KEEP VS koin

Kotlin has value classes. Here's a good overview of how they work in Kotlin: https://github.com/Kotlin/KEEP/blob/master/notes/value-class...

That document is a few years old now and was intended as a design document. But Value classes shipped with Kotlin 1.5. Apparently they are compatible with the project Valhalla value objects that will be added to the JVM at some point. So, this stuff is coming.

I had to look it up because even though I write Kotlin a lot, value classes are not something I have used at all. Looks useful but not that big of a deal and doesn't really solve a problem I have. Data classes and records (in Java) are a bigger deal IMHO.

In practice, the way you deal with immutability in Kotlin is to keep most of your data structures immutable by default unless they need to be mutable. E.g. there's a List and a MutableList interface. Most lists are immutable unless you create a MutableList. Same with val vs. var variables. Val variables can't be reassigned and you kind of use var only by exception when you really have to. The compiler will actually warn you if you do it without good reason. A data class with only vals can't be modified. Java is a bit more sloppy when it comes to mutability semantics. It has records now but all the fields have setters by default. It has var but no val assignments (you can use final to force this but few people do). And so on.

Semantically this is not as strong as what Rust does of course but it's good enough to make e.g. concurrency a lot easier. Mostly, if you avoid having a lot of mutable shared state, that becomes a lot easier.

You could imagine a Kotlin like language with much stronger semantics implementing borrow checking instead of garbage collection. It wouldn't be the same language of course but I don't think it needs to be very different. Using it would not be a massively different.

KEEP: Context receivers

I'd be very interested in a comparison between scala 3 using/given and Kotlin new context receivers https://github.com/Kotlin/KEEP/blob/master/proposals/context...

This will be furthermore simplified with multiple receivers coming very soon

I’m realizing I forgot to mention the scripting proposal in the post, will add it soon.

Tfw no pattern matching. :(

I hadn't gone over the Context Receivers design proposal until now (and still doing so, so take this with a grain of salt), but the use of what is seemingly a function call(but not) to define them seems like a bad choice. I'm sure there are design constraints that pushed this option forward, but it just seems really odd and out of place in the current Kotlin language design.

I'm aware that kotlin decided against this in kotlin itself, see https://github.com/Kotlin/KEEP/issues/82.

It's a Koin issue, not compose. Discussed here https://github.com/InsertKoinIO/koin/issues/1079

Now I will finish up saying Hilt is just an opinionated way to dependency injection on Android, but there are simpler frameworks out there such as Koin or Kodein that can help take away a lot of the troubles that can come when you try to make your own framework. Just know that most other frameworks tend to be runtime injection instead of compile time injection like Hilt, which can be helpful to know at compile time if you are missing a dependency in your graph as opposed to runtime when its out in the wild.

I've been using Angular a lot and I like how it works. I'm also a huge fan of koin for kotlin.

for injection, I suggest Koin (https://insert-koin.io/)

It'd be great if it worked

For DI take a look at Koin. It's a pragmatic lightweight dependency injection framework for Kotlin developers with multiplatform support. PeopleInSpace sample project uses it.

Because of unresolved issues like https://github.com/InsertKoinIO/koin/issues/996

ah, yes

We are using the following libs in a production project (ios/android): Jodatime --> started with Klock but recently ported to kotlinx-datetime Dagger(2) --> koin Gson --> kotlinx.serialization Socket.IO --> Ktor