44. Reflection

Reflection inspects classes and members at runtime. ::class gives a KClass, whose simpleName and isInstance work out of the box.

import kotlin.reflect.full.memberProperties

class Point(val x: Int, val y: Int)

fun main() {
    val point = Point(1, 2)
    val kClass = point::class            // a KClass instance

    println("class: ${kClass.simpleName}")
    println("is Point: ${kClass.isInstance(point)}")

    // .memberProperties comes from kotlin-reflect (kotlin.reflect.full.*)
    val names = Point::class.memberProperties.map { it.name }
    println("properties: $names")
}

simpleName and isInstance are part of the standard library, but richer introspection like memberProperties (from kotlin.reflect.full.*) requires the kotlin-reflect dependency on the classpath. Add org.jetbrains.kotlin:kotlin-reflect to your module.yaml dependencies to run the snippet above.

Running it:

$ kotlin run
class: Point
is Point: true
properties: [x, y]

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