事前知識なしで理解する、静的検査のいろは / Introduction about static analysis without previous knowledge

私は Vim script の静的検査ツール「Vint」の開発者です。この発表では、Vint の開発を通じて学んだ静的検査ツールの仕組みと経験則を、事前知識のない方でも理解できるように詳解します。

この発表で触れるさまざまな基礎技術は、静的検査はもちろん、メタプログラミングやトランスパイラ、独自プログラミング言語の開発にも役立つ重要なものです。これらを技術の引き出しとして覚えておけば、今後の開発体験を豊かにしてくれることでしょう。

https://builderscon.io/tokyo/2018/session/0a3ee8c0-44ce-4cb9-9199-05b350887d79

Transcript

1. ੩తݕࠪͷ͍Ζ͸
   ࣄલ஌ࣝͳ͠Ͱཧղ͢Δ
   Kuniwak - DeNA Co.,Ltd.
   
   2018.09.07 builderscon tokyo 2018
   

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2. "CPVUNF
   

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3. ,VOJXBL
   w ॴଐˠ
   w HJUIVCDPN,VOJXBL
   w RJJUBDPN,VOJXBL
   w ίϯϐϡʔλαΠΤϯεΛ

   ֶΜͰ͖͍ͯ·ͤΜ
   w ࣄલ஌ࣝͳ͠Ͱ੩తղੳ

   πʔϧΛ։ൃ͖ͯͨ͠
   

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4. ͜Ε·Ͱʹ͖ͭͬͯͨ͘

   ੩తݕࠪܥͷπʔϧͷ঺հ
   

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5. 7JNTDSJQUͷ੩తݕࠪπʔϧ
   https://github.com/Kuniwak/Vint
   

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6. $44ͷมߋ఺ΛՄࢹԽ͢Δπʔϧ
   https://github.com/mixi-inc/css-semdiff
   $ css-astdiff a.css b.css --verbose
   extra:
   .extra-1 {
   border: none;
   }
   missing:
   .missing-1 {
   border: none;
   }
   ---------------------------------
   1 extra rules and 1 missing rules
   

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7. मਖ਼ͷӨڹൣғΛڭ͑ͯ͘ΕΔπʔϧ
   https://twitter.com/orga_chem/status/674847225684475905
   ˞લ৬
   

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8. ͜ͷൃදΛฉ͘ͱ

   Θ͔Δ͜ͱ
   ͸͡Ίʹ
   

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9. ੩తղੳΛߏ੒͢Δ͍͔ͭ͘ͷߟ͑ํ
   ͕Θ͔ΔΑ͏ʹͳΔ
   ߟ͑ํ͑͞ཧղͰ͖Ε͹ɺ੩తղੳΛ

   ࣮૷͢Δͷ͸೉͘͠ͳ͍͜ͱ͕Θ͔Δ
   

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10. ΋͏ͪΐͬͱ۩ମతʹ
    ͜ͷൃදͷ໨ඪ
    

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11. if isEmpty('') {
    //CATCH_ME_IF_YOU_CAN
    }
    CATCH_ME_IF_YOU_CANͱॻ͔Εͨੜҙؾͳ

    ίϝϯτʢจࣈྻ಺ͷ͸/(ʣΛݕ஌͢Δ

    ੩తݕࠪΛ៉ྷʹ࣮૷Ͱ͖ΔΑ͏ʹͳΔ
    

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12. ؆୯͗͢ͳ͍ʁͱ

    ࢥͬͨ͋ͳͨ΁
    

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13. ಉ͡ϓϩάϥϜͰ࣍ͷίʔυ΋

    ղੳͰ͖·͔͢ʁ
    fake('', ' //CATCH_ME_IF_YOU_CAN ↩︎
    ')
    ͜Ε͸จࣈྻͳͷͰݕ஌ͯ͠͸͍͚ͳ͍
    ͜ͷվߦ͸ҙਤతͰ͢
    

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14. ͜ͷൃදͰ͸ɺҙ஍ѱͳέʔεʹ΋

    ରԠͰ͖Δ੩తղੳΛઆ໌͠·͢
    

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15. ੩తղੳͱ͸
    Ͱ͸ͬͦ͘͞
    

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16. ੩తݕࠪͱ͸ɺݕ͍ࠪͨ͠ϓϩάϥϜΛ

    ࣮ߦ͠ͳ͍··֤छͷҟৗΛݕࠪ͢Δख๏ͷ͜ͱ
    ݴޠ͝ͱʹ༷ʑͳ੩తݕࠪͷͨΊͷπʔϧ͕͋Δɿ
    w 1ZUIPOͳΒ1ZqBLFT΍NZQZͳͲ
    w 3VCZͳΒ3VCPDPQͳͲ
    w +BWB4DSJQUͳΒ&4-JOUͳͲ
    w +BWBͳΒ4QPU#VHTͳͲ
    

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17. ͜͜Ͱٙ໰
    ͳͥ੩తʹݕ͍ࠪͨ͠ͷ͔
    

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18. ݕ͍ࠪͨ͠ϓϩάϥϜΛ࣮ߦͯ͠ʢಈతʣ

    ݕࠪ͢Δ৔߹ɺݕࠪதʹ௨ա͍ͯ͠ͳ͍

    ίʔυ͸ݕࠪͰ͖ͳ͍
    isFoo = true
    if isFoo {
    }
    else {
    }
    ͪ͜Β͸ಈతʹݕࠪͰ͖Δ
    ͪ͜Β͸ಈతʹݕࠪͰ͖ͳ͍
    

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19. ੩తݕࠪ͸ಈతݕ͕ࠪۤखͳ

    ໢ཏతͳݕ͕ࠪಘҙ
    ͔͠͠੩తݕࠪ͸ಈతݕࠪ΄Ͳ

    ݕࠪ݁Ռ͕ਖ਼֬ʹͳΒͳ͍
    

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20. ੩తݕࠪΛ஌Δ͜ͱͰ

    ։ൃΛޮ཰ԽͰ͖Δཧ༝
    ͳΜͷ໾ʹཱͭͷ͔ٙ໰ͳ͋ͳͨ΁
    

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21. 
    
    ίʔυϨϏϡʔͷҰ෦Λ

    ࣗಈԽͰ͖ΔΑ͏ʹͳΔ
    ศརͳࣾ಺πʔϧΛͭͬͯ͘

    ͋Γ͕͕ͨΒΕΔ
    طଘͷ੩తղੳπʔϧΛվྑɾ

    σόοάͰ͖ΔΑ͏ʹͳΔ
    
    

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22. ίʔυϨϏϡʔࣗಈԽͷྫ
    http://alpha.mixi.co.jp/entry/2015/12/20/000000
    $ css-astdiff a.css b.css --verbose
    extra:
    .extra-1 {
    border: none;
    }
    missing:
    .missing-1 {
    border: none;
    }
    ---------------------------------
    1 extra rules and 1 missing rules
    ߦͷ$44Λ

    ো֐θϩͰ-FTT΁

    Ҡߦͨ͠ࡍͷπʔϧ
    

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23. ศརͳࣾ಺πʔϧʢʁʣͷྫ
    https://twitter.com/orga_chem/status/674847225684475905
    ऍ໌
    WJTVBMJ[BUJPO͸ఘΊ·͕ͨ͠ɺ

    ґଘΛҰཡͰݟΒΕΔαʔϏε

    ͭͬͨ͘Βศརʹ࢖ΘΕ·ͨ͠
    

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24. શମతͳઆ໌ͷྲྀΕ
    ͜Ε͔Βͷ
    

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25. ֓೦Λཧղ͢Δ
    ந৅ߏจ໦Λཧղ͢Δ
    ந৅ߏจ໦ͷ࡞ΓํΛཧղ͢Δ
    ந৅ߏจ໦ͷѻ͍ํΛཧղ͢Δ
    ࡞ΓํΛཧղ͢Δ
    ؆୯ͳ੩తղੳΛ࣮૷͢Δ
    ੩తղੳͷσβΠϯύλʔϯΛ஌Δ
    ࣮ࡍͷ੩తղੳΛಡΉ
    

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26. ந৅ߏจ໦Λཧղ͢Δ
    ·ͣ͸
    

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27. ੩తݕࠪͰऔΓѻ͏୅දతͳ

    σʔλͷछྨ͸͍͔ͭ͋͘Δ
    

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28. ந৅ߏจ໦
    ίʔυΛ໦ߏ଄Ͱදݱͨ͠΋ͷ
    ଟ͘ͷ੩తղੳͷجຊ
    τʔΫϯྻ
    ίʔυͷখ͞ͳߏ੒୯ҐΛ

    ग़ݱॱʹฒ΂ͨ΋ͷ
    ελΠϧʹؔ͢Δ੩తղੳͰ

    Α͘࢖ΘΕΔ
    ੍ޚϑϩʔάϥϑ
    ίʔυͷ৚݅෼ذͳͲͷ

    ੍ޚߏ଄Λ࿈݁ͨ͠ϒϩοΫͰ

    දݱͨ͠΋ͷ
    ίʔϧάϥϑ
    ؔ਺ͷݺͼग़ؔ͠܎ΛάϥϑͰ

    දݱͨ͠΋ͷ
    ະ࢖༻ؔ਺ͷղੳͳͲʹΑ͘

    ࢖ΘΕΔ
    

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29. τʔΫϯྻ
    ίʔυͷখ͞ͳߏ੒୯ҐΛ

    ग़ݱॱʹฒ΂ͨ΋ͷ
    ελΠϧʹؔ͢Δ੩తղੳͰ

    Α͘࢖ΘΕΔ
    ੍ޚϑϩʔάϥϑ
    ίʔυͷ৚݅෼ذͳͲͷ

    ੍ޚߏ଄Λ࿈݁ͨ͠ϒϩοΫͰ

    දݱͨ͠΋ͷ
    ίʔϧάϥϑ
    ؔ਺ͷݺͼग़ؔ͠܎ΛάϥϑͰ

    දݱͨ͠΋ͷ
    ະ࢖༻ؔ਺ͷղੳͳͲʹΑ͘

    ࢖ΘΕΔ
    ந৅ߏจ໦
    ίʔυΛ໦ߏ଄Ͱදݱͨ͠΋ͷ
    ଟ͘ͷ੩తղੳͷجຊ ࠓճղઆ͢Δ΋ͷ
    

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30. if isEmpty('') {
    // COMMENT
    }
    1SPHSBN
    *G4UBUFNFOU
    4USJOH-JUFSBM
    'VOD$BMM
    *EFOUJpFS
    $PNNFOU
    ந৅ߏจ໦
    ίʔυ
    

