多相型、推論、Ruby

Transcript

1. ଟ૬ܕɺ
   ਪ࿦ɺ
   Ruby দຊफଠ࿠
 @soutaro

2. None
3. None

4. ܕ͸ॻ͖ͨ͘ͳ͍

5. ܕ͸ॻ͖ͨ͘ͳ͍ Duck Typingʹͳ͍ͬͯͯཉ͍͠

6. ܕ͸ॻ͖ͨ͘ͳ͍ Duck Typingʹͳ͍ͬͯͯཉ͍͠ ܕਪ࿦

7. ܕ͸ॻ͖ͨ͘ͳ͍ Duck Typingʹͳ͍ͬͯͯཉ͍͠ ܕਪ࿦ typo͙Β͍͸࣮ߦ͠ͳͯ͘΋ൃݟ͍ͨ͠

8. ܕ͸ॻ͖ͨ͘ͳ͍ Duck Typingʹͳ͍ͬͯͯཉ͍͠ ܕਪ࿦ typo͙Β͍͸࣮ߦ͠ͳͯ͘΋ൃݟ͍ͨ͠ ܕ͸ઈରʹॻ͖ͨ͘ͳ͍

9. ܕ͸ॻ͖ͨ͘ͳ͍ Duck Typingʹͳ͍ͬͯͯཉ͍͠ ܕਪ࿦ typo͙Β͍͸࣮ߦ͠ͳͯ͘΋ൃݟ͍ͨ͠ ܕ͸ઈରʹॻ͖ͨ͘ͳ͍ Gradual Typing

10. ͳΜ͔ྑ͍ײ͡ʹܕ͕͍ͭͨ Ruby͕ཉ͍͠ ܕ͸ॻ͖ͨ͘ͳ͍ Duck Typingʹͳ͍ͬͯͯཉ͍͠ ܕਪ࿦ typo͙Β͍͸࣮ߦ͠ͳͯ͘΋ൃݟ͍ͨ͠ ܕ͸ઈରʹॻ͖ͨ͘ͳ͍ Gradual Typing

11. զʑ͕ཉ͍͠΋ͷ ͳΜ͔ྑ͍ײ͡ʹܕ͕͍ͭͨRuby͕ཉ͍͠ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby

12. ଟ૬ܕ w ύϥϝʔλଟ૬
    Parametric Polymorphism
    w ෦෼ܕଟ૬
    Subtyping Polymorphism w ΞυϗοΫଟ૬
    Ad-hoc Polymorphism

    จ຺ʹԠͯ͡ɺҰఆͷ੍ݶͷݩͰɺ
 ࣜʹ͍Ζ͍ΖͳܕΛ༩͑Δ

13. ෦෼ܕଟ૬ w ෦෼ܕ
 “String is a Object” interface X {

    void f(Object x); } X x = …; x.f("Ruby"); x.f(new ArrayList());

14. ෦෼ܕଟ૬ w ෦෼ܕ
 “String is a Object” interface X {

    void f(Object x); } X x = …; x.f("Ruby"); x.f(new ArrayList()); Ҿ਺ͷܕ͸String

15. ෦෼ܕଟ૬ w ෦෼ܕ
 “String is a Object” interface X {

    void f(Object x); } X x = …; x.f("Ruby"); x.f(new ArrayList()); Ҿ਺ͷܕ͸String Ҿ਺ͷܕ͸ArrayList

16. ໊લతɾߏ଄త w ໊લత
    Nominal
 ΫϥεఆٛͰએݴͯ͠෦෼ܕؔ܎Λఆٛ
    w ߏ଄త
    Structual
 ϝιουఆٛͷแؚؔ܎Ͱ෦෼ܕؔ܎ΛఆٛʢΑΓ ॊೈʣ

17. ܕਪ࿦ w ʢ׬શͳʣܕਪ࿦
    w ϩʔΧϧܕਪ࿦

18. ʢ׬શͳʣܕਪ࿦
    [Milner, 1978] w શ͘ܕΛॻ͔ͳͯ͘΋ྑ͍
 ʢܕਪ࿦ͷ׬શੑ
    Completenessʣ
    w ϓϩάϥϛϯάݴޠ΁ͷ੍໿͕େ͖͍ʢMLʣ # let

    has_even_leaf tree = exists_leaf (fun n -> n mod 2 = 0) tree;; val has_even_leaf : tree -> bool = <fun>

