I have this code: ```val (term, definition) = stri...

# announcements

[mplain]

I have this code:

val (term, definition) = string.split(" ")
val card = Card(term, definition)

I would like to do this:

val card = Card(string.split(" "))

but it appears I cannot do that
not even with using the spread operator (*)
am I missing some thick? or no such luck?

[Mark Murphy]

Is Card your own class? If so, you could create a secondary constructor:

data class Card(val term: String, val definition: String) {
  constructor(pieces: List<String>) : this(pieces[0], pieces[1]) {}
}

fun main() {
  println(Card("foo bar".split(" ")))
}

or a factory function:

data class Card(val term: String, val definition: String)
  
fun Card(pieces: List<String>) = Card(pieces[0], pieces[1])

fun main() {
  println(Card("foo bar".split(" ")))
}

or a factory function in a companion object:

data class Card(val term: String, val definition: String) {
  companion object {
    fun newInstance(pieces: List<String>) = Card(pieces[0], pieces[1])
  }
}

fun main() {
  println(Card.newInstance("foo bar".split(" ")))
}

[mplain]

question

[mplain]

I thought "factory" refers to a method that can return different subclasses of a base class

[mplain]

but here and in other contexts i've seen it basically refer to a method that returns an instance of a class

[mplain]

is there a more specific name for a method that returns one of several subclasses, depending on the arguments?

[Shawn]

I mean, maybe just a generic factory? I don’t know if I’ve ever seen a more succinct term to describe what you’re talking about

[Shawn]

a factory method is just a method that handles creation of an object for you, there isn’t necessarily any presumption of class hierarchy aside from the type of the parameters and the stated return type

[Matteo Mirk]

It doesn’t work the way you’d like because split() returns a List, while the spread operator works with arrays. Anyway, if your class accepts two parameters even the spread operator won’t work because your constructor function should be variadic , that means accept a variable number of arguments: class Card(vararg args:String)