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31. if isEmpty('') {
    // COMMENT
    }
    ந৅ߏจ໦
    ίʔυ
    ˞4UBUFNFOU͸ʮจʯͷҙຯͳͷͰɺ*G4UBUFNFOU͸ʮJGจʯͷҙຯͰ͢
    1SPHSBN
    4USJOH-JUFSBM
    'VOD$BMM
    *EFOUJpFS
    $PNNFOU
    *G4UBUFNFOU
    

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32. if isEmpty('') {
    // COMMENT
    }
    1SPHSBN
    *G4UBUFNFOU
    4USJOH-JUFSBM
    *EFOUJpFS
    $PNNFOU
    'VOD$BMM
    ந৅ߏจ໦
    ίʔυ
    

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33. if isEmpty('') {
    // COMMENT
    }
    1SPHSBN
    *G4UBUFNFOU
    4USJOH-JUFSBM
    'VOD$BMM $PNNFOU
    *EFOUJpFS
    ந৅ߏจ໦
    ίʔυ
    

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34. if isEmpty('') {
    // COMMENT
    }
    1SPHSBN
    *G4UBUFNFOU
    'VOD$BMM
    *EFOUJpFS
    $PNNFOU
    4USJOH-JUFSBM
    ந৅ߏจ໦
    ίʔυ
    

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35. if isEmpty('') {
    // COMMENT
    }
    1SPHSBN
    *G4UBUFNFOU
    4USJOH-JUFSBM
    'VOD$BMM
    *EFOUJpFS
    $PNNFOU
    ந৅ߏจ໦
    ίʔυ
    

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36. if isEmpty('') {
    // COMMENT
    }
    ந৅ߏจ໦
    *G4UBUFNFOU
    4USJOH-JUFSBM
    'VOD$BMM
    *EFOUJpFS
    $PNNFOU
    1SPHSBN
    ίʔυ
    

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37. if isEmpty('') {
    // COMMENT
    }
    1SPHSBN
    *G4UBUFNFOU
    4USJOH-JUFSBM
    'VOD$BMM
    *EFOUJpFS
    $PNNFOU
    ந৅ߏจ໦
    ίʔυ
    ந৅ߏจ໦͸ɺίʔυͷߏ଄Λ

    ໦ߏ଄ͷσʔλͱͯ͠දݱͨ͠΋ͷ
    

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38. ໦ߏ଄Ͱ͸1SPHSBN΍

    $PNNFOUͷΑ͏ͳ

    ໦Λߏ੒͢Δઅ఺ͷ͜ͱΛ

    ʮϊʔυʯͱݺͿ
    1SPHSBN
    *G4UBUFNFOU
    4USJOH-JUFSBM
    'VOD$BMM
    *EFOUJpFS
    $PNNFOU
    

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39. ࣮ࡍͷϝδϟʔͳݴޠͷ

    ந৅ߏจ໦ΛݟͯΈΑ͏
    ந৅ߏจ໦͸ͳΜͱͳ͘Θ͔ͬͨͷͰ
    

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40. ϝδϟʔͳݴޠͷந৅ߏจ໦͸

    ҙ֎ͱ؆୯ʹΈΒΕΔ
    ݴޠʹΑͬͯ͸ඪ४ϥΠϒϥϦ͚ͩͰ

    ந৅ߏจ໦ΛΈΒΕͨΓ͢Δ
    

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41. 1ZUIPOͷந৅ߏจ໦ͷݟํ
    import ast
    source = "if is_empty(''):\n" \
    " pass\n"
    node = ast.parse(source, "sample.py")
    print(ast.dump(node))
    

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42. if is_empty(''):
    pass
    ந৅ߏจ໦
    1ZUIPO
    Module(
    body=[
    If(
    test=Call(
    func=Name(
    id='is_empty',
    ctx=Load()
    ),
    args=[
    Str(s='')
    ],
    keywords=[]
    ),
    body=[
    Pass()
    ],
    orelse=[]
    )
    ]
    )
    

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43. if is_empty(''):
    pass
    ந৅ߏจ໦
    1ZUIPO
    Module(
    body=[
    If(
    test=Call(
    func=Name(
    id='is_empty',
    ctx=Load()
    ),
    args=[
    Str(s='')
    ],
    keywords=[]
    ),
    body=[
    Pass()
    ],
    orelse=[]
    )
    ]
    )
    

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44. if is_empty(''):
    pass
    ந৅ߏจ໦
    1ZUIPO
    Module(
    body=[
    If(
    test=Call(
    func=Name(
    id='is_empty',
    ctx=Load()
    ),
    args=[
    Str(s='')
    ],
    keywords=[]
    ),
    body=[
    Pass()
    ],
    orelse=[]
    )
    ]
    )
    

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45. if is_empty(''):
    pass
    ந৅ߏจ໦
    1ZUIPO
    Module(
    body=[
    If(
    test=Call(
    func=Name(
    id='is_empty',
    ctx=Load()
    ),
    args=[
    Str(s='')
    ],
    keywords=[]
    ),
    body=[
    Pass()
    ],
    orelse=[]
    )
    ]
    )
    

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46. if is_empty(''):
    pass
    ந৅ߏจ໦
    1ZUIPO
    Module(
    body=[
    If(
    test=Call(
    func=Name(
    id='is_empty',
    ctx=Load()
    ),
    args=[
    Str(s='')
    ],
    keywords=[]
    ),
    body=[
    Pass()
    ],
    orelse=[]
    )
    ]
    )
    

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47. if is_empty(''):
    pass
    ந৅ߏจ໦
    1ZUIPO
    Module(
    body=[
    If(
    test=Call(
    func=Name(
    id='is_empty',
    ctx=Load()
    ),
    args=[
    Str(s='')
    ],
    keywords=[]
    ),
    body=[
    Pass()
    ],
    orelse=[]
    )
    ]
    )
    

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48. 3VCZͷந৅ߏจ໦ͷݟํ
    require 'ripper'
    require 'pp'
    example = <if is_empty('')
    end
    END
    pp Ripper.sexp(example)
    

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49. ந৅ߏจ໦
    3VCZ
    [:program,
    [
    [:if,
    [:method_add_arg,
    [:fcall,
    [:@ident,
    "is_empty",
    [1, 3]
    ]
    ],
    [:arg_paren,
    [:args_add_block,
    [[:string_literal, [:string_content]]],
    false
    ]
    ]
    ],
    [[:void_stmt]],
    nil
    ]
    ]
    ]
    if is_empty('')
    end
    

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50. [:program,
    [
    [:if,
    [:method_add_arg,
    [:fcall,
    [:@ident,
    "is_empty",
    [1, 3]
    ]
    ],
    [:arg_paren,
    [:args_add_block,
    [[:string_literal, [:string_content]]],
    false
    ]
    ]
    ],
    [[:void_stmt]],
    nil
    ]
    ]
    ]
    ந৅ߏจ໦
    3VCZ
    if is_empty('')
    end
    

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51. [:program,
    [
    [:if,
    [:method_add_arg,
    [:fcall,
    [:@ident,
    "is_empty",
    [1, 3]
    ]
    ],
    [:arg_paren,
    [:args_add_block,
    [[:string_literal, [:string_content]]],
    false
    ]
    ]
    ],
    [[:void_stmt]],
    nil
    ]
    ]
    ]
    ந৅ߏจ໦
    3VCZ
    if is_empty('')
    end
    

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52. [:program,
    [
    [:if,
    [:method_add_arg,
    [:fcall,
    [:@ident,
    "is_empty",
    [1, 3]
    ]
    ],
    [:arg_paren,
    [:args_add_block,
    [[:string_literal, [:string_content]]],
    false
    ]
    ]
    ],
    [[:void_stmt]],
    nil
    ]
    ]
    ]
    ந৅ߏจ໦
    3VCZ
    if is_empty('')
    end
    

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53. [:program,
    [
    [:if,
    [:method_add_arg,
    [:fcall,
    [:@ident,
    "is_empty",
    [1, 3]
    ]
    ],
    [:arg_paren,
    [:args_add_block,
    [[:string_literal, [:string_content]]],
    false
    ]
    ]
    ],
    [[:void_stmt]],
    nil
    ]
    ]
    ]
    ந৅ߏจ໦
    3VCZ
    if is_empty('')
    end
    

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54. +BWB4DSJQUͷந৅ߏจ໦ͷݟํ
    import {default as Esprima} from "esprima";
    const program = "if (isEmpty('')) {\n"
    + "}\n";
    const node = Esprima.parseScript(program);
    console.log("%j", node);
    

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55. ந৅ߏจ໦
    +BWB4DSJQU
    {
    "type": "Program",
    "body": [
    {
    "type": "IfStatement",
    "test": {
    "type": "CallExpression",
    "callee": {
    "type": "Identifier",
    "name": "isEmpty"
    },
    "arguments": [
    {
    "type": "Literal",
    "value": "",
    "raw": "''"
    }
    ]
    },
    "consequent": {
    "type": "BlockStatement",
    "body": []
    },
    "alternate": null
    }
    ],
    "sourceType": "script"
    }
    if (isEmpty('')) {
    }
    

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56. ந৅ߏจ໦
    +BWB4DSJQU
    {
    "type": "Program",
    "body": [
    {
    "type": "IfStatement",
    "test": {
    "type": "CallExpression",
    "callee": {
    "type": "Identifier",
    "name": "isEmpty"
    },
    "arguments": [
    {
    "type": "Literal",
    "value": "",
    "raw": "''"
    }
    ]
    },
    "consequent": {
    "type": "BlockStatement",
    "body": []
    },
    "alternate": null
    }
    ],
    "sourceType": "script"
    }
    if (isEmpty('')) {
    }
    

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57. ந৅ߏจ໦
    +BWB4DSJQU
    if (isEmpty('')) {
    }
    {
    "type": "Program",
    "body": [
    {
    "type": "IfStatement",
    "test": {
    "type": "CallExpression",
    "callee": {
    "type": "Identifier",
    "name": "isEmpty"
    },
    "arguments": [
    {
    "type": "Literal",
    "value": "",
    "raw": "''"
    }
    ]
    },
    "consequent": {
    "type": "BlockStatement",
    "body": []
    },
    "alternate": null
    }
    ],
    "sourceType": "script"
    }
    

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58. ந৅ߏจ໦
    +BWB4DSJQU
    if (isEmpty('')) {
    }
    {
    "type": "Program",
    "body": [
    {
    "type": "IfStatement",
    "test": {
    "type": "CallExpression",
    "callee": {
    "type": "Identifier",
    "name": "isEmpty"
    },
    "arguments": [
    {
    "type": "Literal",
    "value": "",
    "raw": "''"
    }
    ]
    },
    "consequent": {
    "type": "BlockStatement",
    "body": []
    },
    "alternate": null
    }
    ],
    "sourceType": "script"
    }
    

