From 02882dfe81eae37ce09ce9af95864cf9fad49bbe Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sat, 24 Jul 2010 17:59:18 +0100 Subject: [PATCH] Cleanup Position::to_fen() Less invasive then previous patches, but still a good enhancement. Also some indulge on STL algorithms :-) No functional change. Signed-off-by: Marco Costalba --- src/position.cpp | 97 +++++++++++++++++++++++++----------------------- src/square.h | 6 +-- 2 files changed, 53 insertions(+), 50 deletions(-) diff --git a/src/position.cpp b/src/position.cpp index 2126741e..19812ab7 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -22,6 +22,7 @@ //// Includes //// +#include #include #include #include @@ -43,6 +44,8 @@ using std::string; using std::cout; using std::endl; +static inline bool isZero(char c) { return c == '0'; } + struct PieceLetters : std::map { PieceLetters() { @@ -54,6 +57,17 @@ struct PieceLetters : std::map { operator[]('N') = WN; operator[]('n') = BN; operator[]('P') = WP; operator[]('p') = BP; } + + char from_piece(Piece p) const { + + map::const_iterator it; + for (it = begin(); it != end(); ++it) + if (it->second == p) + return it->first; + + assert(false); + return 0; + } }; //// @@ -69,6 +83,7 @@ Key Position::zobExclusion; Score Position::PieceSquareTable[16][64]; static bool RequestPending = false; +static PieceLetters pieceLetters; /// Constructors @@ -155,8 +170,6 @@ void Position::from_fen(const string& fen) { 6) Fullmove number: The number of the full move. It starts at 1, and is incremented after Black's move. */ - static PieceLetters pieceLetters; - char token; std::istringstream ss(fen); Rank rank = RANK_8; @@ -299,67 +312,59 @@ bool Position::set_castling_rights(char token) { } -/// Position::to_fen() converts the position object to a FEN string. This is -/// probably only useful for debugging. +/// Position::to_fen() returns a FEN representation of the position. In case +/// of Chess960 the Shredder-FEN notation is used. Mainly a debugging function. const string Position::to_fen() const { - static const string pieceLetters = " PNBRQK pnbrqk"; string fen; - int skip; + Square sq; + char emptyCnt = '0'; for (Rank rank = RANK_8; rank >= RANK_1; rank--) { - skip = 0; for (File file = FILE_A; file <= FILE_H; file++) { - Square sq = make_square(file, rank); - if (!square_is_occupied(sq)) - { skip++; - continue; - } - if (skip > 0) + sq = make_square(file, rank); + + if (square_is_occupied(sq)) { - fen += (char)skip + '0'; - skip = 0; - } - fen += pieceLetters[piece_on(sq)]; + fen += emptyCnt; + fen += pieceLetters.from_piece(piece_on(sq)); + emptyCnt = '0'; + } else + emptyCnt++; } - if (skip > 0) - fen += (char)skip + '0'; - - fen += (rank > RANK_1 ? '/' : ' '); + fen += emptyCnt; + fen += '/'; + emptyCnt = '0'; } - fen += (sideToMove == WHITE ? "w " : "b "); + + fen.erase(std::remove_if(fen.begin(), fen.end(), isZero), fen.end()); + fen.erase(--fen.end()); + fen += (sideToMove == WHITE ? " w " : " b "); + if (st->castleRights != NO_CASTLES) { - if (initialKFile == FILE_E && initialQRFile == FILE_A && initialKRFile == FILE_H) - { - if (can_castle_kingside(WHITE)) fen += 'K'; - if (can_castle_queenside(WHITE)) fen += 'Q'; - if (can_castle_kingside(BLACK)) fen += 'k'; - if (can_castle_queenside(BLACK)) fen += 'q'; - } - else - { - if (can_castle_kingside(WHITE)) - fen += char(toupper(file_to_char(initialKRFile))); - if (can_castle_queenside(WHITE)) - fen += char(toupper(file_to_char(initialQRFile))); - if (can_castle_kingside(BLACK)) - fen += file_to_char(initialKRFile); - if (can_castle_queenside(BLACK)) - fen += file_to_char(initialQRFile); - } - } else - fen += '-'; + const bool Chess960 = initialKFile != FILE_E + || initialQRFile != FILE_A + || initialKRFile != FILE_H; - fen += ' '; - if (ep_square() != SQ_NONE) - fen += square_to_string(ep_square()); - else + if (can_castle_kingside(WHITE)) + fen += Chess960 ? char(toupper(file_to_char(initialKRFile))) : 'K'; + + if (can_castle_queenside(WHITE)) + fen += Chess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q'; + + if (can_castle_kingside(BLACK)) + fen += Chess960 ? file_to_char(initialKRFile) : 'k'; + + if (can_castle_queenside(BLACK)) + fen += Chess960 ? file_to_char(initialQRFile) : 'q'; + } else fen += '-'; + fen += (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square())); return fen; } diff --git a/src/square.h b/src/square.h index 66b714a1..aa3585c1 100644 --- a/src/square.h +++ b/src/square.h @@ -180,10 +180,8 @@ inline Square square_from_string(const std::string& str) { } inline const std::string square_to_string(Square s) { - std::string str; - str += file_to_char(square_file(s)); - str += rank_to_char(square_rank(s)); - return str; + return std::string(1, file_to_char(square_file(s))) + + std::string(1, rank_to_char(square_rank(s))); } inline bool file_is_ok(File f) { -- 2.39.2