ScalaMatsuri CFPひとめぐり / ScalaMatsuri CFP quick tour

Presented on January 8th 2020 at Pre ScalaMatsuri meetup.

Transcript

1. 4DBMB.BUTVSJ
   $'1ͻͱΊ͙Γ
   ϓϨ4DBMB.BUTVSJ
   

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2. ࣗݾ঺հ
   w 5BJTVLF0F
   w 5XJUUFS!0&@VJB
   w 4DBMB.BUTVSJΛओ࠵͍ͯ͠·͢ɻ
   w εϐʔΧʔܦݧ
   w 4DBMB%BZT
   w +$$POG
   w 4DBMBؔ੢αϛοτ
   w 4DBMB.BUTVSJͳͲ
   

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3. ࠓ೔఻͍͑ͨ͜ͱ
   w εϐʔΧʔָ͍ͬͯ͠Α
   w εϐʔΧʔͱͯ͠ୈҰาΛ౿Έग़͢ಓ͠Δ΂
   

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4. ఻͑ΒΕͳ͍͜ͱ
   w ❌εϐʔΧʔͱͯ͠ͷϕετϓϥΫςΟε
   w ❌4DBMB.BUTVSJͰԠืηογϣϯ͕࠾༻͞ΕΔํ๏
   

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5. ΞδΣϯμ
   w ͦ΋ͦ΋ɺͳͥΧϯϑΝϨϯεͰ஻Δͷ͔ʁ
   w εϐʔΧʔʹͳΔʹ͸ɺͲ͏͢Ε͹͍͍ͷ͔ʁ
   

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6. ͳͥΧϯϑΝϨϯεͰ
   ஻Δͷ͔ʁ
   

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7. ͳͥΧϯϑΝϨϯεͰ
   ஻Δͷ͔ʁ ࢲͷ৔߹
   
   w εϐʔΧʔʹͳΔͷ͕ɺҰ൪ָ͘͠աͤ͝Δɻ
   w ษڧ͢ΔϞνϕʔγϣϯʹͳΔɻ
   w ࣗ෼͕ਪٕ͢ज़Λɺਖ਼͍͠࢖͍ํͱͱ΋ʹ޿ΊΒΕΔɻ
   w ࢀՃඅͷෛ୲͕ݮΔʢՄೳੑ͕ߴ͍ʣɻ
   

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8. w ࣗ෼Λ޿͘஌ͬͯ΋Β͏͖͔͚ͬʹͳΔɻ
   w ໘ന͍Πϕϯτʹ༠ͬͯ΋Β͑ͨΓɺ௕ظతʹ͸ࣗ෼
   ͷ࢓ࣄʹܨ͕ͬͨΓ΋͢Δɻ
   w ॳର໘ͷਓ΋ɺࣗ෼ͷ޷͖ͳ࿩୊ʢొஃωλʣͰ࿩͔͠
   ͚͖ͯͯ͘ΕΔ֬཰্͕͕Δɻ
   w ͦͷ৔ݶΓͷೱ͍ू·ΓʢεϐʔΧʔσΟφʔͳͲʣͰٞ
   ࿦Ͱ͖Δɻ
   ͳͥΧϯϑΝϨϯεͰ
   ஻Δͷ͔ʁ ࢲͷ৔߹
   
   

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9. εϐʔΧʔʹͳΔʹ͸
   Ͳ͏͢Ε͹͍͍ͷʁ
   

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10. εϐʔΧʔʹͳΔʹ͸
    Ͳ͏͢Ε͹͍͍ͷʁ
    w ηογϣϯެืܕͷΧϯϑΝϨϯεͰΑ͋͘ΔྲྀΕ
    ςʔϚΛܾΊΔ
    $'1ʹԠื͢Δ
    ౰མ݁ՌΛ஌Δ
    τʔΫͷ४උ͢ΔʢεϥΠυΛ࡞Δʣ
    ຊ൪౰೔ʹ஻Δ
    

