Hi; I’m trying to access the argument names of a function as a KType. If I println the ktype, I get

(url: kotlin.String, cont: (result: kotlin.String) -> kotlin.Unit) -> kotlin.Unit

…so the information is there, at least internally. Is there any way of getting the ‘url’ and ‘cont’ strings out? I am able to get the types from the arguments() method. I have read about using .reflect() to get a KFunction, but I cannot find a good example of how to do this. for myktype.classifier.reflect(), I get:

Unresolved reference. None of the following candidates is applicable because of receiver type mismatch:
public fun <R> Function<TypeVariable(R)>.reflect(): KFunction<TypeVariable(R)>? defined in kotlin.reflect.jvm

Started playing with kapt, but cannot get Kotlin Reflection from

RoundEnvironment

. Got

TypeElement

but don’t have any idea how to make KClass out of that. Any ideas?

Is it possible to know if a type is a sealed class from a

KType

? I've created a sample of what I'm trying to do: https://pl.kotl.in/zBHj3IlEi

whats the easiest way to call a copy constructor of a data class via reflection?

Do you know how to get all inner object instances of a class e.g. get 

Inner

 from 

Outer::class

 . I figured out  how to do it using java reflection but I would prefer kotlin reflection.

class Outer {
    object Inner : Any() {}
}

var myVar : String
    get() = functionUsingTheVariableName(::field.name)

I would like to do this, but I get:

Unsupported [References to variables aren't supported yet]

any alternative?

Can you confirm that Delegated Properties are accessed only when the variable is read. For example in this context:

object LocalSettings : SettingsClass() {
    var myString by StringType("mytext")
}


open class SettingsClass {

    val settings = Settings()

    inner class StringType(defaultValue : String) {
        val default = defaultValue
        operator fun getValue(thisRef: Any?, property: KProperty<*>): String {
            return settings.getString(property.name, default)
        }
        operator fun setValue(thisRef: Any?, property: KProperty<*>, value: String) {
            settings.putString(property.name, value)
        }
    }

}

can you confirmed that when the LocalSettings object is instantiated, the

StringType

delegate will be called only when accessing

LocalSettings.myString

?

My app started crashing on

Android 6

devices after enabling

R8

with this error:

ReflectKotlinClass.kt line 1 
kotlin.reflect.jvm.internal.impl.descriptors.runtime.components.ReflectClassStructure.loadClassAnnotations

Any ideas on this? It is crashing on Android 6 devices only at the moment.

Hello, I need to store a type (either a KClass or a KType) and was wondering whether it even make sense to want to store a simple type as KClass, or does it not matter if I have everything as KType (regarding space efficiency). Intuitively, I would not use the java-reflect-Type since it seemed more complex than simply Class, but I was wondering if that actually holds up. So what takes less space, a KClass or a KType (String::class or typeOf<String>())

Hey, there! Does anybody knows why property

annotations

for

KClass

returns empty array?

Hey everyone,

val test by Delegate("some value")

is it possible to get the parameter

some value

via reflection

Is there a way in Kotlin to print through reflection the type o a class like Selected<Person>? The goal is to print “Selected<Person>“, but with normal reflection methods it is not possible. The only result at runtime is “Selected”.

Hi, please some one fix this

prop.returnType.isSubtypeOf(ArrayList<String>::class.createType())

this expression raise compile error "Only classes are allowed on the left hand side of a class literal"

is there a way to speed up this code?

object S {
    val string = "String"
}
fun main() {
    println(measureTimeMillis {
        StringProvider(S::class).getContext()
    })
}
class StringProvider(val kClass: KClass<*>) {
    fun getContext(): String {
        return kClass.declaredMemberProperties.single { it.name == "string" }.call(kClass.objectInstance) as String
    }
}

it takes 420ms on my mac

Hi Folks, i currently struggle with Kotlin Annotations and the Annotation Processor. I brought up a custom Annotation

Property

@Target(AnnotationTarget.PROPERTY, AnnotationTarget.PROPERTY_GETTER)
@Retention(AnnotationRetention.RUNTIME)
annotation class Property

When using the annotation on a property e.g.:

data class Example(@Property val key: String)

and introspecting the class with a AnnotationProcessor i can find three different elements which are related to that

key

property. The first one is

key

, the second one is

getKey

and the third (which is currently probably the reason for my confusion) is the

getKey$annotations()

one, which is the only element having the annotation from java annotation processor perspective. I would have assumed that either

key

or

getKey

would also be annotated on byte-code level. Any guidance on how i can access the element

getKey

OR

key

using the annotation processor api? My actual goal is to retrieve the name

key

as well as the type

String

of the annotated element

Is it possible to get the KType of a nested sealed class? All I have access to is

T

and I know

T

is a

Sealed Class

.

