I could use some guidance on when to place code in...

# codingconventions

[Ellen Spertus]

I could use some guidance on when to place code in a companion objects vs. at the top level. For example, I have:

class WordleGame(val secretWord: String) {
  // lots of stuff in here pertaining to a single game of Wordle.
  val guesses = mutableListOf<String>()

  fun guessWord(guess: String): String {
    ...
  }
}

fun playGame() {
  // Load dictionary.
  val wordleGame = WordleGame(dictionary.random())
  // Solicit guesses from user and feed them to game object, etc.
}

Should playGame() be in a companion object in WordleGame? It certainly would be a handy place to keep the dictionary.

[Chris Fillmore]

In my experience this tends to play out according to whether you are using extension methods and whether they need to access private values, say. If they need to access private values, then this values need to be top level.

At the same time, you might also expose public values on companion object. That’s been my experience anyway.