open class Attribute(val name: String) {
    override fun toString(): String {
        return "Attribute(name='$name')"
    }
}

class A:Attribute("A")
class B:Attribute("B")
class C:Attribute("C")
class D:Attribute("D")
class E:Attribute("E")

val list: Array<Attribute> = arrayOf(A(),B(),C(),D(),E())


open class Something(
    val a: A? ,
    val b: B?,
    val c: C?,
    val d: D?,
    val e: E?
) {
    fun attribute(attribute: Attribute): SomethingClosable =
        when(attribute) {
            is A -> SomethingClosable( a = attribute, b = this.b, c = this.c, d = this.d, e = this.e  )
            is B -> SomethingClosable( a = this.a, b = attribute, c = this.c, d = this.d, e = this.e  )
            is C -> SomethingClosable( a = this.a, b = this.b, c = attribute, d = this.d, e = this.e  )
            is D -> SomethingClosable( a = this.a, b = this.b, c = this.c, d = attribute, e = this.e  )
            is E -> SomethingClosable( a = this.a, b = this.b, c = this.c, d = this.d, e = attribute  )
            else -> throw Exception("Unknown attribute")
        }



    override fun toString(): String {
        return "Something(a=$a, b=$b, c=$c, d=$d, e=$e)"
    }


}

class SomethingClosable(a:A?, b:B?, c:C?, d:D?, e:E?): Something(a,b,c,d,e) {
    fun then(): Something =
        Something(a,b,c,d,e)

    fun closeWith(attr: Attribute): SomethingClosable =
        attribute(attr)
}

fun main(args: Array<String>) {

    val result = list.fold(Something(null,null,null,null,null)){ acc: Something, attribute:Attribute  ->
        acc.attribute(attribute).then()
    }

    println(result)

}