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59. ந৅ߏจ໦
    +BWB4DSJQU
    {
    "type": "Program",
    "body": [
    {
    "type": "IfStatement",
    "test": {
    "type": "CallExpression",
    "callee": {
    "type": "Identifier",
    "name": "isEmpty"
    },
    "arguments": [
    {
    "type": "Literal",
    "value": "",
    "raw": "''"
    }
    ]
    },
    "consequent": {
    "type": "BlockStatement",
    "body": []
    },
    "alternate": null
    }
    ],
    "sourceType": "script"
    }
    if (isEmpty('')) {
    }
    

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60. ந৅ߏจ໦ͷ·ͱΊ
    w ந৅ߏจ໦͸ϓϩάϥϜΛ໦ߏ଄Ͱදݱͨ͠΋ͷ
    w ଟ͘ͷ੩తղੳʹந৅ߏจ໦͕ొ৔͢Δ
    w ϝδϟʔͳݴޠͰ͋Ε͹؆୯ʹΈΒΕΔ
    

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61. ந৅ߏจ໦Λͭ͘Δ

    ߏจղੳΛ஌Ζ͏
    ந৅ߏจ໦Λ׬શʹཧղͨ͠ͷͰ
    

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62. ϓϩάϥϜͷςΩετ͔Βந৅ߏจ໦Λ

    ࡞੒͢ΔॲཧΛߏจղੳͱݺͿ
    ߏจղੳΛ஌Δͱɺطଘͷߏจղੳ

    ϥΠϒϥϦΛ࢖͏ͱ͖ͷ஫ҙ఺͕Θ͔Δ
    ͨͱ͑͹ɺੑೳྼԽ͠΍͍͢෦෼ͳͲ͕Θ͔Δ
    

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63. ߏจղੳͷ୅දత࣮૷ख๏
    w ࠶ؼԼ߱๏
    w όοΫτϥοΫ͋Γ
    w ૉ௚ͳ࣮૷
    w 1BSTFS$PNCJOBUPS
    w 1BSTFS&YQSFTTJPO(SBNNBS
    w όοΫτϥοΫͳ͠
    w ʜ
    w ԋࢉࢠॱҐ๏
    w ʜ
    ࠓճղઆ͢Δ࣮૷
    

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64. ͪΌΜͱͨ͠ఆٛ͸೉͘͠ฉ͑͜Δ͕ɺ

    ࣮ࡍͷίʔυΛΈΕ͹͙͢ʹཧղͰ͖Δ
    श͏ΑΓ׳ΕΑ͏
    

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65. จ๏نଇͷ঺հ
    ࠓ͔ΒߏจղੳΛ࣮૷͢Δ
    

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66. := * EOF
    := | |
    := "if " " {\n" * "}" "\n"
    := "\n"
    := "//" [A-Z_ ]* "\n"
    := |
    := "'" ("\'" | [A-Z_ ])* "'"
    := "(" ")"
    := [a-z] [a-z]*
    ͜ͷ··ͩͱΘ͔ΓͮΒ͍ͷͰɺ۩ମྫΛग़͠·͢
    

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67. ίϝϯτ͚ͩϓϩάϥϜ
    // COMMENT ↩︎
    EOF
    &0'͸ϑΝΠϧͷऴྃʢ&OEPG'JMFʣΛҙຯ͢Δه߸
    

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68. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    ͔͜͜ΒݟΔ
    // COMMENT ↩︎
    EOF
    

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69. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    จͷ܁Γฦ͠ʹଓ͍ͯ&0'͕͘Δ
    // COMMENT ↩︎
    EOF
    

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70. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    จͷத਎Λݟʹ͍͘
    // COMMENT ↩︎
    EOF
    

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71. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    จ͸͜ͷ͏ͪͷͲΕ͔ͭ
    // COMMENT ↩︎
    EOF
    

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72. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    ࠓճͷจ͸ίϝϯτจ
    // COMMENT ↩︎
    EOF
    

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73. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτจͷத਎Λݟʹ͍͘
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    // COMMENT ↩︎
    EOF
    

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74. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ʹଓ͍ͯӳେจࣈͱ@ͱۭന͕Կճ͔ଓ͍ͯɺվߦͰऴΘΔ
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    // COMMENT ↩︎
    EOF
    

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75. // COMMENT ↩︎
    EOF
    := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    

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76. // COMMENT ↩︎
    EOF
    := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    ίʔυͱͷରԠ͕Ͱ͖ͨΒɺݟͨॱ൪ΛٯʹḪ͍ͬͯ͘
    

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77. // COMMENT ↩︎
    EOF
    := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    จ΋ίϝϯτจͰରԠ͕औΕͨͷͰḪΔ
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    

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78. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    // COMMENT
    EOF
    ࠓճͷจ͸ճ܁Γฦ͚ͩ͠Ͱɺத਎͸ίϝϯτจ
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    

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79. := * EOF
    := | |
    := "//" [A-Z_ ]* "\n"
    // COMMENT
    EOF
    ࠷ޙ͸&0'ͰऴΘΔ
    ίϝϯτ͚ͩϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    

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80. ͜͜·ͰಡΊΕ͹ɺଞͷίʔυͷ

    จ๏نଇ΋ಡΊΔΑ͏ʹͳΔ
    

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81. print("TEXT")
    EOF
    ؔ਺ݺͼग़͚ͩ͠ϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    := * EOF
    := | |
    := "\n"
    := |
    := "(" ")"
    := [a-z] [a-z]*
    

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82. print("TEXT")
    EOF
    ؔ਺ݺͼग़͚ͩ͠ϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    := * EOF
    := | |
    := "\n"
    := |
    := "(" ")"
    := [a-z] [a-z]*
    ಉ͡Α͏ʹݟ͍͖ͯ·͠ΐ͏
    

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83. print("TEXT")
    EOF
    ؔ਺ݺͼग़͚ͩ͠ϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    := * EOF
    := | |
    := "\n"
    := |
    := "(" ")"
    := [a-z] [a-z]*
    

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84. EOF
    ۭͷϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    := * EOF
    ࣮͸͜Ε΋จ๏نଇ্͸ଥ౰ͳϓϩάϥϜ
    

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85. EOF
    ۭͷϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    := * EOF
    ܁Γฦ͠ճ
    

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86. ෆਖ਼ͳϓϩάϥϜ΋ΈͯΈΑ͏
    

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87. / INVALID
    EOF
    ෆਖ਼ͳϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    ద༻Ͱ͖Δจ๏نଇͳ͠
    

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88. / INVALID
    EOF
    ෆਖ਼ͳϓϩάϥϜ
    ద༻͞Εͨจ๏نଇ
    ͳ͠
    ͜ͷίʔυ͸ϓϩάϥϜͷจͷ͍ͣΕʹ΋

    ͋ͯ͸·Βͳ͍ͷͰɺϓϩάϥϜʹ͋ͯ͸·Βͳ͍
    ͜ͷঢ়گΛʮߏจΤϥʔʢTZOUBYFSSPSʣʯͱ͍͏
    

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89. จ๏نଇ·ͱΊ
    w จ๏نଇ͸۩ମྫΛߟ͑ΔͱΘ͔Γ΍͍͢
    w จ๏نଇʹ͋ͯ͸·Βͳ͍ͱ͖ߏจΤϥʔʹͳΔ
    

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90. ߏจղੳͷ࣮૷
    ͖ͬ͞ͷจ๏نଇʹରԠ͢Δ
    

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91. จ๏نଇͷࠨଆʢͷ෦෼ʣʹ

    ରԠ͢Δந৅ߏจ໦ͷϊʔυΛఆٛ͢Δ
    ఆٛͨ͠ϊʔυ͝ͱʹղੳؔ਺Λ༻ҙ͢Δ
    ߏจղੳͷ࣮૷खॱ
    

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92. := * EOF
    := | |
    := "if " " {\n" * "}" "\n"
    := "\n"
    := "//" [A-Z_ ]* "\n"
    := |
    := "'" ("\'" | [A-Z_ ])* "'"
    := "(" ")"
    := [a-z] [a-z]*
    ͜ͷ͝ͱʹந৅ߏจ໦ͷϊʔυΛఆٛ͢Δ
    

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93. 1SPHSBN
    4UBUFNFOU 4UBUFNFOU
    # := *
    class ProgramNode(Node):
    def __init__(self, statement_nodes):
    # ͸ෳ਺ͷ͔ΒͳΔͷͰɺ
    # ؚ·ΕΔΛ഑ྻͰอ࣋͢Δɻ
    self.statements = statement_nodes
    ϓϩάϥϜʹରԠ͢Δந৅ߏจ໦ͷϊʔυ
    จͷϊʔυͷ഑ྻ
    

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94. # := *
    class ProgramNode(Node):
    def __init__(self, statement_nodes):
    # ͸ෳ਺ͷ͔ΒͳΔͷͰɺ
    # ؚ·ΕΔΛ഑ྻͰอ࣋͢Δɻ
    self.statements = statement_nodes 4UBUFNFOU 4UBUFNFOU
    1SPHSBN
    

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95. # := *
    class ProgramNode(Node):
    def __init__(self, statement_nodes):
    # ͸ෳ਺ͷ͔ΒͳΔͷͰɺ
    # ؚ·ΕΔΛ഑ྻͰอ࣋͢Δɻ
    self.statements = statement_nodes
    1SPHSBN
    4UBUFNFOU 4UBUFNFOU
    

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96. # := "if " " {\n" จ* "}" "\n"
    class IfStatementNode(Node):
    def __init__(self, condition_node, then_statements):
    # if ͷޙͷ৚݅෦ͷ Λอ࣋͢Δɻ
    self.condition_node = condition_node
    # { ͱ } ͷؒͷෳ਺ͷ Λ഑ྻͱͯ͠อ࣋͢Δɻ
    self.then_statements = then_statements
    JGจʹରԠ͢Δந৅ߏจ໦ͷϊʔυ
    

