do/end blockでrescueが 使えるようになった #megurorb

Meguro.rb#10 ここに来ればRuby2.5.0のすべてが分かる！ クリスマス前スペシャル

https://megurorb.connpass.com/event/74033/

Transcript

1. do/end blockͰrescue͕
   ࢖͑ΔΑ͏ʹͳͬͨ
   Meguro.rb#10 (1 min LT - ruby 2.5.0)
   Yoshinori Kawasaki
   

   View Slide

2. 2
   3ඵͰΘ͔Δղઆ
   ͜Ε·Ͱ (2.4)
   0.times do
   begin
   1
   rescue => exception
   2
   else
   3
   ensure
   4
   end
   end
   ͜Ε͔Β (2.5)
   0.times do
   1
   rescue => exception
   2
   else
   3
   ensure
   4
   end
   

   View Slide

3. 3
   ΂ΜΓʂ
   

   View Slide

4. 4
   Matz͸͋Μ·Γؾʹೖͬͯͳ͔ͬͨΒ͍͠
   (ཁ๬͕ଟ͍ͷͰड͚ೖΕͨͱͷ͜ͱ)
   IUUQTCVHTSVCZMBOHPSHJTTVFT
   

   View Slide

5. 5
   ࣗવ͞Λॏࢹͯ͠{…}ͷblockʹద༻͠ͳ͔ͬͨ͋ͨΓ͕
   ྑ͔ͬͨͬΆ͋͞Δ
   IUUQTCVHTSVCZMBOHPSHJTTVFT
   

   View Slide

6. 6
   ͓·͚
   

   View Slide

7. 7
   begin-rescue-else-ensure-end
   ΛΈ͚ͭΔϓϩάϥϜΛॻ͍ͨ
   

   View Slide

8. 8
   ෮श
   ͜Ε·Ͱ (2.4)
   0.times do
   begin
   1
   rescue => exception
   2
   else
   3
   ensure
   4
   end
   end
   ͜Ε͔Β (2.5)
   0.times do
   1
   rescue => exception
   2
   else
   3
   ensure
   4
   end
   

   View Slide

9. 9
   ripperͰparseͯ͠SࣜͰΈΔͱ
   ͜Ε·Ͱ (2.4)
   [:program,
   [[:method_add_block,
   [:call, [:@int, "0", [1, 0]], :".", [:@ident,
   "times", [1, 2]]],
   [:do_block,
   nil,
   [:bodystmt,
   [[:begin,
   [:bodystmt,
   [[:@int, "1", [3, 4]]],
   [:rescue,
   nil,
   [:var_field, [:@ident, "exception", [4,
   12]]],
   [[:@int, "2", [5, 4]]],
   nil],
   [:else, [[:@int, "3", [7, 4]]]],
   [:ensure, [[:@int, "4", [9, 4]]]]]]],
   nil,
   nil,
   nil]]]]]
   ͜Ε͔Β (2.5)
   [:program,
   [[:method_add_block,
   [:call, [:@int, "0", [1, 0]], :".", [:@ident,
   "times", [1, 2]]],
   [:do_block,
   nil,
   [:bodystmt,
   [[:@int, "1", [2, 2]]],
   [:rescue,
   nil,
   [:var_field, [:@ident, "exception", [3, 10]]],
   [[:@int, "2", [4, 2]]],
   nil],
   [:else, [[:@int, "3", [6, 2]]]],
   [:ensure, [[:@int, "4", [8, 2]]]]]]]]]
   ※ripper͸rubyʹbundle͞Ε͍ͯΔެࣜparser
   

   View Slide

10. 10
    breee.rb (begin-rescue-else-ensure-end)
    def breee_body?(sexp)
    raise "Unexpected s-expression: #{sexp}" unless sexp[0] == :bodystmt
    sexp[1..-1].compact.any? do |sub_sexp|
    sub_sexp[0] == :rescue || sub_sexp[0] == :else || sub_sexp[0] == :ensure
    end
    end
    def find_breee_line(sexp)
    raise "Unexpected s-expression: #{sexp}" unless sexp[0] == :bodystmt
    (sexp.flatten.find { |e| e.is_a?(Integer) }) - 1 # heuristic
    end
    def find_breee(sexp)
    case sexp
    when nil, Symbol, String, Numeric, TrueClass, FalseClass
    []
    when Array
    if sexp[0] == :do_block
    sub_sexp = sexp[2][1][0]
    if sub_sexp[0] == :begin && breee_body?(sub_sexp[1])
    line = find_breee_line(sub_sexp[1])
    end
    end
    [line, *sexp.map { |sub_sexp| find_breee(sub_sexp) }].compact.flatten
    else
    raise "Unexpected s-expression: #{sexp}"
    end
    end
    

    View Slide

11. 11
    breee.rb (contd.)
    file_names = Dir.glob('**/*.rb')
    file_names.each do |file_name|
    f = File.open(file_name)
    sexp = Ripper.sexp(f)
    line_nums = find_breee(sexp)
    line_nums.each do |line_num|
    puts "https://github.com/wantedly/wantedly/blob/master/#{file_name}#L#{line_num}"
    end
    end
    IUUQTHJUIVCDPNMVWUFDIOPCSFFFSVCZCMPCNBTUFSCSFFFSC
    

    View Slide

12. 12
    ࣗࣾͷ࠷େrailsϨϙδτϦͰ࣮ߦͯ͠Έͨ
    

    View Slide

13. 13
    ݁Ռ: 17݅ (LOC 109999 த)
    $ ruby ../../luvtechno/ruby-2.5.0/breee.rb
    https://github.com/wantedly/wantedly/blob/master/app/concerns/project_elasticsearch_concern.rb#L144
    https://github.com/wantedly/wantedly/blob/master/app/concerns/social_profile_github_concern.rb#L31
    https://github.com/wantedly/wantedly/blob/master/app/concerns/user_elasticsearch_concern.rb#L593
    https://github.com/wantedly/wantedly/blob/master/app/concerns/user_elasticsearch_concern.rb#L713
    https://github.com/wantedly/wantedly/blob/master/app/controllers/application_controller.rb#L296
    https://github.com/wantedly/wantedly/blob/master/app/controllers/concerns/
    notifications_controller_concern.rb#L9
    https://github.com/wantedly/wantedly/blob/master/app/controllers/enterprise/scouts_controller.rb#L68
    https://github.com/wantedly/wantedly/blob/master/app/models/company.rb#L734
    https://github.com/wantedly/wantedly/blob/master/app/models/journal.rb#L212
    https://github.com/wantedly/wantedly/blob/master/app/models/project.rb#L1065
    https://github.com/wantedly/wantedly/blob/master/app/models/user.rb#L296
    https://github.com/wantedly/wantedly/blob/master/lib/huntr/apply_standard_plan_options.rb#L13
    https://github.com/wantedly/wantedly/blob/master/lib/huntr/date_and_time.rb#L64
    https://github.com/wantedly/wantedly/blob/master/lib/huntr/db_circuit_breaker/circuit/base.rb#L114
    https://github.com/wantedly/wantedly/blob/master/lib/huntr/treasure_data_to_big_query.rb#L6
    https://github.com/wantedly/wantedly/blob/master/spec/models/project_tweet_spec.rb#L266
    https://github.com/wantedly/wantedly/blob/master/spec/rails_helper.rb#L216
    

    View Slide

14. 14
    ҙ֎ͱগͳ͔ͬͨ
    

    View Slide

15. 15
    ͓ΘΓ
    

    View Slide