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11. εϐʔΧʔʹͳΔʹ͸
    Ͳ͏͢Ε͹͍͍ͷʁ
    w 4DBMB.BUTVSJͷྲྀΕ
    ςʔϚΛܾΊΔΠϚίί
    $'1ʹԠื͢Δʜ"OZXIFSFPO&BSUIక੾
    ౰མ݁ՌΛ஌Δʜ݄த
    τʔΫͷ४උ͢ΔʢεϥΠυΛ࡞Δʣʜ݄
    ຊ൪౰೔ʹ஻Δʜ݄೔ɾ೔
    

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12. ςʔϚΛܾΊΔ
    

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13. ࠓ೥͸͕ͧ͘͞Μ
    ΑΖ͓͘͠ئ͍͠·͢ʂ
    ࢀߟϓϨ4DBMB.BUTVSJͷͱ͖ͷࢿྉ
    

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14. $'1ʹԠื͢Δ
    

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15. $'1ʹԠื͢Δ
    w ͜ͷ৔߹ɺ$'1͸$BMMGPS1SPQPTBMT1SFTFOUBUJPOTͷ
    ུɻ
    w ηογϣϯͷҰൠืूͷ͜ͱɻ
    w $'1ʹର͢ΔԠืͷ͏ͪɺ࠾༻͞Εͨ΋ͷ͕λΠϜςʔϒ
    ϧ΁ׂΓ౰ͯΒΕ·͢ɻ
    

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16. 4DBMB.BUTVSJ$'1
    w ࠓ೥ͷΧϯϑΝϨϯε͸̐τϥοΫʂ
    w ৄࡉ͸ͪ͜Β
    w IUUQTTDBMBNBUTVSJPSHKBDGQ
    

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17. Ԡืཁ߲ൈਮ
    Scala Scala
    40 100 20 )
    200 300 (
    )
    3
    1
    Repository Pull Request
    

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18. Ԡืཁ߲ൈਮ
    Scala Scala
    40 100 20 )
    200 300 (
    )
    3
    1
    Repository Pull Request
    

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19. 4DBMBϏΪφʔͷఆٛ
    ͜ͷΧςΰϦ͸ɺScalaͰίʔυΛॻ͖࢝Ίͨਓ͕ΑΓScalaΛ࢖͍͜ͳͯ͠ɺૉૣ͘σόοάͨ͠Γɺద੾
    ͳந৅ԽΛ࢖͍͜ͳͨ͠ΓɺΫϦʔϯͰ҆શͳίʔυΛॻ͚ΔΑ͏ʹͳΔͨΊͷηογϣϯͰ͢ɻ ྫ͑
    ͹ɺҎԼͷΑ͏ͳࢀՃऀΛର৅ͱͨ͠ηογϣϯ͕֘౰͠·͢ɻ
    
    • ScalaͷίϨΫγϣϯૢ࡞Λ͢Δͱ͖ʹmap, flatMap, filter, findͳͲɺجຊతͳ΋ͷҎ֎͋·Γ࢖ͬͨ
    ͜ͱ͕ͳ͍ɻ
    
    • forࣜͰॻ͚Δ΋ͷͱͦ͏Ͱͳ͍΋ͷͷ۠෼΍ɺॻ͚Δ৚͕݅Α͘෼͔Βͳ͍ɻ
    
    • OptionɺTryɺEitherͷ࢖͍෼͚͕Α͘෼͔Βͳ͍ɻ͍ͭྫ֎Λ౤͛ͯ͠·͏ɻ
    
    • case classͱclassɺabstract classɺtraitͳͲͷҧ͍͕Α͘෼͔Βͳ͍ɻ
    
    • ύλʔϯϚονΛɺmatchࣜҎ֎Ͱ࢖ͬͨ͜ͱ͕ͳ͍ɻෳ਺ͷύλʔϯΛ૊Έ߹Θͤͯ࢖͍ͬͯͳ͍ɻ
    
    • ܕύϥϝʔλʔ΍implicitͷ࢖͍ॴ͕Α͘෼͔Βͳ͍ɻͦΕΒ͕࢖ΘΕͨίʔυΛಡΊͳ͍ɻ
    
    ৽͍͠੾ΓޱͰ͜͏͍ͬͨجૅΛղઆ͢Δηογϣϯ΍ɺ࠶ೖ໳͢ΔηογϣϯͳͲɺ͞·͟·ͳ੾Γޱ
    ͰͷηογϣϯΛืू͠·͢ɻͥͻ͝Ԡื͍ͩ͘͞ɻ
    

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20. બߟํ๏ൈਮ
    ScalaMatsuri
    2
    w ͲͪΒͷબߟํ๏ʹ߹Θͤͨํ͕௨Γ΍͍͢ɺ౳͸ʢࠓ
    ೥͸ಛʹʣͳ͍Ͱ͢ɻ
    w ԦಓͰ΋มԽٿͰ΋ɺۀ຿ؔ࿈Ͱ΋झຯܥͰ΋׻ܴͰ͢ɻ
    