Hey there. Is there a solid way to collect all properties of a class included parent-class properties? With my current approach, it misses the fields of the parent class:

open class Person(val name: String)
class Manager(name: String, val isCEO:Boolean) : Person(name)

val declaredMembers = Manager::class.declaredMembers

val properties = declaredMembers
            .filter { it.parameters.toList().size == 1 }
            .filter { it is KProperty }

Usecase: https://github.com/holgerbrandl/krangl/blob/60308cabde760a16fe31782c191b4799da9ba7c9/src/main/kotlin/krangl/Builder.kt#L53 where I'd like to fix it in a way that also super-class attributes are considered.

With the new 1.4.30 IDE plugin,

KFunction1.call()

is marked as red even with the latest org.jetbrains.kotlin:kotlin-reflect:1.4.30 in the classpatth. Still, the code seems to compile fine. Or is it just me? Example

import kotlin.reflect.KFunction1


class Test( val funPointer: KFunction1<String, String>) {
       init{
           funPointer.call("foo")
       }
}

Does this usage require kotlin-reflect.jar? val getter: KMutableProperty1<> = MyClass::myProperty val my value = getter.get(myInstance)

@Marc Knaup are you saying it isn’t possible?

Hey guys, I have a problem using kotlin-reflect with r8 shrinker. I have tried investigating it but could not find the root cause any help would be appreciated. Please see 🧵 for more 🙂

kotlin reflection on the jvm seems to be 100x slower than java reflection for some usecases. is that a known issue?

anyone know how to compare a KType to a actual type? I want to say something like

if( someProp.returnType == Double::class )

In this case I could create an instance of a

Double

and get it's type... but pretend the type is of a class that it's not easy/possible to get an instance of easily.

Is it possible to cast a value to a

KType

or check whether a value is of the type (or if necessary the classifier)?

Hi. I have a question. in the lib graphql-kotlin reflection is used to create GraphQL schema Types. If you are using a java class it will generate the types with all members being mandatory. After discussing with them they use reflection and the flag “isMarkedNullable” to determin if it is nullable or not. My question is: Why is the return type of the members of a Java class marked as non-nullable? Why is it not nullable as standard? Is there the possibility to determine if it is a javaclass or a kotlin class to work around that?

I want to get the name of the actual variable passed on the call site

inline fun <reified T> foo(value: T?): T {
    println(::value.name) // get the name
}

foo(someValue) -> should output "someValue"
foo(someValue2) -> should output "someValue2"

I tried with https://kotlinlang.org/docs/reflection.html#property-references but to no avail. Is this even possible?

i’m trying to integrate our Android app with an sdk which uses reflection to determine which methods of a callback interface have been implemented, i.e.,

private fun getClientMetadata(callback: EventListener?) = ClientMetadata(
    Build.VERSION.SDK_INT,
    Build.MANUFACTURER,
    Build.MODEL,
    Build.PRODUCT,
    Build.DEVICE,
    Build.HARDWARE,
    callback != null && overridesMethod(callback::class, "onLogin"),
    callback != null && overridesMethod(callback::class, "onSuccess"),
    callback != null && overridesMethod(callback::class, "onError"),
    callback != null && overridesMethod(callback::class, "onExit"),
    callback != null && overridesMethod(callback::class, "onEvent"),
)

private fun getUnixTimestamp(): Long {
    return System.currentTimeMillis()
}

private fun overridesMethod(cls: KClass<out EventListener>, methodName: String): Boolean {
    return cls.memberFunctions.first { it.name == methodName } in cls.declaredFunctions
}

and i’m getting the following crash:

Is it possible for me to create a function that would look something like this?

what's the difference between

functions

and

memberFunctions

and

declaredFunctions

and

declaredMemberFunctions

? The docs don't point any obvious differences.