Is there a more idiomatic way to initialize this map in Kotlin?

Question

I am writing a small game, and part of that is to keep track of player's scores. For this, I have a map initialized as follows:

// given: players: List<Player>
var scores: MutableMap<Player, Int> = mutableMapOf(*players.map { it to 0 }.toTypedArray())

What bothers me is that i need to use .toTypedArray() on the result of the map { it to 0 } before I can apply the spread operator *. Is there a way to avoid this? The same problem also occurs when creating a map by zipping two arrays:

// does not compile:
mapOf(*a1.zip(a2))

// works but more verbose:
mapOf(*a1.zip(a2).toTypedArray())

Answer 1

val pointsByPlayer = players.map { it to 0 }.toMap(mutableMapOf())

That said, a better design would probably to simply have a mutable points property in the Player class.

Answer 2

The associate function can also help with solving your problem and looks even better imho:

val scores: MutableMap<Player, Int> = players.associate { it to 0 }.toMutableMap()

And the zipping is even easier:

val zipped = a1.zip(a2).toMap()