Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Sign up for free
Menu
Search
Features
All features
Private URLs
Password Protection
Custom URLS
Scheduled publishing
Remove Branding
Restrict embedding
Deck Collections
Notes
Features
All features
Private URLs
Password Protection
Custom URLS
Scheduled publishing
Remove Branding
Restrict embedding
Deck Collections
Notes
Explore
Featured decks
Featured speakers
Programming
Technology
Storyboards
Explore
Featured decks
Featured speakers
Programming
Technology
Storyboards
Pricing
Search
Sign in
Sign up for free
20210404 Kotlin Tech Talk発表『例外ではなくnullを返すKotlin...
Search
Sponsored
·
Ship Features Fearlessly
Turn features on and off without deploys. Used by thousands of Ruby developers.
→
doyaaaaaken
April 05, 2021
Programming
980
1
Share
Embed
Copy iframe code
Copy JS code
Copy link
Start on current slide
20210404 Kotlin Tech Talk発表『例外ではなくnullを返すKotlinらしいAPIデザイン』
doyaaaaaken
April 05, 2021
More Decks by doyaaaaaken
See All by doyaaaaaken
コンパウンドスタートアップの“疎結合すぎない”チーム設計
doyaaaaaken
5
1.7k
スマートラウンドで試してみた ChatGPT活用成功/失敗事例8選!
doyaaaaaken
3
4.6k
Kotlin製自作OSSの普及戦略 ~kotlin-csvの実例を元に~ @Kotlin Fest 2022
doyaaaaaken
3
1k
20220721 小規模フルリモート組織における入社者オンボーディング設計
doyaaaaaken
0
480
エンジニアによる事業指標計測のススメ
doyaaaaaken
1
500
プラットフォーム型SaaSにおけるマルチテナント設計
doyaaaaaken
5
3k
考えることを仕組み化する
doyaaaaaken
1
780
プルリクへのセルフコメントという小技
doyaaaaaken
0
690
先取りKtor2.0
doyaaaaaken
1
730
Other Decks in Programming
See All in Programming
KiroのSpecで「五目並べ」を作ってみる
satoshi256kbyte
1
370
Are APIs Still Relevant in the AI Era?
soyuka
0
460
mrbgem 三角測量 開発
ogom
0
240
ジョジョの世界をXRで再現する
mofurune
0
150
CodeRabbitの効果検証と過ごしてみた3ヶ月
armondando
0
230
外から家のPCの電源入れたい!をPHPで解決する
kawashimo0
1
130
残高管理から台帳サービスへの進化
artoy
1
200
見えないものを探る要求要件定義に必要な基本的思考 / invisible-requirement-thinking
minodriven
15
8.3k
全ての永続トークンを、生まれる前に消し去りたい!
sylph01
1
310
TechTown - Creating Composable Callables in Contemporary C++
rollbear
0
110
パーソナライズPodcastを作った話
repunit11
0
140
SREの越境 / SRE Collaboration
y0hgi
2
300
Featured
See All Featured
Leading Effective Engineering Teams in the AI Era
addyosmani
9
2.7k
Public Speaking Without Barfing On Your Shoes - THAT 2023
reverentgeek
1
590
Unsuck your backbone
ammeep
672
58k
We Are The Robots
honzajavorek
0
400
The browser strikes back
jonoalderson
0
1.8k
Fireside Chat
paigeccino
