Objective-C と比べて Swift が強力だと感じた4つの点

Transcript

1. Objective-C ͱൺ΂ͯ Swift ͕ ڧྗͩͱײͨ͡4ͭͷ఺
2. Yusuke Minami • @yuuxeno • iOS ΤϯδχΞ
3. let , var
4. mutable (Մม) immutable (ෆม) Λ໌֬ʹ۠ผͰ͖Δ
5. mutable(Մม) ͷϠό͞ var item = Item(id: 1, name: “Swift”) item = Item(id: 1, name: “Objective-C") ⛏ ৭ʑͳॲཧ ⛏
6. mutable ͳ΋ͷ͸ɾɾɾ • Ͳ͜Ͱ஋͕มΘΔͷ͔ΛৗʹಡΈख͕ҙࣝ͢ Δඞཁ͕͋ΔͷͰՄಡੑ͕௿͍ • ࠓͲ͏͍͏ঢ়ଶͳͷ͔ΛৗʹಡΈख͕ҙࣝ͢ Δඞཁ͕͋ΔͷͰͭΒ͍
7. ίʔυΛಡΜͰ͍Δ࣌ؒͷେ෦෼Λ mutable ͳ΋ͷʹඅ΍͍ͯ͠Δ • ͜ͷঢ়ଶ͕มΘͬͨ࣌ʹॲཧ͸Ͳ͏มΘΔͷ ͔ ? • ͦΕʹΑͬͯผͷঢ়ଶ͸Ͳ͏มΘΔͷ͔ ? • ҎԼϧʔϓ
8. όά Մಡੑ௿Լ ֦ுੑ௿Լ
9. ͍͍ͩͨίΠπͷ͍ͤ
10. શ͕ͯ immutable ͷੈք
11. ࠷ߴ !
12. ݱ࣮
13. ΞϓϦ͸ঢ়ଶͩΒ͚ɾɾɾ
14. શ෦ແ͘͢ͷ͸ແཧͳͷͰ
15. ແବͳঢ়ଶΛ࡞Βͳ͍ let isImmutable = true var text: String if isImmutable { text = "immutable" } else { text = "mutable" } let isImmutable = true let text: String = { if isImmutable { return "immutable" } else { return "mutable" } }()
16. ঢ়ଶΛ؅ཧ͢Δ •Redux !
17. ϠόΠ΍ͭʹ var ҹΛ͚ͭΔ final class ItemViewController: UIViewController { let ɾɾɾ let itemDataStore = ItemDataStore() var item: Item? let totalItem = 100 let ɾɾɾ
18. • Objective-C ʹ͸ immutable Λදݱग़དྷΔ const ͸͕͋ͬͨɺ mutable Λ໌ࣔతʹදݱ ग़དྷΔ΋ͷ͸ͳ͔ͬͨ • ϓϩύςΟͷ readwrite ΋লུՄೳͩͬͨ • let -> var ͷॻ͖׵͑͸ίʔυϨϏϡʔͰؾͮ ͖΍͍͢
19. ͦͷ ຊ౰ʹඞཁͰ͔͢ ? ͦͷ ຊ౰ʹ৻ॏʹѻͬͯ·͔͢ ?
20. var = = औѻ஫ҙ
21. MutableProperty Variable
22. map, flatMap, filter, reduce
23. mutable ͳ΋ͷΛݮΒͤΔ let items = [Item(id: 1, price: 100), Item(id: 2, price: 200), Item(id: 3, price: 300)] var fetchedItems = [Item]() for item in items { if item.price >= 200 { fetchedItems.append(item) } } let fetchedItems = items.filter { $0.price >= 200 }
24. ԿΛ͍ͯ͠Δ͔͕Ұ໨Ͱ෼͔Δ let items = [Item(id: 1, price: 100), Item(id: 2, price: 200), Item(id: 3, price: 300)] var fetchedItems = [Item]() for item in items { if item.price >= 200 { fetchedItems.append(item) } } let fetchedItems = items.filter { $0.price >= 200 }
25. ݟ௨͕͘͢͠͝ྑ͘ͳΔ • mutable ͳ΋ͷ͸Ͳ͜Ͱঢ়ଶ͕มΘΔͷ͔ҙ ࣝ͢Δඞཁ͕͋ΔͷͰಡΈʹ͍͘ • ιʔείʔυ͕͋Δఔ౓ͷن໛ʹͳΔͱɺશ ͯͷ෦෼ʹ͍ͭͯࡉ෦·Ͱ۩ମతʹԿΛͯ͠ ͍Δ͔Λ೺Ѳ͢Δͷ͸ແཧ -> งғؾ͚ͩͰ΋ ௫Έ͍ͨ
26. var, for, if map, flatMap, filter, reduce
27. Optional
28. nil Λ୳ཱྀ͢ʹඅ΍͕࣌ؒ͢େ෯ʹݮͬͨ
29. ૝ఆ֎ͷ݁Ռ ɾɾɾ
    CSFBLQPJOU
    /4-PH OJM OJM OJM
30. ͳ͓ͥલ ( nil ) ͕ͦ͜ʹ͍ΔΜͩ ?
