Ruby Under a Microscope を読んでみた （つまみぐい紹介編）

Ruby Under a Microscope 
を読んで面白かったので、一部の内容を社内勉強会「万葉究楽部」第四回で共有しました。

Transcript

1. Ruby Under a
   Microscope 

   ΛಡΜͰΈͨ
   ʢͭ·Έ͙͍঺հฤʣ
   ສ༿ڀָ෦ #4 2014.01.16

   ௗҪઇ @yotii23
   

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2. جຊॻࢽ৘ใ
   ஶऀɿPat Shaughnessy
   ग़൛ࣾɿno starch press
   ISBNɿ9781593275273
   O’REILLYɿ

   http://shop.oreilly.com/product/9781593275273.do
   

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3. ͲΜͳ಺༰ʁ
   "An Illustration Guide" 

   #=> ਤೖΓͰ
   "to Ruby Internals"

   #=> Rubyͷ಺෦࣮૷Λղઆʂ
   ͍ͭ΋ॻ͍͍ͯΔRubyͷίʔυ
   ͕ɺͲΜͳ෩ʹ࣮ߦ͞ΕΔͷ͔
   ΛɺCͷίʔυͳ͠ͰɺਤೖΓ
   Ͱղઆͯ͘͠ΕΔຊ
   Ruby 2.0ରԠ
   

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4. 1: Tokenization and ParsingʢίʔυΛύʔπʹόϥͯ͠ɺߏจΛղੳ͢Δʣ
   2: CompilationʢίϯύΠϧΑ͏͠ΒΜɺͱࢥͬͨΒKoichi Sasadaͷ໊લ͕ʣ
   3: How Ruby Executes Your CodeʢRuby͸Ͳ͏΍ͬͯ͜ͷίʔυΛ࣮ߦͯ͠Δͷ͔ʣ
   4: Control Structures and Method Dispatch ʢ੍ޚߏ଄ͱ͔ϝιουݺͼग़͠ͱ͔ʣ
   5: Objects and ClassesʢΦϒδΣΫτͱΫϥεɺͳɻ͋Εͳɻʣ
   6: Method Lookup and Constant Lookup ʢϝιου୳ࡧͱఆ਺୳ࡧʣ
   7: The Hash Table: The Workhorse of Ruby Internals

   ʢϋογϡςʔϒϧɺRuby಺෦ͷ͸ͨΒ͖Ϟϊʣ
   8: How Ruby Borrowed a Decades-Old Idea from Lisp

   ʢϒϩοΫ͸Rubyಠࣗͷಛ௃ͱ͔͡ΌͶ͔͑Βʂʣ
   9: Metaprogramming ʢࠇຐज़ʣ
   10: JRuby: Ruby on the JVM ʢJVMʣ, 11: Rubinius: Ruby Implemented with Ruby ʢRubiniusʣ 12: Garbage Collection in MRI,
   JRuby, and Rubinius ʢॲཧܥʹΑΔGC͍Ζ͍Ζʣ
   ໨࣍ͬ͟ͱݟ
   

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5. ΦϒδΣΫτͱΫϥε

   ɾΦϒδΣΫτͷ಺෦ߏ଄

   ɾΠϯελϯεม਺ͷ୳ࡧํ๏

   ɾΫϥεͷ಺෦ߏ଄
   Ϟδϡʔϧ: include, extend, prepend
   ຊ೔ͷͭ·Έ͙͍ϝχϡʔ
   

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6. ΦϒδΣΫτͱΫϥε
   

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7. ΦϒδΣΫτͷ಺෦ߏ଄
   จதఆٛ:
   “͢΂ͯͷRubyͷΦϒ
   δΣΫτ͸ɺΫϥε
   ϙΠϯλͱΠϯελ
   ϯεม਺ͷ഑ྻͷί
   ϯϏͰ͋Δ”
   ko1νΣοΫ:ϢʔβʔఆٛΫϥεͷ͜ͱɻ