43
4.1k
How To Stay Up To Date on Web Technology
chriscoyier
790
250k
Leveraging Curiosity to Care for An Aging Population
cassininazir
1
530
Code Reviewing Like a Champion
maltzj
529
40k
How To Speak Unicorn (iThemes Webinar)
marktimemedia
1
590
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
35
2.6k
So, you think you're a good person
axbom
PRO
2
2.2k
Transcript
ྫ֎Ͱͳ͘nullΛฦ͢ KotlinΒ͍͠APIσβΠϯ Kotlin Tech Talk 2021/04/05 খࢁ݈ଠ(Kenta Koyama) @doyaaaaaaken
ࣗݾհ • ࣄ • גࣜձࣾsmartround ۀϝϯόʔ / CTO • αʔόαΠυKotlinɾVueJSΛࠓΑ͘ॻ͍͍ͯ·͢
• OSS׆ಈ • kotlin-csvͷ࡞ऀʢ⭐: 250ʣ • KtorɾExposedɾkotestͷίϯτϦϏϡʔτ • झຯ • ອըɾήʔϜɾϓϩάϥϛϯάɾάϧϝɾςχεɾϘʔυήʔϜɾຑɾཱྀߦ…etc
͋Δײͨ͡՝ • java.time.LocalDateͷparseϝιου͕͍ͮΒ͍ • LocalDate.parse(dateStr: String): LocalDate • ՝1: yyyy-MM-ddܗࣜͷจࣈྻ͔͠ड͚͚ͳ͍
• ՝2: ྫ֎ͷ߹ʹඋ͑try-catchΛॻ͘ඞཁ͕͋Γ
՝ͷରॲ • จࣈྻΛύʔε͢ΔutilityؔΛ࡞ͬͨ • fun parseLocalDate(dateStr: String): LocalDate? • ՝1:
yyyy-MM-ddܗࣜͷจࣈྻ͔͠ड͚͚ͳ͍ 㱺 ෳͷϑΥʔϚοτΛύʔεՄೳʹɻղܾʂʂ • ՝2: ྫ֎ͷ߹ʹඋ͑try-catchΛॻ͘ඞཁ͕͋Γ 㱺 ྫ֎Ͱͳ͘nullΛฦ͢Α͏ʹɻղܾʂʂ
ίʔυϨϏϡʔ • ࣭༰ • ࣭ɿʰ ྫ֎Ͱͳ͘nullΛฦ͢Α͏ʹͨ͠ͷͳͥʁʱ • ݩʑJavaඪ४ϥΠϒϥϦ͕ྫ֎Λฦ͢ͷཧ༝͕͋ΔͷͰͳ͍͔ʁ • ճ
1. ྫ֎Λฦ͢ඞવੑ͕ͳ͍ͨΊ 2. nullableʹ͢Δઃܭͷ΄͏͕try-catchΛॻ͔ͣʹࡁΈɺίʔυهड़ྔ͕গͳ͘ͳΔ 3. Kotilnͷඪ४ϥΠϒϥϦͱ͔Λݟͯͯɺͪ͜Βͷ΄͏͕KotlinͬΆ͍͔Β
ίʔυϨϏϡʔ • ࣭༰ • ࣭ɿʰ ྫ֎Ͱͳ͘nullΛฦ͢Α͏ʹͨ͠ͷͳͥʁʱ • ݩʑJavaඪ४ϥΠϒϥϦ͕ྫ֎Λฦ͢ͷཧ༝͕͋ΔͷͰͳ͍͔ʁ • ճ
1. ྫ֎Λฦ͢ඞવੑ͕ͳ͍ͨΊ 2. nullableʹ͢Δઃܭͷ΄͏͕try-catchΛॻ͔ͣʹࡁΈɺίʔυهड़ྔ͕গͳ͘ͳΔ 3. Kotilnͷඪ४ϥΠϒϥϦͱ͔Λݟͯͯɺͪ͜Βͷ΄͏͕KotlinͬΆ͍͔Β ओ؍తͳճͳͷͰɺ͏গ͖ͪ͠ΜͱݴޠԽͯ͠આ໌͍ͨ͠ͱײ͍ͯͨ͡
༗ࣝऀͷݟղ • JetbrainsͷKotlin։ൃϦʔυͷਓ͕ॻ͍ͨهࣄ͕ෲམͪ͢Δ༰ͩͬͨ • Kotlin and Exceptions • ཁ •
KotlinΒ͍͠APIσβΠϯͱͯ͠… 1. ϝιουͷฦΓΛnullઐ༻ܕʹ͢Δ͜ͱͰɺϝιουͷৼΔ͍Λදݱ͖͢ 2. ྫ֎༧ظͤ͵ൃੜ࣌ʹ͛ɺͦͷྫ֎ΞϓϦέʔγϣϯͷϧʔτϨϕϧͰHandling͖͢ • JavaϥΠϒϥϦ͕ྫ֎Λฦ͢͜ͱ͕ଟ͍ͷݕࠪྫ֎͕͋Δ͔Β • Kotlinඪ४ϥΠϒϥϦ OrNull ͕͍ͭͨͷ͕ଟ͍ • ྫɿStringܕͷtoIntOrNull, ListܕͷgetOrNull, firstOrNull …
ͦͷଞɿࢀߟهࣄհ • ࠓճͷ༰ͷৄࡉҎԼهࣄʹ·ͱ·͍ͬͯ·͢ • ʰKotlinΒ͍͠APIσβΠϯʹ͢Δʹྫ֎Ͱͳ͘nullΛฦ͢ʱ ※ ଞʹKotlinؔ࿈ͷTipsܥهࣄΛ৭ʑॻ͍ͯ·͢ • ʰKotlinͷlazyʢԆॲཧʣͷΈΛௐͯࣗͰ؆қʹ࣮ͯ͠Έͨʱ •
ʰKotlinͷΫϥεҕৡͷ͍ॴʱ • ʰKotlinʹ͓͚ΔFactoryϝιουͷ࣮ύλʔϯʱ • ʰKotlinͰωετߏͷDSLΛ࣮͢Δํ๏ʱ • ʰܕ҆શʹIDͷܕΛએݴ͢Δ࣮ύλʔϯʢKotlinͷ߹ʣʱ • ʰKotlinͷSequenceͱListͷڍಈͷҧ͍ʹ͍ͭͯʱ
ձࣾએ • smartroundͰΤϯδχΞΛ ઈࢍืू͍ͯ͠·͢ʂʂ • ʰελʔτΞοϓɾࢿՈؒͷσʔλڞ༗ɾཧ ϓϥοτϑΥʔϜʱΛ։ൃ • ελʔτΞοϓ1500ࣾɾࢿՈ100͕ࣾొ •
αʔόαΠυKotlinɾVue.jsɾAWSΛར༻ • ࣾһ10໊ఔͷϑΣʔζͰ͢ ͚ͩฉ͍͍ͨํେܴͳͷͰWantedlyɾTwitter DM͔Β͓ؾܰʹ͝Ԡื͍ͩ͘͞ʂ ࢀߟ63- w αʔϏε-1ϖʔδ w ٕज़հࢿྉʰTNBSUSPVOEΛࢧ͑Δٕज़ʱ w XBOUFEMZ࠾༻ϖʔδ
͝ਗ਼ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠ @doyaaaaaken