kotlin pythonの__new__みたいなやつ

foo.kt

open class DayOfTheWeek {
    var s = 0
    constructor() {
        this.s = 0
    }
    
    constructor(foo: Int) {
        this.s = foo
    }
    
    companion object {
        operator fun invoke(s: Int): DayOfTheWeek {
            return Monday(s)
        }
    }

    class Monday(s: Int) : DayOfTheWeek()
    class Tuesday(s: Int) : DayOfTheWeek()
}

fun main() {   
   println(DayOfTheWeek(234).s)
   println(DayOfTheWeek().s)
}