Greetings! Sorry for barging in and immediately ne...

# announcements

[Tijmen van der Kemp]

Greetings! Sorry for barging in and immediately needing help :(
I'm also not sure whether to post it here or in the reflection channel, but I'm hoping to solve the problem without reflection if possible.

Short version: I have a collection of POJO's that are linked together in such a way:

A {
    value1
    value2
    B {
        value3
        ...
    }
}

etc, done a million times before.
My task is to create the following: an external party comes in with an XML definition of which entities/values they want to receive, a la GraphQL / ProtoBuf. In addition to this, we need to create "standard" messages with predefined schemas, so not only do the external party give XML, our programmers also need to define some of those messages.
I want to do this last part type safe, so my first thought was a Kotlin DSL. I've got most of it working, it's kind of looking like this:

aScope = scope(AModel) {
    addField(AModel.value1)
    addEntity(BModel) {
        addField(BModel.value3)
    }
}

object AModel {
    val value1 = field<String>()
    val value2 = field<Int>()
}

This all works fine already, but I want it to be type-safe. For example, right now this is legal:

aScope = scope(AModel) {
    addField(BModel.value3)
}

To add to the complexity, some entities have common fields, so like a good OO monkey I gave the Model objects abstract superclasses with more fields in them, which is nice, because you can do AModel.commonField and BModel.commonField and they're different unique fields :D

I think to accomplish this, I have to encode the enclosing Model class on a field somehow. Then I could do something like

fun Scope<ModelClass>.addField(field: Field<ModelClass>) { ... }

but I can't figure out how to do this without being extremely verbose like

object AModel {
    val value1 = field<AModel, String>()
}

and even then I can't get the common fields to work, because I can't seem to pass the actual Model class upwards to the abstract superclass.

Any advice is welcome, and sorry for the book! Your help is much appreciated!
Kind regards, Tijmen