ϓϩάϥϛϯάྺ൒೥ͷ Rubyist͕ GoΛֶͼ࢝Ίͯށ࿭ͬͨ఺ @nagata03

ࣗݾ঺հ • Sho Nagata • όοΫΤϯυΤϯδχΞˏΧΧΫίϜ • ৯΂ϩάͷϚΠΫϩαʔϏεԽΛਪਐத • Ruby / Railsʢྺ͸9ϲ݄ʣ • GoΛֶͼ࢝Ίͯ3ϲ݄ • ޷͖ͳݴޠ͸Python ˏs_naga03 Sho Nagata nagata03

ʹͳΓ͍ͨ ͕޷͖ͳ ist

GoΛֶͼ࢝Ίͯށ࿭ͬͨ͜ͱ 1. ྫ֎ػߏ͕ͳ͍ 2. ΠϯλϑΣʔεͬͯͳΜͧʁ

1. ྫ֎ػߏ͕ͳ͍ • Goʹ͸ྫ֎ػߏ͕ͳ͍ʢRubyͰݴ͏ begin~rescue~end ͕ͳ͍ʣ • ؔ਺͸ෳ਺ͷ໭Γ஋Λฦ͢Α͏ఆٛ • Τϥʔ಺༰ΛׂΓ౰ͯΔerrorܕͷม਺Λฦ͢Α͏ʹ͢Δ • ؔ਺ͷ໭Γ஋ͰΤϥʔ͕ൃੜ͔ͨ͠Ͳ͏͔Λࣔ͢

1. ྫ֎ػߏ͕ͳ͍ • ؔ਺Λݺͼग़͢͝ͱʹifจͰΤϥʔ൑ఆ • ͘Ͳ͍ʁ • idiomԽͯͯ͠γϯϓϧ • ελοΫτϨʔεऔΕͳ͍ • pkg/errorsύοέʔδΛ࢖͑͹ελοΫτϨʔεऔΕΔʂ͚Ͳ… • osύοέʔδͷOpenؔ਺ • 2ͭ໨ͷ໭Γ஋͸errorܕ

1. ྫ֎ػߏ͕ͳ͍ Ҿ༻ɿeurekaϒϩάʮGoݴޠʹ͓͚ΔΤϥʔϋϯυϦϯάΛࠓҰ౓ৼΓฦΔʯ

2. ΠϯλϑΣʔεͬͯͳΜͧʁ • ܕͷҰछ • ܕͷॊೈੑΛ୲อ͢Δ • ʮͲͷΑ͏ͳϝιουΛ࣮૷͢Δ΂͖͔ʯΛنఆ

3. ΠϯλϑΣʔεͬͯͳΜͧʁ errorΠϯλϑΣʔεΛ࣮૷͢Δʹ͸ stringܕͷม਺Λฦ͢Error()ϝιουΛ࣮૷͢Ε͹ྑ͍ MyErrorܕʹerrorΠϯλϑΣʔεΛ࣮૷ MyErrorܕ͸errorܕͱͯ͠ѻ͑Δ ߏ଄ମͷMyErrorܕΛఆٛ

3. ΠϯλϑΣʔεͬͯͳΜͧʁ fmtύοέʔδ͸fmt.StringerΠϯλϑΣʔεΛ࣮૷ͨ͠ܕͰ͋Ε͹ Stringϝιου͕ฦ͢จࣈྻΛग़ྗʹ࢖༻ͯ͘͠ΕΔɻ https://github.com/golang/go/blob/master/src/fmt/print.go Tܕʹfmt.StringerΠϯλϑΣʔεΛ࣮૷

2. ΠϯλϑΣʔεͬͯͳΜͧʁ • interface{}ܕ͸͋ΒΏΔܕͱޓ׵ੑΛ࣋ͭʁ - ͋ΒΏΔܕ͸interface{}ܕͱͯ͠ѻ͑Δ - ͦͷٯ͸੒Γཱͨͳ͍

2. ΠϯλϑΣʔεͬͯͳΜͧʁ • ͋Δܕ͕ͲͷΠϯλϑΣʔεΛ࣮૷͍ͯ͠Δ͔͸͙͢Θ͔ Δͷʁ - godocίϚϯυʁ - go/typesύοέʔδʁ

·ͱΊ • Goʹ͸ྫ֎ػߏ͕ͳ͍ - ྫ֎ػߏ͕ͳͯ͘͘͢͝ࠔΔʂͱ͍͏͜ͱ͸ͳͦ͞͏ - ࣮ࡍGoΛ࢖͍ͬͯΔαʔϏεͰ͸ͲͷΑ͏ʹΤϥʔϋϯυϦϯάͯ͠ ͍Δͷ͔஌Γ͍ͨ • ΠϯλϑΣʔεΛ࢖͏͜ͱͰܕΛॊೈʹѻ͑Δ - ࢖͍ํΛݟ͍ͯΔ͏ͪʹҿΈࠐΊͯ͘Δ - ͲͷΠϯλϑΣʔεΛ࣮૷͍ͯ͠Δͷ͔͸Ͳ͏΍ͬͯௐ΂Δʁ

ࢀߟจݙ • ॻ੶ - ʮελʔςΟϯάGoݴޠʯ • eurekaϒϩά - ʮGoݴޠʹ͓͚ΔΤϥʔϋϯυϦϯάΛࠓҰ౓ৼΓฦΔʯ • Qiita - ʮΠϯλϑΣʔεͷ࣮૷ύλʔϯ #golangʯ@tenntenn • GitHub - ʮgo/golang ϦϙδτϦʯ

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