Is your server sending :banana: when you were expe...

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[xxfast]

Is your server sending 🍌 when you were expecting 🍎and 🍊? Here's a tale of unconfined enums in kotlin
https://link.medium.com/v9MoWVdk8pb

[ephemient]

my preferred approach is more like

value class Fruit(val name: String) {
    @StringRes val stringRes: Int
        get() = when (this) {
            Apple -> R.string.fruit_apple
            else -> 0
        }

    companion object {
        val Apple = Fruit("Apple")
    }
}

but YMMV

[xxfast]

How would the use-site look? There wouldn't be any exhaustion checks at compile time right?

[ephemient]

no exhaustion checks because the type is non exhaustive, but most use sites look similar to enums by defining the known values as companion object members

[ephemient]

for this case I'd define another

fun Fruit.getLocalizedName(resources: Resources): String {
    val id = stringRes
    return if (id != Resources.ID_NULL) resources.getString(id) else name
}

to avoid having to write that check in multiple places though

[xxfast]

the interface approach lets you have some exhaustive type checks, and its nice that you can still safely enumerate over possible values when there's a whole hierarchy of em.

@Composable
fun FruitView(fruit: Fruit) {
  when (fruit) {
    is Pome -> when (fruit) {
      Apple -> AppleView(fruit)
      Pears -> PearView(fruit)
      Quince -> QuinceView(fruit)
    }
    
    is Citrus -> when(fruit){
      Oranges -> OrangeView(fruit)
      Lime -> LimeView(fruit)
      Lemon -> LemonView(fruit)
    }

    else -> OtherFruitView(fruit.name)
  }
}

p.s mind the nested whens here