KTypes

KTypes is a zero-dependency Kotlin library for accurately introspecting type information

Examples

import kotlin.reflect.full.createType

interface Bar<T1, T2, T3>

interface Foo<T1, T2> : Bar<T2, T1, List<T2?>>

class FooImpl : Foo<String?, Int>

fun main() {
    val fooImplType = FooImpl::class.createType()
    val barType = fooImplType.findSuperType(Bar::class)

    println(barType)// Bar<Int, String?, List<Int?>>
}

import kotlin.reflect.full.createType

interface Bar<T> : List<Array<T?>>

interface Foo : Bar<String>

fun main() {
    val fooType = Foo::class.createType()
    val collectionElementType = fooType.collectionElementType

    println(collectionElementType)// Array<String?>
}

import kotlin.reflect.full.createType

interface Bar<T1, T2> : Map<T1, List<T2>?>

interface Foo : Bar<String, Int?>

fun main() {
    val fooType = Foo::class.createType()
    val mapType = fooType.findSuperType(Map::class)
    val mapKeyType = fooType.mapKeyType
    val mapValueType = fooType.mapValueType

    println(mapType)// Map<String, List<Int?>?>
    println(mapKeyType)// String
    println(mapValueType)// List<Int?>?
}

import kotlin.reflect.full.createType

interface Bar<T> : List<Array<T?>>

interface Foo : Bar<String>

fun main() {
    val fooType = Foo::class.createType()

    println(fooType.isFinal)// false
    println(fooType.isOpen)// false
    println(fooType.isAbstract)// true
    println(fooType.isSealed)// false
    println(fooType.isData)// false
    println(fooType.isInner)// false
    println(fooType.isCompanion)// false
    println(fooType.isFun)// false
    println(fooType.isInterface)// true
    println(fooType.isConcrete)// false
    println(fooType.isPrimitive)// false
    println(fooType.isAnnotation)// false
    println(fooType.isEnum)// false
    println(fooType.isArray)// false
    println(fooType.isList)// true
    println(fooType.isSet)// false
    println(fooType.isCollection)// true
    println(fooType.isCollectionLike)// true
    println(fooType.isMap)// false
}

annotation class Ann(val type: KClass<*>)

private object StringMap : TypeCapture<Map<String, String?>>

@Ann(type = StringMap::class)
class Foo

fun main() {
    val type = Foo::class
        .findAnnotation<Ann>()
        ?.type
        ?.let { if (it.isSubclassOf(TypeCapture::class)) (it as KClass<TypeCapture<*>>).capture() else it.starProjectedType }

    println(type)// Map<String, String?>
}

Download

Gradle:

dependencies {
  implementation 'cloud.pluses:ktypes:1.1.0'
}

Maven:

<dependency>
  <groupId>cloud.pluses</groupId>
  <artifactId>ktypes</artifactId>
  <version>1.1.0</version>
</dependency>