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Masafumi Okura
February 01, 2020
Programming
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I finally understand instance_eval
Masafumi Okura
February 01, 2020
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Transcript
instance_evalશʹཧ ղͨ͠ɿinstance_exec ΕΔͳฤ Speaker: େխ࢙ Event: Burikaigi2020 Date: 2020-02-01
self.inspect • ໊લɿେխ࢙ • ॴଐɿϑϦʔϥϯε • Rubyྺɿ7 • ͖ͳΤσΟλɿVim
self.inspect • ࠷ۙͷ՝ɿ໊ͱϚελεϥΠυͷσβΠ ϯΛͲ͏͢Δ͔ • झຯɿᘖᘣΛᔸΕΔʢࠓϑϨϯνϓϨεʣ • ͖ͳϝιουɿinstance_eval <- ࠓͷ
͡Ίʹ
͜ͷτʔΫʹ͍ͭͯʢϝλʣ • εϥΠυຕɿ29ຕ • ࣌ؒɿ25 • ओͳλʔήοτɿϝλϓϩάϥϛϯάॳ৺ऀ ͔Βதڃऀ • σϞ༗Γ
·͓ͣ͞Β͍
instance_eval ͱ • evalͷ1ͭͰɺҙͷΦϒδΣΫτ ʢBasicObjectؚΉʣͷίϯςΩετͰจࣈྻ ͷධՁ·ͨϒϩοΫͷ࣮ߦ͕Մೳ • DSLͷߏஙͳͲʹଟ༻͞ΕΔ • RubyͷॊೈੑΛࢧ͍͑ͯΔʢݸਓͷݟղʣ
ॳֶऀ͚ิɿධՁͬͯʁ • evalจࣈྻΛRubyͷίʔυʹݟཱ࣮ͯͯ ߦ͢Δ • irb͕͍ͬͯΔ͜ͱɺͱ͍͏ͱΠϝʔδ͠ ͍͔͢ • ධՁӳޠͰevaluationͳͷͰॖΊͯeval
ॳֶऀ͚ิɿϒϩοΫ • ϒϩοΫͷதͷίʔυ͙͢ʹ࣮ߦ͞Εͳ ͍ʢίʔϧόοΫ͞ΕΔɺͱݴ͏ʣ • ϒϩοΫͦͷ··ͰมೖͰ͖ͳ͍ ͕ɺ&blockͳͲͰड͚ͨͷೖՄೳ • ϒϩοΫΛݺͼग़͢ʢcallͱ͔yieldͱ͔ʣͱ ͖ɺҾΛ͢ͱͦΕ͕ϒϩοΫҾʹͳΔ
instance_evalͱଞͷeval Ͳ͏ҧ͏ͷ͔ • evalจࣈྻ͔͠ධՁͰ͖ͳ͍ʢϒϩοΫΛ࣮ ߦͰ͖ͳ͍ʣ • class_evalධՁͷίϯςΩετ͕ҧ͏ • ʢevalͰͳ͍͚Ͳʣinstance_execจࣈྻ ͷධՁ͕Ͱ͖ͳ͍ʢϒϩοΫͷ࣮ߦ͔͠Ͱ͖ͳ
͍ʣɺϒϩοΫҾ͕ͤΔ
σϞͱ͍͏͔؆୯ͳ͍ํ
σϞ͔ΒΘ͔Δ͜ͱ • instance_evalʹͨ͠ϒϩοΫͰselfϨ γʔόΛࢦ͍ͯ͠Δ • ͳͷͰɺϒϩοΫͰselfΛলུ͢ΔͱϨγʔό ͷϝιου͕ݺΔ • self͕লུͰ͖ΔͷͰϓϥΠϕʔτϝιουΠ ϯελϯεมΞΫηε͠์
ެࣜυΩϡϝϯτΛಡΉ
ެࣜυΩϡϝϯτΛಡΉ • https://docs.ruby-lang.org/en/2.7.0/ BasicObject.html#method-i-instance_eval • https://docs.ruby-lang.org/ja/2.7.0/class/ BasicObject.html#I_INSTANCE_EVAL • ༨ஊͳ͕Βɺinstance_evalBasicObjectʹੜ ͍͑ͯΔ
ཁ͢ΔʹԿ͕ॻ͍ͯ͋Δͷ͔ • จࣈྻΛड͚Δͱ͖ͱϒϩοΫΛड͚Δͱ͖ ͱͰڍಈ͕ҧ͏ʢͨΓલʣ • จࣈྻΛड͚Δͱ͖جຊతʹevalͱಉ͡ಈ ͖Λ͢Δ • ϒϩοΫΛड͚Δͱ͖ϒϩοΫΛ࣮ߦ͢Δ ࡍʹϒϩοΫҾʹϨγʔόΛ͢
ॏཁͳ͜ͱ • ϒϩοΫʹҾΛͤͳ͍ • ϒϩοΫʹҾΛͤͳ͍ <-େࣄͳ͜ͱ • DSLΛߏங͢Δࡍʹ͍ͮΒ͍ͱ͖͕͋Δ
࣮ྫ
࣮ྫσϞ͔ΒΘ͔ͬͨ͜ͱ • instance_evalͱinstance_execڍಈ͕ҟͳ Γɺ༻్·ͨҟͳΔ • instance_execड͚ͨϒϩοΫͷҾʹҙͷ ΦϒδΣΫτΛͤΔ • ϒϩοΫΛ࣮ߦ͢Δ͚ͩͳΒinstance_execͷ΄ ͏͕͍͍ͷ͔ʁ
ͪΐͬͱ͓͠Ζ͍
ಛҟʢγϯάϧτϯʣϝιου • Πϯελϯεʹ͔͠ఆٛ͞Ε͍ͯͳ͍ϝιο υ • instance_evalΛ͏ͱେྔੜ͕؆୯ • ࣮ΫϥεϝιουͱݺΕ͍ͯΔͷ͜ ͷҰछ
ಛҟϝιουΛੜͯ͠ΈΔ
instance_evalͰdef͕ݺΔ • Կ͕ى͖͍ͯΔͷͩΖ͏͔ • ͦͷṖΛ໌Β͔ʹ͘͢ɺզʑRubyͷԞ ʢιʔείʔυʣͱཱཱྀͬͨ…
RubyͷιʔείʔυΛಡΉ
ιʔείʔυ͔ΒΘ͔Δ͜ͱ • CݴޠͰॻ͍ͯ͋ΔʢͦΕͦ͏ʣ • vm_eval.cͱ͍͏ϑΝΠϧʹinstance_evalͷ࣮ ͕͋Δ • execution_contextͱ͍͏ͷ͕ॏཁͦ͏
͍͠
RubiniusΛಡΜͰΈΔ
Rubiniusͷinstance_evalΑΓ • RubyͷϒϩοΫ࣮ߦʹ͓͍ͯείʔϓඇৗ ʹॏཁʢʰϝλϓϩάϥϛϯάRubyʱಡ ͏ʣ • CRubyͱಡΈൺΔͱ͍͍͔
·ͱΊ
instance_evalָ͍͠