board.cpp

std::string Board::prettyPrint(bool useUnicodeChars) const
{
  std::string_view charPieces[2][6] = {
      {
          useUnicodeChars ? "\u2659" : "P",
          useUnicodeChars ? "\u2657" : "B",
          useUnicodeChars ? "\u2658" : "N",
          useUnicodeChars ? "\u2656" : "R",
          useUnicodeChars ? "\u2655" : "Q",
          useUnicodeChars ? "\u2654" : "K",
      },
      {
          useUnicodeChars ? "\u265F" : "p",
          useUnicodeChars ? "\u265D" : "b",
          useUnicodeChars ? "\u265E" : "n",
          useUnicodeChars ? "\u265C" : "r",
          useUnicodeChars ? "\u265B" : "q",
          useUnicodeChars ? "\u265A" : "k",
      },
  };

  std::stringstream ss;

  auto printIcon = [&](Square square) {
    auto const pieces = {
        Piece::Pawn,
        Piece::Bishop,
        Piece::Knight,
        Piece::Rook,
        Piece::Queen,
        Piece::King,
    };

    for (auto&& color : {Color::White, Color::Black}) {
      for (auto&& piece : pieces) {
        if (mPieces[color][piece] & square) {
          ss << charPieces[color][piece] << ' ';
          return true;
        }
      }
    }
    return false;
  };

  ss << "  +-----------------+\n";

  // For each rank
  for (auto r = Rank::Rank8; r >= Rank::Rank1; --r) {
    // print the rank number
    ss << static_cast<int>(r) + 1 << " | ";
    // and each file
    for (auto f = File::FileA; f <= File::FileH; ++f) {
      if (!printIcon(makeSquare(f, r))) {
        ss << ". ";
      }
    }

    ss << "|\n";
  }

  ss << "  +-----------------+\n";
  ss << "    A B C D E F G H" << std::endl;
  return ss.str();
}