2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2009 Marco Costalba
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
38 //// Local definitions
55 Ambiguity move_ambiguity(const Position& pos, Move m);
56 const string time_string(int milliseconds);
57 const string score_string(Value v);
65 /// move_to_san() takes a position and a move as input, where it is assumed
66 /// that the move is a legal move from the position. The return value is
67 /// a string containing the move in short algebraic notation.
69 const string move_to_san(const Position& pos, Move m) {
72 assert(move_is_ok(m));
79 pt = type_of_piece(pos.piece_on(move_from(m)));
85 else if (m == MOVE_NULL)
87 else if (move_is_long_castle(m) || (int(to - from) == -2 && pt == KING))
89 else if (move_is_short_castle(m) || (int(to - from) == 2 && pt == KING))
95 san += piece_type_to_char(pt, true);
96 switch (move_ambiguity(pos, m)) {
100 san += file_to_char(square_file(from));
103 san += rank_to_char(square_rank(from));
106 san += square_to_string(from);
112 if (pos.move_is_capture(m))
115 san += file_to_char(square_file(move_from(m)));
118 san += square_to_string(move_to(m));
119 if (move_promotion(m))
122 san += piece_type_to_char(move_promotion(m), true);
125 // Is the move check? We don't use pos.move_is_check(m) here, because
126 // Position::move_is_check doesn't detect all checks (not castling moves,
127 // promotions and en passant captures).
132 san += p.is_mate()? "#" : "+";
138 /// move_from_san() takes a position and a string as input, and tries to
139 /// interpret the string as a move in short algebraic notation. On success,
140 /// the move is returned. On failure (i.e. if the string is unparsable, or
141 /// if the move is illegal or ambiguous), MOVE_NONE is returned.
143 Move move_from_san(const Position& pos, const string& movestr) {
147 MovePicker mp = MovePicker(pos, false, MOVE_NONE, OnePly, History());
150 if (movestr == "O-O-O" || movestr == "O-O-O+")
153 while ((m = mp.get_next_move()) != MOVE_NONE)
154 if (move_is_long_castle(m) && pos.pl_move_is_legal(m))
159 else if (movestr == "O-O" || movestr == "O-O+")
162 while ((m = mp.get_next_move()) != MOVE_NONE)
163 if (move_is_short_castle(m) && pos.pl_move_is_legal(m))
169 // Normal moves. We use a simple FSM to parse the san string.
170 enum { START, TO_FILE, TO_RANK, PROMOTION_OR_CHECK, PROMOTION, CHECK, END };
171 static const string pieceLetters = "KQRBN";
172 PieceType pt = NO_PIECE_TYPE, promotion = NO_PIECE_TYPE;
173 File fromFile = FILE_NONE, toFile = FILE_NONE;
174 Rank fromRank = RANK_NONE, toRank = RANK_NONE;
178 for (size_t i = 0; i < movestr.length(); i++)
180 char type, c = movestr[i];
181 if (pieceLetters.find(c) != string::npos)
183 else if (c >= 'a' && c <= 'h')
185 else if (c >= '1' && c <= '8')
194 pt = piece_type_from_char(c);
197 else if (state == PROMOTION)
199 promotion = piece_type_from_char(c);
200 state = (i < movestr.length() - 1) ? CHECK : END;
209 fromFile = toFile = file_from_char(c);
212 else if (state == TO_FILE)
214 toFile = file_from_char(c);
217 else if (state == TO_RANK && toFile != FILE_NONE)
219 // Previous file was for disambiguation
221 toFile = file_from_char(c);
227 if (state == TO_RANK)
229 toRank = rank_from_char(c);
230 state = (i < movestr.length() - 1) ? PROMOTION_OR_CHECK : END;
232 else if (state == TO_FILE && fromRank == RANK_NONE)
234 // It's a disambiguation rank instead of a file
235 fromRank = rank_from_char(c);
241 if (state == TO_RANK)
243 // Previous file was for disambiguation, or it's a pawn capture
247 else if (state != TO_FILE)
251 if (state == PROMOTION_OR_CHECK)
257 if (state == PROMOTION_OR_CHECK || state == CHECK)
271 // Look for a matching move
272 Move m, move = MOVE_NONE;
273 to = make_square(toFile, toRank);
276 while ((m = mp.get_next_move()) != MOVE_NONE)
277 if ( pos.type_of_piece_on(move_from(m)) == pt
279 && move_promotion(m) == promotion
280 && (fromFile == FILE_NONE || fromFile == square_file(move_from(m)))
281 && (fromRank == RANK_NONE || fromRank == square_rank(move_from(m))))
286 return (matches == 1 ? move : MOVE_NONE);
290 /// line_to_san() takes a position and a line (an array of moves representing
291 /// a sequence of legal moves from the position) as input, and returns a
292 /// string containing the line in short algebraic notation. If the boolean
293 /// parameter 'breakLines' is true, line breaks are inserted, with a line
294 /// length of 80 characters. After a line break, 'startColumn' spaces are
295 /// inserted at the beginning of the new line.
