Is there a specific reason why

Set<T>.map {}

returns a

List

and not a

Set

?

You can look at the definition of the extension function, I think it’s defined on

Iterable

so

List

is the return type that makes the most sense given the generic receiver.

Right, there's no

Set<T>.map {}

...

Also, even if it was defined on

Set

, it wouldn't necessarily make sense to return a set, as we don't know if the mapping function will return unique values. So dropping data when mapping to a set should be explicit.

@Ruckus right, makes sense

A set can’t contain duplicate values, by definition

Mmm right, and since the order or iteration is not defined, what data is going to be dropped would not be defined either

If you want a set, use mapTo and supply one