   Πϯελϯεม਺഑ྻͷͳ͍ΦϒδΣΫτ΋͋Δ
   

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8. ΦϒδΣΫτͷ಺෦ߏ଄
   RObject :ΦϒδΣΫτߏ଄ମ
   RBasic: ΦϒδΣΫτͷجຊཁૉ
   flags:಺෦తͳ͍ΖΜͳਅِ஋ͳͲ
   klass:classΛࣔ͢ϙΠϯλ
   numiv:Πϯελϯεม਺ͷ਺
   ivptr:Πϯελϯεม਺ͷ഑ྻΛ
   ࣔ͢ϙΠϯλ
   

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9. ྫʣಉ͡Ϋϥεͷ̎ͭͷΦϒδΣΫτ
   class Mathematician
   attr_accesor :first_name
   attr_accesor :last_name
   end
   !
   euler = Mathematician.new
   euler.first_name = “Leonhard”
   euler.last_name = “Euler”
   !
   euclid = Mathematician.new
   euclid.first_name = “Euclid”
   RClass
   Mathematician
   RObject
   klass
   numiv: 2
   ivptr
   RObject
   klass
   numiv: 1
   ivptr
   Leonhard
   Euler
   Euclid
   

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10. δΣωϦοΫΦϒδΣΫτ

    simple ruby value
    String info… Array info…
    VALUE
    RSring
    flags
    klass
    RBasic
    VALUE
    RArray
    flags
    klass
    RBasic
    integer value Flags
    RObject δΣωϦοΫΦϒδΣΫτ
    FIXNUM_FLAG : 1
    simple ruby value
    RObject
    numiv
    ivptr
    VALUE
    flags
    klass
    RBasic
    ଞɺRRegexp ͳͲ૊ΈࠐΈͷ

    ΦϒδΣΫτ
    ଞɺsymbolͳͲ
    ୯७ͳ஋
    

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11. δΣωϦοΫΦϒδΣΫτͷ

    Πϯελϯεม਺
    > str = “ͳʹ͔จࣈྻ
    => “ͳʹ͔จࣈྻ”
    > str.instance_variables
    => [ ]
    > str.instance_variables_set(“@val1”, “value one”)
    => “value one”
    > str.instance_variables
    => [:@val1]
    RSring
    generic_iv_tbl
    “ͳʹ͔จࣈྻ”
    str => hash etc… etc…
    @val1 => “value 1” @val2 => “value 2”
    

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12. Πϯελϯεม਺ͷ୳͠ํ
    _ko1ઌੜߨٛϊʔτ
    value Flags
    valueͷflags ʹΑͬͯ

    ߏ଄ମΛ͔࣋ͭ൑ผ
    RObject
    δΣωϦοΫΦϒδΣΫτ
    simple ruby value
    ࣋ͨͳ͍
    RBasicͷflagsͰ
    δΣωϦοΫΦϒδΣΫτ͔൑ผ
    ࣋ͭ
    flags
    klass
    RBasic
    ࣗ෼ͷ஋Λkeyʹɺgeneric_iv_tblΛ୳͢
    ࣗ෼ͷclassͱivptr͔Β

    ୳͢
    

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13. genelic_iv_table͸஗͍
    _ko1ઌੜߨٛϊʔτ
    Object
    String
    Regexp
    

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14. ivptr
    (instance variables pointer)
    Ruby1.8 Ruby1.9
    RObject
    klass
    numiv: 2
    ivptr
    @val1 => “value 1” @val2 => “value 2”
    RClass
    RObject
    klass
    numiv: 2
    ivptr
    ”value 1” “value 2”
    @val1 => 0
    @val2 => 1
    

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15. ɹΈ͖ͯͨ͜ͱɿΦϒδΣΫτ
    ΦϒδΣΫτͷ಺෦ߏ଄

