Use Kotlin Classes
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Extending on interfaces, you’ll see that not every conventional rule must be followed. The Kotlin language allows you to build code that makes little logical sense but could help define behaviors.
interface Shape {
var name: String
get() = names[this]?.uppercase() ?: "Unknown shape"
set(value) {
names[this] = value
}
var vertices: Int
get() = vertexCount[this] ?: -1
set(value) {
vertexCount[this] = value
}
val details: String
get() = "The $name has $vertices vertices"
companion object {
private val names = mutableMapOf<Shape, String>()
private val vertexCount = mutableMapOf<Shape, Int>()
}
}
class Triangle : Shape
class Square : Shape
fun main() {
val triangle = Triangle()
triangle.name = "Triangle"
triangle.vertices = 3
val square = Square()
square.name = "Square"
square.vertices = 5
println(triangle.details) // The TRIANGLE has 3 vertices
println(square.details) // The SQUARE has 5 vertices
}
companion object {
val names = mutableMapOf<Shape, String>()
}
Shape.names.forEach { name ->
println(name.value)
}
// Triangle
// Square