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21. 4DBMB.BUTVSJ$'1
    w కΊ੾Γ͸"OZXIFSFPO&BSUI
    w +45
    

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22. 4DBMB.BUTVSJ౰མ
    w ηογϣϯืूͷకΊ੾Γ͔Βɺि͔ؒΒϲ݄͙Β͍Ͱૹ෇
    ͞Ε·͢ɻ4DBMB.BUTVSJͰ͸ɺ݄຤ࠒʙ݄ॳ०Λ༧ఆ͍ͯ͠
    ·͢ɻ
    w Α͋͘ΔޡղΑ͋͘Δޡղʮ࠾༻͞Εͳ͍࣭͕௿͍ʯͰ͸͋
    Γ·ͤΜɻૉ੖Β͍͠ηογϣϯͰ΋ɺௌऺͷ૚ʹ͋Θͳ͔ͬ
    ͨΓɺΧςΰϦͷภΓʹΑͬͯ͸࠾༻͞Εͳ͔ͬͨΓ͠·͢ɻ
    ؾΛམͱ͞ͳ͍Ͱ͍ͩ͘͞ɻ
    w 4DBMB.BUTVSJͰ͸ʹΞϯΧϯϑΝϨϯεΛ։࠵͠·͢ɻ
    ౰೔ʹొஃ࿮͕ܾఆ͞Ε·͢͠ɺ਺΋ଟ͍ͷͰɺͥͻͦͪΒ΋
    νϟϨϯδͯ͠Έ͍ͯͩ͘͞ɻ
    

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23. εϥΠυ࡞੒
    w εϥΠυ࡞੒͠͸͡ΊΔલʹɺ࿦ࢫΛ໌֬ʹ͠·͠ΐ͏ʂ
    w ʮҰ൪఻͍͑ͨϝοηʔδʯͬͯͳΜͩΖʁࣗ෼ͷϝο
    ηʔδΛཧղͯ͠΋Β͏ʹ͸ɺͲΜͳ஌ࣝ΍ࠜڌ͕ඞཁ
    ͩΖ͏ʁͲ͏ͯ͠΋఻͓͖͍͑ͯͨࣄ࣮ͬͯɺͳΜͩΖ
    ͏ʁ
    

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24. ٕज़తݕূ
    w ٕज़తͳهड़ʹؒҧ͍͕ͳ͍͔ɺࣗ෼Ͱݕূ͢ΔบΛͭ
    ͚·͠ΐ͏ɻ
    w ݴ༿ͷఆ͕ٛਖ਼͔֬ओޠ͕ద੾ͳେ͖͔͞
    w அݴ͍ͯ͠Δ΋ͷʹ͍ͭͯɺྫ֎͸ଘࡏ͠ͳ͍ͷ͔
    

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25. ٕज़తݕূ
    w ίʔυΛॻ͍ͯಈ͔ͯ͠ݕূͯ͠ΈΔ
    w ΦϑΟγϟϧͷυΩϡϝϯτ΍ʢධ൑ͷྑ͍ʣॻ੶ͳͲ
    ͱɺໃ६͕ͳ͍͔ௐ΂Δ
    w ʢ044ͳΒ͹ʣ֘౰͢ΔιʔείʔυΛಡΉ
    w ͦͷ্Ͱɺಉ྅ͳͲʹϨϏϡʔΛґཔ͢Δͷ͸ྑ͍ϓϥ
    ΫςΟεͰ͢ʂ
    