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97. ಉ༷ʹ͢΂ͯͷʹରԠ͢Δ

    ந৅ߏจ໦ͷϊʔυΛఆٛ͠·͢
    

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98. ͢΂ͯͷϊʔυΛఆٛ͠ऴΘͬͨΒɺ

    ͜ΕΛ࡞੒͢Δؔ਺Λॻ͍͍ͯ͘
    

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99. ʹରԠ͢Δؔ਺ͷҾ਺ͱ໭Γ஋ʹ͸ɺ

    Α͋͘Δఆ൪ͷύλʔϯ͕͋Δ
    ͜ͷύλʔϯʹै͏ͱɺؔ਺Λ

    ૊Έ߹Θͤ΍͘͢ͳΔͷͰ͓֮͑ͯ͜͏
    

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100. ͍͖ͳΓϓϩάϥϜʹରԠ͢Δؔ਺Λ

     ॻ͘ͱઆ໌͕೉͍͠ͷͰɺίϝϯτจʹ

     ରԠ͢Δؔ਺͔Βઆ໌͢Δ
     

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101. # := "//" [A-Z_ ]* "\n"
     def parse_comment_statement(text, index):
     # TODO: ͪΌΜͱ࣮૷͢Δ
     next_index = 1234 # TODO: Ծͷ࣮૷
     node = CommentStatementNode(
     comment_content=" COMMENT" # TODO: Ծͷ࣮૷
     )
     return node, next_index
     ίϝϯτจʹରԠ͢Δؔ਺ͷҾ਺ͱ໭Γ஋Λ֬ೝ͠Α͏
     ؔ਺ͷ಺෦͸·ͩԾͷ΋ͷͰɺ͋ͱͰ࣮૷͍ͯ͘͠
     

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102. # := "//" [A-Z_ ]* "\n"
     def parse_comment_statement(text, index):
     # TODO: ͪΌΜͱ࣮૷͢Δ
     next_index = 1234 # TODO: Ծͷ࣮૷
     node = CommentStatementNode(
     comment_content=" COMMENT" # TODO: Ծͷ࣮૷
     )
     return node, next_index
     ʮQBSTFʯ͸ʮߏจղੳ͢Δʯͷҙຯ
     

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103. # := "//" [A-Z_ ]* "\n"
     def parse_comment_statement(text, index):
     # TODO: ͪΌΜͱ࣮૷͢Δ
     next_index = 1234 # TODO: Ծͷ࣮૷
     node = CommentStatementNode(
     comment_content=" COMMENT" # TODO: Ծͷ࣮૷
     )
     return node, next_index
     ղੳ͍ͨ͠ςΩετશମ ղੳ͍ͨ͠ςΩετͷҐஔ
     

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104. # := "//" [A-Z_ ]* "\n"
     def parse_comment_statement(text, index):
     # TODO: ͪΌΜͱ࣮૷͢Δ
     next_index = 1234 # TODO: Ծͷ࣮૷
     node = CommentStatementNode(
     comment_content=" COMMENT" # TODO: Ծͷ࣮૷
     )
     return node, next_index
     ղੳͰ͖ͨίϝϯτจʹ

     ରԠ͢Δந৅ߏจ໦ͷϊʔυ ίϝϯτจ͕ऴΘͬͨҐஔ
     

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105. ͱΓ͋͑ͣؔ਺ͷ࢖ΘΕํΛΈͯΈΑ͏
     

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106. (comment_node, next_index) = parse_comment_statement("// COMMENT\n", 0)
     ϓϩάϥϜͷઌ಄͔Βղੳ͢Δύλʔϯ ઌ಄ͳͷͰJOEFY͸
     ղੳ͕ऴΘͬͨҐஔ
     ίϝϯτจʹରԠ͢Δந৅ߏจ໦ͷϊʔυ
     

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107. (comment_node, next_index) = parse_comment_statement("'123'\n// COMMENT\n", 6)
     ϓϩάϥϜͷ్த͔Βղੳ͢Δύλʔϯ
     ղੳ͕ऴΘͬͨҐஔ
     ్தͷจࣈ໨͔Βղੳ͢Δ
     ίϝϯτจʹରԠ͢Δந৅ߏจ໦ͷϊʔυ
     

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108. (comment_node, next_index) = parse_comment_statement("'123'\n/ INVALID", 6)
     ղੳʹࣦഊ͢Δύλʔϯ
     ࣦഊͨ͠ΒҐஔ͸ಈ͔͞ͳ͍Ͱͷ··ʹ͢Δ
     ͜ͷΑ͏ʹɺࣦഊͨ͠ΒԿ΋ͳ͔ͬͨΑ͏ʹ

     ר͖໭Δ͜ͱΛʮόοΫτϥοΫʯͱݺͿ
     ղੳʹࣦഊͨ͠ͷͰ/POF
     ్தͷจࣈ໨͔Βղੳ͢Δ
     

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109. Ҿ਺
     w ղੳ͢Δจࣈྻશମͱ࢝ΊΔҐஔ
     ໭Γ஋
     w ղੳͰ͖ͨந৅ߏจ໦ͷϊʔυͱऴΘͬͨҐஔ
     w ࣦഊͨ͠Β/POFΛฦͯ͠ɺ

     Ґஔ͸ಈ͔͞ͳ͍
     ͜͜ͰҾ਺ͱ໭Γ஋Λ੔ཧ͠Α͏ɿ
     

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110. Ҿ਺
     w ղੳ͢Δจࣈྻશମͱ࢝ΊΔҐஔ
     ໭Γ஋
     w ղੳͰ͖ͨந৅ߏจ໦ͷϊʔυͱऴΘͬͨҐஔ
     w ࣦഊͨ͠Β/POFΛฦͯ͠ɺ

     Ґஔ͸ಈ͔͞ͳ͍
     ͜͜ͰҾ਺ͱ໭Γ஋Λ੔ཧ͠Α͏ɿ
     ؔ਺͕૊Έ߹Θͤ΍͘͢ͳΔͱ

     ݴ͍ͬͯͨͷ͸͜ͷ෦෼
     લͷؔ਺ʹΑΔղੳ͕ऴΘͬͨ

     Ґஔ͔Βɺ࣍ͷؔ਺ʹΑΔղੳΛ

     ࠶։͢ΔΠϝʔδ
     

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111. ࣮ࡍͷॲཧͷྲྀΕΛΈͯΈΑ͏
     Ҿ਺ͱ໭Γ஋͕ͳΜͱͳ͘Θ͔ͬͨͷͰ
     

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112. := "//" [A-Z_ ]* "\n"
     ίϝϯτจͷจ๏نଇͷಡΈํͷ͓͞Β͍ɿ
     ͸͡Ίʹ͕͋Δ
     ଓ͚ͯӳେจࣈ͔@͔ۭന͕ճҎ্ଓ͘
     ࠷ޙʹվߦ͕͋Δ
     

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113. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     := "//" [A-Z_ ]* "\n"
     

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114. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     := "//" [A-Z_ ]* "\n"
     ίϝϯτจʹରԠ͢Δؔ਺
     

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115. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ͜͜Ͱ͸͕JOEFYͷҐஔʹ͋Δ͔Ͳ͏͔֬ೝ͍ͯ͠Δ
     FYQFDU@LFZXPSE͸ޙͰઆ໌͢Δ͕ɺΛݟ͚ͭͨΒ

     JOEFYΛͷޙ·ͰҠಈͤ͞Δ
     := "//" [A-Z_ ]* "\n"
     

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116. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ͕Έ͔ͭΒͳ͚Ε͹ίϝϯτจͰ͸ͳ͍ͷͰऴྃ
     := "//" [A-Z_ ]* "\n"
     

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117. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ͜ͷ഑ྻʹίϝϯτ಺ͷจࣈΛ֨ೲ͍ͯ͘͠
     := "//" [A-Z_ ]* "\n"
     

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118. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ίϝϯτ಺ͷจࣈ͸܁Γฦ͠ͳͷͰɺϧʔϓͰॲཧ͢Δ
     := "//" [A-Z_ ]* "\n"
     

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119. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     JOEFYͷҐஔʹ;@>͕͋Δ͔֬ೝ͍ͯ͠Δ
     FYQFDU@FJUIFSʹ͍ͭͯ͸ޙͰઆ໌͢Δ
     := "//" [A-Z_ ]* "\n"
     

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120. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ΋͠;@>ʹҰக͠ͳ͔ͬͨΒɺίϝϯτͷ

     ಺༰෦෼͕ऴΘͬͨͷͰɺϧʔϓ͔Β୤ग़
     := "//" [A-Z_ ]* "\n"
     

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121. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ΋͠;@>Ͱ͋Ε͹ɺίϝϯτจࣈྻ͕·ͩଓ͔͘΋

     ͠Εͳ͍ͷͰɺจࣈΛه࿥ͯ͠ϧʔϓΛ࠶։
     := "//" [A-Z_ ]* "\n"
     

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122. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ίϝϯτ಺ͷจࣈ͕ऴΘͬͨͷͰɺ࠷ޙʹ

     վߦ͕͋Δ͔Ͳ͏͔֬ೝ͍ͯ͠Δ
     := "//" [A-Z_ ]* "\n"
     

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123. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     aO͕ͳ͚Ε͹ɺίϝϯτจͰ͸ͳ͍ͷͰ/POFͱ

     ݩͷJOEFYΛฦ͢
     := "//" [A-Z_ ]* "\n"
     

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124. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ه࿥͓͍ͯͨ͠ίϝϯτ಺ͷจࣈΛ݁߹ͯ͠ɺ

     ίϝϯτͷ಺༰จࣈྻΛ෮ݩ͢Δ
     := "//" [A-Z_ ]* "\n"
     

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125. def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ෮ݩͨ͠ίϝϯτจࣈྻ͔ΒίϝϯτจʹରԠ͢Δ

     ந৅ߏจ໦ͷϊʔυΛ࡞੒ͯ͠ɺਐΊͨJOEFYͱฦ͢
     := "//" [A-Z_ ]* "\n"
     

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126. := "//" [A-Z_ ]* "\n"
     def parse_comment_statement(text, index):
     is_success, next_index = expect_keyword("//", text, index)
     if not is_success:
     return None, index
     comment_content_chars = []
     while True:
     comment_content_char, next_index = \
     expect_either(uppercase + [" ", "_"], text, next_index)
     if comment_content_char is None:
     break
     comment_content_chars.append(comment_content_char)
     is_success, next_index = expect_keyword("\n", text, next_index)
     if not is_success:
     return None, index
     comment_content_chars = "".join(comment_content_chars)
     return CommentStatementNode(comment_content_chars), next_index
     ίϝϯτจʹରԠ͢Δؔ਺Λॻ͚ͨ
     

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127. FYQFDUdͳؔ਺ͷ͸ͨΒ͖
     ్தͰͰ͖ͯͨFYQFDUd͕ؾʹͳΔํ΁
     

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128. ઌ΄ͲͷQBSTF@DPNNFOU@TUBUFNFOUͷ࣮૷࣌ʹ

