よりよいネーミングを目指して / 20171003 #orecon_ios #akibaswift

俺コン Vol.1 / Day. 2 - connpass
https://orecon.connpass.com/event/64285/
での発表資料です。

# 参考資料

リーダブルコード ―より良いコードを書くためのシンプルで実践的なテクニック (Theory in practice) | Dustin Boswell, Trevor Foucher, 須藤 功平, 角 征典 |本 | 通販 | Amazon
https://www.amazon.co.jp/dp/4873115655

Amazon | 新装版 リファクタリング―既存のコードを安全に改善する― (OBJECT TECHNOLOGY SERIES) | Martin Fowler, 児玉 公信, 友野 晶夫, 平澤 章, 梅澤 真史 通販
https://www.amazon.co.jp/dp/427405019X

Transcript

1. ΑΓΑ͍ ωʔϛϯάΛ໨ࢦͯ͠ by. 2017/10/3 Զίϯ Vol.1 / Day.2 1
2. takasek iOS Developer @takasek OSS ActionClosurable Notifwift౳ 2
5. ͦ͜·Ͱໃ६͠ͳͯ͘΋… ΍ͬͯ·ͤΜ͔ʁ 4 update() Ͱಛఆͷ৚݅Ͱ͸updateͤͣʹ໭ Δ 4 fetch() ͱ͍͍ͭͭUIͷߋ৽΋ͯ͠Δ 4 ໊લʹࠔͬͯ func didReceive(hoge: Hoge) 5
6. ໃ६ίʔυΛ ͦͷ··ʹͯ͠͠·͏ཧ༝ 4 ΊΜͲ͍͘͞ 4 ಈ͍͍ͯΔίʔυʹ৮Γͨ͘ͳ͍ 4 ద੾ͳ໊લ͕ࢥ͍͔ͭͳ͍ 4 ·͋ɺશମΛಡΊ͹ཧղͰ͖Δ 4 ผʹόά͡Όͳ͍ 6
7. Ͱ΋ɺωʔϛϯάΛ ͦͷ··ʹ ͓ͯ͘͠ͱ… 7
8. 1 1 ετϧʔϓޮՌ - Wikipediaɹhttps://ja.wikipedia.org/wiki/ %E3%82%B9%E3%83%88%E3%83%AB%E3%83%BC%E3%83%97%E5%8A%B9%E6%9E%9C 8
9. ໃ६ίʔυ͸ ίʔυϦʔσΟϯάΛ ஗͘͢Δ 9
10. ΋ͬͱةݥͳͷ͸ɺ ؔ܎ͳ͍ॲཧ͕ೖΓࠐΉ 伱͕Ͱ͖Δ໰୊ 4 ܕ΍ϝιουͷ੹຿ͷൣғ͕ఆ·Βͳ͍ 4 ܕ΍ϝιου͕ංେԽ͢Δɾॲཧ͕֤ॴʹ෼ࢄ ͢Δ 4 ࠷ѱɺόά͕࢓ࠐ·ΕΔ 10
11. 4 update() Ͱಛఆͷ৚݅Ͱ͸updateͤͣʹ໭ Δ 4 σʔλߋ৽ޙ΋ը໘͸ߋ৽͞Εͳ͍… ͱࢥͬͨΒॲཧ్͕தͰguard͞Εͯͨ ! 4 fetch() ͱ͍͍ͭͭUIͷߋ৽΋ͯ͠Δ 4 ࢥΘ͵࣌ʹදࣔ͞ΕΔAlert ⚠ 4 ໊લʹࠔͬͯ func didReceive(hoge: Hoge) 4 isFetching: Bool ͷ؅ཧՕॴ͕෼ࢄʂ # 11
12. ໊લ͕;Θͬͱͯ͠Δ͔Β ༨ܭͳ͜ͱΛͯ͠͠·͏ 12
13. Α໊͍લΛ ͚ͭΑ͏✨ 13
14. Ͱ΋ɺͲ͏΍ͬͯʁ 14
15. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯ 2 1. ໌֬ͳ୯ޠΛબͿ 2. ൚༻తͳ໊લΛආ͚Δʢ͋Δ͍ ͸ɺ࢖͏ঢ়گΛબͿʣ 3. ந৅తͳ໊લΑΓ΋۩ମతͳ໊લ Λ࢖͏ 4. ઀ඌࣙ΍઀಄ࣙΛ࢖ͬͯ৘ใΛ௥ Ճ͢Δ 5. ໊લͷ௕͞ΛܾΊΔ 6. ໊લͷϑΥʔϚοτͰ৘ใΛ఻͑Δ 2 ʮϦʔμϒϧίʔυʯDustin Boswell, Trevor Foucher, 2012 P10 15
16. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶃ ໌֬ͳ୯ޠΛબͿ 4 ❌ HogeStorage.set(fuga) ⭕ HogeStorage.store(fuga) 4 ❌ RxSwift.Observable ⭕ RxSwift.Single as you can! 16
17. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶃ ໌֬ͳ୯ޠΛબͿ ❌ employees.remove(x) view.dismiss(false) let text = words.split(12) ⭕ employees.remove(at: x) view.dismiss(animated: false) let text = words.split(maxSplits: 12) 17
18. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶄ ൚༻తͳ໊લΛආ͚Δ ʢ͋Δ͍͸ɺ࢖͏ঢ়گΛબͿʣ ❌ final class HogeViewController { private let margin: CGFloat = 2.0 private let defaultSize = CGSize(width: 100, height: 50) ... } !ԿͷϚʔδϯͱαΠζ΍ͶΜ 18
19. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶄ ൚༻తͳ໊લΛආ͚Δ ʢ͋Δ͍͸ɺ࢖͏ঢ়گΛબͿʣ ⭕ func calculateComponentWidth (paralleling contentSizes: [CGSize]) -> CGFloat { return contentSizes.reduce(margin) { result, size in let margin: CGFloat = 2 result + size.width + margin } } !Ͱ΋͜ΕͳΒڐͤΔɻείʔϓ͕ڱ͍ͷͰɻ 19
20. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶄ ൚༻తͳ໊લΛආ͚Δ ʢ͋Δ͍͸ɺ࢖͏ঢ়گΛબͿʣ ⭕ var userID: Int? { switch self.userState { case .id(id): return id case .entity(e): return e.id case .unavailable: return nil } } ͋͑ͯࡶͳ໊લΛ͚ͭͯʮҰ࣌తͳ΋ͷʯͩͱࣔ͢ 20
21. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶅ ந৅తͳ໊લΑΓ΋ ۩ମతͳ໊લΛ࢖͏ ❌ class HogeListViewController : UIViewController { ... func fetch() func fetchBackground() func fetchReally(_ id: String, show: Bool) ... } ͲΕ͕Ͳ͏͍͏໾ׂʁ! 21
22. class HogeListViewController : UIViewController { /// ௨৴ͯ͠ɺࣦഊͨ͠ΒΞϥʔτΛදࣔ͢Δ func fetch() { fetchReally(textField.text!, show: true) } /// ௨৴ͯ͠ɺࣦഊͯ͠΋Ξϥʔτ͸දࣔ͠ͳ͍ func fetchBackground() { fetchReally(textField.text!, show: false) // !Ͳ͏΍ΒʮΞϥʔτΛදࣔ͠ͳ͍ʯ͔Βbackgroundͱ͍͏Β͍͠ɻӕͩΖ!? } func fetchReally(_ id: String, show: Bool) { api.fetch(id) { [weak self] models in self?.didReceive(models: models, showsAlertIfFailed: show) } // !ʮ۩ମతͳ௨৴ॲཧ͕ॻ͍ͯ͋Δʯ͔Βreallyͱ͍͏Β͍͠ } } 22
23. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶅ ந৅తͳ໊લΑΓ΋ ۩ମతͳ໊લΛ࢖͏ ❌ func fetch() func fetchBackground() func fetchReally(_ id: String, show: Bool) ⭕ func startFetchingHogesWithFailureAlert() func startFetchingHogesWithoutFailureAlert() func fetchHoges(withID id: String, showsAlertIfFailed: Bool) 23
24. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶆ ઀ඌࣙ΍઀಄ࣙΛ࢖ͬͯ ৘ใΛ௥Ճ͢Δ ❌ let text1 = "100%25%E5%8B%87%E6%B0%97" let text2 = text1.removingPercentEncoding! // "100%༐ؾ" let text3 = text2.removingPercentEncoding! // CRASH" ⭕ let encodedText = "100%25%E5%8B%87%E6%B0%97" let decodedText = encodedText.removingPercentEncoding! // "100%༐ؾ" // ΋͏$͸decodeࡁΈͩͱΘ͔Δ 24
25. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶇ ໊લͷ௕͞ΛܾΊΔ ௕໊͍લͷೖྗࣗମ͸໰୊͡Όͳ͍ɻίʔυิ׬͕͋ Δ͔Βɻ !লུܗʢbackend→beͱ͔ʣ͸఻ΘΒͳ͍͔Βආ͚Δɻ 25
26. ʮ໊લʹ৘ใΛ٧ΊࠐΉ¥ʯᶇ ໊લͷ௕͞ΛܾΊΔ Ͱ΋ɺෆཁͳ୯ޠ͸౤ࣺ͛ͯΔɻʢSwift3 ͸౤ࣺ͛ͯࡇΓͰͨ͠Ͷʂʣ 26
27. ʮ໊લʹ৘ใΛ٧ΊࠐΉʯᶈ ໊લͷϑΥʔϚοτͰ৘ใΛ఻͑Δ SwiftͰݴ͑͹… 4 େจࣈ࢝·Γ͸ܕ໊ɺͦΕҎ֎͸খจࣈ࢝·Γ 4 ΞϯμʔείΞ࢝·ΓͷAPI͸publicͳ΋ͷͰ ͸ͳ͍ ྫ: _kvcKeyPathString ໰୊ https://bugs.swift.org/browse/SR-5220 27
28. Ҏ্͕ʮ໊લʹ৘ใΛ٧ΊࠐΉʯ Ͱͨ͠ 1. ໌֬ͳ୯ޠΛબͿ 2. ൚༻తͳ໊લΛආ͚Δʢ͋Δ͍͸ɺ࢖͏ঢ়گΛબͿʣ 3. ந৅తͳ໊લΑΓ΋۩ମతͳ໊લΛ࢖͏ 4. ઀ඌࣙ΍઀಄ࣙΛ࢖ͬͯ৘ใΛ௥Ճ͢Δ 5. ໊લͷ௕͞ΛܾΊΔ 6. ໊લͷϑΥʔϚοτͰ৘ใΛ఻͑Δ 28
29. ʮϦϑΝΫλϦϯάʯ ΋͍͍͜ͱݴͬͯͨ "ϝιου໊ʹ͸ɺ಺෦ͰͲͷ Α͏ʹॲཧΛ͍ͯ͠Δ͔Ͱͳ ͘ɺͦͷίʔυ͕ԿΛ͢Δͷ ͔ͱ͍͏ҙਤΛࣔ͠·͢ɻ"4 4 ʮ৽૷൛ɹϦϑΝΫλϦϯάɹطଘͷίʔυΛ҆શ ʹվળ͢Δʯ2014೥ P77 29
30. Swift ͷ API design guideline ʹै͏ https://swift.org/documentation/api-design-guidelines/#naming 4 ྲྀெͳӳจʹݟ͑ΔΑ͏ʹ 4 ม਺ɾҾ਺ɾ෇ଐܕͷωʔϛϯά͸ɺͦͷ੍໿ΑΓ΋໾ׂʹԠͯ͡ߦ͏ 4 ϝιου໊ͷ඼ࢺΛɺ෭࡞༻͋Δͳ͠ͰมԽͤ͞Δ 4 ෭࡞༻ͳ͠: ໊ࢺɺಈࢺͷաڈ෼ࢺɺݱࡏ෼ࢺΛ࢖͏ 4 e.g. array.sorted 4 ෭࡞༻͋Γ: ಈࢺͷ໋ྩܗΛ࢖͏ɻ͋Δ͍͸ form Λ಄ʹ͚ͭΔ 4 e.g. array.sort ɹ/ɹ y.formUnion() 4 લྫΛ࠾༻͠·͠ΐ͏ 4 etc... 30
31. Swift Foundation / Cocoaͷྲّྀʹ ै͏ API design guidelineͷ "લྫΛ࠾༻͠·͠ΐ͏" Λ࠾༻͠·͠ΐ͏ 4 Bool ܕ ͸ isʙ ɺcanʙ ɺneedsʙ ͳͲͰ࢝·Δ 4 delegate ϝιουͷ໊෇͚ํ 4 ❌ func willBlog(_ blog: Blog) ⭕ func atendeeWillBlog(_ blog: Blog) 4 APIΛશମݕࡧͰ͖ΔΑ͏ʹ͓ͯ͘͠ͱศར 4 https://developer.apple.com/search/?q={query} &type=Reference 31
