Simon Wirtz s1monw1

☁️

Hello, cloud.

Kotlin Enthusiast & Pioneer, Oracle Certified for Java. Other languages: Go, JavaScript, Python Twitter: s1m0nw

s1monw1 / errorSealed.kt

Created May 30, 2023 19:22

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

s1monw1 / mammalsSealed.kt

Created May 29, 2023 08:14

	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 / greetMammalWithElse.kt

Created May 29, 2023 08:10

	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 / greetMammalError.kt

Created May 29, 2023 08:05

	// 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 / mammalsHierarchySimple.kt

Last active May 29, 2023 08:10

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

s1monw1 / customprint-type.kt

Created March 17, 2023 13:52

	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 / multiple-scope-nesting.kt

Last active March 17, 2023 13:18

s1monw1 / multiple-scopes.kt

Last active March 17, 2023 13:26

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

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

	context(PrintingScope, TimeScope)

s1monw1 / context-example.kt

Last active March 17, 2023 13:26

 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 / scope-member-fun.kt

Last active March 16, 2023 14:55

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

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