Kotlin 1.3 さらっとContracts + α

Transcript

1. Kotlin 1.3 ͞ΒͬͱContracts + α LINE Developers Meetup #47 in

   Fukuoka @dashimaki_dofu

2. ϓϩϑΟʔϧ • ໊લ: ߴ Յହ (Yoshiyasu KO) • ॴଐ: ϕΨίʔϙϨʔγϣϯ

   • AndroidΤϯδχΞ • : @dashimaki_dofu

3. ϓϩϑΟʔϧ ʮ͠ΜͪΌΜͷਓʯͱ֮͑ͯؼ͍ͬͯͩ͘͞ • ໊લ: ߴ Յହ (Yoshiyasu KO) • ॴଐ:

   ϕΨίʔϙϨʔγϣϯ • AndroidΤϯδχΞ • : @dashimaki_dofu

4. What is Kotlin?

5. Kotlinʢ͜ͱΓΜʣ • 2013೥ JetBrains͕ࣾ։ൃͨ͠ ΦϒδΣΫτࢦ޲ܕݴޠ • JVM্Ͱಈ࡞ • Android Studio

   3.0ΑΓ ެࣜαϙʔτ

6. 2018.10.30 Kotlin 1.3ϦϦʔεʂ

7. Kotlin 1.3 • Coroutines ਖ਼ࣜ൛ • Kotlin/Native β൛ • Contracts

   • when Ҿ਺ͷείʔϓ࠷దԽ etc...

8. Kotlin 1.3 • Coroutines ਖ਼ࣜ൛ • Kotlin/Native β൛ • Contracts

   • when Ҿ਺ͷείʔϓ࠷దԽ etc... ࠓ೔࿩͢ͷ͸ͪ͜Β

9. Contracts

10. Contracts = ܖ໿ • ؔ਺ͷৼΔ෣͍Λʮܖ໿ʯ͢Δ • ίϯύΠϥʹؔ਺ͷৼΔ෣͍Λڭ͑Δ

11. ?????

12. Smart Cast fun foo(s: String?) { if (s != null)

    s.length }

13. Smart Cast fun foo(s: String?) { if (s != null)

    s.length } T
    ͸
    /VMMBCMF

14. Smart Cast fun foo(s: String?) { if (s != null)

    s.length } /PU/VMMΛอূ

15. Smart Cast fun foo(s: String?) { if (s != null)

    s.length } /PU/VMMΛอূ 
    ͕ෆཁ

16. ྫ: isNullOrEmpty() fun foo(s: String?) { if (!s.isNullOrEmpty()) s!!.length }

    ~ Kotlin 1.2

17. ྫ: isNullOrEmpty() fun foo(s: String?) { if (!s.isNullOrEmpty()) s!!.length }

    T
    ͕
    ʮOVMM
    PS
    ۭจࣈʯͰ͋Ε͹USVF
    
    OVMM
    Ͱ΋
    ۭจࣈͰ΋ͳ͚Ε͹
    GBMTF
    
    GBMTF
    Ͱ͋Ε͹/PU/VMM͕อূ͞ΕΔ͸ͣ ~ Kotlin 1.2

18. ྫ: isNullOrEmpty() fun foo(s: String?) { if (!s.isNullOrEmpty()) s!!.length }

    ίϯύΠϥ
    ͸
    JT/VMM0S&NQUZ
    ͷʮৼΔ෣͍ʯ͕෼͔Βͳ͍
    
    4NBSU
    $BTU
    ͕ޮ͔ͳ͍ɾɾɾ ~ Kotlin 1.2

19. ྫ: isNullOrEmpty() fun foo(s: String?) { if (!s.isNullOrEmpty()) s.length }

    Kotlin 1.3 JT/VMM0S&NQUZ
    ʹ࣮૷͞Εͨ
    $POUSBDUT
    ʹΑͬͯ
    4NBSU
    $BTU͕ޮ͘Α͏ʹͳΔʂ

20. ྫ: isNullOrEmpty() @kotlin.internal.InlineOnly public inline fun CharSequence?.isNullOrEmpty(): Boolean { contract

    { returns(false) implies (this@isNullOrEmpty != null) } return this == null || this.length == 0 } Kotlin 1.3

21. ྫ: isNullOrEmpty() @kotlin.internal.InlineOnly public inline fun CharSequence?.isNullOrEmpty(): Boolean { contract

    { returns(false) implies (this@isNullOrEmpty != null) } return this == null || this.length == 0 } Kotlin 1.3

22. ྫ: isNullOrEmpty() @kotlin.internal.InlineOnly public inline fun CharSequence?.isNullOrEmpty(): Boolean { contract

    { returns(false) implies (this@isNullOrEmpty != null) } return this == null || this.length == 0 } %4- ޙड़ Ͱهड़͞ΕΔ Kotlin 1.3

23. ྫ: isNullOrEmpty() @kotlin.internal.InlineOnly public inline fun CharSequence?.isNullOrEmpty(): Boolean { contract

    { returns(false) implies (this@isNullOrEmpty != null) } return this == null || this.length == 0 } GBMTF
    Λฦ࣌͢ Kotlin 1.3