19. ϩʔΧϧܕਪ࿦
    [Pierce, 1997] w ϩʔΧϧม਺ͷܕ͸ॻ͔ͳͯ͘΋ྑ͍
 ϝιουͱ͔ͷܕ͸ॻ͘ɻ
    w ͍ΖΜͳϓϩάϥϛϯάݴޠʹಋೖͰ͖Δ
 ʢScala/Swift/C#/C++ʣ func

    greet(person: String) -> String { let greeting = "Hello, " + person + "!" return greeting }

20. ϩʔΧϧܕਪ࿦
    [Pierce, 1997] w ϩʔΧϧม਺ͷܕ͸ॻ͔ͳͯ͘΋ྑ͍
 ϝιουͱ͔ͷܕ͸ॻ͘ɻ
    w ͍ΖΜͳϓϩάϥϛϯάݴޠʹಋೖͰ͖Δ
 ʢScala/Swift/C#/C++ʣ func

    greet(person: String) -> String { let greeting = "Hello, " + person + "!" return greeting } greetingͷܕ͸ਪ࿦͞ΕΔ

21. ϩʔΧϧܕਪ࿦
    [Pierce, 1997] w ϩʔΧϧม਺ͷܕ͸ॻ͔ͳͯ͘΋ྑ͍
 ϝιουͱ͔ͷܕ͸ॻ͘ɻ
    w ͍ΖΜͳϓϩάϥϛϯάݴޠʹಋೖͰ͖Δ
 ʢScala/Swift/C#/C++ʣ func

    greet(person: String) -> String { let greeting = "Hello, " + person + "!" return greeting } greetingͷܕ͸ਪ࿦͞ΕΔ ؔ਺ͷܕ͸ॻ͘

22. զʑ͕ཉ͍͠΋ͷ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby ͳΜ͔ྑ͍ײ͡ʹܕ͕͍ͭͨRuby͕ཉ͍͠

23. OCamlͳΜ͔͍ۙͷͰ͸ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby # let f x

    = print_string x#to_s;; val f : < to_s : string; .. >
 -> unit = <fun>

24. OCamlͳΜ͔͍ۙͷͰ͸ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby # let f x

    = print_string x#to_s;; val f : < to_s : string; .. >
 -> unit = <fun> #Ͱϝιουݺͼग़͠

25. OCamlͳΜ͔͍ۙͷͰ͸ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby # let f x

    = print_string x#to_s;; val f : < to_s : string; .. >
 -> unit = <fun> to_sͱ͍͏ϝιου͕͋Ε͹ͳΜͰ΋͍͍ #Ͱϝιουݺͼग़͠

26. OCamlͰ͸μϝͳͱ͜Ζ w OCaml΋ΦϒδΣΫτͷपΓͰ͸ܕΛॻ͘ඞཁ͕ ͋Δ
    w OCamlͰ͸ॻ͚ͳ͍ϝιου
    w Array#map
    String#split

27. զʑ͕ཉ͍͠΋ͷ w ·ʔແཧ
 ͳʹ͔ΛఘΊͳ͍ͱ͍͚ͳ͍ɻ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby

28. զʑ͕ཉ͍͠΋ͷ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby

29. զʑ͕ཉ͍͠΋ͷ RubyͷػೳΛ੍ݶ͍ͯͬͯ͠ɺܕਪ࿦Ͱ͖ ΔΑ͏ʹͳΒͳ͍͔ʁʁ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby

30. eval w ແཧ
    w evalͷฦΓ஋ͷܕ͸anyΈ͍ͨͳܕʹͯ͠͠·͑͹ ͍͍ͷͰ͸ʢGradual Typing [Siek and Taha,

    2006]ʣ eval(gets)