    ɾΫϥεϙΠϯλ

    ɾ͍͔ͭ͘ͷΦϒδΣΫτͷछྨͱߏ੒

    ɾΦϒδΣΫτม਺ͷΞΫηε
    

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16. Ϋϥεͷߏ଄
    จதఆٛɿ
    ”Ϋϥε͸ϝιουఆٛɺ
    attribute namesɺεʔύʔ
    Ϋϥε΁ͷϙΠϯλɺఆ
    ਺ςʔϒϧΛ࣋ͬͨRuby
    ͷΦϒδΣΫτͰ͋Δ”
    http://www.flickr.com/photos/22326055@N06/5220652648/sizes/m/
    

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17. Πϯελϯεϝιουͱ

    Πϯελϯεม਺໊
    DMBTT.BUIFNBUJDJBO
    EFGpSTU@OBNF
    !pSTU@OBNF
    FOE
    EFGpSTU@OBNF WBM
    
    !pSTU@OBNFWBM
    FOE
    EFGMBTU@OBNF
    !MBTU@OBNF
    FOE
    EFGMBTU@OBNF WBM
    
    !MBTU@OBNFWBM
    FOE
    FOE
    RClass
    flags
    klass
    RBasic
    method table
    first_name
    first_name=
    last_name
    last_name=
    attribute names
    @first_name
    @last_name
    Ruby͸Ϋϥε΋ΦϒδΣΫτʂ
    

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18. Ϋϥεͷܧঝ
    DMBTT.BUIFNBUJDJBO1FSTPO
    ҎԼུʣ
    Q.BUIFNBUJDJBODMBTT
    $MBTT
    Q.BUIFNBUJDJBOTVQFSDMBTT
    1FSTPO
    RClass
    RClass
    flags
    klass
    RBasic
    method table
    first_name
    first_name=
    last_name
    last_name=
    attribute names
    @first_name
    @last_name
    Class
    RClass
    Person
    super
    superclass:
    

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19. ΫϥεͷΠϯελϯεม਺ͱ
    Ϋϥεม਺
    DMBTT.BUIFNBUJDJBO
    !UZQFl(FOFSBMz
    EFGTFMGUZQF
    !UZQF
    FOE
    FOE
    !
    $MBTT4UBUJTUJDJBO.BUIFNBUJDJBO
    !UZQFl4UBUJTUJDTz
    FOE
    !
    QVUT4UBUJTUJDJBOUZQF
    ໰୊
    QVUT.BUIFNBUJDJBOUZQF
    ໰୊
    DMBTT.BUIFNBUJDJBO
    !!UZQFl(FOFSBMz
    EFGTFMGUZQF
    !!UZQF
    FOE
    FOE
    !
    $MBTT4UBUJTUJDJBO.BUIFNBUJDJBO
    !!UZQFl4UBUJTUJDTz
    FOE
    !
    QVUT4UBUJTUJDJBOUZQF
    ໰୊
    QVUT.BUIFNBUJDJBOUZQF
    ໰୊
    

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20. ΫϥεͷΠϯελϯεม਺ͱ
    Ϋϥεม਺
    DMBTT.BUIFNBUJDJBO
    !UZQFl(FOFSBMz
    EFGTFMGUZQF
    !UZQF
    FOE
    FOE
    !
    $MBTT4UBUJTUJDJBO.BUIFNBUJDJBO
    !UZQFl4UBUJTUJDTz
    FOE
    !
    QVUT4UBUJTUJDJBOUZQF
    l4UBUJTUJDTz
    QVUT.BUIFNBUJDJBOUZQF
    l(FOFSBMz
    DMBTT.BUIFNBUJDJBO
    !!UZQFl(FOFSBMz
    EFGTFMGUZQF
    !!UZQF
    FOE
    FOE
    !
    $MBTT4UBUJTUJDJBO.BUIFNBUJDJBO
    !!UZQFl4UBUJTUJDTz
    FOE
    !
    QVUT4UBUJTUJDJBOUZQF
    l4UBUJTUJDTz
    QVUT.BUIFNBUJDJBOUZQF
    l4UBUJTUJDTz
    

