I need to deduplicate a list of data classes by a ...

# stdlib

[Marcin Wisniowski]

I need to deduplicate a list of data classes by a particular property of the data class. I have this, but it feels like a roundabout way of doing it:

list.groupBy { it.property }.map { (_, list) -> list.first() }

Is there a simpler way? This is something I would normally solve with .toSet(), except I only want to consider one property of the data class, not the entire item.

[molikuner]

I think you're searching for this: https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/distinct-by.html

list.distinctBy { it.property }

[ephemient]

which is equivalent to

list.filter(mutableSetOf<Any?>()::add)

but it's nice to have it as its own function :)

[Marcin Wisniowski]

distinctBy is exactly what I was hoping for thanks!