     ͋Γ͕ͪͳϛε͕ɺJOEFYͷਐΊ๨Ε΍ਐΊ෯ͷؒҧ͍
     FYQFDU@LFZXPSE΍FYQFDU@FJUIFS͸͜ΕΒͷؒҧ͍Λ

     ༧๷͢ΔͨΊͷϢʔςΟϦςΟؔ਺
     

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129. text = "abc"
     is_success, next_index = expect_keyword("a", text, 0)
     is_success, next_index = expect_keyword("x", text, 0)
     Bͷ࣍ͷJOEFYͳͷͰ
     JOEFYͷҐஔʢͳͷͰઌ಄ʣʹB͕͋ΔͷͰ5SVF
     ͳ͍৔߹͸JOEFYΛม͑ͳ͍ͷͰ
     JOEFYͷҐஔʢͳͷͰઌ಄ʣʹY͸ͳ͍ͷͰ'BMTF
     

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130. ൺֱͨ͠จࣈྻͷ௕͚ͩ͞JOEFYΛਐΊΔͷͰɺ

     ਐΊ෯ͷؒҧ͍ͱਐΊ๨ΕΛ๷͛Δ
     ศརʜ
     

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131. def expect_keyword(expected, text, index):
     expected_len = len(expected)
     actual = text[index:index+expected_len]
     if actual != expected:
     return False, index
     return True, index + expected_len
     def expect_either(expected_list, text, index):
     for expected in expected_list:
     is_success, next_index = expect_keyword(expected, text, index)
     if is_success:
     return expected, next_index
     return None, index
     

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132. def expect_keyword(expected, text, index):
     expected_len = len(expected)
     actual = text[index:index+expected_len]
     if actual != expected:
     return False, index
     return True, index + expected_len
     def expect_either(expected_list, text, index):
     for expected in expected_list:
     is_success, next_index = expect_keyword(expected, text, index)
     if is_success:
     return expected, next_index
     return None, index
     ৄࡉͳ࣮૷͸͋ͱͰղಡͯ͠Έ͍ͯͩ͘͞ʂ
     

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133. ͜͜·ͰͰίϝϯτจͷ

     ղੳؔ਺Λ࣮૷Ͱ͖ͨ
     

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134. ࣍ʹɺจʹର͢Δؔ਺͔Βઌ΄Ͳ

     ࣮૷ͨ͠ίϝϯτจʹରԠ͢Δؔ਺Λ

     ࢖͏ํ๏ΛΈͯΈΑ͏
     ϙΠϯτ͸ɺจ๏نଇͷͷӈଆʹ͕

     ͋ͬͨΒରԠ͢Δղੳؔ਺ʹ೚ͤΔ͜ͱ
     

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135. := | |
     จͷจ๏نଇͷಡΈํͷ͓͞Β͍ɿ
     จ͸ɺJGจɺࣜจɺίϝϯτจͷ͍ͣΕ͔
     

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136. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     := | |
     

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137. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     ·ͣɺJGจʹରԠ͢Δؔ਺ͰղੳͰ͖Δ͔Ͳ͏͔ࢼ͢
     := | |
     

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138. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     ΋͠ɺJGจͱͯ͠ͷղੳʹ੒ޭ͢Ε͹จ͸JGจͩͬͨͱ͍͏͜ͱ
     JGจʹରԠ͢Δந৅ߏจ໦ͱɺJGจͷղੳͰਐΜͩJOEFYΛฦ͢
     := | |
     

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139. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     JGจͱͯ͠ͷղੳʹࣦഊͨ͠Βɺ࣍ʹࣜจͱͯ͠ͷղੳΛࢼ͢
     := | |
     

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140. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     ΋͠ɺࣜจͱͯ͠ͷղੳʹ੒ޭ͢Ε͹จ͸ࣜจͩͬͨͱ͍͏͜ͱ
     ࣜจʹରԠ͢Δந৅ߏจ໦ͱɺࣜจͷղੳͰਐΜͩJOEFYΛฦ͢
     := | |
     

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141. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     ࣜจͱͯ͠ͷղੳʹ΋ࣦഊͨ͠Βɺ࠷ޙʹίϝϯτจͱͯ͠ͷղੳΛࢼ͢
     := | |
     

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142. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     ΋͠ɺίϝϯτจͱͯ͠ͷղੳʹ੒ޭ͢Ε͹จ͸ίϝϯτจͩͬͨͱ͍͏͜ͱ
     ίϝϯτจʹରԠ͢Δந৅ߏจ໦ͱɺίϝϯτจͷղੳͰਐΜͩJOEFYΛฦ͢
     := | |
     

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143. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     JGจɺࣜจɺίϝϯτจͷ͍ͣΕͰ΋ͳ͚Ε͹ɺ

     จͰ͸ͳ͍ͷͰɺ/POFͱݩͷJOEFYΛฦͯ͠ऴྃ
     := | |
     

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144. def parse_statement(text, index):
     if_statement_node, next_index = parse_if_statement(text, index)
     if if_statement_node is not None:
     return if_statement_node, next_index
     expr_statement_node, next_index = parse_expr_statement(text, index)
     if expr_statement_node is not None:
     return expr_statement_node, next_index
     comment_statement_node, next_index = parse_comment_statement(text, index)
     if comment_statement_node is not None:
     return comment_statement_node, next_index
     return None, index
     := | |
     ͜ͷΑ͏ʹʹରԠ͢Δؔ਺Λఆ͍ٛͯ͘͠ͱɺ

     ࠷ऴతʹϓϩάϥϜʹରԠ͢Δؔ਺ΛఆٛͰ͖Δ
     ͜ͷϓϩάϥϜʹରԠ͢Δؔ਺͕ɺҰൠతʹ

     ఏڙ͞Ε͍ͯΔߏจղੳثͱݺ͹ΕΔ΋ͷ
     

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145. ࠓճͷઆ໌Ͱ৮Εͳ͔ͬͨ͜ͱ
     w ࣮༻తͳߏจղੳثʹ͢Δʹ͸ɺந৅ߏจ໦΍

     ߏจΤϥʔʹίʔυ্ͷҐஔ৘ใΛؚΊͨํ͕Α͍
     w όοΫτϥοΫ͋Γͷ࣮૷͸ɺ୯७͔͔ͭͳΓ޿͍ൣғͷ

     จ๏نଇΛղੳͰ͖Δ͕ɺܭࢉྔ͸େ͖͍
     w ࣮͸Ұ൪೉͍͠ͷ͸όάͷͳ͍จ๏نଇΛߟ͑Δ͜ͱ
     w όά͕͋Δͱߏจղੳث͕ແݶϧʔϓͨ͠Γ͢Δ
     

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146. ૉ௚ͳ࣮૷ͷ·ͱΊ
     w ࣮૷͸ҎԼͷεςοϓͰͰ͖Δɿ
     w ʹରԠ͢Δந৅ߏจ໦Λఆٛ͢Δ
     w ʹରԠ͢Δؔ਺Λఆٛ͢Δ
     w จ๏نଇͷӈଆʹ͕͋Δ৔߹͸ɺ

     ͦͷʹରԠ͢Δؔ਺ʹղੳΛ೚ͤΔ
     

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147. 1BSTFS$PNCJOBUPSͷҖྗ
     ΋ͬͱΤϨΨϯτͳํ๏Λνϥݟͤ
     

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148. ࠓճ঺հͨ͠ૉ௚ͳ࣮૷Λ1BSTFS$PNCJOBUPSͰ࣮૷͢Δͱɺ

     ಉ͡ॲཧͳͷʹڻ͘΄Ͳ࣮૷͕୹͘ͳΓɺ͔ͭ࠶ར༻ੑ্͕͕Δɿ
     parse_comment = sequence(
     string("//"),
     sequence(
     many(char(uppercase + ["_", " "])),
     string("\n")
     )
     )
     ؾʹͳΔਓ͸ɺεϥΠυ຤ඌͷࢀߟจݙ#Λࢀর
     

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149. ߏจղੳͷ·ͱΊ
     w ߏจղੳ͸ίʔυΛղੳͯ͠ந৅ߏจ໦Λ

     ࡞੒͢Δॲཧ
     w ͞·͟·ͳߏจղੳͷΞϧΰϦζϜ͕͋Δ
     w ࠓճ͸όοΫτϥοΫ͋Γͷ

     ࠶ؼԼ߱෼ੳΛૉ௚ʹ࣮૷ͨ͠
     

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150. ந৅ߏจ໦Λॲཧ͢Δ

     ୅දతͳ࣮૷ύλʔϯ
     ߏจղੳͷ͓࣍͸
     

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151. ͜Ε·Ͱ͸ɺந৅ߏจ໦ͷ֓ཁ΍࡞੒ํ๏ΛΈ͖ͯͨ
     ࣍ʹɺ͜͜Ͱ͸ந৅ߏจ໦Λ͔͋ͭ͏୅දతͳ

     ࣮૷ύλʔϯΛ঺հ͢Δ
     ΋ͬͱ΋සൟʹ࢖͏࣮૷ύλʔϯͱͯ͠ɺந৅ߏจ໦Λ

     ॱ൪ʹ୳ࡧ͍ͯ͘͠૸ࠪؔ਺Λ঺հ͢Δ
     

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152. ૸ࠪؔ਺
     ந৅ߏจ໦Λ͔͋ͭ͏୅දతύλʔϯ
     

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153. ૸ࠪؔ਺͸ɺந৅ߏจ໦ͷϊʔυΛॱʹḷ͍ͬͯͬͯɺ

     ϊʔυʹ๚ΕΔ཭ΕΔͨͼʹॲཧΛ࣮ߦ͢Δؔ਺
     traverse(node, on_enter, on_leave)
     PO@FOUFSͱPO@MFBWF͸ͲͪΒ΋ؔ਺Λ౉͢
     ϊʔυʹ๚ΕΔ཭ΕΔͱ࣮ߦ͞ΕΔ
     Կ͕ى͜Δ͔Θ͔ΓͮΒ͍ͷͰਤղ͠·͢
     

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154. def print_enter(node):
     print("enter: {node}".format(node=type(node)))
     def print_leave(node):
     print("leave: {node}".format(node=type(node)))
     traverse(node, print_enter, print_leave)
     PO@FOUFSͱPO@MFBWF͕Θ͔ΔΑ͏ʹQSJOU͢Δؔ਺Λ༻ҙ
     

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155. ͜ͷUSBWFSTFʹΑͬͯQSJOU͞ΕΔ݁ՌΛΈͯΈ·͠ΐ͏
     QSJOU݁Ռ
     1SPHSBN
     *G4UBUFNFOU
     4USJOH-JUFSBM
     'VOD$BMM
     *EFOUJpFS
     $PNNFOU
     