31. ActiveRecord w DBʹ઀ଓ͠ͳ͍ͱΞτϦϏϡʔτ͕Θ͔Βͳ͍
    w anyͰͳΜͱ͔͠Α͏ class Person < ApplicationRecord belongs_to

    :group has_many :contacts end

32. ϝλϓϩάϥϛϯά define_method(:name=) do |x| @attributes[:name] = x end

33. ϝλϓϩάϥϛϯά class Location attr_reader :line attr_reader :column end

34. require w require͕࣮ߦ͞ΕΔॠؒ·ͰͲͷϓϩάϥϜ͕ಡ· ΕΔ͔Θ͔Βͳ͍
    w require͸ϝιουͳͷͰɺ࠶ఆٛͰ͖Δ͠ɺͲ͜ ʹͰ΋ॻ͚Δ͠ɺҾ਺ʹ͕ࣜॻ͚Δ
    w $LOAD_PATH΋͋ΔΑʂ
    w

    requireΛߏจʹͯ͠จࣈྻ͔͠ड͚औΕͳ͍ˍτο ϓϨϕϧʹ͔͠ॻ͚ͳ͍Α͏ʹ͢Ε͹ྑ͍ͷͰ͸

35. RubyGems ⚰Bundler

36. RubyΛ੍ݶͯ͠΋͏·͍͔͘ͳ͍ w ଞʹ΋໰୊͕͋Γɺݱ࣮తͳ੍ݶ͕ݟ͚ͭΒΕͳ͍ ʢࠓޙɺݟ͔ͭΔ͔΋͠Εͳ͍ʣ
    w ܕΛॻ͔ͳ͍લఏͰ͸ɺҰճanyʹࣦΘΕͨܕ৘ใ ΛऔΓ໭͢ํ๏͕ͳ͍

37. զʑ͕ཉ͍͠΋ͷ ύϥϝʔλଟ૬
    
    ߏ଄తͳ෦෼ܕଟ૬

    
    ׬શͳܕਪ࿦
    
    Ruby

38. ͝ఏҊ w ߏ଄తͳ෦෼ܕଟ૬
    
    ϩʔΧϧܕਪ࿦
    
    Gradual Typing
    w ʢΘΓͱʣDuck TypingͰ͖ΔͷͰخ͍͠
    w

    ॻ͔ͳͯ͘ྑ͍ܕ͸ॻ͔ͳ͍
    w ܕ͕ॻ͍ͯͳ͍ͱ͖͸ࠓͷRubyͱಉ͡
    w ܕͷͨΊͷݴޠ͸Rubyͱผ
 requireͱ͔ΦʔϓϯΫϥεͱ͔ϝλϓϩάϥϛϯάͱ ͔͸ߟ͑ͳ͍ɻ

39. ͍͍ͩͨTypeScript

40. # group.rbi interface String def gsub: (Regexp, String) -> String

    end interface IGroup def people: ActiveRecord.Association<IPerson> end interface IPerson def email: String end # foo_controller.rb group: IGroup = Group.create!(name: name) person = group.people.new escaped = person.email.map {|x| … }

41. # group.rbi interface String def gsub: (Regexp, String) -> String

    end interface IGroup def people: ActiveRecord.Association<IPerson> end interface IPerson def email: String end # foo_controller.rb group: IGroup = Group.create!(name: name) person = group.people.new escaped = person.email.map {|x| … } ผͷϑΝΠϧͰɺΠϯλʔϑΣΠεΛએݴ͢Δ

42. # group.rbi interface String def gsub: (Regexp, String) -> String

    end interface IGroup def people: ActiveRecord.Association<IPerson> end interface IPerson def email: String end # foo_controller.rb group: IGroup = Group.create!(name: name) person = group.people.new escaped = person.email.map {|x| … } ผͷϑΝΠϧͰɺΠϯλʔϑΣΠεΛએݴ͢Δ ΠϯλϑΣʔεʹϝιουͱܕΛએݴ͢Δ

43. # group.rbi interface String def gsub: (Regexp, String) -> String

    end interface IGroup def people: ActiveRecord.Association<IPerson> end interface IPerson def email: String end # foo_controller.rb group: IGroup = Group.create!(name: name) person = group.people.new escaped = person.email.map {|x| … } ผͷϑΝΠϧͰɺΠϯλʔϑΣΠεΛએݴ͢Δ ܕ஫ऍ ΠϯλϑΣʔεʹϝιουͱܕΛએݴ͢Δ

