#arrowkt — Public Fediverse posts

A nice article, starting with harmless maps and flatMaps in Kotlin and ending with functors and monads, hopefully without scaring the reader:

https://blog.akquinet.de/2025/02/28/the-map-and-flatmap-patterns/#writing-our-own-mappable-and-flatmappable-types

#fp #functionalprogramming #kotlin #arrowkt

The new 1.2.3 version of #ArrowKt is finally here! With new modules, many new features, read all about it https://arrow-kt.io/community/blog/2024/02/28/arrow-1-2-3/.

Thank you everyone involved, and kudos to the 8 new contributors! #Kotlin

2.x.x will become the new main branch!! (Expect alpha releases soon!)

Two weeks ago I published a post about a functional modeling approach to event sourcing. This week I'd like to dig deeper into an example implementation in Kotlin.

https://dev.to/jakub_zalas/functional-event-sourcing-example-in-kotlin-3245

#functionalprogramming #eventsourcing #kotlin #arrowkt #ddd #dddesign

#ArrowKt Optics exposes a nice DSL to work with immutable data to avoid deeply nested copies in an elegant way without any of the complexities of the underlying mechanism.

I hope to one day see something like this in #kotlin itself!

In the previous post, we looked at the benefits of a domain model implemented in a purely functional code.

This time, we’ll consider how it might work in practice by applying the event sourcing pattern to a functional domain model.

As it turns out the two go very well together.

Read more in my latest post “Functional event sourcing”: https://dev.to/jakub_zalas/functional-event-sourcing-1ea5

#eventsourcing #fp #functionalprogramming #ddd #kotlin #arrow #ArrowKt

#ArrowKt wants to support #kotlin by building DEV & EAP versions, and producing/testing experimental targets like #wasm.

We need your help! There is 12 days left in #hacktoberfest, and 77 open issues so far towards this goal!

Check them out here: https://github.com/arrow-kt/arrow/issues?q=is%3Aopen+is%3Aissue+label%3Ahacktoberfest

Interesting talk about functional programming using Kotlin and Arrow.kt https://www.youtube.com/watch?v=g79A6HmbW5M #Kotlin #FunctionalProgramming #Arrowkt

I had an awesome time with Anton Arhipov at the webinar!

I think quite some interesting content on #kotlin with #JetBrains #Ktor, #SqlDelight, #ArrowKt, etc

We build an entire feature live, and discussed context receivers!

The repo in discussing can be found here (participating #hacktoberfest): https://github.com/nomisRev/ktor-arrow-example

https://www.youtube.com/watch?v=g79A6HmbW5M

I had an awesome time with Anton Arhipov at the webinar!

I think quite some interesting content on #kotlin with #JetBrains #Ktor, #SqlDelight, #ArrowKt, etc

We build an entire feature live, and discussed context receivers!

The repo in discussing can be found here (participating #hacktoberfest): https://github.com/nomisRev/ktor-arrow-example

https://www.youtube.com/watch?v=g79A6HmbW5M

I had an awesome time with Anton Arhipov at the webinar!

I think quite some interesting content on #kotlin with #JetBrains #Ktor, #SqlDelight, #ArrowKt, etc

We build an entire feature live, and discussed context receivers!

The repo in discussing can be found here (participating #hacktoberfest): https://github.com/nomisRev/ktor-arrow-example

https://www.youtube.com/watch?v=g79A6HmbW5M

I had an awesome time with Anton Arhipov at the webinar!

I think quite some interesting content on #kotlin with #JetBrains #Ktor, #SqlDelight, #ArrowKt, etc

We build an entire feature live, and discussed context receivers!

The repo in discussing can be found here (participating #hacktoberfest): https://github.com/nomisRev/ktor-arrow-example

https://www.youtube.com/watch?v=g79A6HmbW5M

I had an awesome time with Anton Arhipov at the webinar!

I think quite some interesting content on #kotlin with #JetBrains #Ktor, #SqlDelight, #ArrowKt, etc

We build an entire feature live, and discussed context receivers!

The repo in discussing can be found here (participating #hacktoberfest): https://github.com/nomisRev/ktor-arrow-example

https://www.youtube.com/watch?v=g79A6HmbW5M

Are you ready for #Hacktoberfest!?

I've prepared my #JetBrains #Ktor #ArrowKt
example with #SqlDelight
#testcontainers and #kotest in #Kotlin with 19 issues for hacktoberfest!

I'll be giving personal guidance to everyone wanting to learn, and contribute.

https://github.com/nomisRev/ktor-arrow-example

Are you ready for #Hacktoberfest!?

I've prepared my #JetBrains #Ktor #ArrowKt
example with #SqlDelight
#testcontainers and #kotest in #Kotlin with 19 issues for hacktoberfest!

