プルプル…ボクはわるいScalaじゃないよ

2017/12/21に開催された「教養としてのScala ~ そろそろ始めてみたい2017冬」で使用された発表資料です。

Transcript

1. ϓϧϓϧʜ
   ϘΫ͸ΘΔ͍εΧϥ͡Όͳ͍Α
   ೥݄೔
   גࣜձࣾϏζϦʔν ؠদཽ໵
   

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2. ओ࠵ऀͷ൓Ԡ
   

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3. ࣗݾ঺հ
   ؠদཽ໵
   גࣜձࣾϏζϦʔν)3.04ࣄۀ෦
   ೥݄ೖࣾ
   ೖࣾҎདྷ4DBMBʹΑΔ"54˞։ൃʹܞΘΔ
   υϥΫΤ͸͔Βશ෦ϓϨΠࡁ
   ͕·ͩΫϦΞͰ͖͍ͯ·ͤΜ ༡ͼ͍ͨ
   
   ˞"QQMJDBOU5SBDLJOH4ZTUFN
   

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4. ಥવͰ͕͢4DBMBͷΠϝʔδ͸ʁ
   

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5. ؔ਺ܕ
   

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6. Ϟφυ
   

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7. มͳࣄݴ͏ͱౖΒΕΔ
   

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8. ͳΜ͔ා͍ʂ
   

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9. ͳΜ͔ා͍ʂ
   

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10. Ͱ΋ͪΐͬͱ·ͬͯʂ
    

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11. 4DBMB͸ා͘ͳ͍Αʂ
    ͳΜͱεΧϥ͕͓͖͕͋Γ
    ͳ͔·ʹͳΓͨͦ͏ʹͪ͜ΒΛΈ͍ͯΔ
    ͳ͔·ʹͯ͋͛͠·͔͢ʁ
    ͸͍
    ͍͍͑
    

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12. ࠓ೔ͷझࢫ
    ଞͷݴޠ஌ࣝΛϕʔεʹ4DBMBΛֶͿ
    

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13. ࠓ೔ͷझࢫ
    ଞͷݴޠ஌ࣝΛϕʔεʹ4DBMBΛֶͿ
    ා͘ͳ͍ʂ
    

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14. ࠓ೔ͷझࢫ
    ଞͷݴޠ஌ࣝΛϕʔεʹ4DBMBΛֶͿ
    ා͘ͳ͍ʂ
    4DBMBΛ஥ؒʹ͠Α͏ʂ
    

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15. 4DBMBͷجຊΛ஌Ζ͏ʂ
    Α͘Θ͔Βͳ͍
    

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16. 4DBMBͷجຊΛ஌Ζ͏ʂ
    Α͘Θ͔Βͳ͍
    ͜Θ͍ʜ
    

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17. 4DBMBͷجຊΛ஌Ζ͏ʂ
    Α͘Θ͔Δ
    

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18. 4DBMBͷجຊΛ஌Ζ͏ʂ
    ͜Θ͘ͳ͍ʂ
    Α͘Θ͔Δ
    

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19. ࢛ଇԋࢉ
    1 + 1
    2 - 1
    2 * 2
    4 / 2
    3VCZ 1ZUIPO 4DBMB
    1 + 1
    2 - 1
    2 * 2
    4 / 2
    1 + 1
    2 - 1
    2 * 2
    4 / 2
    

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20. ׬શʹҰகʂ
    

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21. ม਺ɾ഑ྻ
    3VCZ 1ZUIPO 4DBMB
    foo = [1, 2, 3]
    print(foo)
    foo = [1, 2, 3]
    print(foo)
    val foo = List(1, 2, 3)
    print(foo)
    

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22. ͍͍ͩͨҰகʂ
    

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23. ϝιου
    3VCZ 1ZUIPO 4DBMB
    def foo
    print("hello")
    end
    foo()
    def foo():
    print("hello")
    foo()
    def foo = {
    println("hello")
    }
    foo()
    

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24. GPSJG
    3VCZ 1ZUIPO 4DBMB
    for x in 0..2 do
    puts(x)
    end
    for x in range(3):
    print(x)
    for (n <- 0 to 2) {
    println(n)
    }
    b = true
    if b then
    puts("true!")
    else
    puts("false!")
    end
    b = True
    if b:
    print("true!")
    else:
    print("false!")
    val b = true
    if (b) {
    println("true!")
    } else {
    println("false!")
    }
    

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25. TXJUDI
    3VCZ 1ZUIPO 4DBMB
    x = "Ruby"
    case x
    when "Ruby" then
    puts("this is ruby")
    when "Python" then
    puts("this is python")
    when "Scala" then
    puts("this is scala")
    end
    o = "Python"
    if o is "Ruby":
    print("this is ruby!")
    elif o is "Python":
    print("this is python!")
    elif o is "Scala":
    print("this is scala!")
    val o = "Scala"
    o match {
    case "Ruby" =>
    println("this is ruby!")
    case "Python" =>
    println("this is python!")
    case "Scala" =>
    println("this is scala!")
    case _ => // No Action
    }
    

