Hi all I wrote an article about applying Haskell's...

# library-development

[Damian Lattenero]

Hi all I wrote an article about applying Haskell's Applicative Functor pattern to Kotlin coroutines fr parallel orchestration. The idea: .ap = parallel (<*>), .flatMap = sequential (>>=), the code shape is the execution plan. Includes side-by-side comparisons with raw coroutines and Arrow, JMH benchmarks.
Article: https://dev.to/damian_lattenero/i-applied-haskells-applicative-functors-to-kotlin-coroutines-heres-what-happened-l06
GitHub: https://github.com/damian-rafael-lattenero/coroutines-applicatives
Would love feedback on the API shape especially from anyone who's used Haskell's Applicative in other contexts.

[ephemient]

in Haskell <*> isn't necessarily "parallel"; it's still sequential in IO

[ephemient]

I think a more natural Kotlin API would be more like

val ctx = awaitAllAndTransform(
    async { fetchProfile(userId) },
    async { fetchPreferences(userId) },
    async { fetchTier(userId) },
) { profile, preferences, tier ->
    UserContext(profile, preferences, tier)
}

[Damian Lattenero]

yes thank you I updated it with that idea

[simon.vergauwen]

Arrow-kt calls that parZip.

val ctx = parZip(
    { fetchProfile(userId) },
    { fetchPreferences(userId) },
    { fetchTier(userId) },
) { profile, preferences, tier ->
    UserContext(profile, preferences, tier)
}