普段C#を使っている僕から見たKotlin

普段C#を使っている僕から見たKotlin

2015/06/05(金)に開催された第3回 かわいいKotlin勉強会の発表資料です。

#jkug

https://kotlin.doorkeeper.jp/events/23515

Transcript

1. ීஈC#࢖͍ͬͯΔ๻͔ΒݟͨɺKotlin @RyotaMurohoshi
2. ͍΍ʔɺΈͳ͞Μ͢͹Β͍͠LTͰͨ͠Ͷ
3. ࢒೦ͳ͕Βɺ ๻ͷLT͸ٕज़తͳ಺༰ബ͘ͳͬͯ·͢ ա౓ͳظ଴͸͠ͳ͍ͰԼ͍͞
4. ීஈC#࢖͍ͬͯΔ๻͔ΒݟͨɺKotlin
5. ͓·͑ͩΕΑ • ࣨ੕྄ଠ • UnityͰϞόΠϧήʔϜ։ൃ • 3೥͘Β͍લ·ͰAndroid։ൃ • C#(Unityͩͱɺdynamic΍asyncͳͲ͸࢖͑ͳ͍) • 26ࡀɺϓϩάϥϚ4೥໨
6. C#͕޷͖Ͱ͢ ΋ͪΖΜɺKotlin΋޷͖Ͱ͢Α ࣮͸Groovyͱ͔΋޷͖Ͱ͢
7. ͜ͷ৔ʹ͍Δํ͸ɺ • Kotlinʹগ͠Ͱ΋ڵຯ͕͋Δํ • KotlinΛ͜Ε͔Βษڧ͍ͯͨ͠ͱࢥ͍ͬͯΔํ • KotlinΛ࢖͍ͬͯͯྲྀߦΒ͍ͤͨํ ͩͱࢥ͍·͢ɻ
8. KotlinΛ࢖͍ͬͯͯྲྀߦΒ͍ͤͨํ ͦͯ͠ Kotlin(ษڧதͰ)஥ؒΛ૿΍͍ͨ͠ํ
9. ͪΐͬͱฉ͍͍ͯͩ͘͞ɻ
10. ScalaϓϩάϥϚͷํʹ KotlinΛ͢͢ΊΔͱɽɽɽ
11. KotlinެࣜɺComparison-to-Scala-ΑΓ Taking'this'into'account,'if'you'are'happy'with'Scala,'you'probably' do'not'need'Kotlin h"p:/ /kotlinlang.org/docs/reference/comparison6to6scala.html
12. ScalaϓϩάϥϚͷํʹ͸ɺ ΍͸ΓScalaͰຬ଍ʁ
13. ๻ͷओு
14. KotlinΛྲྀߦΒ͍ͤͨํɺ C#ϓϩάϥϚͷਓʹקΊΔͷ͍͍ͷͰ͸ʂ
15. C#͕େ޷͖ͳC#ϓϩάϥϚɺ ͚ͩͲ࢓ࣄͰJVMݴޠΛ࢖͏ඞཁ͕͋Δํ (C#ʹׂͱ͍ۙػೳΛ࣋ͭ)KotlinͰϓϩμΫτΛ࡞Γͳ͕Β C#6.0ͰՃΘͬͨΓɾࠓޙՃΘΓͦ͏ͳػೳΛࢼ͢ͷɺ ͍͍ͱࢥ͏ΜͰ͢Αʂ
16. (͋͘·Ͱ๻ͷໝ૝Ͱ͕͢ɽɽɽ) C#ϓϩάϥϚ͕ɺ JavaͰԿ͔ॻ͘ඞཁ͕ग़͖ͯͨͱͯ͠ɽɽɽ
17. ʮ͋ͷػೳ͕ͳ͍ʯ ʮC#ͩͱͰ͖Δͷʹɽɽɽʯ ͬͯͳΓͦ͏(͋͘·Ͱ๻ͷໝ૝Ͱ͢)
18. ͋͘·Ͱ๻ͷໝ૝Ͱ͢
19. ྫΛڍ͛·͢
20. C#ͱKotlinʹ͸͋Δ͚ΕͲ Javaʹͳͯͭ͘Β͍ػೳ ݸਓతʹୈ1Ґ
21. ྫͦͷ1"໊લ෇͖Ҿ਺ ϝιουݺͼग़͕͠௒ಡΈ΍͘͢ͳΔ
22. ྫ͑͹͜Μͳϝιου͕͋ͬͨͱͯ fun reformat( str: String, normalizeCase: Boolean, upperCaseFirstLetter: Boolean, divideByCamelHumps: Boolean, wordSeparator: Character) { (ུ) }
23. ݺͼग़͠ଆ͸͜Μͳײ͡ reformat(str, true, true, false, '_') ͳΔ΄ͲɺΘ͔ΒΜɻ࣮૷Λݟͳ͍ͱɻ IDEͩͬͨΒ࣮૷ଆʹδϟϯϓ͢Ε͹͍͍͚ΕͲ githubͱ͔Ͱ͜͏͍͏ͷͷϦϏϡʔͩΔ͍
24. ݺͼग़͠ଆͰ໊લ෇͖Ҿ਺Λ࢖͏ͱʂ reformat( str, normalizeCase = true, uppercaseFirstLetter = true, divideByCamelHumps = false, wordSeparator = '_' ) ͲͷҾ਺͕ͲͷΑ͏ͳҙຯͳͷ͔ɺ͢ΜͳΓಡΊΔʂ
25. ໊લ෇͖Ҿ਺͸σϑΥϧτҾ਺(C#ͷΦϓγϣφϧҾ਺) ͱ૊Έ߹ΘͤΔͱ͞Βʹڧྗʂ ೿ख͞͸ͳ͍͚Ͳɺ࢖͑Δͱ͜Ζଟͯ͘ศར