297 const string line_to_san(const Position& pos, Move line[], int startColumn, bool breakLines) {
303 size_t maxLength = 80 - startColumn;
306 for (int i = 0; line[i] != MOVE_NONE; i++)
308 moveStr = move_to_san(p, line[i]);
309 length += moveStr.length() + 1;
310 if (breakLines && length > maxLength)
312 s << '\n' << std::setw(startColumn) << ' ';
313 length = moveStr.length() + 1;
317 if (line[i] == MOVE_NULL)
320 p.do_move(line[i], st);
326 /// pretty_pv() creates a human-readable string from a position and a PV.
327 /// It is used to write search information to the log file (which is created
328 /// when the UCI parameter "Use Search Log" is "true").
330 const string pretty_pv(const Position& pos, int time, int depth,
331 uint64_t nodes, Value score, Move pv[]) {
335 s << std::setw(2) << depth << " ";
338 s << std::setw(8) << score_string(score);
341 s << std::setw(8) << time_string(time) << " ";
344 if (nodes < 1000000ULL)
345 s << std::setw(8) << nodes << " ";
346 else if (nodes < 1000000000ULL)
347 s << std::setw(7) << nodes/1000ULL << 'k' << " ";
349 s << std::setw(7) << nodes/1000000ULL << 'M' << " ";
352 s << line_to_san(pos, pv, 30, true);
360 Ambiguity move_ambiguity(const Position& pos, Move m) {
362 Square from = move_from(m);
363 Square to = move_to(m);
364 Piece pc = pos.piece_on(from);
366 // King moves are never ambiguous, because there is never two kings of
368 if (type_of_piece(pc) == KING)
369 return AMBIGUITY_NONE;
371 MovePicker mp = MovePicker(pos, false, MOVE_NONE, OnePly, History());
372 Move mv, moveList[8];
375 while ((mv = mp.get_next_move()) != MOVE_NONE)
376 if (move_to(mv) == to && pos.piece_on(move_from(mv)) == pc && pos.pl_move_is_legal(mv))
380 return AMBIGUITY_NONE;
383 for (int i = 0; i < n; i++)
385 if (square_file(move_from(moveList[i])) == square_file(from))
388 if (square_rank(move_from(moveList[i])) == square_rank(from))
392 return AMBIGUITY_FILE;
395 return AMBIGUITY_RANK;
397 return AMBIGUITY_BOTH;
401 const string time_string(int milliseconds) {
404 s << std::setfill('0');
406 int hours = milliseconds / (1000*60*60);
407 int minutes = (milliseconds - hours*1000*60*60) / (1000*60);
408 int seconds = (milliseconds - hours*1000*60*60 - minutes*1000*60) / 1000;
413 s << std::setw(2) << minutes << ':' << std::setw(2) << seconds;
418 const string score_string(Value v) {
422 if (v >= VALUE_MATE - 200)
423 s << "#" << (VALUE_MATE - v + 1) / 2;
424 else if(v <= -VALUE_MATE + 200)
425 s << "-#" << (VALUE_MATE + v) / 2;
428 float floatScore = float(v) / float(PawnValueMidgame);
432 s << std::setprecision(2) << std::fixed << floatScore;