KaMPKit VS kotlin-result

In KaMP Kit we actually use Koin to add the Application instance: https://github.com/touchlab/KaMPKit/blob/main/app/src/main/kotlin/co/touchlab/kampkit/android/MainApp.kt

So yes I would recommend using KMP. If you already use kotlin then it's an easy transition, you just have to learn how all the pieces work together. If you're unsure about it start with a small module and import that into your android sample. You can also view some sample projects to get started like https://github.com/touchlab/KaMPKit and https://github.com/JetBrains/compose-multiplatform-template.

I've been using Kotlin Multiplatform Mobile (KMM) heavily for the past 2 years on my current startup. I'm currently in the process of removing the entire thing.

KMM is an alternative to a cross platform mobile library like Flutter, React Native, etc. The idea is that we could write all of our mobile app's business logic, networking layer, and caching layer in Kotlin, and KMM will codgen the matching iOS code. "We only need to write it once!" is the selling point. Then we get a blank canvas to build our UI using 100% native SwiftUI & Jetpack.

In reality, the codegened iOS code gets you 90% of the way there, the but extra 10% is extremely frustrating to work with. Enums (Sealed Classes in Kotlin) get mangled in translation and you lose exhaustive switch statements. Basic data types like Bool and Int get wrapped so you can only access them using additional .boolValue or Int64(..) constructors. Entire companies are being built around solving the pain point of this last 10%: https://touchlab.co

In my opinion, the fatal mistake the KMM team made was designing it to support Objective-C, instead of just Swift. So you're using a Kotlin layer -> mangled through Objective-C -> accessed from Swift. It's a confusing decision, as the only iOS teams still actively using Objective-C are legacy apps (like the Twitter app), which seems like the opposite target market for new mobile tech like KMM. Kotlin and Swift are both modern languages, and my gut says the interop between the two would be much better without Objective-C in the middle.

Further discussion from Droidcon if you're interested: https://www.droidcon.com/2022/08/01/sdk-design-and-publishin...

> As you progress beyond "POC" to integrating and shipping real production code, the design of the "SDK surface" becomes more complicated and nuanced (or, possibly, problematic)... An Android consumer can see all the richness of the Kotlin language, but the iOS side gets filtered through Objctive-C into Swift. Much can get lost along the way.

You may check out this commit where I made these changes for the KaMPKit project

KaMPKit This one is really good, and is kinda a best practice starting point. Touchlab is a very active contributor to the KMM community and it's definitely worth keeping an eye on their blog linked above.

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Hey folks, Brady from Touchlab here. I've only been at Touchlab since the beginning of the year, but KaMP Kit, our simple-but-not-too-simple sample project to help those considering Kotlin Multiplatform, started way back at the end of 2019. Back then, Jetpack Compose had just been announced in May. It was a time full of optimism about the modern mobile UI development experience, but also of wild instability. The first method of getting Jetpack Compose to work on your machine involved pulling down the AndroidX development toolchain, and running a special version of Android Studio via terminal commands. Eventually, preview, alpha, and beta version of Compose could be used in the canary version of Android Studio (more history). Starting July 28, 2021, Compose went stable, and a version of Android Studio Arctic Fox, which supports Compose, was released in the stable channel shortly thereafter. Now we can use a stable version of Compose with a stable version of Android Studio. We at Touchlab have been excited about Compose for a long time; you can watch us geek out about it here. And though the community has been interested in Compose for KaMP Kit since at least May 2020, we didn't want folks who are trying out Kotlin Multiplatform with KaMP Kit to also have to learn a changing Jetpack Compose API, and require them to use a special version of Android Studio. Now that these obstacles have been removed, we feel comfortable fully endorsing Jetpack Compose in KMM.

I recently started using Google One Tap and Facebook login for some auth work for one of our clients at Touchlab, and wanted to make sure I was using the recommended best practices using coroutines and the new Activity Result API. This was trickier than I realized, because the docs for Google One Tap are out of date, and the API for Facebook login is out of date. So after figuring it out, I wanted to share some code snippets for my future self, and I hope you get something useful from it as well.

Multiplatform Settings is a solid multiplatform key-value store, created by Touchlab's own Russell Wolf, used extensively at Touchlab, as well as in Jetbrains' KMM Production Sample. There is a Settings interface that is implemented for Android, iOS, MacOS, and JVM platforms. At first glance, it doesn't look like Multiplatform Settings offers any encrypted storage. But thanks to the abstraction that Android has built into SharedPreferences and Multiplatform Settings' support for saving to the iOS keychain, our work is pretty easy.

Author here. I have no idea what you could possibly mean with this comment. The coroutineBinding implementation correctly uses the coroutines API for parallel decomposition of Result bindings, exactly how the Kotlin Corotines guide tells you to (backed by a [Mutex](https://github.com/michaelbull/kotlin-result/blob/master/kot...)). The coroutineBinding isn't even the main selling point of the library, you can use it without using this feature entirely.

Please could you elaborate on what "looking thread safe" means to you? The only portion of the library that supports concurrency *is* thread safe - the unit tests prove it and the use of concurrency primitives such as Kotlin's Mutex are indicative of this. I truly have no idea how you've judged the entirely of the lbirary on whether it's "thread safe" when there is a single function that's related to concurrency and it is very clearly using concurrency primitives.

Sealed classes in combination with a library like https://github.com/michaelbull/kotlin-result will get you what you need. Essentially at that point you'll be doing error handling the way you would in Rust, where a 1-level deep sealed class containing data classes as children act as the root error type and each of its variants. If you have errors coming from two different domains you just create a wrapper error type for each domain.

This is a great result lib: https://github.com/michaelbull/kotlin-result

Lastly I do not like kotlin's Result and we use the kotlin-result library which is more expressive and not tied to Throwable (similar to Arrow's Either).

In my own code, I started to use explicit error handling. I'm currently experimenting with Result (from https://github.com/michaelbull/kotlin-result) and Raise (from https://arrow-kt.io/).

un-related to multiplatform i've found it extremely helpful to wrap things in a Result type. If something can throw an error, it get's a Result return type. It sounds like that would help your use case too. The built in Result may be useful too

This is a better impl.

Using a result type can help to differentiate quite nicely. https://github.com/michaelbull/kotlin-result

kotlin-result