, 2) switch point { case (0, 0): println("(0, 0) is at the origin.") case (-2...2, -2...2): println("(\(point.0), \(point.1)) is near the origin.") default: println("The point is at (\(point.0), \(point.1)).") } // prints "(1, 2) is near the origin."
47. @auto_closure
48. delay(5, println("Hello World"))
49. func delay(time:UInt32, block:@auto_closure) { sleep(time) block() }
50. BUILDING ASSERT() IN SWIFT
51. assert(someExpensiveComputation() != 42)
52. func assert(predicate : () -> Bool) { #if !NDEBUG if !predicate() { abort() } #endif }
53. PLAYGROUNDS
54. PLAYGROUNDS
55. SWIFT
56. SAFER
57. CONVENTIONS
58. CONVENTIONS
59. LANGUAGE CONSTRAINTS
60. BETTER CODE
61. BETTER DEVELOPERS
62. LESS BUGS
63. WE'RE ALL BEGINNERS
65. "I DON'T KNOW IF IT'S A BUG OR I'M DOING IT WRONG" ASH FURROW
66. FILE RADARS
67. SHAPE
68. APPLE WILL break YOUR CODE
69. FOR GOOD, NOT EVIL
70. XCODE 6 GM?
71. "WE EXPECT TO LOCK THIS DOWN"
72. "BUT NOT BY THE FINAL RELEASE OF SWIFT THIS FALL."
73. EARLY
74. FUTURE
75. COMMON PATTERNS
76. TWITTER.COM/KYLEFULLER