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21. ΫϥεͷΠϯελϯεม਺ͱ
    Ϋϥεม਺
    RClass
    ΫϥεϨϕϧ

    Πϯελϯεม਺:
    ˏtype
    @@type
    ͲͪΒ΋֨ೲ͞ΕΔςʔϒ
    ϧ͸Ұॹ
    ҧ͏ͷ͸ΞΫηεͷ࢓ํ
    

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22. ΫϥεͷΠϯελϯεม਺ͱ
    Ϋϥεม਺
    RClass: Mathematician
    ΫϥεϨϕϧΠϯελϯεม਺:
    “General”
    etc…
    DMBTT.BUIFNBUJDJBO
    !UZQFl(FOFSBMz
    FOE
    DMBTT4UBUJTUJDJBO
    !UZQFl4UBUJTUJDTz
    FOE
    RClass: Statistician
    ΫϥεϨϕϧΠϯελϯεม਺:
    “Statistics”
    etc…
    ΫϥεͷΠϯελϯεม਺ @type
    

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23. ΫϥεͷΠϯελϯεม਺ͱ
    Ϋϥεม਺
    RClass: Mathematician
    ΫϥεϨϕϧΠϯελϯεม਺:
    “General”
    etc…
    DMBTT4UBUJTUJDJBO
    !!UZQFl4UBUJTUJDTz
    FOE
    RClass: Statistician
    Ϋϥεม਺ @@type
    @@type͋Δʁ
    @@type͋Δʁ
    super
    ΫϥεϨϕϧΠϯελϯεม਺:
    

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24. ΫϥεͷΠϯελϯεม਺ͱ
    Ϋϥεม਺
    DMBTT4UBUJTUJDJBO
    !!UZQFl4UBUJTUJDTz
    FOE
    ΫϥεͷΠϯελϯεม਺ @@type
    @@typeͳ͍…
    @@type͋Δ!
    ॻ͖׵͑Δʂ
    RClass: Mathematician
    ΫϥεϨϕϧΠϯελϯεม਺:
    “Statistic”
    etc…
    RClass: Statistician
    super
    ΫϥεϨϕϧΠϯελϯεม਺:
    

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25. ࣮ࡍͷΫϥεͷ಺෦ߏ଄
    VALUE
    rb_classext_struct
    RClass
    RBasic
    flags
    klass
    m_tbl
    iv_index_tbl
    ptr
    super
    iv_tbl
    const_tbl
    origin
    refined_class
    allocator
    ΫϥεϙΠϯλ
    ϝιουςʔϒϧϙΠϯλ
    Πϯελϯεม਺໊ςʔϒϧ
    εʔύʔΫϥεϙΠϯλ
    ΫϥεϨϕϧΠϯελϯεม਺ɾΫϥεม਺
    ఆ਺ςʔϒϧ
    ৽͍͠ΦϒδΣΫτͷϝϞϦ֬อʹ࢖͏
    Module#prependʹ࢖͏
    refinementsʹ࢖͏
    

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26. Ϋϥεϝιου
    Ϋϥεϝιου͸Ͳ͜ʹఆ
    ٛ͞ΕΔʁ
    DMBTT.BUIFNBUJDJBO
    DMBTTTFMG
    EFGDMBTT@NFUIPE
    QVUTlDMBTTNFUIPEz
    FOE
    FOE
    FOE
    

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27. Ϋϥεϝιου
    RClass: Mathematician
    klass
    RClass: Class
    m_tbl
    “class_method”
    ?
    DMBTT"OPUIFS$MBTTFOE
    "OPUIFS$MBTTDMBTT@NFUIPE
    VOEFpOFENFUIPE
    lDMBTT@NFUIPEzʜ
    MathematicianΫϥε͸Class
    ΫϥεͷΦϒδΣΫτ

    =>Ϋϥεϝιου͸Class
    Ϋϥεʹఆٛ͞ΕΔ

    #=> false!
    