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156. *G4UBUFNFOU
     4USJOH-JUFSBM
     'VOD$BMM
     *EFOUJpFS
     $PNNFOU
     1SPHSBN
     ·ͣ͸1SPHSBNʹ๚ΕΔʢFOUFS1SPHSBNΛQSJOUʣ
     FOUFS1SPHSBN
     QSJOU݁Ռ
     

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157. 1SPHSBN
     4USJOH-JUFSBM
     'VOD$BMM
     *EFOUJpFS
     $PNNFOU
     *G4UBUFNFOU
     ࣍ʹ1SPHSBNͷࢠͰ͋Δ*G4UBUFNFOU΁๚ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     QSJOU݁Ռ
     

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158. 1SPHSBN
     *G4UBUFNFOU
     4USJOH-JUFSBM
     *EFOUJpFS
     $PNNFOU
     'VOD$BMM
     ࣍ʹ*G4UBUFNFOUͷࢠͰ͋Δ'VOD$BMMΛ๚ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     QSJOU݁Ռ
     

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159. 1SPHSBN
     *G4UBUFNFOU
     4USJOH-JUFSBM
     'VOD$BMM $PNNFOU
     *EFOUJpFS
     QSJOU݁Ռ
     ࣍ʹ'VOD$BMMͷࢠͰ͋Δ*EFOUJpFSΛ๚ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     

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160. 1SPHSBN
     *G4UBUFNFOU
     4USJOH-JUFSBM
     'VOD$BMM $PNNFOU
     *EFOUJpFS
     QSJOU݁Ռ
     *EFOUJpFSʹࢠ͸͍ͳ͍ͷͰɺ*EFOUJpFS͔Β཭ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     

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161. 1SPHSBN
     *G4UBUFNFOU
     'VOD$BMM $PNNFOU
     *EFOUJpFS 4USJOH-JUFSBM
     QSJOU݁Ռ
     'VOD$BMMͷ࣍ͷࢠͰ͋Δ4USJOH-JUFSBMΛ๚ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     

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162. 1SPHSBN
     *G4UBUFNFOU
     'VOD$BMM $PNNFOU
     *EFOUJpFS 4USJOH-JUFSBM
     QSJOU݁Ռ
     4USJOH-JUFSBMʹࢠ͸͍ͳ͍ͷͰɺ4USJOH-JUFSBM͔Β཭ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     MFBWF4USJOH-JUFSBM
     

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163. 1SPHSBN
     *G4UBUFNFOU
     $PNNFOU
     *EFOUJpFS 4USJOH-JUFSBM
     'VOD$BMM
     QSJOU݁Ռ
     'VOD$BMMͷ͢΂ͯͷࢠΛ๚໰ͨ͠ͷͰɺ'VOD$BMM͔Β཭ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     MFBWF4USJOH-JUFSBM
     MFBWF'VOD$BMM
     

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164. 1SPHSBN
     *G4UBUFNFOU
     *EFOUJpFS 4USJOH-JUFSBM
     'VOD$BMM $PNNFOU
     QSJOU݁Ռ
     *G4UBUFNFOUͷ࣍ͷࢠͰ͋Δ$PNNFOUΛ๚ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     MFBWF4USJOH-JUFSBM
     MFBWF'VOD$BMM
     FOUFS$PNNFOU
     

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165. 1SPHSBN
     *G4UBUFNFOU
     *EFOUJpFS 4USJOH-JUFSBM
     'VOD$BMM $PNNFOU
     QSJOU݁Ռ
     $PNNFOUʹࢠ͸͍ͳ͍ͷͰɺ$PNNFOU͔Β཭ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     MFBWF4USJOH-JUFSBM
     MFBWF'VOD$BMM
     FOUFS$PNNFOU
     MFBWF$PNNFOU
     

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166. 1SPHSBN
     *EFOUJpFS 4USJOH-JUFSBM
     'VOD$BMM $PNNFOU
     *G4UBUFNFOU
     QSJOU݁Ռ
     *G4UBUFNFOUͷ͢΂ͯͷࢠΛ๚໰ͨ͠ͷͰɺ཭ΕΔ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     MFBWF4USJOH-JUFSBM
     MFBWF'VOD$BMM
     FOUFS$PNNFOU
     MFBWF$PNNFOU
     MFBWF*G4UBUFNFOU
     

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167. *EFOUJpFS 4USJOH-JUFSBM
     'VOD$BMM $PNNFOU
     *G4UBUFNFOU
     1SPHSBN
     QSJOU݁Ռ
     1SPHSBNͷ͢΂ͯͷࢠΛ๚໰ͨ͠ͷͰɺ૸ࠪ׬ྃ
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     MFBWF4USJOH-JUFSBM
     MFBWF'VOD$BMM
     FOUFS$PNNFOU
     MFBWF$PNNFOU
     MFBWF*G4UBUFNFOU
     MFBWF1SPHSBN
     

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168. *EFOUJpFS 4USJOH-JUFSBM
     'VOD$BMM $PNNFOU
     *G4UBUFNFOU
     1SPHSBN
     QSJOU݁Ռ
     ཁ͢Δʹɺந৅ߏจ໦Λਂ͞༏ઌ୳ࡧ͢Δؔ਺
     FOUFS1SPHSBN
     FOUFS*G4UBUFNFOU
     FOUFS'VOD$BMM
     FOUFS*EFOUJpFS
     MFBWF*EFOUJpFS
     FOUFS4USJOH-JUFSBM
     MFBWF4USJOH-JUFSBM
     MFBWF'VOD$BMM
     FOUFS$PNNFOU
     MFBWF$PNNFOU
     MFBWF*G4UBUFNFOU
     MFBWF1SPHSBN
     

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169. ͜ͷΑ͏ͳந৅ߏจ໦Λ૸ࠪ͢Δؔ਺͕

     ༻ҙ͞Ε͍ͯΔͱɺ͞ΒʹޙͰ঺հ͢Δ

     ੩తݕࠪͷίʔυ͕ͱͯ΋ॻ͖΍͘͢ͳΔ
     

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170. ͢΂ͯͷந৅ߏจ໦ͷϊʔυʹɺࣗ਎ͷ

     ࢠͷҰཡΛฦؔ͢਺Λ௥Ճ͢Δ
     ϊʔυΛ๚ΕͨΒͷࢠͷҰཡΛऔಘͯ͠ɺ

     ࠶ؼతʹ๚Ε͍ͯؔ͘਺Λ࣮૷͢Δ
     ૸ࠪؔ਺ͷ࣮૷खॱ
     

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171. class Node:
     def children(self):
     raise NotImplementedError()
     class ProgramNode(Node):
     def __init__(self, statement_nodes):
     self.statements = statement_nodes
     def children(self):
     return self.statements
     ந৅ߏจ໦ͷϊʔυ͕ࣗ਎ͷࢠΛฦ͢Α͏ʹཁٻ͢ΔجఈΫϥεΛ༻ҙ
     

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172. class Node:
     def children(self):
     raise NotImplementedError()
     class ProgramNode(Node):
     def __init__(self, statement_nodes):
     self.statements = statement_nodes
     def children(self):
     return self.statements
     ͦΕͧΕͷந৅ߏจ໦ͷϊʔυʹ࣮૷ͯ͠΋Β͏
     

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173. class Node:
     def children(self):
     raise NotImplementedError()
     class ProgramNode(Node):
     def __init__(self, statement_nodes):
     self.statements = statement_nodes
     def children(self):
     return self.statements
     ϓϩάϥϜͷ͢΂ͯͷࢠͷҰཡΛ഑ྻͱͯ͠ฦ͢
     ࠓճ͸จͷ഑ྻҎ֎ʹࢠ͸ͳ͍ͷͰͦͷ··ฦͤ͹Α͍
     

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174. class IfStatementNode(Node):
     def __init__(self, condition_node, then_statements):
     self.condition_node = condition_node
     self.then_statements = then_statements
     def children(self):
     children = [self.condition_node]
     return children + self.then_statements
     ผͷέʔεͱͯ͠ɺJGจͷந৅ߏจ໦ͷϊʔυ΋ΈͯΈΑ͏
     

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175. class IfStatementNode(Node):
     def __init__(self, condition_node, then_statements):
     self.condition_node = condition_node
     self.then_statements = then_statements
     def children(self):
     children = [self.condition_node]
     return children + self.then_statements
     JGจͷࢠ͸৚݅෦ͷࣜͱɺ\^ͷதͷ

     ෳ਺ͷจͳͷͰɺ·ͱΊͯҰཡʹͯ͠ฦ͢
     

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176. class IfStatementNode(Node):
     def __init__(self, condition_node, then_statements):
     self.condition_node = condition_node
     self.then_statements = then_statements
     def children(self):
     children = [self.condition_node]
     return children + self.then_statements
     ಉ༷ʹɺ͢΂ͯͷந৅ߏจ໦ͷϊʔυʹDIJMESFOΛ࣮૷ͤ͞Δ
     

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177. ४උ͕੔ͬͨͷͰɺ૸ࠪؔ਺ͷ

     ຊମΛ࣮૷͍ͯ͘͠
     

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178. def traverse(node, on_enter=None, on_leave=None):
     if on_enter is not None:
     on_enter(node)
     for child in node.children():
     traverse(child, on_enter, on_leave)
     if on_leave is not None:
     on_leave(node)
     

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179. def traverse(node, on_enter=None, on_leave=None):
     if on_enter is not None:
     on_enter(node)
     for child in node.children():
     traverse(child, on_enter, on_leave)
     if on_leave is not None:
     on_leave(node)
     ந৅ߏจ໦ͷϊʔυΛ๚ΕͨͷͰPO@FOUFSΛ࣮ߦ͢Δ
     ΋͠PO@FOUFS͕লུ͞Ε͍ͯΔ৔߹͸Կ΋͠ͳ͍
     

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180. def traverse(node, on_enter=None, on_leave=None):
     if on_enter is not None:
     on_enter(node)
     for child in node.children():
     traverse(child, on_enter, on_leave)
     if on_leave is not None:
     on_leave(node)
     ந৅ߏจ໦ͷϊʔυ͔ΒࢠͷҰཡΛ

     औಘ͠ɺࢠΛ࠶ؼతʹ૸͍ࠪͯ͘͠
     

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181. def traverse(node, on_enter=None, on_leave=None):
     if on_enter is not None:
     on_enter(node)
     for child in node.children():
     traverse(child, on_enter, on_leave)
     if on_leave is not None:
     on_leave(node)
     ࢠͷ૸͕ࠪऴΘͬͨͷͰɺࠓͷϊʔυ͔Βୀग़͢Δ
     

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182. ͜͜·ͰͰ؆୯ʹ૸ࠪؔ਺Λ࣮૷Ͱ͖ͨ
     ૸ࠪؔ਺͸഑ྻͰ͍͏GPS&BDIͷΑ͏ͳ

