Is it a good practice?

data class Property(
    val name: String,
    val value: String
)

data class Element(
    val name: String,
    val properties: List<Property>?,
    val elements: List<Element>?  ---> REFERENCE ITSELF
)

Also I would just use a

Map<String, String>

instead of a

List<Property>

unless

Property

is a placeholder for something more complex than two strings.

@dalexander That would be semantically different. There's no indication

name

can't repeat, or it may just be that order is important and uniqueness is handled manually.

You at-ed the wrong person. But I suppose that's true.

Yeah, the list updated right before I hit enter 😠

Generally something called "properties" can't / doesn't want to have duplicates though, which is why I added that.

Agreed. I actually have a similar issue in a project I'm working on where I have to use a List and handle uniqueness manually as being able to change the order is important, which is why it came to mind.

Also a data class comes with field names for the "key" and "value" which is syntactically pleasing 😉

Instead of

entry.key

you have

property.name

which is more context.

Ah, I see what you're saying. Sorry about that 🙂

I could have explained it better 🙃