val transforms = listOf<(String) -> String>(
    { it.toLowerCase() },
    { it.split(",").first() }
)
val data = listOf("foo, 42", "BAR, 33")

val result = data.mapAll(transforms) // result has ["foo", "bar"]

allPositions

allProducts

Route

Router

.handler()

Router

.route()

.Companion

class Foo {
    companion object {
        val bar: Int = 42
    }
}
// Works
val member2 = Foo.Companion::bar
// Doesn't work: unresolved reference
val member = Foo::bar

private fun filterFunction(direction: DType?, iban: String?, minAmount: Int?,
                           maxAmount: Int?, descrIncluded: String?): Predicate<Transaction> {
    val predicates: MutableList<Predicate<Transaction>> = ArrayList()
    direction?.let { predicates.add(Predicate { t: Transaction -> t.direction == direction }) }
    iban?.let { predicates.add(Predicate { t: Transaction -> t.iban.equals(iban) }) }
    minAmount?.let { predicates.add(Predicate { t: Transaction -> t.amount >= minAmount }) }
    maxAmount?.let { predicates.add(Predicate { t: Transaction -> t.amount <= maxAmount }) }
    descrIncluded?.let { predicates.add(Predicate { t: Transaction -> t.descr.contains(descrIncluded, true) }) }
    return Predicate { transaction: Transaction ->
        predicates.all { predicate: Predicate<Transaction> -> predicate.test(transaction) }
    }
}

val fishnet="Net"to"Catch fish"

val(tool,use)=fishnet
println("$tool and $use")

if(x != null) y = x

x?.let { y = x }

ifNotNull(x) { y = it }

y = x ?: y

HIDDEN

WARNING

BigInteger

+

plus()

fun main() {
    BigInteger.ONE + BigInteger.ONE
}

libpaycoin_kref_com_ionspin_kotlin_bignum_integer_BigInteger

Summary

SummaryCalculation

data class Summary(val aProperty:String, val items:List<BillableItem>)

//This I don't know
data class BillingSummary(initialSummary:Summary, totalItemsBilled:Long):Summary

fun main() {
    var value: Any? = "hello"

    if (value != null) {
        for (i in 1..10) {
            value = nonNullFoo(value) // smart casting fails
        }
    }
}

fun nonNullFoo(obj: Any): Any {
    return "World"
}