In kotlin, it's possible to check via reflection i...

# reflect

[vmironov]

In kotlin, it's possible to check via reflection if property was declared as nullable. For example, the following code

public class Magic {
  private val foo: String? = null
  private val bar: String = "not"
}

public fun main(args: Array<String>) {
  Magic::class.members.forEach {
    println("${it.name}, nullable = ${it.returnType.isMarkedNullable}")
  }
}

prints:

bar, nullable = false
foo, nullable = true
equals, nullable = false
hashCode, nullable = false
toString, nullable = false

The question is, how is KType.isMarkedNullable implemented? I don't see any nullability information in generated bytecode. Public properties are annotated with NotNull and Nullable annotations, but private ones don't have such annotations.

(I'm doing some bytecode instrumentation and want to know if field is nullable or not)