Android with Functional Programming

Transcript

1. "OESPJE
   XJUI
   'VODUJPOBM
   1SPHSBNNJOH !UBLBTG[
   $"54
   .&&561
   
   
   
2. ؔ਺ܕϓϩάϥϛϯάͬͯԿʁ
3. ؔ਺ܕϓϩάϥϛϯάͱ͸ 'VODUJPOBM
   DPEF
   JT
   DIBSBDUFSJTFE
   CZ
   POF
   UIJOH
   UIF
   BCTFODF
   PG
   TJEF
   FGGFDUT
   *U
   EPFTO`U
   SFMZ
   PO
   EBUB
   PVUTJEF
   UIF
   DVSSFOU
   GVODUJPO
   BOE
   JU
   EPFTO`U
   DIBOHF
   EBUB
   UIBU
   FYJTUT
   PVUTJEF
   UIF
   DVSSFOU
   GVODUJPO
   &WFSZ
   PUIFS
   lGVODUJPOBMz
   UIJOH
   DBO
   CF
   EFSJWFE
   GSPN
   UIJT
   QSPQFSUZ "O
   JOUSPEVDUJPO
   UP
   GVODUJPOBM
   QSPHSBNNJOH
   IUUQTDPEFXPSETSFDVSTFDPNJTTVFTPOFBOJOUSPEVDUJPOUPGVODUJPOBMQSPHSBNNJOH
4. ؔ਺ܕϓϩάϥϛϯάͱ͸ w ෭࡞༻͕ͳ͍͜ͱ
   w ݱࡏͷؔ਺ͷ֎ʹଘࡏ͢ΔσʔλʹཔΒͣ ɺ
 ݱࡏͷؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛมߋ͠ͳ͍
   w ͦͷଞͷʮؔ਺ܕʯͳ΋ͷ͸͢΂ͯɺ͜ͷಛੑͷ೿ੜͰ͋Δ
   w ෆมσʔλɺୈҰڃؔ਺ɺΧϦʔԽɺߴ֊ؔ਺ɺͳͲ "O
   JOUSPEVDUJPO
   UP
   GVODUJPOBM
   QSPHSBNNJOH
   IUUQTDPEFXPSETSFDVSTFDPNJTTVFTPOFBOJOUSPEVDUJPOUPGVODUJPOBMQSPHSBNNJOH
5. var num: Int = 0 fun incrementNum() { num += 1 } ෭࡞༻ͷ͋Δؔ਺
6. var num: Int = 0 fun incrementNum() { num += 1 } ෭࡞༻ͷ͋Δؔ਺ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
   ؔ਺ͷத͔Βࢀর͍ͯ͠Δ
7. var num: Int = 0 fun incrementNum() { num += 1 } ෭࡞༻ͷ͋Δؔ਺ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
   ؔ਺ͷத͔Βมߋ͍ͯ͠Δ
8. fun incrementNum(num: Int): Int { return num + 1 } ෭࡞༻ͷͳ͍ؔ਺
9. fun incrementNum(num: Int): Int { return num + 1 } ෭࡞༻ͷͳ͍ؔ਺ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
   ؔ਺ͷத͔Β௚઀ࢀর͠ͳ͍
10. fun incrementNum(num: Int): Int { return num + 1 } ෭࡞༻ͷͳ͍ؔ਺ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
    ؔ਺ͷத͔Β௚઀มߋ͠ͳ͍
11. fun KeirinCup.isHeld(): Boolean { return this.startDate.isBefore(LocalDate.now()) && this.endDate.isAfter(LocalDate.now()) } ෭࡞༻ͷ͋Δؔ਺
12. fun KeirinCup.isHeld(): Boolean { return this.startDate.isBefore(LocalDate.now()) && this.endDate.isAfter(LocalDate.now()) } ෭࡞༻ͷ͋Δؔ਺ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
    ࢀর͍ͯ͠Δ
13. fun KeirinCup.isHeld(now: LocalDate): Boolean { return this.startDate.isBefore(now) && this.endDate.isAfter(now) } ෭࡞༻ͷͳ͍ؔ਺
14. fun KeirinCup.isHeld(now: LocalDate): Boolean { return this.startDate.isBefore(now) && this.endDate.isAfter(now) } ෭࡞༻ͷͳ͍ؔ਺ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
    ࢀর͠ͳ͍
15. fun divide(x: Double, y: Double): Double { if (y == 0.0) { throw IllegalArgumentException() } return x / y } ෭࡞༻ͷ͋Δؔ਺ʁ
16. fun divide(x: Double, y: Double): Double { if (y == 0.0) { throw IllegalArgumentException() } return x / y } ෭࡞༻ͷ͋Δؔ਺ʁ ྫ֎͕ൃੜ͢Δͱɺؔ਺ͷ֎ͷঢ়ଶ͕มԽ͢Δ
    