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26. ͦΜͳʹมΘΒͳ͍Ͱ͢Ͷ☺
    

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27. Ϋϥε
    3VCZ 1ZUIPO 4DBMB
    class Foo
    def say()
    puts("Foo!")
    end
    end
    Foo.new.say()
    class Foo:
    def say(self):
    print("Foo!")
    Foo().say()
    class Foo {
    def say() = println("Foo!")
    }
    new Foo().say()
    

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28. ΋͏4DBMB͕ॻ͚·͢Ͷʂ
    

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29. EXBOHP͞Μͷࢿྉ΋ࢀߟʹ
    IUUQEXBOHPHJUIVCJPTDBMB@UFYU
    

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30. ஥ؒʹͯ͠ΈΑ͏ʂ
    ͜Μͳͱ͖Ͳ͏ॻ͘ͷʁ
    Λ͓͑ͯ͞ΈΑ͏ʂ
    

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31. ίϨΫγϣϯૢ࡞
    3VCZ 1ZUIPO 4DBMB
    [1,2,3].map { |x| x + 1 }
    map(lambda x: x + 1, [1,2,3])
    [x + 1 for x in [1, 2, 3]]
    List(1,2,3).map { x => x + 1 }
    List(1,2,3).map(_ + 1)
    [1,2,3].select { |x| x % 2 == 0 }
    filter(lambda x: x % 2 == 0, [1,2,3])
    [x for x in [1,2,3] if x % 2 == 0]
    List(1,2,3).filter(_ % 2 == 0)
    

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32. γϯϓϧʹॻ͚·͢Αʂ
    

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33. μοΫλΠϐϯά
    3VCZ
    class Foo
    def say
    puts("Foo!")
    end
    end
    class Bar
    def say
    puts("Bar!")
    end
    end
    [Foo.new, Bar.new].each do |x|
    x.say()
    end
    

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34. μοΫλΠϐϯά
    class Foo:
    def say(self):
    print("Foo!")
    class Bar:
    def say(self):
    print("Bar!")
    for x in [Foo(), Bar()]:
    x.say()
    1ZUIPO
    

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35. μοΫλΠϐϯά
    trait Talkable {
    def say(): Unit
    }
    class Foo extends Talkable {
    def say() = println("Foo!")
    }
    class Bar extends Talkable {
    def say() = println("Bar!")
    }
    def say(x: Talkable) = x.say()
    say(new Foo)
    say(new Bar)
    4DBMB
    

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36. μοΫλΠϐϯά
    class Foo {
    def say() = println("Foo!")
    }
    class Bar {
    def say() = println("Bar!")
    }
    def say[E <: { def say() }](x: E) = x.say()
    say(new Foo)
    say(new Bar)
    4DBMB
    

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37. NJYJO
    3VCZ
    module Foo
    def say()
    puts("Foo!")
    end
    end
    module Bar
    include Foo
    def say()
    puts("Bar!")
    end
    end
    module Baz
    include Foo
    def say()
    puts("Baz!")
    end
    end
    class Qux
    include Bar
    include Baz
    def say()
    puts("Qux!")
    end
    end
    Qux.new.say()
    

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38. NJYJO
    1ZUIPO
    class Foo:
    def say(self):
    print("Foo!")
    class Bar(Foo):
    def say(self):
    print("Bar!")
    class Baz(Foo):
    def say(self):
    print("Baz!")
    class Qux(Bar, Baz):
    def say(self):
    print("Qux!")
    Qux().say()
    

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39. NJYJO
    trait Foo {
    def say() = println("Foo!")
    }
    trait Bar extends Foo {
    override def say() = println("Bar!")
    }
    trait Baz extends Foo {
    override def say() = println("Baz!")
    }
    class Qux extends Bar with Baz {
    override def say() = println("Qux!")
    }
    new Qux say()
    4DBMB
    

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40. 4DBMBͰ999͕͍ͨ͠ʂ
    

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41. 4DBMBͰ999͕͍ͨ͠ʂ
    

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42. ஥ؒʹͰ͖·ͨ͠Ͷʂ
    

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43. Ұॹʹઓ͓͏ʂ
    Ͳ͏͍͏ͱ͖ʹ࢖͑Δͷʁ
    Λ͓͑ͯ͞ΈΑ͏ʂ
    

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44. 4DBMBͷྑ͍ͱ͜Ζ
    ܕ҆શ
    ؔ਺ܕ
    ฒྻɾ෼ࢄ
    

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45. ؔ਺ܕʹ͠ͳ͍ɺܕ҆શʹ͠ͳ͍
    ͱ͍͏ࣄ΋Ͱ͖·͢
    

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46. ࢖͍ํΛબͿࣄ͕Ͱ͖Δʂ
    

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47. ΍Γ͍ͨࣄʹ߹Θͤͯ
    ॊೈʹྗΛൃش
    

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48. ༐ऀλΠϓʂ
    

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49. ·ͱΊ
    جຊతͳ͜ͱ͓͑͞Α͏ʂ
    Α͋͘Δ࢖͍ํΛ͓͑͞Α͏ʂ
    ࢖͍ॴΛ͓͑͞Α͏ʂ
    

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50. ͜Θ͘ͳ͍Αʂ
    པΓʹͳΔ஥ؒͩΑʂ
    

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51. ͦͯ͠ͰΜͤͭ΁ʜ
    ͍ͤͪ͝ΐ͏͋Γ͕ͱ͏͍͟͝·ͨ͠
    

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