2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
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
50 const History H; // Used as dummy argument for MovePicker c'tor
52 Ambiguity move_ambiguity(const Position& pos, Move m);
53 const string time_string(int milliseconds);
54 const string score_string(Value v);
62 /// move_to_san() takes a position and a move as input, where it is assumed
63 /// that the move is a legal move from the position. The return value is
64 /// a string containing the move in short algebraic notation.
66 const string move_to_san(Position& pos, Move m) {
69 assert(move_is_ok(m));
72 Square from = move_from(m);
73 Square to = move_to(m);
74 PieceType pt = type_of_piece(pos.piece_on(move_from(m)));
78 else if (m == MOVE_NULL)
80 else if (move_is_long_castle(m) || (int(to - from) == -2 && pt == KING))
82 else if (move_is_short_castle(m) || (int(to - from) == 2 && pt == KING))
88 san += piece_type_to_char(pt, true);
90 switch (move_ambiguity(pos, m)) {
94 san += file_to_char(square_file(from));
97 san += rank_to_char(square_rank(from));
100 san += square_to_string(from);
106 if (pos.move_is_capture(m))
109 san += file_to_char(square_file(move_from(m)));
112 san += square_to_string(move_to(m));
113 if (move_is_promotion(m))
116 san += piece_type_to_char(move_promotion_piece(m), true);
120 // The move gives check ? We don't use pos.move_is_check() here
121 // because we need to test for mate after the move is done.
125 san += pos.is_mate() ? "#" : "+";
132 /// move_from_san() takes a position and a string as input, and tries to
133 /// interpret the string as a move in short algebraic notation. On success,
134 /// the move is returned. On failure (i.e. if the string is unparsable, or
135 /// if the move is illegal or ambiguous), MOVE_NONE is returned.
137 Move move_from_san(const Position& pos, const string& movestr) {
141 MovePicker mp = MovePicker(pos, MOVE_NONE, OnePly, H);
142 Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
145 if (movestr == "O-O-O" || movestr == "O-O-O+")
148 while ((m = mp.get_next_move()) != MOVE_NONE)
149 if (move_is_long_castle(m) && pos.pl_move_is_legal(m, pinned))
154 else if (movestr == "O-O" || movestr == "O-O+")
157 while ((m = mp.get_next_move()) != MOVE_NONE)
158 if (move_is_short_castle(m) && pos.pl_move_is_legal(m, pinned))
164 // Normal moves. We use a simple FSM to parse the san string.
165 enum { START, TO_FILE, TO_RANK, PROMOTION_OR_CHECK, PROMOTION, CHECK, END };
166 static const string pieceLetters = "KQRBN";
167 PieceType pt = PIECE_TYPE_NONE, promotion = PIECE_TYPE_NONE;
168 File fromFile = FILE_NONE, toFile = FILE_NONE;
169 Rank fromRank = RANK_NONE, toRank = RANK_NONE;
173 for (size_t i = 0; i < movestr.length(); i++)
175 char type, c = movestr[i];
176 if (pieceLetters.find(c) != string::npos)
178 else if (c >= 'a' && c <= 'h')
180 else if (c >= '1' && c <= '8')
189 pt = piece_type_from_char(c);
192 else if (state == PROMOTION)
194 promotion = piece_type_from_char(c);
195 state = (i < movestr.length() - 1) ? CHECK : END;
204 fromFile = toFile = file_from_char(c);
207 else if (state == TO_FILE)
209 toFile = file_from_char(c);
212 else if (state == TO_RANK && toFile != FILE_NONE)
214 // Previous file was for disambiguation
216 toFile = file_from_char(c);
222 if (state == TO_RANK)
224 toRank = rank_from_char(c);
225 state = (i < movestr.length() - 1) ? PROMOTION_OR_CHECK : END;
227 else if (state == TO_FILE && fromRank == RANK_NONE)
229 // It's a disambiguation rank instead of a file
230 fromRank = rank_from_char(c);
236 if (state == TO_RANK)
238 // Previous file was for disambiguation, or it's a pawn capture
242 else if (state != TO_FILE)
246 if (state == PROMOTION_OR_CHECK)
252 if (state == PROMOTION_OR_CHECK || state == CHECK)
266 // Look for a matching move
267 Move m, move = MOVE_NONE;
268 to = make_square(toFile, toRank);
271 while ((m = mp.get_next_move()) != MOVE_NONE)
272 if ( pos.type_of_piece_on(move_from(m)) == pt
274 && move_promotion_piece(m) == promotion
275 && (fromFile == FILE_NONE || fromFile == square_file(move_from(m)))
276 && (fromRank == RANK_NONE || fromRank == square_rank(move_from(m))))
281 return (matches == 1 ? move : MOVE_NONE);
285 /// line_to_san() takes a position and a line (an array of moves representing
286 /// a sequence of legal moves from the position) as input, and returns a
287 /// string containing the line in short algebraic notation. If the boolean
288 /// parameter 'breakLines' is true, line breaks are inserted, with a line
289 /// length of 80 characters. After a line break, 'startColumn' spaces are
290 /// inserted at the beginning of the new line.