I'll be giving personal guidance to everyone wanting to learn, and contribute.

https://github.com/nomisRev/ktor-arrow-example

Are you ready for #Hacktoberfest!?

I've prepared my #JetBrains #Ktor #ArrowKt
example with #SqlDelight
#testcontainers and #kotest in #Kotlin with 19 issues for hacktoberfest!

I'll be giving personal guidance to everyone wanting to learn, and contribute.

https://github.com/nomisRev/ktor-arrow-example

Are you ready for #Hacktoberfest!?

I've prepared my #JetBrains #Ktor #ArrowKt
example with #SqlDelight
#testcontainers and #kotest in #Kotlin with 19 issues for hacktoberfest!

I'll be giving personal guidance to everyone wanting to learn, and contribute.

https://github.com/nomisRev/ktor-arrow-example

Are you ready for #Hacktoberfest!?

I've prepared my #JetBrains #Ktor #ArrowKt
example with #SqlDelight
#testcontainers and #kotest in #Kotlin with 19 issues for hacktoberfest!

I'll be giving personal guidance to everyone wanting to learn, and contribute.

https://github.com/nomisRev/ktor-arrow-example

Me, from a month ago:

“I'm going to build this personal project in #Kotlin, and I'll only do it with super-stable dependencies.” 💪

Me, today:

“That's it, I'm enabling -Xcontext-receivers, as it improves #ArrowKt” 😅

The recording of my talk at
#kotlinconf is out 🥳 https://youtu.be/tplA17M9Y4Q

I talk about #ArrowKt, and our journey of making #functionalprogramming accessible to everyone in #kotlin! 🥰

This tweet also comes with an updated profile picture (Is there no bald + moustache emoji?)😂

In #Kotlin, resource handling is basically error-prone for people not very familiar with the fine details of how coroutines work, unless they use a third-party abstraction, such as #ArrowKt's Resource:

https://arrow-kt.io/learn/coroutines/resource-safety/

Given the delightful reuse of try/catch/finally statements in Kotlin, this was not something I expected.

Awesome article comparing different ways of working with errors in #Kotlin by Mitchell Yuwono.

https://medium.com/@mitchellyuwono/typed-error-handling-in-kotlin-11ff25882880

Comparing different approaches by their lowest cognitive and cyclomatic complexity!

Spoiler, #arrowkt
and #functionalprogramming in #kotlin come out well!

An improved transcript of my talk Arrow 2.0's Trajectory #kotlinconf, and slides are available on my blog. https://nomisrev.github.io/arrows-2-0-trajectory/

Had an absolute blast talking about #ArrowKt at #kotlinconf and the amazing progress of the last 10 years of #functionalprogramming in #kotlin!

#ArrowKt appearing in the #KotlinConf keynote 🥳

Was great meeting so many passionate people yesterday, and looking forward to meeting many more today! 🥰

Come by the Arrow boot and say hi 😊 Or virtually say hi in the arrow channel on #kotlin Slack.

Today I am speaking #kotlinconf about #ArrowKt ’s trajectory towards 2.0 at 11:15!

Super excited to meeting you all, and be sure to come say hi at e Arrow booth!

If you cannot make it, you can can help my talk on the livestream here

https://m.youtube.com/live/a5tG4al3GkQ?feature=share

#kotlin

@kotlinconf I’ll be talking about @arrow_kt, our history, and future.

Evolving libraries is hard, breaking APIs even harder but sometimes essential to the success/benefit of the project/community.

#openrewrite #kotlin is looking very promising, and their team is super friendly!

#kotlinconf #arrowkt #automation

Last week I gave a webinar with @antonarhipov on zero-downtime deployments on #kubernetes with #Ktor in #Kotlin with #ArrowKt.

You can find the webinar here, https://www.youtube.com/watch?v=zKrTBH8jqH4

And all the source-code, and instructions to run the sample locally can be found here. https://github.com/nomisRev/ktor-k8s-zero-downtime

Don't miss the webinar on Thursday #Kotlin!

As always there is too much I want to talk about😅 Composing different #arrowkt DSLs and #KotlinX #Coroutines to running #Kotlin JVM/Native
#JetBrains #Ktor on #Kubernetes with zero-downtime.

& be sure to bring all your questions! ☺️

https://info.jetbrains.com/kotlin-webinar-february16-2023.html?utm_campaign=webinar-february16-2023

I’ll be giving a workshop about #FP in #Kotlin with #arrowkt together with @raulraja, @trupill and Francisco Díaz! So it’s going to be 🔥

Be sure to get your tickets here! Looking forward to @kotlinconf. It’s going to be great seeing everyone and doing a workshop and a talk 😱

https://kotlinconf.com/workshops/

Next week Thursday the 16th I'll be talking with
@antonarhipov again about #JetBrains #Ktor and #ArrowKt.