    ෭࡞༻͕͋Δ
17. fun divide(x: Double, y: Double): Double { if (y == 0.0) { return Double.NaN } return x / y } ෭࡞༻ͷͳ͍ؔ਺
18. ෭࡞༻͕ͳ͍ͱɺԿ͕خ͍͠ͷʁ
19. ؔ਺ܕϓϩάϥϛϯάͱ͸
    ࠶ w ෭࡞༻͕ͳ͍͜ͱ
    w ݱࡏͷؔ਺ͷ֎ʹଘࡏ͢ΔσʔλʹཔΒͣ ɺ
 ݱࡏͷؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛมߋ͠ͳ͍
20. ࢀরಁաੑ w ಉ͡Ҿ਺Λ༩͑Ε͹ɺඞͣಉ݁͡Ռ͕ฦΔ w ଞͷ͍͔ͳΔػೳͷ݁ՌʹӨڹΛ༩͑ͳ͍
21. ࢀরಁաੑ w ಉ͡Ҿ਺Λ༩͑Ε͹ɺඞͣಉ݁͡Ռ͕ฦΔ w ଞͷ͍͔ͳΔػೳͷ݁ՌʹӨڹΛ༩͑ͳ͍ ˠ ෭࡞༻͕ͳ͍
    ˺
    ࢀরಁաੑ͕ߴ͍
22. ࢀরಁաੑ͕ߴ͍ͱ w ॲཧͷཧղͷ͠΍͢͞
    w ෭࡞༻ʹΑΔόάΛੜΈͮΒ͍
    w ςετ΍อक͕͠΍͍͢
23. ෭࡞༻͕ͳ͍͜ͱͷσϝϦοτ w ঢ়ଶΛ࣋ͭॲཧΛهड़ͮ͠Β͍
    w ྫ͑͹ɺಈըͷϩʔυதɺ࠶ੜதɺఀࢭதͳͲ
24. 8JO5JDLFU
    "OESPJE
    ʹ͓͚Δ
    ؔ਺ܕϓϩάϥϛϯά
25. w ࿮൪ɺं൪
    w બख৘ใ
    ࢯ໊ɺ෎ݝɺڃ൝ͳͲ
    w લճग़৔ͨ͠Ϩʔεͷ੒੷
    w ։࠵৔ॴ
    w άϨʔυ
    w ֤Ϩʔεͷ݁Ռ ग़૸ද
    
    લ৔ॴ
26. w ࿮൪ɺं൪
    w બख৘ใ
    ࢯ໊ɺ෎ݝɺڃ൝ͳͲ
    w લճग़৔ͨ͠Ϩʔεͷ੒੷
    w ։࠵৔ॴ
    w άϨʔυ
    w ֤Ϩʔεͷ݁Ռ ग़૸ද
    