31. ͳͥͩΖ͏ • nil νΣοΫΛ๨ΕΔͱ͙͢ʹ૝ఆ֎ͷॲཧ͕ ߦΘΕΔ • nil νΣοΫ๨ΕΔͱ૝ఆ֎ͷ஋͕ͲΜͲΜਂ ͍ͱ͜ΖʹྲྀΕ͍ͯ͘ • ͳ͔ͥ͋Γ͑ͳ͍ͱ͜Ζʹ nil ͕ೖͬͯΔ
32. Optional • ͋Δ͔΋͠Εͳ͍ɺͳ͍͔΋͠Εͳ͍ͱ͍͏ ࣄʹରͯ͠໌֬ͳܕ͕Ͱ͖ͨ • ৗʹॻ͖खʹ nil Λҙࣝͤ͞ɺߟ͑ͤ͞Δ ( ͜ ͷม਺ʹ͸࣮૷্ nil ͕དྷΔͷ͔ͳͲ ) • ஋ΛऔΓग़͢৔߹ʹnil Λඞͣҙࣝͤ͞Δ
33. ϛεͬͯ nil Λྲྀͯ͠͠·͏ࣄ͕গͳ͘ͳͬͨ
34. ଘࡏ͢Δͱଘࡏ͢Δ͔΋͠Εͳ͍͸ શ͘ผͷ͜ͱͩͬͨ
35. protocol extension
36. ɾɾɾ
    ܧঝ $MBTT
    " $MBTT
    # #BTF
    $MBTT $MBTT
    $
37. ඞཁҎ্ͷ΋ͷʹґଘ͢Δ • ܧঝݩΫϥεͷҰ෦ͷػೳΛ࢖͍͍͕ͨͨΊʹɺ༷ʑͳػೳ Λ࣋ͬͨܧঝݩͷΫϥεશͯʹґଘ͢Δ • Ұ෦ͷػೳΛมߋ͠Α͏ͱ͢ΔͱɺͦͷΫϥεͷܧঝઌͷΫ ϥεશͯνΣοΫ͢Δඞཁ͕͋Δ -> গ͠ͷมߋͰ΋Өڹൣ ғ͕େ͖͍ͷͰ؆୯ʹϦϑΝΫλϦϯάͰ͖ͳ͍ • ܧঝݩͷΫϥε͕༷ʑͳ໾ׂΛ࣋ͭͨΊݟ௨͕͘͢͠͝ѱ͘ ͳΔ ( ܧঝઌͷΫϥεΛݟͳ͍ͱͲ͏͍͏ҙਤͰ࣮૷͞Εͨ ͷ͔͕Θ͔Βͳ͍)
38. ϦϑΝΫλϦϯάͰ͖ͳ͍ͷͰ ޙ͸ͲΜͲΜଠ͍ͬͯ͘ͷΈ
39. ɾɾɾ
    ద߹ $MBTT
    " $MBTT
    # QSPUPDPM
    FYUFOTJPO $MBTT
    $
40. protocol extension ͳΒ • ΫϥεΑΓ΋ࡉ͔͍ύʔπʹ෼͚ΒΕ࠶ར༻ੑ͕ߴ ͍ • ΫϥεΑΓந৅౓ͷߴ͍ protocol ʹґଘ͢ΔͨΊม ߋʹڧ͍ • Өڹൣғ͸ͦͷ protocol extension ͕࣮ݱ͢Δػೳ ʹґଘ͍ͯ͠Δ෦෼ʹݶΒΕΔͨΊϦϑΝΫλϦϯ ά͕༰қ
42. ࢀߟ • SwiftͷOptionalͷϕετϓϥΫςΟε http://qiita.com/ koher/items/8b6156c8263b9b23c43c