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28. Ϋϥεϝιου:Ϋϥεͷੜ੒
    0CKFDU4QBDFDPVOU@PCKFDUT<5@$-"44>
    
    DMBTT.BUIFNBUJDJBOFOE
    OJM
    0CKFDU4QBDFDPVOU@PCKFDUT<5@$-"44>
    ໰୊
    ObjectSpace.count_objects[:T_CLASS] … Ϋϥεͷ਺ΛΧ΢ϯτ͢Δ
    ໰୊ɿҰͭΫϥεΛ৽͘͠ੜ੒ͨ࣌͠ɺ

    Ϋϥεͷ૯਺͸͍ͭ͘૿͑Δ͔
    

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29. Ϋϥεϝιου:Ϋϥεͷੜ੒
    0CKFDU4QBDFDPVOU@PCKFDUT<5@$-"44>
    
    DMBTT.BUIFNBUJDJBOFOE
    OJM
    0CKFDU4QBDFDPVOU@PCKFDUT<5@$-"44>
    
    ౴͑ɿ+ 2
    ObjectSpace.count_objects[:T_CLASS] … Ϋϥεͷ਺ΛΧ΢ϯτ͢Δ
    

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30. Ϋϥεϝιου:Ϋϥεͷੜ੒
    RObject
    klass
    RClass: Mathematician RClass
    method tablel
    first_name=
    first_name
    last_name=
    last_name
    flags
    klass
    RBasic
    flags
    klass
    RBasic
    method table
    class_method
    Singleton_class
    
    RClass: Class
    m_tbl m_tbl
    

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31. Έ͖ͯͨ͜ͱ2ɿΫϥε
    Ϋϥεͷ಺෦ߏ଄

    ɾΠϯελϯεม਺ͱΠϯελϯεϝιου

    ɾܧঝͷsuper

    ɾΫϥεͷΠϯελϯεม਺ʗΫϥεม਺
    ΫϥεϝιουͱγϯάϧτϯΫϥε
    

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32. Ϟδϡʔϧ
    http://www.flickr.com/photos/glitchpunk/5320924205/sizes/m
    

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33. Ϟδϡʔϧͷ಺෦ߏ଄
    m_tbl
    VALUE
    RClass:module
    rb_classext_struct
    RBasic
    flags
    klass
    ptr
    super
    iv_tbl
    const_tbl
    origin
    ModuleͰ͔ͭΘͳ͍΋ͷ
    ɾiv_index_tbl: Πϯελϯεม਺໊ςʔϒϧɹɹ
    ɾallocator: ৽͍͠ΦϒδΣΫτͷϝϞϦ֬
    อ༻
    

    ※Ϟδϡʔϧ͸ΠϯελϯεΛ࡞Εͳ͍
    ※಺෦తʹ͸super͸࣋ͭ

    ʢ೚ҙͷsuperΛࢦఆ͢Δ͜ͱ͸ग़དྷͳ͍ʣ
    

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34. Ϋϥεܧঝؔ܎ͷϝιου୳ࡧॱ
    RClass: Mathematician
    super
    RClass: Person
    super
    DMBTT.BUIFNBUJDJBO1FSTPO
    FOE
    RClass: AnotherSClass
    super
    RClass: Object
    super
    1
    3
    2
    4
    

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35. Ϟδϡʔϧͷϝιου୳ࡧॱ
    RClass: Mathematician
    super
    RClass: Person
    super
    RClass: Object
    NPEVMF1SPGFTTPSFOE
    !
    DMBTT.BUIFNBUJDJBO1FSTPO
    JODMVEF1SPGFTTPS
    FOE
    RClass: AnotherSClass
    RClass: Professor
    super
    super
    1
    3
    2
    4
    5
    

