Kotlin Delegation Example

ByDouble.kt

class ByDouble(incrementer: Incrementer) : Incrementer by incrementer {

    override fun increment(number: Int): Int {
        return super.increment(number) * 2
    }
}

ByTwo.kt

class ByTwo : Incrementer {

    override val by: (Int) -> Int = { it + 2 }
}

Incrementer.kt

interface Incrementer {

    val by: (Int) -> Int

    fun increment(number: Int): Int {
        return by(number)
    }

}

Usage.kt

ByDouble(ByTwo()).increment(10)
//devuelve 24 -> (10+2) * 2