kanmoba-returns-02.pdf

Transcript

1. 5෼ͰΘ͔ͬͨؾʹͳΔKotlin Corou,nes @takuji31 ؼ͖ͬͯͨؔ੢ϞόΠϧΞϓϦݚڀձ #2
2. ࣗݾ঺հ
3. ࣗݾ঺հ • @takuji31 id:takuji31 • Takuji Nishibayashi • Hatena Co., Ltd. • App Team • ίϛοΫDAYS • δϟϯϓϧʔΩʔʂ • ΧΫϤϜ
4. ࣗݾ঺հ • Android • Kotlin • Flu-er • ! h-ps:/ /blog.takuji31.jp • " h-ps:/ /nazuna.takuji31.jp • # $ h-ps:/ /photo.takuji31.jp
5. Kotlin Corou+nes
6. ࢖ͬͯ·͔͢ʁ
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
8. Corou%neʹ͍͓ͭͯ͞Β͍͠· ͠ΐ͏
9. suspended func*on
10. தஅՄೳͳؔ਺
11. suspend function fetchUser() : User { val user = // ωοτϫʔΫ௨৴ͳͲͷॏ͍ॲཧ return user }
12. Corou%neContext
13. Corou%neͷίϯςΩετ
14. ෳ਺ͷElementΛ૊Έ߹Θͤͯ࡞Δ
15. Job
16. Dispatcher
17. Name
18. Excep&onHandler
19. ωετՄೳ
20. val context = Job() + Dispatchers.Main launch(context) { // run in main thread delay(100) val response = withContext(Dispatchers.Default) { // run in background thread networkAccess() } }
21. Corou%neScope
22. Corou%neͷείʔϓ
23. ContextΛ࣋ͭ
24. ωετՄೳ
25. async/launchͰ্ཱͪ͛ͨίϧʔν ϯ಺Ͱྫ֎͕ى͖Δͱείʔϓશମ ͕ࢮ͵ͷͰ஫ҙ
26. Ϋϥογϡ͢Δ΍ͭ // ྫ֎Ͱείʔϓશମ͕ࢮΜͰΫϥογϡ͢Δ coroutineScope { try { val user = async { fetchUser() } val series = async { fetchSeries("12345") } doSomething(user.await(), series.await()) } catch (e: IOException) { // catch͞Εͳ͍ } }
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 } }
28. Deferred
29. ϊϯϒϩοΩϯάͳFuture
30. val user = async { fetchUser() } // Deferred<User> val series = async { fetchSeries("12345") } // Deferred<Series> doSomething(user.await(), series.await())
31. Channel
32. ϗοτͳετϦʔϜ
33. val channel = Channel<User>(Channel.CONFLATED) userObserver.addOnChangeListener { user -> launch { channel.send(user) } } channel.consumeEach { user -> doSomething(user) }
34. Flow
35. ίʔϧυͳετϦʔϜ
36. Preview status
37. 1.3.0-M1ͰExperimentalʹ
38. val userFlow = flow<User> { emit(observeUser()) } val seriesFlow = flow<Series> { emit(observeSeries()) } userFlow.combineLatest(seriesFlow) { user, series -> createItemModels(user, series) }.collect { itemModels -> // show items }
39. Enjoy Kotlin Corou.nes life!