Seed7_Tic-Tac-Toe

$ include "seed7_05.s7i";

const func string: boardToStr(array[3,3] of char: board) is func
begin
  result := "";
  var integer: i;
  var integer: j;

  for i range 1 to 3 do
    for j range 1 to 3 do
      result +:= " " + board[i, j] + " ";
      if j < 3 then
        result +:= "|";
      end if;
    end for;
    if i < 3 then
      result +:= "\n---+---+---\n";
    end if;
  end for;
end func;

const func void: printBoard(array[3,3] of char: board) is func
begin
  writeln(boardToStr(board));
end func;

const func boolean: isWinningMove(array[3,3] of char: board, char: player) is func
begin
  result := false;
  
  # Check rows
  for var integer: i range 1 to 3 do
    if board[i,1] = player and board[i,2] = player and board[i,3] = player then
      result := true;
      return;
    end if;
  end for;

  # Check columns
  for var integer: j range 1 to 3 do
    if board[1,j] = player and board[2,j] = player and board[3,j] = player then
      result := true;
      return;
    end if;
  end for;

  # Check diagonals
  if (board[1,1] = player and board[2,2] = player and board[3,3] = player) or
     (board[1,3] = player and board[2,2] = player and board[3,1] = player) then
    result := true;
  end if;
end func;

const func boolean: isDraw(array[3,3] of char: board) is func
begin
  result := true;
  for var integer: i range 1 to 3 do
    for var integer: j range 1 to 3 do
      if board[i, j] = ' ' then
        result := false;
        return;
      end if;
    end for;
  end for;
end func;

const func boolean: isValidMove(array[3,3] of char: board, integer: row, integer: col) is func
begin
  result := (row >= 1 and row <= 3 and col >= 1 and col <= 3 and board[row, col] = ' ');
end func;

const proc: playGame is func
begin
  var array[3,3] of char: board is [[' ', ' ', ' '], [' ', ' ', ' '], [' ', ' ', ' ']];
  var char: currentPlayer is 'X';
  var integer: row;
  var integer: col;
  var boolean: gameWon is false;

  repeat
    printBoard(board);
    writeln("Player ", currentPlayer, ", enter your move (row and column): ");
    row := getln().getInt();
    col := getln().getInt();

    if isValidMove(board, row, col) then
      board[row, col] := currentPlayer;

      if isWinningMove(board, currentPlayer) then
        printBoard(board);
        writeln("Player ", currentPlayer, " wins!");
        gameWon := true;
      elsif isDraw(board) then
        printBoard(board);
        writeln("It's a draw!");
        gameWon := true;
      else
        currentPlayer := (if currentPlayer = 'X' then 'O' else 'X');
      end if;
    else
      writeln("Invalid move. Try again.");
    end if;
  until gameWon;
end proc;

const proc: main is func
begin
  writeln("Welcome to Tic-Tac-Toe!");
  playGame();
end proc;