26. ྫͦͷ2"֦ுϝιου(֦ுؔ਺) ΫϥεʹϝιουΛ௥Ճ͍ͨ͠ɺܧঝͤͣʹ
27. ྫ͑͹ɽɽɽ java.u&li.Collec&onʹisNotEmptyϝιουΛ௥Ճ͍ͨ͠ (ཁૉ͕ଘࡏ͢Ε͹trueΛɺۭͳΒfalseΛฦ͢ϝιου) ࣮͸KotlinͰ͸ɺ֦ுؔ਺Ͱ͜Ε͕ඪ४Ͱ௥Ճ͍ͯ͞ΕΔ
28. h"ps:/ /github.com/JetBrains/kotlin/blob/build90.12.1525/libraries/stdlib/src/kotlin/collec>ons/JU>l.kt@ ΑΓ package kotlin import java.util.* (લུ) /** Returns true if the collection is not empty */ public fun <T> Collection<T>.isNotEmpty(): Boolean = !isEmpty() (ޙུ)
29. ࡶͳղઆ • ໊લۭؒͷԼʹؔ਺͕ఆٛͰ͖Δ • ֦ுؔ਺Ͱؔ਺ͷ௥Ճ • ୯Ұࣜؔ਺
30. h"ps:/ /github.com/JetBrains/kotlin/blob/build90.12.1525/libraries/stdlib/src/kotlin/collec>ons/JU>l.kt@ ΑΓ package kotlin import java.util.* (લུ) /** Returns true if the collection is not empty */ public fun <T> Collection<T>.isNotEmpty(): Boolean = !isEmpty() (ޙུ)
31. C#͔Βݟ͖ͨͬ͞ͷྫ • จ๏΍ఆٛͰ͖Δ৔ॴ͸ҧ͏͚ͲΫϥεʹؔ਺Λ௥ՃͰ͖Δ • C#6.0ͷexpression/bodiedΈ͍ͨʹࣜܗࣜͰؔ਺Λॻ͚Δ
32. C##6.0͚ͩͰͳ͘ɺߋʹͦͷઌ
33. ֦ுϓϩύςΟ /** * Returns the index of the last item in the list or -1 if the list is empty * * @sample test.collections.ListSpecificTest.lastIndex */ public val <T> List<T>.lastIndex: Int get() = this.size() - 1
34. this͕ແͯ͘΋֦ுؔ਺(ϓϩύςΟ)͕ݺ΂Δ Test fun lastIndex() { assertEquals(-1, empty.lastIndex) assertEquals(1, data.lastIndex) }
35. C#7.0ͰೖΔ͔Ͳ͏͔෼͔Βͳ͍͚ΕͲ σΟεΧογϣϯ͞Ε͍ͯΔ΋ͷɺ KotlinͰ͸΋͢Ͱʹ࢖͑Δʂʂʂ
36. ීஈC#࢖͍ͬͯΔ๻͔ΒݟͨɺKotlin
37. KotlinɺC#ʹΘΓͱ͍ۙؾ͕͢Δͷ
38. Kotlin஥ؒ૿΍͢ͳΒ ScalaόϦόϦͷਓΛק༠͞ΕΔΑΓ΋ JVMݴޠΛ΍ΔඞཁʹͳͬͨC#όϦόϦͷํ ק༠͞Εͯ͸Ͳ͏Ͱ͠ΐ͏ʁ
39. ͦͯ͠ະདྷͷC#͸ɺ Kotlinͱࣅ͍ͯΔ෦෼͕૿͑Δؾ͕͢Δ
40. ·ͱΊ C#erͳ๻͸ɺKotlin͕͖͢Ͱ͢
41. ऄ଍
42. C#ͱ͔Groovyͱ͔ษڧ͍ͯͯ͠ deprecateʹͳ͍ͬͯΔػೳɾจ๏ɾΫϥε͕͋ͬͨΓ ྺ࢙తͳܦҢͰม͑ΒΕͳ͍΋ͷ͕ଟ͍ͷ͕ͪΐ͍ͭΒ͍ Kotlin͸ͦΕΒͷࣦഊ͔ΒֶΜͩΓɺഁյతͳมߋ͕Ͱ͖ͨΓ͢ Δ ͷ͔ͳ(?)
43. kotlinύοέʔδͷϝιουͷιʔεಡΉͷ໘ന͍ Kotlinͷจ๏ͷ෮शʹͳΔͱࢥ͏ͷ
44. ࠙਌ձͰ ࢓ࣄͰ͸࢖Θͳ͍͔΋͠Εͳ͍ʮݴޠʯΛֶͿࣄͱɺ࢓ࣄͰͷʮ࣮༻ʯʹ͍ͭͯ ͓࿩ͤͯ͠͞΋Β͑Δͱخ͍͠Ͱ͢