$ whois kotlin

Kotlin

first released in 2011 · by Andrey Breslav

$ guessprog --inspect kotlin

year: 2011
paradigm: object oriented
family: c like
memory: automatic gc
binding: static
safety: strong

KOTLIN(7)

AUTHORS: Andrey Breslav
HISTORY: Kotlin was created at JetBrains, the company behind IntelliJ IDEA, in a team led by Andrey Breslav at its Saint Petersburg office. JetBrains unveiled it in 2011, looking for a more concise and safer language than Java that would still run on the JVM and mix freely with existing Java code. It is named after Kotlin Island near Saint Petersburg, a wink at Java being named after an island too. Version 1.0 shipped in 2016, and a year later Google announced official support for Kotlin on Android.
USAGE: A mainstream language. Kotlin is Google's preferred language for Android apps, and it is widely used for server-side JVM development, build scripts with Gradle and, increasingly, code shared across platforms with Kotlin Multiplatform.
SEE ALSO: Kotlin on Wikipedia ↗

$ cat users.kt

data class User(val name: String, val email: String? = null)

fun String.shout() = uppercase() + "!"

fun describe(user: User) =
    "${user.name}: ${user.email ?: "no email"}"

fun main() {
    val users = listOf(User("ada"), User("linus", "[email protected]"))
    users.map(::describe).forEach(::println)
    println(users.first().name.shout())
}