32. ͦ΋ͦ΋ ద੾ͳωʔϛϯά͕ Ͱ͖ͳ͍ྫ΋͋Δ 32
33. class HogeListViewController : UIViewController { ... func startFetchingHogesWithFailureAlert() { fetchHoges(withID: textField.text!, showsAlertIfFailed: true) } func startFetchingHogesWithoutFailureAlert() { fetchHoges(withID: textField.text!, showsAlertIfFailed: false) } func fetchHoges(withID id: String, showsAlertIfFailed: Bool) { api.fetchHoges(withID: id) { [weak self] hoges in self?.didReceive( hoges: hoges, showsAlertIfFailed: showsAlertIfFailed ) } } ... } 33
34. ద੾ͳωʔϛϯά͕Ͱ͖ͳ͍ྫᶃ ඇಉظॲཧ func fetchHoges(withID id: String, showsAlertIfFailed: Bool) { api.fetchHoges(withID: id) { [weak self] hoges in self?.didReceive( hoges: hoges, showsAlertIfFailed: showsAlertIfFailed ) } } !fetchޙͷ׬ྃॲཧ΋୲͍ͬͯΔΜ͔ͩΒɺ ɹfetch ͬͯϝιου໊͚ͩͰ͸͓͔͘͠ͳ͍ʁ 34
35. ߏ଄Խϓϩάϥϛϯάͷେݪଇ ϝιου͸ ೖޱ(Ҿ਺) ͱ ग़ޱ(໭Γ஋) Λ࣋ͭ ͔͠͠ඇಉظॲཧͷ݁Ռ͸ ໭Γ஋ ʹ൓ө͞Εͳ͍ 35
36. Ҿ਺͔໭Γ஋Ͱ ඇಉظॲཧ݁ՌΛड͚ΒΕΔ σβΠϯύλʔϯΛ࢖͓͏ 36
37. ద੾ͳωʔϛϯά͕Ͱ͖ͳ͍ྫᶃ ඇಉظॲཧ ඇಉظॲཧ͸ callback ΍ Promiseύλʔϯ Λ࢖ͬͯ Α͏΍͘ਖ਼͘͠ݴ͍දͤΔ ! func fetchHoges(withID id: String, showsAlertIfFailed: Bool) "callback func fetchHoges(withID id: String, completion: ([Hoge] -> Void)) #promise func fetchHoges(withID id: String) -> RxSwift.Single<[Hoge]> 37
38. ద੾ͳωʔϛϯά͕Ͱ͖ͳ͍ྫᶄ ʁʁʁʁʁʁʁʁʁ func postProfileWith(name: String?, address: String?, tel: String?, profileImage: UIImage?, profileImageURL: URL?) -> RxSwift.Single<Bool> γϯϓϧͰ෼͔Γ΍͍͢ϝιου໊… 38
39. ద੾ͳωʔϛϯά͕Ͱ͖ͳ͍ྫᶄ ʁʁʁʁʁʁʁʁʁ func postProfileWith(name: String?, address: String?, tel: String?, profileImage: UIImage?, profileImageURL: URL?) -> RxSwift.Single<Bool> γϯϓϧͰ෼͔Γ΍͍͢ϝιου໊… ͬͯɺຊ౰ʁ 39