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36. Ϟδϡʔϧ…includeͷ࣮૷
    RClass: Mathematician
    super
    RClass: Person
    super
    RClass: Professor
    RClass: AnotherSClass
    super
    RClass: Object
    super
    1
    3
    2
    4
    5
    RClass: Professor
    super
    inculde࣌ʹϞδϡʔϧͷίϐʔ͕
    Ϋϥεͱͯ͠࡞੒͞Εɺ
    ܧঝπϦʔʹࠩ͠ࠐ·ΕΔ
    super
    ίϐʔʂ (module)
    (class)
    

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37. 1ͭͷΫϥεʹೋͭͷϞδϡʔϧ
    DMBTT.BUIFNBUJDJBO1FSTPO
    JODMVEF1SPGFTTPS
    JODMVEF&NQMPZFF
    FOE
    RClass: Mathematician
    super
    RClass: Person
    super
    RClass: Professor
    1
    4
    2
    RClass: Professor
    ίϐʔʂ
    super
    RClass: Employee
    RClass: Employee
    super
    3
    

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38. ϞδϡʔϧΛΠϯΫϧʔυͨ͠

    Ϟδϡʔϧ
    NPEVMF1SPGFTTPS
    JODMVEF&NQMPZFF
    FOE
    RClass: Professor
    super
    RClass: Employee
    super
    RClass: Employee
    super
    ίϐʔʂ
    Ϟδϡʔϧͷsuper͕includeͨ͠

    ϞδϡʔϧͷίϐʔΫϥεΛࢦ͢
    

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39. ϞδϡʔϧΛΠϯΫϧʔυͨ͠

    ϞδϡʔϧͷΠϯΫϧʔυ
    NPEVMF1SPGFTTPS
    JODMVEF&NQMPZFF
    FOE
    DMBTT.BUIFNBUJDJBO1FSTPO
    JODMVEF1SPGFTTPS
    FOE
    RClass: Mathematician
    super
    RClass: Person
    super
    1
    4
    2
    ίϐʔʂ
    RClass: Professor
    super
    RClass: Employee
    super
    RClass: Professor
    super
    RClass: Employee
    super
    RClass: Employee
    super
    3
    

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40. Ϟδϡʔϧ…extendͷ࣮૷
    RObject:
    klass
    RClass: Person
    super
    1
    3
    2
    extend࣌ʹϞδϡʔϧͷίϐʔΫϥε͕

    ࡞੒͞ΕɺΦϒδΣΫτͷΫϥεʹͳΔ
    RClass: Professor
    RClass: Professor
    super super
    ίϐʔʂ (module)
    (class)
    RClass: Mathematician
    super
    NPEVMF1SPGFTTPSFOE
    DMBTT.BUIFNBUJDJBO1FSTPO
    FOE
    N.BUIFNBUJDJBOOFX
    NFYUFOE1SPGFTTPS
    

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41. Ϟδϡʔϧ…prepend
    (1. includeͰ͏·͘ߦ͔ͳ͍ྫ)
    NPEVMF1SPGFTPS
    EFGOBNF
    l1SPG\TVQFS^z
    FOE
    FOE
    !
    DMBTT.BUIFNBUJDJBO
    BUUS@BDDFTTPSOBNF
    JODMVEF1SPGFTTPS
    FOE
    !
    QPJODBSF.BUIFNBUJDBOOFX
    QPJODBSFOBNFl)FOSJ1PJODBSFz
    !
    QQPJODBSFOBNF
    l)FOSJ1PJODBSFz
    ˌinclude
    ”Prof.”͕͔ͭͳ͍
    RClass: Mathematician
    super
    RClass: Object
    super
    RClass: Professor
    super
    1
    2
    3
    attr_accessor: name
    def name
    “Prof. #{name}”
    end
    Mathematican͕ઌʹ୳͞ΕΔ