    લ৔ॴ
27. w બख৘ใϦετ
    w બख
    *%
    લճग़৔ͨ͠Ϩʔεͷ
    *%
    લ ճग़৔ͨ͠Ϩʔεͷ݁ՌϦετ
    
    w ϨʔεΧοϓϦετ
    w ϨʔεΧοϓ
    *%
    ϨʔεΧοϓ໊শ
    άϨʔυ
    ڝྠ৔
    *%
    
    w ڝྠ৔Ϧετ
    w ڝྠ৔
    *%
    ڝྠ৔໊শ
     αʔό͔Β໯͏σʔλ
28. var response: KeirinRaceResponse? = null var entries = mutableListOf<EntryTable>() fun parse() { for (record in response!!.recordsList) { var previousCup: KeirinCup? = null for (cup in response!!.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup .. αʔό͔Β໯ͬͨσʔλΛύʔε͢Δ
29. var response: KeirinRaceResponse? = null var entries = mutableListOf<EntryTable>() fun parse() { for (record in response!!.recordsList) { var previousCup: KeirinCup? = null for (cup in response!!.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup .. αʔό͔Β໯ͬͨσʔλΛύʔε͢Δ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
    ࢀর͍ͯ͠Δ
30. var response: KeirinRaceResponse? = null var entries = mutableListOf<EntryTable>() fun parse() { for (record in response!!.recordsList) { var previousCup: KeirinCup? = null for (cup in response!!.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup .. αʔό͔Β໯ͬͨσʔλΛύʔε͢Δ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
    มߋ͍ͯ͠Δ
31. var response: KeirinRaceResponse? = null var entries = mutableListOf<EntryTable>() fun parse() { for (record in response!!.recordsList) { var previousCup: KeirinCup? = null for (cup in response!!.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup .. αʔό͔Β໯ͬͨσʔλΛύʔε͢Δ
32. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { var previousCup: KeirinCup? = null for (cup in response.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup break } .. ؔ਺ͷ֎΁ͷ෭࡞༻Λͳ͘͢
33. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { var previousCup: KeirinCup? = null for (cup in response.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup break } .. ؔ਺ͷ֎΁ͷ෭࡞༻Λͳ͘͢ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
    ؔ਺ͷத͔Β௚઀ࢀর͠ͳ͍
34. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { var previousCup: KeirinCup? = null for (cup in response.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup break } .. ؔ਺ͷ֎΁ͷ෭࡞༻Λͳ͘͢ ؔ਺ͷ֎ʹଘࡏ͢ΔσʔλΛ
    ؔ਺ͷத͔Β௚઀มߋ͠ͳ͍
35. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { var previousCup: KeirinCup? = null for (cup in response.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup break } .. ؔ਺ͷ֎΁ͷ෭࡞༻Λͳ͘͢
36. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { var previousCup: KeirinCup? = null for (cup in response.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup break } .. ؔ਺ͷ֎΁ͷ෭࡞༻Λͳ͘͢
37. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { var previousCup: KeirinCup? = null for (cup in response.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup break } .. ؔ਺ͷ֎΁ͷ෭࡞༻Λͳ͘͢ GPS
    ϒϩοΫͷ֎ʹଘࡏ͢ΔσʔλΛ
    GPS
    ϒϩοΫͷத͔Βมߋ͍ͯ͠Δ
38. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { var previousCup: KeirinCup? = null for (cup in response.cupsList) { if (cup.id == record.previousCupId) { previousCup = cup break } .. ؔ਺ͷ֎΁ͷ෭࡞༻Λͳ͘͢
39. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. entries.add(EntryTable(record, previousCup, cupVenue)) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢
40. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. entries.add(EntryTable(record, previousCup, cupVenue)) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢ pSTU
    ৚݅ʹ౰ͯ͸·Δ࠷ॳͷཁૉΛฦ͢
41. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. entries.add(EntryTable(record, previousCup, cupVenue)) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢
42. fun parse(response: KeirinRaceResponse): List<EntryTable> { val entries = mutableListOf<EntryTable>() for (record in response.recordsList) { val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. entries.add(EntryTable(record, previousCup, cupVenue)) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢ GPS
    ϒϩοΫͷ֎ʹଘࡏ͢ΔσʔλΛ
    GPS
    ϒϩοΫͷத͔Βมߋ͍ͯ͠Δ
43. fun parse(response: KeirinRaceResponse): List<EntryTable> { return response.recordsList.map { record -> val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. EntryTable(record, previousCup, cupVenue) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢
44. fun parse(response: KeirinRaceResponse): List<EntryTable> { return response.recordsList.map { record -> val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. EntryTable(record, previousCup, cupVenue) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢ NBQ
    ֤ཁૉʹϒϩοΫͷॲཧΛద༻ͨ͠
    ݁ՌͷϦετΛฦ͢
45. fun parse(response: KeirinRaceResponse): List<EntryTable> { return response.recordsList.map { record -> val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. EntryTable(record, previousCup, cupVenue) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢
46. fun parse(response: KeirinRaceResponse): List<EntryTable> { return response.recordsList.map { record -> val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. EntryTable(record, previousCup, cupVenue) GPS
    ϒϩοΫͷ֎΁ͷ෭࡞༻Λͳ͘͢ Ұக͢Δσʔλ͕ͳ͍ͱ͖
    ྫ֎͕ൃੜ͢Δ
47. "SSPX w ܕ෇͖ؔ਺ܕݴޠΛ࣮ݱ͢ΔͨΊͷ
    ,PUMJO
    ޲͚ϥΠϒϥϦ
    w "SSPX5SZ
    w ྫ֎͕ൃੜ͢ΔՄೳੑͷ͋Δؔ਺ͷݺͼग़͠Λ
 ϞσϧԽ͢Δ <+1>
    'VODUJPOBM
    1SPHSBNNJOH
    JO
    ,PUMJO
    XJUI
    "SSPX
    IUUQTTQFBLFSEFDLDPNXBTBCFFGKQGVODUJPOBMQSPHSBNNJOHJOLPUMJOXJUIBSSPX
48. sealed class Try<out A> : TryOf<A> { data class Failure(val exception: Throwable) : Try<Nothing>() data class Success<out A>(val value: A) : Try<A>() inline operator fun <A> invoke(f: () -> A): Try<A> = try { Success(f()) } catch (e: Throwable) { Failure(e) } "SSPX5SZ
49. val tried = Try { .. } if (tried.isFailure()) { .. } if (tried.isSuccess()) { .. } tried.fold( ifFailure = { .. }, ifSuccess = { .. } ) "SSPX5SZ
    ͷγϯϓϧͳ࢖͍ํ
50. val tried = Try { .. } if (tried.isFailure()) { .. } if (tried.isSuccess()) { .. } tried.fold( ifFailure = { .. }, ifSuccess = { .. } ) "SSPX5SZ
    ͷγϯϓϧͳ࢖͍ํ 5SZ
    \
    ^
    ϒϩοΫ಺Ͱ
    ྫ֎͕ൃੜ͢ΔՄೳੑͷ͋ΔॲཧΛߦ͏
51. val tried = Try { .. } if (tried.isFailure()) { .. } if (tried.isSuccess()) { .. } tried.fold( ifFailure = { .. }, ifSuccess = { .. } ) "SSPX5SZ
    ͷγϯϓϧͳ࢖͍ํ ྫ֎͕ൃੜͨ͠৔߹ͷॲཧ
52. val tried = Try { .. } if (tried.isFailure()) { .. } if (tried.isSuccess()) { .. } tried.fold( ifFailure = { .. }, ifSuccess = { .. } ) "SSPX5SZ
    ͷγϯϓϧͳ࢖͍ํ ॲཧ͕੒ޭͨ͠৔߹ͷॲཧ
53. val tried = Try { .. } if (tried.isFailure()) { .. } if (tried.isSuccess()) { .. } tried.fold( ifFailure = { .. }, ifSuccess = { .. } ) "SSPX5SZ
    ͷγϯϓϧͳ࢖͍ํ GPME
    Ͱ·ͱΊͯهड़͢Δ͜ͱ΋Ͱ͖Δ
54. fun parse(response: KeirinRaceResponse): List<EntryTable> { return response.recordsList.map { record -> val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. EntryTable(record, previousCup, cupVenue) ॲཧͷࣦഊΛ໭Γ஋Ͱදݱ͢Δ Ұக͢Δσʔλ͕ͳ͍ͱ͖
    ྫ֎͕ൃੜ͢Δ
55. fun parse(response: KeirinRaceResponse): Try<List<EntryTable>> { return Try { response.recordsList.map { record -> val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. EntryTable(record, previousCup, cupVenue) ॲཧͷࣦഊΛ໭Γ஋Ͱදݱ͢Δ
56. fun parse(response: KeirinRaceResponse): Try<List<EntryTable>> { return Try { response.recordsList.map { record -> val previousCup: KeirinCup = response.cupsList.first { it.id == record.previousCupId } val cupVenue: KeirinVenue = response.venuesList.first { it.id == previousCup.venueId } .. EntryTable(record, previousCup, cupVenue) ॲཧͷࣦഊΛ໭Γ஋Ͱදݱ͢Δ ෭࡞༻͕ͳ͘ɺ҆શʹ
    ύʔεͰ͖ΔΑ͏ʹͳͬͨʂ
57. w ࿮൪ɺं൪
    w બख৘ใ
    ࢯ໊ɺ෎ݝɺڃ൝ͳͲ
    w લճग़৔ͨ͠Ϩʔεͷ੒੷
    w ։࠵৔ॴ
    w άϨʔυ
    w ֤Ϩʔεͷ݁Ռ ग़૸ද
    
    લ৔ॴ
58. ·ͱΊ w 8JO5JDLFU
    "OESPJE
    ΞϓϦ͸ɺཧղ͠΍͘͢ɾ҆શͰɾςε τ͠΍͍͢ίʔυΛॻͨ͘Ίʹɺؔ਺ܕϓϩάϥϛϯάͷཁ ૉΛऔΓೖΕ͍ͯ·͢
    w ޲͖ෆ޲͖͕͋ΔͷͰɺ༻๏༻ྔΛकͬͯਖ਼͘͠࢖͍·͠ΐ ͏