kanmoba-returns-02.pdf

Transcript

1. 5෼ͰΘ͔ͬͨؾʹͳΔKotlin
   Corou,nes
   @takuji31
   ؼ͖ͬͯͨؔ੢ϞόΠϧΞϓϦݚڀձ #2
   

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2. ࣗݾ঺հ
   

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3. ࣗݾ঺հ
   • @takuji31 id:takuji31
   • Takuji Nishibayashi
   • Hatena Co., Ltd.
   • App Team
   • ίϛοΫDAYS
   • δϟϯϓϧʔΩʔʂ
   • ΧΫϤϜ
   

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4. ࣗݾ঺հ
   • Android
   • Kotlin
   • Flu-er
   •
   !
   h-ps:/
   /blog.takuji31.jp
   •
   "
   h-ps:/
   /nazuna.takuji31.jp
   •
   # $
   h-ps:/
   /photo.takuji31.jp
   

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5. Kotlin Corou+nes
   

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6. ࢖ͬͯ·͔͢ʁ
   

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7. ίϧʔνϯʢӳ: co-rou(neʣͱ͸ϓϩάϥ
   ϛϯάͷߏ଄ͷҰछɻαϒϧʔνϯ͕Τϯτ
   Ϧʔ͔ΒϦλʔϯ·ͰΛҰͭͷॲཧ୯Ґͱ͢
   Δͷʹର͠ɺίϧʔνϯ͸͍ͬͨΜॲཧΛ
   தஅͨ͠ޙɺଓ͖͔ΒॲཧΛ࠶։Ͱ͖Δɻ
   — h$ps://ja.wikipedia.org/wiki/
   %E3%82%B3%E3%83%AB%E3%83%BC%E3%83%81%E3%83%B3
   

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8. Corou%neʹ͍͓ͭͯ͞Β͍͠·
   ͠ΐ͏
   

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9. suspended func*on
   

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10. தஅՄೳͳؔ਺
    

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11. suspend function fetchUser() : User {
    val user = // ωοτϫʔΫ௨৴ͳͲͷॏ͍ॲཧ
    return user
    }
    

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12. Corou%neContext
    

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13. Corou%neͷίϯςΩετ
    

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14. ෳ਺ͷElementΛ૊Έ߹Θͤͯ࡞Δ
    

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15. Job
    

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16. Dispatcher
    

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17. Name
    

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18. Excep&onHandler
    

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19. ωετՄೳ
    

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20. val context = Job() + Dispatchers.Main
    launch(context) {
    // run in main thread
    delay(100)
    val response = withContext(Dispatchers.Default) {
    // run in background thread
    networkAccess()
    }
    }
    

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21. Corou%neScope
    

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22. Corou%neͷείʔϓ
    

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23. ContextΛ࣋ͭ
    

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24. ωετՄೳ
    

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25. async/launchͰ্ཱͪ͛ͨίϧʔν
    ϯ಺Ͱྫ֎͕ى͖Δͱείʔϓશମ
    ͕ࢮ͵ͷͰ஫ҙ
    

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26. Ϋϥογϡ͢Δ΍ͭ
    // ྫ֎Ͱείʔϓશମ͕ࢮΜͰΫϥογϡ͢Δ
    coroutineScope {
    try {
    val user = async { fetchUser() }
    val series = async { fetchSeries("12345") }
    doSomething(user.await(), series.await())
    } catch (e: IOException) {
    // catch͞Εͳ͍
    }
    }
    

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27. ରࡦ
    coroutineScope {
    try {
    // Nested scope
    val (user, series) = coroutineScope {
    val user = async { fetchUser() }
    val series = async { fetchSeries("12345") }
    Pair(user, series)
    }
    doSomething(user.await(), series.await())
    } catch (e: IOException) {
    // show error
    }
    }
    

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28. Deferred
    

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29. ϊϯϒϩοΩϯάͳFuture
    

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30. val user = async { fetchUser() } // Deferred
    val series = async { fetchSeries("12345") } // Deferred
    doSomething(user.await(), series.await())
    

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31. Channel
    

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32. ϗοτͳετϦʔϜ
    

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33. val channel = Channel(Channel.CONFLATED)
    userObserver.addOnChangeListener { user ->
    launch { channel.send(user) }
    }
    channel.consumeEach { user ->
    doSomething(user)
    }
    

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34. Flow
    

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35. ίʔϧυͳετϦʔϜ
    

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36. Preview status
    

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37. 1.3.0-M1ͰExperimentalʹ
    

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38. val userFlow = flow {
    emit(observeUser())
    }
    val seriesFlow = flow {
    emit(observeSeries())
    }
    userFlow.combineLatest(seriesFlow) { user, series ->
    createItemModels(user, series)
    }.collect { itemModels ->
    // show items
    }
    

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39. Enjoy Kotlin Corou.nes life!
    

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