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26. ࿅श
    w εϥΠυΛΑΓྑ͘͢ΔͨΊͷ࿅श
    w εϥΠυ͕Ұ௨ΓͰ͖ͨΒɺ·ͣ͸εϥΠυͷϒϥο
    γϡΞοϓͷͨΊʹܰ͘࿅शͯ͠Έ·͠ΐ͏ɻ
    w ͻͱΓͰ࿅श
    w ·ͣ͸ҰਓͰ௨ͯ͠஻ͬͯΈΔͷ͕ΦεεϝͰ͢ɻ୯७
    ʹ࿩׳ΕΔ͚ͩͰͳ͘ɺ࿩ͷےಓͷෆࣗવ͞΍ɺ৑௕ͳ
    ෦෼ͳͲʹؾ͖ͮ·͢ɻ
    

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27. ࿅श
    w εϥΠυͷϒϥογϡΞοϓ͕ਐΜͰ͖ͨΒɺࣾ಺ൃදձ
    ΍ɺษڧձͳͲͷ࿅श৔ॴΛͭ͘Γ·͠ΐ͏ɻ
    w ϑΟʔυόοΫΛੵۃతʹ΋Β͏ͱɺ࿦ࢫͷෆ໌ྎͳ఺
    ΍ɺٕज़తͳؒҧ͍ͳͲʹؾ͖ͮ΍͍͢Ͱ͢ɻ
    

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28. εϥΠυఏग़
    w ΧϯϑΝϨϯεʹΑͬͯ͸ඞཁͰ͢ɻ
    w 4DBMB.BUTVSJͰ͸ɺӳޠɾࣈນ΍$P$ͷ֬ೝͷͨΊɺ
    ݄ͷఏग़Λ͓ئ͍͍ͯ͠·͢ɻ
    w ͦͷޙ΋ඍमਖ਼͸ՄೳͰ͢ɻͦͷ৔߹͸ɺ׬੒εϥΠυΛ
    ࠶౓ૹ෇͍ͯͩ͘͠͞ɻ
    

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29. ຊ൪લͷ࿅श
    w ൃදʹ׳ΕΔͨΊʹɺ࿅श͍͖ͯ͠·͠ΐ͏ɻ࠷ॳͷ͏ͪ
    ͸ɺࣗ෼ͷ࿩͍ͯ͠Δ༷ࢠΛಈըͰࡱͬͯݟฦ͢ͱɺ͍Ζ͍
    Ζͳؾ෇͖͕͋Γ·͢ɻ
    w ࿅श͢Ε͹͢Δ΄Ͳɺྲྀெʹ஻ΕΔΑ͏ʹͳΓ·͢ɻྲྀெʹ
    ஻ΕΔͱɺࣗ৴͕ੜ·Ε·͢ʂʢٯʹ๩ͯ͘͠࿅श͕ෆे෼
    ͩͱɺ౰೔͏·͘஻Εͣʹɺ༨ܭʹযͬͨΓ͠·͢ʜʣ
    w ࣭໰͞Εͦ͏ͳ͜ͱʹ͍ͭͯɺௐ΂͓͖ͯ·͠ΐ͏ɻΈΜͳ
    ͷલͰ࿅श͢ΔͱɺԿʹಥͬࠐ·ΕΔ͔ɺΑ͘Θ͔Γ·͢ɻ
    

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30. ຊ൪
    w εϥΠυΛ࡞ΓࠐΜͰɺ࿅श΋े෼͓͚ͯ͠͹ɺ͋ͱ͸ຊ
    ൪Ͱ஻Δ͚ͩͰ͢ɻલ೔͸͙ͬ͢Γ৸ͯɺΧϯϑΝϨϯ
    ε౰೔͸ָ͠Ή͜ͱʹूத͠·͠ΐ͏ʂ
    w εϐʔΧʔʹͳΔͷͬͯɺ༐ؾ͕͍Δ͜ͱͰ͢ΑͶɻΈ
    ͳ͞Μɺ·ͣ͸ୈҰาΛ౿Έग़͞Εͨ͜ͱ͕ɺૉ੖Β͠
    ͍ͱࢥ͍·͢ɻ
    w εϐʔΧʔʹͳΔ͜ͱͰɺΑΓָ͍࣌ؒ͠Λաͤͨ͝Γɺ
    ྑ͖ग़ձ͍͕͋Δ͜ͱΛف͍ͬͯ·͢ʂ
    

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