Collections in Swift

Talk at CocoaConf Chicago, March 2016

Transcript

1. Collections in Swift
2. Nate’s favorite part of Swift: The Standard Library Collections System
3. Protocol-oriented programming
4. Protocols in Objective-C
5. Protocols in Swift
6. Protocols of Swift collections
7. This session 1. The “Problem” 2. How Swift's collections work 3. New approaches
9. ! " #
12. ! " #
16. This session 1. The “Problem” 2. How Swift's collections work 3. New approaches
19. A sequence is a series of values we can access one at a time » 6'2", 5'7", 5'9", 5'4", 5'11" » 0xEF 0xBB 0xBF 0x4E 0x61 0x74 0x65 » 22, 27, 4, 8, 28, 14, ... » 0, 1, 2, 3, 4, 5, 6, 7, ...
20. Sequences
21. SequenceType GeneratorType
22. SequenceType requirements func generate() -> Generator GeneratorType requirements func next() -> Element?
23. One element at a time
24. let numbers = [1, 2, 3, 4] for num in numbers { print(num) } ...is equivalent to: var gen = numbers.generate() while let num = gen.next() { print(num) }
25. Iteration » contains(_:) » minimumElement() / maximumElement() » map(_:) / filter(_:) / reduce(_:combine:) » prefix(_:) / dropFirst(_:)
26. demo
29. Collections provide indexed subscript access to their elements » Arrays » String views (i.e., "Hi there".characters) » Sets » Dictionaries
30. CollectionType
31. CollectionType requirements var startIndex: Index var endIndex: Index subscript(i: Index) -> Generator.Element
32. Quick diversion: Index types » Forward index types » Bidirectional index types » Random-access index types
33. CollectionType requirements var startIndex: Index var endIndex: Index subscript(i: Index) -> Generator.Element
34. Indexed access to elements » Collections are sequences, too » prefixUpTo(_:), prefixThrough(_:), suffixFrom(_:) » subscript(Range<Index>) » count, isEmpty » indices
35. Sequenception
36. demo
39. Range-replaceable collections support arbitrary subrange replacement » Pretty much just arrays
40. RangeReplaceableCollectionType requirements init() func replaceRange<C: CollectionType where C.Generator.Element == Generator.Element> (subRange: Range<Index>, with newElements: C)
41. Mix-and-match » append(_:), appendContentsOf(_:) » insert(_:), insertContentsOf(_:) » removeAtIndex(_:), removeRange(_:) » removeAll()
42. demo
45. This session 1. The “Problem” 2. How Swift's collections work 3. New approaches
46. demo
47. SwiftDoc.org
49. Thank you! Nate Cook @nnnnnnnn