   end
 
   @doc """
-  Adds `letter` to the list of letters in `player`. Letter must
-  be a string containing a single character between `a..z` or `A..Z`.
-  """
-  def add_letter(%Player{letters: letters} = player, letter) do
-    if valid_letter?(letter) do
-      Map.put(player, :letters, [letter | letters])
-    else
-      player
-    end
-  end
-
-  @doc """
-  Removes the first occurence of `letter` from `player`'s letters.
-  """
-  def remove_letter(%Player{letters: letters} = player, letter) do
-    Map.put(player, :letters, List.delete(letters, letter))
-  end
-
-  @doc """
   Replaces the letters for `player` with the new `letters`.
   `letters` should be a list of single character strings, each
   between between `a..z` or `A..Z`.

    end
  end

  defp valid_letter?(letter) do
    ?a..?z
    |> Enum.concat(?A..?Z)

  a player in a multiplayer game.
  """

  alias WordsWithEnemies.{Player, Letters}

  defstruct name: nil, score: 0, letters: []