40. ద੾ͳωʔϛϯά͕Ͱ͖ͳ͍ྫᶄ Ҿ਺ͷදݱྗ͕ऑ͍ func postProfileWith(name: String?, address: String?, tel: String?, profileImage: UIImage?, profileImageURL: URL?) -> RxSwift.Single<Bool> 4 Optional͹͔Γ͚ͩͲɺඞਢύϥϝʔλ͸Կͳͷ͔ 4 tel ☎ ͸Ͳ͏͍͏ϑΥʔϚοτͰจࣈྻԽ͢Ε͹͍͍ͷ͔ 4 Կނ profileImage ͱ profileImageURL ͕྆ํ͋Δͷ͔ɻͲͪ Β΋౉ͨ͠Βɺ͋Δ͍͸ͲͪΒ΋౉͞ͳ͔ͬͨΒͲ͏ͳΔͷ͔ɻ 40
41. Ҿ਺΋ωʔϛϯάͷ಺ (໭Γ஋΋) 41
42. Ҿ਺ͷදݱྗΛߴΊΔ func postProfileWith(name: String?, address: String?, tel: String?, profileImage: UIImage?, profileImageURL: URL?) -> RxSwift.Single<Bool> ɹɹɹɹɹɹɹɹɹɹɹɹɹɹɹ! func postProfileWith(textData: ProfileTextData?, imageData: ProfileImageData) -> RxSwift.Single<Bool> 42
43. // ͢΂ͯͷཁૉ͕ඞཁͳ৔߹ (AND) ͸ struct ͰදݱͰ͖Δ struct ProfileTextData { let name: String let address: String let tel: Tel? } // ͍ͣΕ͔ͷཁૉ͕ඞཁͳ৔߹ (OR) ͸ enum ͰදݱͰ͖Δ enum ProfileImageData { case image(UIImage) case url(URL) } 43
44. Ҿ਺ͷදݱྗΛߴΊΔ func postProfileWith(textData: ProfileTextData?, imageData: ProfileImageData) -> RxSwift.Single<Bool> 4 ProfileTextData (name & address & tel?) ͸ 4 ἧ͑ͯ౉͢ or ׬શεϧʔ 4 ProfileImageData (UIImage | URL) ͸ 4 ͍ͣΕ͔Λ౉͢ ͳΔ΄Ͳʂ! 44
45. ద੾ͳ໊લΛߟ͑Δ ⊃ ઃܭͷݟ௚͠ 45
46. = ϦϑΝΫλϦϯά 46
47. ਖ਼໊͘͠෇͚Α͏ͱ͢Δͱ ϝιουͷ໊લ͕ ΍ͨΒ௕͔ͬͨΓ΅Μ΍Γ͢Δ! →❌ ෆਖ਼֬Ͱ΋ ୹͘ཁ໿ͪ͠Ό͓͏" 47
48. ਖ਼໊͘͠෇͚Α͏ͱ͢Δͱ ϝιουͷ໊લ͕ ΍ͨΒ௕͔ͬͨΓ΅Μ΍Γ͢Δ! →⭕ ϝιουͷ໾ׂ͕େ͖͗͢ ͭ·ΓϦϑΝΫλϦϯά͕ ඞཁͩͱ͍͏αΠϯͩʂ" 48
49. ʮϝιουΦϒδΣΫτʯ ϝιουࣗ਎ → ໊ࢺԽͯ͠ܕ(ΦϒδΣΫτ) ʹ શͯͷϩʔΧϧม਺ → ܕͷϓϩύςΟ ʹ ϝιου → ܕ಺ͷϝιου܈ ʹ class ProfilePoster { let textData: ProfileTextData? let imageData: ProfileImageData func run() -> RxSwift.Single<Bool> private func ... } 49
50. ʮಛੑͷԣ࿀ูʯ ʢ͋Δϝιου͕ɺࣗ෼ͷΫϥεΑΓ΋ଞͷΫϥεʹڵຯΛ࣋ͭʯঢ়ଶʣ ❌ class ProfilePoster { ... private func isTelValid(tel: String) -> Bool { return (try! NSRegularExpression(pattern: "^[0-9]+-[0-9]+-[0-9]+$")) .firstMatch(in: tel, range: NSRange( location: 0, length: (tel as NSString).length )) != nil } } ※isTelValid(tel:) ͷڵຯ͸ ʮϓϩϑΟʔϧͷฤूը໘ʯͰ͸ͳ͘ʮ☎ి࿩൪߸ʯ 50