    …Professor ·Ͱ୳͞ͳ͍Ͱղܾ
    

    View Slide

42. Ϟδϡʔϧ…prepend
    ʢ̎.prependͰղܾͨ͠ྫʣ
    NPEVMF1SPGFTPS
    EFGOBNF
    l1SPG\TVQFS^z
    FOE
    FOE
    !
    DMBTT.BUIFNBUJDJBO
    BUUS@BDDFTTPSOBNF
    QSFQFOE1SPGFTTPS
    FOE
    !
    QPJODBSF.BUIFNBUJDBOOFX
    QPJODBSFOBNFl)FOSJ1PJODBSFz
    !
    QQPJODBSFOBNF
    l1SPG)FOSJ1PJODBSFz
    ˌprepend
    RClass: Mathematician
    super
    RClass: Object
    super
    RClass: Professor
    super
    1
    2
    3
    attr_accessor :name
    def name
    “Prof. #{name}”
    end
    Professor͕ઌʹ୳͞ΕΔ
    ٙ໰ɿpoincare͸MathematicianͷΦϒδΣΫτ

    Ͳ͏΍ͬͯܧঝπϦʔΛલʹ໭Δͷʁ
    

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43. Ϟδϡʔϧ…prependͷ࣮૷
    RClass: Mathematician
    super
    RClass: Oject
    super
    RClass: Professor
    super
    attr_accessor :name
    def name
    “Prof. #{name}”
    end
    RClass: Mathematician
    super
    origin
    #prepend͸

    1. Mathematican

    ͷίϐʔ(OriginΫϥεʣΛɺ

    ΠϯΫϧʔυ͞ΕͨϞδϡʔϧͷ

    εʔύʔΫϥεʹ͢Δɻ
    2. ΦϦδφϧͷΫϥεͷ

    શͯͷϝιουΛɺ

    OriginΫϥεʹҠ͢
    Original
    Origin
    

    View Slide

44. ໰୊: ΠϯΫϧʔυޙͷϞδϡʔϧ΁ͷ

    ϝιου௥Ճ
    NPEVMF1SPGFTPSFOE
    !
    DMBTT.BUIFNBUJDJBO
    JODMVEF1SPGFTTPS
    FOE
    !
    NPEVMF1SPGFTTPS
    EFGQSJNBSZ@DMBTTSPPN
    Ql"z
    FOE
    FOE
    !
    QPJODBSF.BUIFNBUJDJBOOFX
    !
    QPJODBSFQSJNBSZ@DMBTTSPPN
    ໰୊
    ΠϯΫϧʔυޙʹϞδϡʔϧΛ

    ࠶Φʔϓϯͯ͠ϝιουΛ௥Ճ
    No Method Error? or “A-101”?
    

    View Slide

45. ղ౴: ΠϯΫϧʔυޙͷϞδϡʔϧ΁ͷ

    ϝιου௥Ճ
    QPJODBSFQSJNBSZ@DMBTTSPPN
    l"z
    ΠϯΫϧʔυޙʹϞδϡʔϧʹ௥Ճ͞Εͨ

    ϝιου΋ݺͼग़ͤΔ

    ˎϝιουςʔϒϧͰ͸ͳ͘ɺ

    ϝιουςʔϒϧ΁ͷϙΠϯλΛίϐʔ͢ΔͨΊ
    method table
    primary_classroom
    RClass: Mathematician
    super ίϐʔʂ
    RClass: Professor
    super
    m_tbl
    RClass: Professor
    super
    m_tbl
    

    View Slide

46. Έ͖ͯͨ͜ͱ3ɿ Ϟδϡʔϧ
    Ϟδϡʔϧͷ಺෦ߏ଄
    include/extend/prepend ͷ࣮૷
    

    View Slide

47. ·ͱΊ
    Ruby Under a Microscope : 

    Rubyͷϝδϟʔͳͱ͜Ζͷ಺෦ߏ଄Λେ·͔ʹཧղ
    ͤͯ͘͞ΕΔྑ͍ຊ
    ʮ͜͏͍͏͜ͱΛ͢Δͱ͜ͷڍಈʹͳΔʯͷཧ༝͕
    ෼͔ΔͱRubyͱ஥ྑ͘ͳΕΔؾ͕͢Δ
    ͝঺հͨ͠ͷ͸΄ΜͷҰ෦Ͱ͢
    

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