24. ྫ: isNullOrEmpty() @kotlin.internal.InlineOnly public inline fun CharSequence?.isNullOrEmpty(): Boolean { contract

    { returns(false) implies (this@isNullOrEmpty != null) } return this == null || this.length == 0 } GBMTF
    Λฦ࣌͢ /PU/VMMΛอূ͢Δ͜ͱΛ
    ܖ໿͢Δ Kotlin 1.3

25. ྫ: isNullOrEmpty() @kotlin.internal.InlineOnly public inline fun CharSequence?.isNullOrEmpty(): Boolean { contract

    { returns(false) implies (this@isNullOrEmpty != null) } return this == null || this.length == 0 } GBMTF
    Λฦ࣌͢ /PU/VMMΛอূ͢Δ͜ͱΛ
    ܖ໿͢Δ ίϯύΠϥʹؔ਺ͷৼΔ෣͍Λ఻͑Δ͜ͱ͕Ͱ͖Δ Kotlin 1.3

26. Contracts DSL • returns() • ؔ਺ͷ࣮ߦʹ੒ޭͨ࣌͠ • returns(Boolean?) • ؔ਺͕Ҿ਺ͷ஋Λฦͨ࣌͠

    • returnsNotNull() • ؔ਺͕NotNullΛฦͨ࣌͠ • callsInPrace(block, InvocationKind) • block ͕ݺ͹ΕΔճ਺Λ InvocationKind Ͱอূ͢Δ

27. Contracts DSL • returns() • ؔ਺ͷ࣮ߦʹ੒ޭͨ࣌͠ • returns(Boolean?) • ؔ਺͕Ҿ਺ͷ஋Λฦͨ࣌͠

    • returnsNotNull() • ؔ਺͕NotNullΛฦͨ࣌͠ • callsInPrace(block, InvocationKind) • block ͕ݺ͹ΕΔճ਺Λ InvocationKind Ͱอূ͢Δ ࣗ෼Ͱ$POUSBDUΛ࡞ΕΔ
    
    $VTUPN
    $POUSBDUT

28. when Ҿ਺ͷείʔϓ࠷దԽ

29. when Ҿ਺ͷείʔϓ࠷దԽ fun Request.getBody() { val response = executeRequest() return

    when (response) { is Success -> response.body is HttpError -> throw HttpException(response.status) } } ~ Kotlin 1.2

30. when Ҿ਺ͷείʔϓ࠷దԽ fun Request.getBody() { val response = executeRequest() return

    when (response) { is Success -> response.body is HttpError -> throw HttpException(response.status) } } ~ Kotlin 1.2 ϩʔΧϧม਺Λ͜͜Ͱ ఆٛ͢Δඞཁ͕͋Δ

31. when Ҿ਺ͷείʔϓ࠷దԽ fun Request.getBody() { val response = executeRequest() return

    when (response) { is Success -> response.body is HttpError -> throw HttpException(response.status) } } ~ Kotlin 1.2 ϩʔΧϧม਺Λ͜͜Ͱ ఆٛ͢Δඞཁ͕͋Δ XIFO
    ͚ͩͰ࢖͏ม਺ͷείʔϓ͕޿͕ͬͯ͠·͏

32. when Ҿ਺ͷείʔϓ࠷దԽ fun Request.getBody() = when (val response = executeRequest())

    { is Success -> response.body is HttpError -> throw HttpException(response.status) } Kotlin 1.3

33. when Ҿ਺ͷείʔϓ࠷దԽ fun Request.getBody() = when (val response = executeRequest())

    { is Success -> response.body is HttpError -> throw HttpException(response.status) } Kotlin 1.3 Ҿ਺಺ͰϩʔΧϧม਺͕
    ఆٛͰ͖Δ

34. when Ҿ਺ͷείʔϓ࠷దԽ fun Request.getBody() = when (val response = executeRequest())

    { is Success -> response.body is HttpError -> throw HttpException(response.status) } Kotlin 1.3 Ҿ਺಺ͰϩʔΧϧม਺͕
    ఆٛͰ͖Δ Ҿ਺Ͱར༻͢Δม਺ͷείʔϓΛ
    XIFO
    ϒϩοΫ಺ͰऩΊΔ͜ͱ͕Ͱ͖Δ \

35. ࠓ೔࿩ͨ͜͠ͱ • Contract • ίϯύΠϥʹؔ਺ͷʮৼΔ෣͍ʯΛ఻͑Δ • ελϯμʔυϥΠϒϥϦʹ΋૊Έࠐ·Ε͍ͯΔ • DSL Ͱهड़͞ΕΔ

    • Custom Contracts ΋ఆٛͰ͖Δ • when จͷҾ਺ͷείʔϓ࠷దԽ • ϩʔΧϧม਺ΛҾ਺಺ͰఆٛͰ͖Δ • when ϒϩοΫ಺ʹείʔϓ͕ऩΊΒΕΔ

36. ·ͱΊ

37. ͔Ώ͍ॴʹ
    ख͕ಧ͍ͨκʂ

38. ͡Ό ͦΏ͜ͱͰʙ