Scope Functions in Kotlin

ScopeFunctions.kt

import java.time.LocalDate
import java.time.Period
import kotlin.system.exitProcess

fun main() {
    println("Please insert your birthday in this format: yyyy-MM-dd")
    readLine().takeUnless {
        it.isNullOrBlank() || it.isEmpty()
    }?.let {
        LocalDate.parse(it)
    }.apply {
        if (this == null) {
            println("The date is not valid")
            exitProcess(1)
        }
    }?.also {
        println("You wrote $it")

    }.run {
        with(Period.between(this, LocalDate.now())) {
            println("The difference between the date you wrote and today is ${this.years}")
        }
    }
}