Modelling ADTs: union types vs mixin

[ShahOdin]

I want to end up generating the following scala code:

saeld trait Foo {
  val internal_id: String
  val external_id: String 
}

object Foo{
  case object Bar extends Foo {
    val internal_id: String = "1"
    val external_id: String = "2"
  }

  case object Baz extends Foo {
    val internal_id: String = "10"
    val external_id: String = "20"
  }
}

as closely as possible. What would be the cleanest/preferred way of achieving this in smithy? Think both union types and mixins would give me something close enough 🤔

ideally, It'd be nice if we can have an enumeratum style Foo.all method generated for us as well. that would return Seq(Bar, Baz)

[lewisjkl]

Hey ShahOdin, you aren't going to be able to generate something exactly like this. The primary reason is that what you want isn't even expressible in smithy. For example,

structure Bar {
  internal_id: String = "1"
}

this structure does not represent an instance of a class, but rather a definition of a class. This means that the "1" here represents a default parameter as seen in:

final case class Bar(internal_id: String = "1")

So you definitely can get close to what you want with mixins (though mixins do not generate sealed traits, but rather open traits) and unions, but not exactly.

I hope this helps, but feel free to follow up with any questions!