Extending kotlinx.serialization functionality with Arrow Meta (Joker 2021/KotlinDevDay 2022)

Transcript

1. 1 Extending kotlinx.serialization functionality with Arrow Meta Karin-Aleksandra Monoid Kotlin Dev Day 2022
2. 2 • Senior Software Engineer at CircleCI • Background in Kotlin & Scala (both front and backend) • Living in Germany with two cats • GDE in Kotlin About
3. 3 • Senior Software Engineer at CircleCI • Background in Kotlin & Scala (both front and backend) • Living in Germany with two cats • GDE in Kotlin About
4. 4 Agenda Why? What is Arrow Meta? Sample project Showtime!
5. 5 Project Stack • Just backend with Ktor + Arrow • Jackson was kind of "default" • Smooth but not Kotlin-first
6. 6 kotlinx.serialization – pros 🚀 • Kotlin-first • No boilerplate for sealed classes
7. 7 kotlinx.serialization – cons • Not a lot of serializers out of the box • No global naming strategy
8. 8 Global Naming Strategy UPPER_SNAKE_CASE -> camelCase USER_NAME -> userName
9. 9 Jackson: Object Mapper val objectMapperUpperSnakeCase = jacksonObjectMapper().apply { propertyNamingStrategy = PropertyNamingStrategies.UPPER_SNAKE_CASE }
10. 10 Issue #33 https://github.com/Kotlin/kotlinx.serialization/issues/33
11. 11 Global Naming Strategy @SerialName("USER_NAME") val userName: String
12. 12 What is Arrow Meta?
13. 13 “Functional companion to Kotlin's Compiler” What is Arrow Meta? Image source: https://arrow-kt.io/
14. 14 GIF source: https://github.com/arrow-kt/arrow-meta
15. 15 • Already using other part of Arrow for FP Why Arrow Meta?
16. 16 Why Arrow Meta? • More functionality than KSP/KAPT • Easier than kotlinc
17. 17 Sample Project
18. 18 https://bit.ly/3C2lHGp Link to repo
19. 19 • various animals (actually, only cats and dogs) • various sources (= 3rd party services) • various standards of documentation (in JSON format with different naming policies) Setting: a Zoo
20. 20 Live coding time
21. 21 • It works • ??? • Requires more knowledge than expected • KSP is preferable if it fits Thoughts
22. 22 Resources • https://meta.arrow-kt.io/ • https://github.com/arrow-kt/arrow-meta-examples • https://paranoidmonoid.github.io/articles/Kotlin%20and%20frien ds/Naming%20strategy%20plugin