I'll be doing some live coding again showing Arrow's Resource DSL & SuspendApp running on
#kubernetes with #Kotlin JVM & Native!😱

Register here: https://info.jetbrains.com/kotlin-webinar-february16-2023.html?utm_source=marketo&utm_medium=email&utm_content=event&utm_campaign=kotlin

I had a great time talking at
@fosdem! Thanks for the great questions, and organisation 🥰

My slide deck is available here, https://speakerdeck.com/nomisrev/functional-fun-in-kotlin and the recording will soon be available.

#kotlin #functionalprogramming #ArrowKt

SuspendApp 0.4.0 is now available! This release adds a new integration module for #Ktor.

Read more details about this release at https://xebia.com/blog/suspendapp-0-4-0-is-now-available/.

The full changelog is available on Github: https://github.com/arrow-kt/suspendapp/releases/tag/0.4.0

#JetBrainsKtor #ArrowKt #kotlin #FunctionalProgramming

New version of #ArrowKt was released. 1.1.4 & 1.1.5 for #Kotlin 1.7.22 and 1.8.0 respectively.

TL;DR use 1.1.5 if you don’t use KSP.

New APIs towards 2.0, and a bunch of other improvements and fixes. A lot of new contributors 🥳❤️

Check out the release post here, https://www.47deg.com/blog/arrow-v1-01-4-release/

And the changelog on GitHub: https://github.com/arrow-kt/arrow/releases/tag/1.1.5

External _compile time_ validation, invariants, guards, pre/post conditions, etc for #kotlin #arrowkt

https://arrow-kt.io/docs/analysis/laws/

It's piggybacking off of runtime checks and making it available at compile time.

When did Kotlin get so sexy!?

Full #arrowkt 2.0 and #kotlin context receivers toy example, including a small json codec toy library to try my hand at non trivial stuff:
https://github.com/agile-jordi/arrow2example

@jillesvangurp
🆒
#Cloud
#opensearch
#kotlin
But suspend and throw
No #ArrowKt: I'm afraid it confirms those CatsEffect libraries are still a niche.
Not always cloud ☁️ apps are written in #golang

(((Even for desktop, I find that gnome #rust is so elegant with async and idiomatic builder, but can anyone patch gnome apps (e.g. gnome-calendar) in anything else than C?)))

https://github.com/jillesvangurp/kt-search/blob/master/search-client/src/commonMain/kotlin/com/jillesvangurp/ktsearch/SearchClient.kt

@routis Yes! I forgot for a second that _Java_ was not allowed 😂 vavr is the one that turns Java upside down 😉

Here is an updated example with vavr, showing how easy it is to integrate any data type into #ArrowKt in #kotlin.

Another #ArrowKt snippet today! Similarly to how #kotlin #Coroutines allows you to easily integrate with other concurrency frameworks through suspend.

Arrow will allow integration with other #functional data types 😍

Context receivers power this slick DSLs. Stable when? 🥲

Bas De Groot gave a great talk about #Functional Error Handling in #kotlin with #ArrowKt.

Great build up, with a bunch of really cool examples at the end about mixing wrapperless error handling with #concurrency!

Check it out: https://www.youtube.com/watch?v=T04ynq2IVFs

#Kotlin 1.7.21 is rolling out 🥳

It might be a small release with mostly bug fixes, but this seems significant to me 😍 MPP is moving forward 💪

"KT-54387 - Remove MPP alpha stability warning"

I've been playing with the eco-system, and got a #Ktor server running on Linux & Mac with #ArrowKt #postgresql powered by #SqlDelight.

https://github.com/nomisRev/ktor-native-server

#Kotlin 1.7.21 is rolling out 🥳

It might be a small release with mostly bug fixes, but this seems significant to me 😍 MPP is moving forward 💪

"KT-54387 - Remove MPP alpha stability warning"

I've been playing with the eco-system, and got a #Ktor server running on Linux & Mac with #ArrowKt #postgresql powered by #SqlDelight.

https://github.com/nomisRev/ktor-native-server

#Kotlin 1.7.21 is rolling out 🥳

It might be a small release with mostly bug fixes, but this seems significant to me 😍 MPP is moving forward 💪

"KT-54387 - Remove MPP alpha stability warning"

I've been playing with the eco-system, and got a #Ktor server running on Linux & Mac with #ArrowKt #postgresql powered by #SqlDelight.

https://github.com/nomisRev/ktor-native-server

#Kotlin 1.7.21 is rolling out 🥳

It might be a small release with mostly bug fixes, but this seems significant to me 😍 MPP is moving forward 💪

"KT-54387 - Remove MPP alpha stability warning"

I've been playing with the eco-system, and got a #Ktor server running on Linux & Mac with #ArrowKt #postgresql powered by #SqlDelight.

https://github.com/nomisRev/ktor-native-server