hey all a question regarding some code we have in ...

# getting-started

[nadi]

hey all
a question regarding some code we have in our project
We have an extension method defined on KFunction - "someExtensionMethod". and then we call it from a data class like this: SomeDataClass::someExtensionMethod ::SomeDataClass.someExtensionMethod

now im going through kotlin doc and im still not quite sure how is this possible. or what exactly is happening?
if for example that SomeDataClass has 4 params in its constructor it will invoke the extension method
KFunction4.someExtensionMethod

can you refer me to the place in docs that explain such behvaior?

[Joffrey]

Could you please post a snippet that shows this behavior?
I get an error:
https://pl.kotl.in/K2RGafV4J

[nadi]

data class SomeDataClass(val param: String)
import kotlin.reflect.KFunction1
 
 fun <String, T0> KFunction1<String, T0>.someMethod(
      param:String
 ) = println("i can be called from a data class reference " + param )

::SomeDataClass.someMethod("my param")
i can be called from a data class reference my param

i executed it inside kotlin repl

[Joffrey]

Ah ::SomeDataClass.someMethod is different from SomeDataClass::someMethod

[nadi]

ops, sorry

[Joffrey]

I should have thought that's what you meant, no worries

[Joffrey]

In the code you posted, the constructor takes a string and spits a SomeDataClass so it is a valid KFunction1<String, SomeDataClass>

[Joffrey]

And ::SomeDataClass is a reference to the constructor, so it's ok to call the extension function on it

[nadi]

::SomeDataClass is of type Function?

[nadi]

nevermind it is

[nadi]

i got confused hehe

[nadi]

sorrrry

[nadi]

(::SomeDataClass)::class
res15: kotlin.reflect.KClass<out kotlin.reflect.KFunction1<kotlin.String, Line_0.SomeDataClass>> = class Line_17$res15$1