51. ʮಛੑͷԣ࿀ูʯ ʢ͋Δϝιου͕ɺࣗ෼ͷΫϥεΑΓ΋ଞͷΫϥεʹڵຯΛ࣋ͭʯঢ়ଶʣ ☎͕ڵຯͷத৺Ͱ͋ΔܕΛ࡞Γɺ isTelValid(tel:) ΛҠಈ ⭕ struct Tel { let value: String var isValid: Bool { return try! value.matches(pattern: "^[0-9]+-[0-9]+-[0-9]+$") // ※ String.matches(pattern:) ͸ String ʹੜ΍ͨ͠ extension } } 51
52. ओޠͱͳΔܕʹॲཧΛୗ͢͜ͱͰɺ ໌ྎ؆ܿͳωʔϛϯάʹͳΔ !before! ProfilePoster.isTelValid(tel: String) -> Bool "after" Tel.isValid: Bool 4 ॲཧର৅͕selfͱͳΔ 4 ϝιουج෦ʹॻ͍͍ͯͨॲཧର৅Λɺܕࣗ਎͕આ໌ͯ͘͠Ε Δ 4 ॲཧର৅Λ͋ΒΘ͢Ҿ਺΋ফ͑Δ 52
53. ͪͳΈʹ Tel.isValid: Bool ΑΓ΋ྑ͍ઃܭ: init࣌ʹόϦσʔτͯ͠ɺͦ΋ͦ΋ෆਖ਼ͳ Tel ܕ Λ࡞Εͳ͍Α͏ʹ͢Δ struct Tel { enum Error: Swift.Error { case invalidFormat } let value: String init(value: String) throws { guard try value.matches(pattern: "^[0-9]+-[0-9]+-[0-9]+$") else { throw Error.invalidFormat } self.value = value } } 53
54. ܕ ʹඋΘΔදݱྗ! 54
55. ΦϒδΣΫτࢦ޲Ͱॻ͘ݶΓ ϝιου΋ϓϩύςΟ΋ ԿΒ͔ͷܕͷ ϝϯό 55
56. ΑΓྑ͍ωʔϛϯάͷͨΊʹ͸ "ԿΛ͢Δ/ԿͰ͋Δ" ͚ͩͰͳ͘ "୭͕/୭ͷ" Λҙࣝ͢Δ 56
57. Happy Naming!! 57
58. ͓·͚ ΑΓ๛͔ͳ ωʔϛϯάͷͨΊʹ 58
59. returns Optional vs throws struct Tel { enum Error: Swift.Error { case invalidFormat } let value: String ! init(value: String) throws { guard try value.matches(pattern: "^[0-9]+-[0-9]+-[0-9]+$") else { throw Error.invalidFormat } self.value = value } } init?(value: String) ͱ͍͏ख΋͋Δ͚Ͳ…ʁ 59
60. returns Optional vs throws returns Optional 4 ! ͓खܰ؆୯ʹѻ͑Δ 4 " ෇Ճ৘ใ͕๡͍͠ ྫ֎ॲཧ(throws) 4 !ʮࣦഊ͠͏Δʯ͜ͱΛ໌֬ʹදͤΔ 4 ! try? ߏจͰOptionalʹม׵Մೳ 4 ! Error Λఆٛͯ͠ࡉ΍͔ʹࣦഊݪҼΛ఻͑ΒΕΔ 4 " Error Λఆٛ͢Δඞཁ͕͋Δ 60
61. ݴޠػೳΛۦ࢖͠Α͏ 4 ࣗ෼ࣗ਎ͷܕΛฦ͢static func 4 operator 4 ه߸ʹΑΔॲཧΛఆٛ͢Δ 4 લஔɾதஔɾޙஔ 4 subscript 4 e.g.ɹ reversiBoard[x: 10, y: 8] 4 ෳ਺ͷҾ਺ɺϥϕϧ෇༩΋Մೳ 61
62. ίϚϯυɾΫΤϦ෼཭ݪଇ (CQRS) 4 ίϚϯυʢ໭Γ஋ͳ͠ɺ෭࡞༻Λى͜͢ʣ 4 ΫΤϦʢ໭Γ஋Λظ଴ɺԿ౓ݺΜͰ΋ಉ݁͡Ռ(ႈ ౳)ʣ Λ෼͚Δͱઃܭ͕͖ͬ͢Γ͢ΔΑͱ͍͏࿩ var canFetch: Bool func startFetching(id: Int) -> Void let hoges: Rx.Observable<[Hoge]> 62
63. Happy Happy Naming!! 63