44. # group.rbi interface String def gsub: (Regexp, String) -> String

    end interface IGroup def people: ActiveRecord.Association<IPerson> end interface IPerson def email: String end # foo_controller.rb group: IGroup = Group.create!(name: name) person = group.people.new escaped = person.email.map {|x| … } ผͷϑΝΠϧͰɺΠϯλʔϑΣΠεΛએݴ͢Δ ܕ஫ऍ ӈลͷܕ͕Θ͔ΔͷͰɺܕ஫ऍ͸ෆཁ ΠϯλϑΣʔεʹϝιουͱܕΛએݴ͢Δ

45. # group.rbi interface String def gsub: (Regexp, String) -> String

    end interface IGroup def people: ActiveRecord.Association<IPerson> end interface IPerson def email: String end # foo_controller.rb group: IGroup = Group.create!(name: name) person = group.people.new escaped = person.email.map {|x| … } ผͷϑΝΠϧͰɺΠϯλʔϑΣΠεΛએݴ͢Δ ܕ஫ऍ ӈลͷܕ͕Θ͔ΔͷͰɺܕ஫ऍ͸ෆཁ person.emailͷܕ͕StringͩͱΘ ͔ΔͷͰɺmap͕ͳ͍͜ͱ͕Θ͔Δ ΠϯλϑΣʔεʹϝιουͱܕΛએݴ͢Δ

46. ܕ஫ऍ͕ͳ͚Ε͹͜Ε·ͰͷRubyͱಉ͡ group = Group.create!(name: name) person = group.people.new escaped =

    person.email.map {|x| … }

47. ܕ஫ऍ͕ͳ͚Ε͹͜Ε·ͰͷRubyͱಉ͡ group = Group.create!(name: name) person = group.people.new escaped =

    person.email.map {|x| … } ܕ஫ऍ͕ͳ͍ͷͰશ෦anyʹͳΔ
    
    Կ΋ݕࠪ͠ͳ͍

48. ܕ஫ऍ͕ͳ͚Ε͹͜Ε·ͰͷRubyͱಉ͡ group = Group.create!(name: name) person = group.people.new escaped =

    person.email.map {|x| … } map͕ແ͍͜ͱ͸࣮ߦ࣌ʹൃ֮ ܕ஫ऍ͕ͳ͍ͷͰશ෦anyʹͳΔ
    
    Կ΋ݕࠪ͠ͳ͍

49. # group.rbi interface String def gsub: (Regexp, String) -> String

    ... end interface IGroup def people: ActiveRecord.Association<IPerson> end interface IPerson def email: String end # foo_controller.rb group: IGroup = Group.create!(name: name) person = group.people.new escaped = person.email.map {|x| … }

50. – Rubyͷ෕
    Matz lܕ͸ઈରॻ͖ͨ͘ͳ͍z

51. w Group.create!ͷܕ͕GroupʹͳΔͷ͸Θ͔Βͳ͍ͷʁ
 Groupͷܕ͕Θ͔ΔͱࢥͬͯΔͷʁʁ
    w ܕΛҰͭ΋ॻ͍͍ͯͳ͍ͱͳʹ΋Θ͔Βͳ͍ͷʁʁ
 ϦςϥϧͳΜ͔͸Θ͔Δ͸ͣɻҙ֎ͱ͍Ζ͍Ζݟ͔ͭΔͷͰ͸ɻ
    w Ϋϥεఆٛʹ͸ܕΛॻ͚ͳ͍ͷʁΦʔϓϯΫϥε͸Ͳ͏ͳΔͷʁ
 ࠓޙͷ՝୊ɻΦʔϓϯΫϥεͱ0CKFDUJWF
    $ͷ$BUFHPSZͳΜ͔ ͸͍ۙؾ͕͢Δɻ
    

    w ࣮૷͸ͳ͍ͷʁ
 Α͘ݟΔͱɺʢܕ஫ऍΛίϝϯτͱ͔Ͱॻ͘͜ͱʹ͢Ε͹ʣ͙͢ ʹ࣮૷Ͱ͖Δͳ͜Εʜʜ