Instantiating type T in Kotlin - kotlin

Question

In short, I would like to omit the repeated getT() in the example below. I have read Instantiating a generic type in Kotlin, but what does it mean 'to take () -> T as a parameter'? How can I apply that to below?
interface Food
{
var isHeated:Boolean;
var name:String;
}
abstract class Cooker<T:Food>
{
abstract fun getT():T;
abstract fun enhance(t:T);
fun cook(): T
{
var food = getT();
food.isHeated = true;
food.name = "heated " + food.name;
enhance(food);
return food;
}
}
class PotatoChip:Food
{
override var isHeated = false;
override var name = "potato chip";
}
class PotatoChipCooker:Cooker<PotatoChip>()
{
override fun getT(): PotatoChip {
return PotatoChip();
}
override fun enhance(t:PotatoChip)
{
t.name = "salted " + t.name;
}
}
class Pancake:Food
{
override var isHeated = false;
override var name = "pancake";
}
class PancakeCooker:Cooker<Pancake>()
{
override fun getT(): Pancake {
return Pancake();
}
override fun enhance(t:Pancake)
{
t.name = t.name + " coated with maple syrup";
}
}
fun main(args: Array<String>)
{
val result = PotatoChipCooker().cook();
println(result.name);
val result2 = PancakeCooker().cook();
println(result2.name);
}

Answer 1

You could make the initialization function part of the primary constructor. As a result, implementing classes will have to pass a function that specifies how the corresponding type is being created:
abstract class Cooker<T : Food>(private val initT: () -> T) {
abstract fun enhance(t: T)
fun cook(): T {
val food = initT()
food.isHeated = true
food.name = "heated $name"
enhance(food)
return food
}
}
class PotatoChipCooker : Cooker<PotatoChip>({ PotatoChip() }) {
override fun enhance(t: PotatoChip) {
t.name = "salted ${t.name}"
}
}
class PancakeCooker : Cooker<Pancake>({ Pancake() }) {
override fun enhance(t: Pancake) {
t.name = "${t.name} coated with maple syrup"
}
}
Note that I removed the optional semicolons and used string templates instead of concatenations. Also, the cook method can be simplified to:
fun cook() = initT().apply {
isHeated = true
name = "heated $name"
enhance(this)
}