Guess a Coordinate

Allow the players to guess coordinates

Guessing coordinates is the most important action in the game. In order to process a guess, we need to know which player is guessing. We also need to know the row and column values the player is guessing.

We start with a client function, guess_coordinate/4, that takes those values. This wraps a GenServer.call/2 with a tuple representing the four arguments and the action. We can see this here:

def guess_coordinate(game, player, row, col) when player in @players, do:
  GenServer.call(game, {:guess_coordinate, player, row, col})

One of the tricky things to remember about guessing is that players guess against their opponent’s board. We’ve written a convenience function to get the key of a player’s opponent. From there, we get the opponent’s board with player_board/1.

defp opponent(:player1), do: :player2
defp opponent(:player2), do: :player1

We need to check a ...