292 const string line_to_san(const Position& pos, Move line[], int startColumn, bool breakLines) {
298 size_t maxLength = 80 - startColumn;
299 Position p(pos, pos.thread());
301 for (Move* m = line; *m != MOVE_NONE; m++)
303 moveStr = move_to_san(p, *m);
304 length += moveStr.length() + 1;
305 if (breakLines && length > maxLength)
307 s << "\n" << std::setw(startColumn) << " ";
308 length = moveStr.length() + 1;
321 /// pretty_pv() creates a human-readable string from a position and a PV.
322 /// It is used to write search information to the log file (which is created
323 /// when the UCI parameter "Use Search Log" is "true").
325 const string pretty_pv(const Position& pos, int time, int depth, uint64_t nodes,
326 Value score, ValueType type, Move pv[]) {
328 const uint64_t K = 1000;
329 const uint64_t M = 1000000;
334 s << std::setw(2) << depth << " ";
337 s << (type == VALUE_TYPE_LOWER ? ">" : type == VALUE_TYPE_UPPER ? "<" : " ")
338 << std::setw(7) << score_string(score);
341 s << std::setw(8) << time_string(time) << " ";
345 s << std::setw(8) << nodes / 1 << " ";
346 else if (nodes < K * M)
347 s << std::setw(7) << nodes / K << "K ";
349 s << std::setw(7) << nodes / M << "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, MOVE_NONE, OnePly, H);
372 Bitboard pinned = pos.pinned_pieces(pos.side_to_move());
373 Move mv, moveList[8];
376 while ((mv = mp.get_next_move()) != MOVE_NONE)
377 if (move_to(mv) == to && pos.piece_on(move_from(mv)) == pc && pos.pl_move_is_legal(mv, pinned))
381 return AMBIGUITY_NONE;
384 for (int i = 0; i < n; i++)
386 if (square_file(move_from(moveList[i])) == square_file(from))
389 if (square_rank(move_from(moveList[i])) == square_rank(from))
393 return AMBIGUITY_FILE;
396 return AMBIGUITY_RANK;
398 return AMBIGUITY_BOTH;
402 const string time_string(int millisecs) {
404 const int MSecMinute = 1000 * 60;
405 const int MSecHour = 1000 * 60 * 60;
408 s << std::setfill('0');
410 int hours = millisecs / MSecHour;
411 int minutes = (millisecs - hours * MSecHour) / MSecMinute;
412 int seconds = (millisecs - hours * MSecHour - minutes * MSecMinute) / 1000;
417 s << std::setw(2) << minutes << ':' << std::setw(2) << seconds;
422 const string score_string(Value v) {
426 if (v >= VALUE_MATE - 200)
427 s << "#" << (VALUE_MATE - v + 1) / 2;
428 else if (v <= -VALUE_MATE + 200)
429 s << "-#" << (VALUE_MATE + v) / 2;
432 float floatScore = float(v) / float(PawnValueMidgame);
436 s << std::setprecision(2) << std::fixed << floatScore;