s1monw1

sealed interface Error // implementations in same package and module only

s1monw1

sealed class Mammal(val name: String)
class Cat(val catName: String) : Mammal(catName)
class Human(val humanName: String, val job: String) : Mammal(humanName)

fun greetMammal(mammal: Mammal): String {
    return when (mammal) {
        is Human -> "Hello ${mammal.name}; You're working as a ${mammal.job}"
        is Cat -> "Hello ${mammal.name}"
    }
}

s1monw1

fun greetMammal(mammal: Mammal): String {
    return when (mammal) {
        is Human -> "Hello ${mammal.name}; You're working as a ${mammal.job}"
        is Cat -> "Hello ${mammal.name}"
        else -> "Hello unknown creature"
    }
}

s1monw1

// This does not compile because the `when` is not exhaustive
fun greetMammal(mammal: Mammal): String {
    return when (mammal) {
        is Human -> "Hello ${mammal.name}; You're working as a ${mammal.job}"
        is Cat -> "Hello ${mammal.name}"
    }
}

s1monw1

open class Mammal(val name: String)
class Cat(val catName: String) : Mammal(catName)
class Human(val humanName: String, val job: String) : Mammal(humanName)

s1monw1

context(PrintingScope, TimeScope)
fun <K, V> Map<K, V>.customPrint() {
    // ...
}

// get type in two different ways

val funType1: KFunction3<PrintingScope, TimeScope, Map<String, String>, Unit> =
  Map<String, String>::customPrint

s1monw1

val mapping = mapOf("a" to 1, "b" to 2, "c" to 3)

with(PrintingScope()) {
    with(TimeScope()) {
        mapping.customPrint()
    }
}

s1monw1

class PrintingScope(
    val separator: String = "________________"
)

class TimeScope {
    fun getCurrentTime(): LocalTime =
        LocalDateTime.now().toLocalTime().truncatedTo(ChronoUnit.SECONDS)
}

context(PrintingScope, TimeScope)

s1monw1

class PrintingScope(
    val separator: String = "________________"
)

context(PrintingScope)
fun <K, V> Map<K, V>.customPrint() {
    forEach { (k, v) ->
        println("K: $k")
        println("V: $v")
        println(separator)

s1monw1

val mapping = mapOf("a" to 1, "b" to 2, "c" to 3)
val customizer = PrintingCustomizer()

// usage
with(customizer){
    mapping.customPrint()
}