It s not that uncommon tho You have a set of items that shar kotlinlang #announcements

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g

ghedeon

12/22/2018, 11:07 PM

It's not that uncommon tho. You have a set of items that share common properties and differ by one field. The result of modeling this will be quite chatty.

🤔 1

g

gildor

12/23/2018, 2:28 AM

Maybe in this case better to use composition rather than inheritance?

g

ghedeon

12/23/2018, 10:08 AM

You mean to repeat common fields, without having them in the parent? But then you lose polymorphism and ability to process them in a generic way... I'm wondering what Scala and Haskell can say about this ADT aspect.

a

Andreas Sinz

12/23/2018, 11:47 AM

In Haskell there is no subtype polymorphism, everything is done with composition

The example you posted could be written in a different way:

class Person(val id: Int, val name: String, val type: PersonType)

sealed class PersonType {
    class Developer(/*custom parameters */): PersonType()
    class Painter(/*custom parameters */): PersonType()
}

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