I like extension functions

README.md

In the code the removeSelf function is not allowed to access the outer class if included in the AstMutator interface but if it is written as an extension function it is. Is there an other (better) way to do this? Is this a proper use case for an extension function? Anyway I think kotlin is a really fun language to program in.

Parent.kt

interface Parent {

    /**
     * This property is null when this isn't attached to anything.
     */
    val parent: Parent?
    val children: List<Parent>

    /**
     * @throws NoMutationAllowedException
     */
    val mutate: AstMutator

    interface AstMutator : MutableList<Parent>

    fun AstMutator.removeSelf() {
        parent?.mutate?.remove(this@Parent)
    }
}