Apologies if this question isn’t appropriate to KS...

# ksp

[leandro]

Apologies if this question isn’t appropriate to KSP, as my understanding of it is quite small.
Let’s say I have several classes that inherit from an interface throughout my project, and would like to create some kind of output (CSV or so, not to be used in the project) that looks at all implementations of that interface together with its properties (e.g. a Map with simple types/enums). Would it be possible with KSP to do such a thing? Or should I look for a fully fledged compiler plugin?

[Ting-Yuan Huang]

If the values (e.g., initializers) of the properties are not needed, then I think KSP could be a good fit.

[leandro]

Awesome, thank you. A follow-up: I’m unsure what you mean by initializers though. Let’s say I have a class implementing this interface:

public class MyEvent(foo: MyEnum) : Event {
  override val name: String = "Event Name"
  override val properties: Map<String, Any> = mapOf("Foo" to foo)
}

Would KSP not be able to grab the values name and properties?

[jw]

No. Those are only available at runtime inside instantiated instances of that type.

[leandro]

Would my only option be a compiler plugin? Or not even?

[yigit]

i think the compiler has some constnat evaluation logic that is used for annotation values but as jake mentioned, everything else in that sample is a runtime value.
So even a compiler plugin cannot do that unless you implement some evaluation logic for those values (notice that, those values can be anything such that the classes used there may not be part of the compiler's own classpath)

[Fabio]

I have a similar but not quite same problem. Pls see an example of DI for koin below:

class CoffeeApp : KoinComponent {

    val maker: CoffeeMaker by inject()
    val aaa = "aaa"
    val l by lazy {  "lazy" }
}

I'd like to find all properties that use by inject() . I don't need the value, I'd simply want to know whether maker 's value is going to be provided by DI, so I put that in a list. So far all I can do is is isDelegated, but that's also true for l by lazy .

[jw]

You cannot. Those are implementation detail behind the properties. Also, that's not DI it's service location because it lacks inversion of control.

[Fabio]

fair enough,
is this something annotation processors could do?

[Fabio]

or maybe ByteBuddy or arrow-meta? what would be the recommended approach?

[jw]

annotation processors cannot do this. bytebuddy is just a library so you would need to run it in the context of something, but i assume it would run as a bytecode transformation which does have access to everything but at which determining these things is more challenging. i have never looked at arrow-meta but a regular Kotlin compiler plugin would have access to it, yes.