i have a setter method:

fromJson(JsonToObjectMapper jsonToObjectMapper)

(java), which configures how my library does json-mapping:

public interface JsonToObjectMapper {
    <T> T map(String json, Class<T> targetClass);
}

calling this method works fine from java, but kotlin is unable to infer types. if i try to to:

val gson = GsonBuilder().create()
myPlugin.fromJson(gson::fromJson)

i just get

None of the following functions can be called with the arguments supplied.

any ideas?

@tipsy

JsonToObjectMapper

is a kotlin interface, right?

i've tried both java and kotlin, java gets me bit farther (the one i pasted here is java)

if you define the interface in java, you can try

myPlugin.fromJson { json, cls -> gson.fromJson(json, cls) }

yeah, and you can't have lambdas with generics

does

JsonToObjectMapper

only have a single method?

yes

you could use a function type instead of an interface:

typealias JsonToObjectMapper<T> = (String, Class<T>) -> T

fun MyPlugin.fromJson(map: JsonToObjectMapper<T>) {
    ....
}

i believe this will work fine from kotlin, but not java

it should work just fine (if

kotlin-stdlib

is included in the java project), function types are just functional interfaces

alright, i'll give it a try, thanks