Kotlin – Filter() 매핑 예

val customerMap = mapOf(Pair(Customer("Jack", 25), Address("NANTERRE CT", "77471")),
                        Pair(Customer("Mary", 37), Address("W NORMA ST", "77009")),
                        Pair(Customer("Peter", 17), Address("S NUGENT AVE", "77571")),
                        Pair(Customer("Amos", 23), Address("E NAVAHO TRL", "77449")),
                        Pair(Customer("Craig", 45), Address("AVE N", "77587")),
                        Pair(Customer("Laura", 32), Address("NANTERRE CT", "77471")),
                        Pair(Customer("Steven", 39), Address("S NUGENT AVE", "77571")),
                        Pair(Customer("Paul", 18), Address("E NAVAHO TRL", "77449")),
                        Pair(Customer("Mary", 61), Address("S NUGENT AVE", "77571")))

public inline fun <K, V> Map<out K, V>.filter(predicate: (Map.Entry<K, V>) -> Boolean): Map<K, V>

var map = customerMap.filter { (customer, address) -> customer.age > 18 && address.street === "S NUGENT AVE" }
map.forEach{println("${it.key}, ${it.value}")}
/*
    Customer(name=Steven, age=39), Address(street=S NUGENT AVE, postcode=77571)
    Customer(name=Mary, age=61), Address(street=S NUGENT AVE, postcode=77571)
*/