     جૅతͳؔ਺ͩͱߟ͑ΔͱΘ͔Γ΍͍͢
     ͦͷͨΊɺͱͯ΋Ԡ༻ͷൣғ͕޿͍
     

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183. w ৚݅ʹ͋ͬͨந৅ߏจ໦ͷϊʔυͷநग़
     w ม਺ؔ਺ͷείʔϓղੳ
     w ʜ
     ૸ࠪؔ਺ͰͰ͖Δ͜ͱ
     

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184. found = find_nodes(node, condition)
     ৚݅ʹ͋ͬͨந৅ߏจ໦ͷϊʔυͷநग़
     ୳ࡧ͍ͨ͠ந৅ߏจ໦ ݕࡧ͍ͨ͠৚݅ͷؔ਺
     ͜ͷநग़ؔ਺͸૸ࠪؔ਺Λ࢖ͬͯ

     ؆୯ʹ࣮૷Ͱ͖Δ
     

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185. def find_nodes(node, condition):
     found_nodes = []
     def collect_nodes(entered_node):
     if not condition(entered_node):
     return
     found_nodes.append(entered_node)
     traverse(node, collect_nodes)
     return found_nodes
     

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186. def find_nodes(node, condition):
     found_nodes = []
     def collect_nodes(entered_node):
     if not condition(entered_node):
     return
     found_nodes.append(entered_node)
     traverse(node, collect_nodes)
     return found_nodes
     ݕࡧ৚݅ʹ͋ͯ͸·Δந৅ߏจ໦ͷϊʔυΛूΊΔ഑ྻ
     

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187. def find_nodes(node, condition):
     found_nodes = []
     def collect_nodes(entered_node):
     if not condition(entered_node):
     return
     found_nodes.append(entered_node)
     traverse(node, collect_nodes)
     return found_nodes
     ந৅ߏจ໦ͷϊʔυΛ๚ΕΔλΠϛϯάͰݕࡧ৚݅ͷ

     ؔ਺Λ࣮૷͠ɺ৚݅ʹ͋ͯ͸·ΔϊʔυΛूΊΔؔ਺
     

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188. def find_nodes(node, condition):
     found_nodes = []
     def collect_nodes(entered_node):
     if not condition(entered_node):
     return
     found_nodes.append(entered_node)
     traverse(node, collect_nodes)
     return found_nodes
     ந৅ߏจ໦ͷϊʔυΛूΊΔؔ਺Λ

     PO@FOUFSʹࢦఆͯ͠૸ࠪΛ։࢝
     

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189. def find_nodes(node, condition):
     found_nodes = []
     def collect_nodes(entered_node):
     if not condition(entered_node):
     return
     found_nodes.append(entered_node)
     traverse(node, collect_nodes)
     return found_nodes
     ݟ͔ͭͬͨந৅ߏจ໦ͷϊʔυͷ഑ྻΛฦ͢
     

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190. def find_nodes(node, condition):
     found_nodes = []
     def collect_nodes(entered_node):
     if not condition(entered_node):
     return
     found_nodes.append(entered_node)
     traverse(node, collect_nodes)
     return found_nodes
     ૸ࠪؔ਺Λ࢖͏͜ͱͰɺͱͯ΋؆୯ʹ࣮૷Ͱ͖ͨ
     

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191. ଞʹ΋ɺ૸ࠪؔ਺Λ࢖͏ͱείʔϓղੳΛ

     ࣮૷͠΍͘͢ͳΔ
     είʔϓղੳͱ͸ɺม਺ͷఆٛ͞Ε͍ͯΔ

     είʔϓΛղੳ͢Δ͜ͱͰɺະఆٛͷม਺΍

     ະ࢖༻ͷม਺Λݟ͚ͭΔख๏
     

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192. ίʔυ͕͔ͳΓ௕͘ͳΔͷͰɺ࣮ࡍͷίʔυ͸ׂѪ͢Δ͕ɺ

     େ·͔ʹҎԼͷखॱͰείʔϓΛղੳͰ͖Δɿ
     ؔ਺એݴͷߏจ໦΁ͷPO@FOUFSͰ

     είʔϓΦϒδΣΫτΛ࡞੒͢Δ
     ࡞੒ͨ͠είʔϓΦϒδΣΫτΛ

     ݱࡏͷείʔϓͷελοΫʹੵΉ
     ݟ͔ͭͬͨม਺એݴΛελοΫͷઌ಄ͷ

     είʔϓΦϒδΣΫτ΁Ճ͍͑ͯ͘
     ؔ਺એݴͷߏจ໦͔ΒͷPO@MFBWFͰ

     ઌ಄ͷείʔϓΦϒδΣΫτΛ

     ελοΫ͔ΒऔΓআ͘
     
     
     
     
     

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193. • https://github.com/estools/escope
     • https://github.com/rubocop-hq/rubocop

     ͷ VariableForce
     • https://github.com/Kuniwak/vint

     ͷ scope_plugin
     ࢀߟʹͳΔείʔϓղੳͷ࣮૷
     

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194. ૸ࠪؔ਺ͷ࣮૷Ͱઆ໌͠ͳ͔ͬͨ͜ͱ
     w ૸ࠪͷதஅ΍ࢠͷ୳ࡧͷεΩοϓػೳ
     w ύϑΥʔϚϯεվળͷͨΊʹॏཁ
     w ୈڃؔ਺Λ࢖Θͳ͍૸ࠪؔ਺ͷ࣮૷
     w ݴޠʹΑͬͯ͸ؔ਺ΛҾ਺ʹ౉ͤͳ͍͜ͱ΋͋Δ
     w ͦͷ৔߹͸(P'ͷ7JTJUPSύλʔϯͰ୅ସՄೳ
     

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195. ૸ࠪؔ਺ͷ·ͱΊ
     w ந৅ߏจ໦ͷ૸ࠪؔ਺Λఆ͓ٛͯ͘͠ͱศར
     w ૸ࠪؔ਺ͷ࣮૷͸೉͘͠ͳ͍
     w ૸ࠪؔ਺͸͞·͟·ͳॲཧ΁Ԡ༻Ͱ͖Δ
     

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196. ؆୯ͳ੩తղੳΛ

     ࣮૷ͯ͠ΈΑ͏
     Α͏΍͘ΰʔϧ
     

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197. if isEmpty('') {
     //CATCH_ME_IF_YOU_CAN
     }
     ͓୊͸ɺੜҙؾͳίϝϯτ਺Λใࠂ͢Δ੩తղੳ
     report_specific_comments(text)
     # Found 1 namaiki comments!
     

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198. ߏจղੳͯ͠ந৅ߏจ໦Λ࡞੒͢Δ
     ந৅ߏจ໦Λ૸ࠪͯ͠ྫͷίϝϯτΛूΊΔ
     ूΊͨίϝϯτΛใࠂ͢Δ
     ࣮૷ͷྲྀΕ
     

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199. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ίʔυ͔ΒੜҙؾͳίϝϯτΛݟ͚ͭͯ਺Λใࠂ͢Δؔ਺
     

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200. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ίʔυΛߏจղੳͯ͠ந৅ߏจ໦Λ࡞੒͢Δ
     

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201. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ߏจղੳʹࣦഊͨ͠ΒɺߏจΤϥʔΛදࣔ
     

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202. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ૸ࠪؔ਺ͷར༻ྫͱ࣮ͯ͠૷ͨ͠ɺݕࡧؔ਺Λ࢖ͬͯੜҙؾͳίϝϯτΛूΊΔ
     

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203. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ݕࡧؔ਺ͷ৚݅ʹࢦఆͨ͠ɺੜҙؾίϝϯτ͔Ͳ͏͔൑ఆ͢Δؔ਺
     

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204. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ·ͣɺந৅ߏจ໦͕ίϝϯτจͰͳ͚Ε͹ɺ

     ੜҙؾͳίϝϯτͰ͸ͳ͍ͷͰɺ'BMTFΛฦͯ͠ऴྃ
     

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205. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ίϝϯτจͩͬͨ৔߹ɺίϝϯτͷ಺༰ʹੜҙؾͳ

     ΋ͷؚ͕·Ε͍ͯΕ͹5SVFɺͦΕҎ֎͸'BMTFΛฦ͢
     

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206. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ઌ΄Ͳͷؔ਺Ͱ5SVF͕ฦ͞Εͨந৅ߏจ໦ʢੜҙؾͳίϝϯτʣ͕

     Ұཡʹͯ͠ฦ͞ΕΔ
     

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207. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ੜҙؾͳίϝϯτͷ਺Λใࠂͯ͠ऴྃ
     

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208. def report_namaiki_comments(text):
     node = parse_program(text)
     if node is None:
     print("Syntax Error!")
     return
     namaiki_comments = find_nodes(node, is_namaiki_comment)
     print("Found {count} comments!".format(count=len(namaiki_comments)))
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ߏจղੳثɾ૸ࠪؔ਺ɾݕࡧؔ਺Λ

     ૊Έ߹Θͤͯ࢖͏͜ͱͰɺͱͯ΋

     ؆୯ʹ੩తݕࠪΛ࣮૷Ͱ͖ͨ
     

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209. ؆୯ͳ੩తݕࠪͷ࣮૷·ͱΊ
     ੩తݕࠪ͸ɺߏจղੳثɾ૸ࠪؔ਺ɾݕࡧؔ਺Λ

     ૊Έ߹ΘͤΔ͜ͱͰɺ͘͝؆୯ʹ࣮૷Ͱ͖Δ
     

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210. ෳࡶͳ੩తղੳΛ

     ෼ׂ͢ΔςΫχοΫ
     ΰʔϧୡ੒ͷͦͷઌ΁
     

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211. ઌ΄Ͳ͸ͭͷ੩తݕࠪϧʔϧͷΈΛ࣮૷͕ͨ͠ɺ

     ݱ࣮ʹ͸ෳ਺ͷݕࠪϧʔϧΛ࣮૷͢Δ͜ͱ͕ଟ͍
     ͜ͷͱ͖ɺͲͷΑ͏ʹίʔυΛ෼ׂ͢Δ͔ʹΑͬͯ

     อकੑ͕େ͖͘มΘΔ
     

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212. ݕࠪϧʔϧʹΑΔ෼ׂΛ঺հ
     ༗໊ͳ੩తղੳπʔϧͷ൒਺Ҏ্͕࠾༻͍ͯ͠Δ
     

