Hey is there a way to call an extension method with appropri kotlinlang #announcements

12/29/2017, 10:41 PM

Hey, is there a way to call an extension method with appropriate namespace, as you would with a static method? Basically to deal with name conflicts?

12/29/2017, 10:42 PM

how do you imagine it to be?

extension functions should already be in their respective namespace (extending the class)

12/29/2017, 10:45 PM

yeah, it's kind of a weird question. This would be to resolve an extension function conflict due to subclassing.

It's a weird scenario though that maybe indicates something is wrong.

12/29/2017, 10:46 PM

can you post an example?

12/29/2017, 10:46 PM

I wanted to write and extension to a Json base base class which implicitely casts to a JsonArray, and then maps the values.

inline fun <T> JsonElement?.map(transform: (JsonElement) -> T): List<T> =
    (this as JsonArray).map(transform)

JsonArray implements list, which is what I want to use, but it just ends up being recursive.

inline fun <T> JsonElement?.map(transform: (JsonElement) -> T): List<T> =
    (this as JsonArray as Iterable<JsonElement>).map(transform)

That works, but seems a bit weird.

12/29/2017, 10:49 PM

you might as well take out the

as JsonArray

in that one?

12/29/2017, 10:50 PM

yeah, I can I can do that. It gives a casting warning, which is the only reason I was doing the two casts, but I guess that doesn't really matter.

I guess I was hoping for a

.map@kotlin.collections(transform)

, or something like that.

12/29/2017, 10:51 PM

tbh I’d be more inclined to have a separate method to cast it to an array, as that can fail, e.g.

JsonElement?.asArray() = this as JsonArray

I understand what you mean, but I haven’t seen any way of doing that

12/29/2017, 10:52 PM

yeah, not a big deal, but figured i'd check. Thanks.