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213. ݕࠪϧʔϧʹΑΔ෼ׂͰ͸ɺͭͷݕࠪϧʔϧ͕

     ͭͷίϯϙʔωϯτʢΫϥεPSؔ਺ʣʹରԠ͢Δ
     ͜ΕʹΑͬͯݕࠪϧʔϧ͕͓ޓ͍ʹૄʹͳΓɺ

     ݕࠪϧʔϧͷ௥Ճमਖ਼࡟আΛ΍Γ΍͘͢ͳΔ
     

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214. class Policy:
     def get_violations(self, node):
     raise NotImplementedError()
     ݕࠪϧʔϧͷڞ௨ΠϯλʔϑΣʔεΛܾΊΔ
     

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215. class Policy:
     def get_violations(self, node):
     raise NotImplementedError()
     ந৅ߏจ໦ͷϊʔυ͔Βݟ͔ͭͬͨ໰୊Λɺจࣈྻͷ

     ഑ྻͱͯ͠ฦ͢ϝιουɻ͜ͷϝιου͸ɺ΄͔ͷ

     ίϯϙʔωϯτ಺Ͱ૸ࠪؔ਺͔Βݺ͹ΕΔΠϝʔδ
     

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216. class Policy:
     def get_violations(self, node):
     raise NotImplementedError()
     ྫ͑͹ɺҾ਺ʹੜҙؾͳίϝϯτจ͕͖ͨΒ

     ࢦఠϝοηʔδΛฦ࣮͢૷΍ɺJGจ͕͖ͨΒ

     ৚݅෦෼ͷࣜΛݕࠪ͢Δͧɺͱ͍͏࣮૷͕͋Γ͑Δ
     ॏཁͳͷ͸ɺݕࠪϧʔϧ͕ผͳΒผͷΫϥεʹ

     ෼ׂ࣮ͯ͠૷͢Δ͜ͱɻҰॹʹ͢Δͱอक͕େมʹͳΔ
     

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217. class NamaikiCommentPolicy(Policy):
     def get_violations(self, node):
     if not is_namaiki_comment(node):
     return []
     return ["FOUND YOU!"]
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     લʹ࣮૷ͨ͠ͷͱಉ͡ɺੜҙؾͳίϝϯτจΛࢦఠ͢Δݕࠪϧʔϧ
     

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218. class NamaikiCommentPolicy(Policy):
     def get_violations(self, node):
     if not is_namaiki_comment(node):
     return []
     return ["FOUND YOU!"]
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     Ҿ਺ͷந৅ߏจ໦ͷϊʔυ͕ੜҙؾͳίϝϯτจʼͳΒɺ

     ʮݟ͚ͭͨͧʂʯͱ͍͏ϝοηʔδΛฦ͢Α͏ʹ࣮૷
     

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219. class NamaikiCommentPolicy(Policy):
     def get_violations(self, node):
     if not is_namaiki_comment(node):
     return []
     return ["FOUND YOU!"]
     def is_namaiki_comment(entered_node):
     if not isinstance(entered_node, CommentStatementNode):
     return False
     comment_node = entered_node
     return "CATCH_ME_IF_YOU_CAN" in comment_node.comment_content
     ੜҙؾͳίϝϯτจΛ൑ఆ͢Δؔ਺͸લͷ΋ͷΛྲྀ༻
     

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220. class Policies(Policy):
     def __init__(self, policies):
     self.policies = policies
     def get_violations(self, node):
     return reduce(
     lambda violations, policy: violations + policy.get_violations(node),
     self.policies,
     []
     )
     ෳ਺ͷݕࠪϧʔϧΛଋͶΔݕࠪϧʔϧΛ४උ
     

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221. class Policies(Policy):
     def __init__(self, policies):
     self.policies = policies
     def get_violations(self, node):
     return reduce(
     lambda violations, policy: violations + policy.get_violations(node),
     self.policies,
     []
     )
     ݕࠪϧʔϧͱಉ͡ڞ௨ΠϯλʔϑΣʔεΛ࣮૷͢Δ
     

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222. class Policies(Policy):
     def __init__(self, policies):
     self.policies = policies
     def get_violations(self, node):
     return reduce(
     lambda violations, policy: violations + policy.get_violations(node),
     self.policies,
     []
     )
     ಺෦ͷෳ਺ͷݕࠪϧʔϧΛϧʔϓͯ͠ݕࠪͯ͠ɺ݁ՌΛ߹੒ͯ͠ฦ͢
     

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223. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     

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224. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ෳ਺ͷݕࠪϧʔϧͰ·ͱΊͯݕࠪ͢Δؔ਺
     

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225. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ༩͑ΒΕͯจࣈྻΛߏจղੳͯ͠ந৅ߏจ໦Λ࡞੒
     

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226. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ߏจղੳʹࣦഊͨ͠ΒɺߏจղੳࣦഊͷϝοηʔδΛ݁Ռͱͯ͠ฦ͢
     

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227. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ෳ਺ͷݕࠪϧʔϧΛଋͶͯɺͭͷݕࠪϧʔϧʹ·ͱΊΔ

     ʢ͜ͷྫͰ͸ɺੜҙؾͳίϝϯτΛݕࠪ͢Δϧʔϧ͚ͩʣ
     

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228. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ݕࠪϝοηʔδΛूΊΔ഑ྻΛ४උ
     

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229. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ༩͑ΒΕͨந৅ߏจ໦ͷϊʔυ͔ΒɺݕࠪϝοηʔδΛूΊΔؔ਺
     

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230. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ந৅ߏจ໦Λ૸ࠪͯ͠ɺݕࠪϝοηʔδΛूΊ͍ͯ͘
     

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231. def lint(text):
     node = parse_program(text)
     if node is None:
     return ["Syntax Error!"]
     policies = Policies([NamaikiCommentPolicy()])
     violations_buffer = []
     def collect_violations(entered_node):
     violations = policies.get_violations(entered_node)
     violations_buffer.append(violations)
     traverse(node, collect_violations)
     all_violations = []
     return reduce(add, violations_buffer, all_violations)
     ू·ͬͨݕࠪϝοηʔδΛͭͷ഑ྻʹ·ͱΊͯฦ͢
     

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232. text = "if isEmpty('') {\n// CATCH_ME_IF_YOU_CAN\n}\n"
     violations = lint(text)
     ෳ਺ͷݕࠪϧʔϧͰ੩తղੳͰ͖ΔΑ͏ʹͳͬͨ
     

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233. ݕࠪϧʔϧʹΑΔ෼ׂͷ·ͱΊ
     w ੩తݕࠪͷݕࠪϧʔϧ͸ݸผͷίϯϙʔωϯτ

     ͱ࣮ͯ͠૷͢Δͱอक͠΍͍͢
     w ଟ͘ͷ੩తݕࠪπʔϧ͸͜ͷύλʔϯʹԊͬͯ

     ࣮૷͞Ε͍ͯΔ
     

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234. ଞʹ΋࣮૷ύλʔϯ͸ͨ͘͞Μ͋Δ͕ɺ

     ࣌ؒͷ౎߹ʢͱࠓͷମྗʣͰ͸঺հ͖͠Εͳ͍
     ͞Βʹ஌Γ͍ͨํ͸ɺʮ7JNTDSJQUͷ-JOU࡞ऀʹ

     ΑΔ୭ಘσβΠϯύλʔϯʯͱ͍͏هࣄΛࢀর
     https://qiita.com/Kuniwak/items/d6a2d22711e4d7856edd
     

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235. ࣮ࡍͷ੩తݕࠪπʔϧͷ

     ࣮૷ΛಡΜͰΈΑ͏
     ීஈ࢖͍ͬͯΔ
     

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236. 1ZUIPO
     w ߏจղੳث
     w BTUQBSTFʢඪ४ϥΠϒϥϦʣ
     w ૸ࠪؔ਺
     w BTU/PEF7JTJUPSʢඪ४ϥΠϒϥϦʣ
     w ੩తݕࠪϧʔϧ
     w $IFDLFS53:ʢQZqBLFTͷQZqBLTDIFDLFSQZʣ
     

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237. 3VCZ
     w ߏจղੳث
     w 1BSTFS3VCZ

     (JU)VCͷXIJUFRVBSLQBSTFSͷMJCQBSTFSSVCZZ
     
     w ૸ࠪؔ਺
     w 3VCPDPQ"455SBWFSTBM

     3VCPDPQͷMJCSVCPDPQBTUUSBWFSTBMSC
     
     w ੩తݕࠪϧʔϧ
     w 3VCPDPQ$PQ-JOU&NQUZ&OTVSF

     3VCPDPQͷMJCSVCPDPQDPQMJOUFNQUZ@FOTVSFSC
     
     

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238. +BWB4DSJQU
     w ߏจղੳث
     w 1BSTFSʢ(JU)VCͷBDPSOKTBDPSOͷTSDTUBUFKT
     
     w ૸ࠪؔ਺
     w 5SBWFSTFUSBWFSTF

     &4-JOUͷMJCVUJMUSBWFSTFKT
     
     w ੩తݕࠪϧʔϧ
     w SVMFTOPFNQUZGVODUJPO

     &4-JOUͷMJCSVMFTOPFNQUZGVODUJPOKT
     
     

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239. ͜Ε·Ͱͷ஌ࣝʹΑͬͯ

     ࡞ΕΔΑ͏ʹͳΔ΋ͷ
     కΊ͘͘Γʹ
     

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240. ෳ਺ͷݕࠪϧʔϧʹΑΔ੩తݕࠪ
     https://github.com/Kuniwak/Vint
     

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241. $44ͷந৅ߏจ໦Λൺֱ͢Δπʔϧ
     https://github.com/mixi-inc/css-semdiff
     $ css-astdiff a.css b.css --verbose
     extra:
     .extra-1 {
     border: none;
     }
     missing:
     .missing-1 {
     border: none;
     }
     ---------------------------------
     1 extra rules and 1 missing rules
     

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242. ؆қతͳߏจղੳͰґଘؔ܎σʔλϕʔεΛ࡞੒
     https://twitter.com/orga_chem/status/674847225684475905
     

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243. ·ͱΊ
     ੩తղੳΛߏ੒͢Δجຊతͳߟ͑ํΛ঺հɿ
     w ந৅ߏจ໦
     w ߏจղੳ
     w ૸ࠪؔ਺
     w ݕࠪϧʔϧͷ෼ׂ
     ੩తղੳ͸ҙ֎ͱ؆୯ʹ࣮૷Ͱ͖·͢
     

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244. ࢀߟจݙ
     ͍·Ͳ͖ͷϓϩάϥϜݴޠͷ࡞ΓํʢஶSBOEZʣ
     https://www.amazon.co.jp/dp/4839919232
     .POBEJD1BSTFS$PNCJOBUPS
     http://www.cs.nott.ac.uk/~pszgmh/monparsing.pdf
     #
     "
     

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