#include <iostream>
#include <sstream>
#include <string>
+#include <vector>
#include "evaluate.h"
#include "misc.h"
namespace {
// FEN string for the initial position
- const string StartPositionFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
+ const char* StarFEN = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1";
- // UCIParser is a class for parsing UCI input. The class
- // is actually a string stream built on a given input string.
- typedef istringstream UCIParser;
+ // Keep track of position keys along the setup moves (from start position to the
+ // position just before to start searching). This is needed by draw detection
+ // where, due to 50 moves rule, we need to check at most 100 plies back.
+ StateInfo StateRingBuf[102], *SetupState = StateRingBuf;
- void set_option(UCIParser& up);
- void set_position(Position& pos, UCIParser& up);
- bool go(Position& pos, UCIParser& up);
- void perft(Position& pos, UCIParser& up);
+ void set_option(istringstream& up);
+ void set_position(Position& pos, istringstream& up);
+ bool go(Position& pos, istringstream& up);
+ void perft(Position& pos, istringstream& up);
}
-/// execute_uci_command() takes a string as input, uses a UCIParser
-/// object to parse this text string as a UCI command, and calls
-/// the appropriate functions. In addition to the UCI commands,
-/// the function also supports a few debug commands.
+/// Wait for a command from the user, parse this text string as an UCI command,
+/// and calls the appropriate functions. Also intercepts EOF from stdin to
+/// ensure that we exit gracefully if the GUI dies unexpectedly. In addition to
+/// the UCI commands, the function also supports a few debug commands.
-bool execute_uci_command(const string& cmd) {
+void uci_loop() {
- static Position pos(StartPositionFEN, false, 0); // The root position
+ Position pos(StarFEN, false, 0); // The root position
+ string cmd, token;
+ bool quit = false;
- UCIParser up(cmd);
- string token;
-
- up >> token; // operator>>() skips any whitespace
+ while (!quit && getline(cin, cmd))
+ {
+ istringstream is(cmd);
- if (token == "quit")
- return false;
+ is >> skipws >> token;
- if (token == "go")
- return go(pos, up);
+ if (token == "quit")
+ quit = true;
- if (token == "ucinewgame")
- pos.from_fen(StartPositionFEN, false);
+ else if (token == "go")
+ quit = !go(pos, is);
- else if (token == "isready")
- cout << "readyok" << endl;
+ else if (token == "ucinewgame")
+ pos.from_fen(StarFEN, false);
- else if (token == "position")
- set_position(pos, up);
+ else if (token == "isready")
+ cout << "readyok" << endl;
- else if (token == "setoption")
- set_option(up);
+ else if (token == "position")
+ set_position(pos, is);
- else if (token == "perft")
- perft(pos, up);
+ else if (token == "setoption")
+ set_option(is);
- else if (token == "d")
- pos.print();
+ else if (token == "perft")
+ perft(pos, is);
- else if (token == "flip")
- pos.flip();
+ else if (token == "d")
+ pos.print();
- else if (token == "eval")
- {
- read_evaluation_uci_options(pos.side_to_move());
- cout << trace_evaluate(pos) << endl;
- }
+ else if (token == "flip")
+ pos.flip();
- else if (token == "key")
- cout << "key: " << hex << pos.get_key()
- << "\nmaterial key: " << pos.get_material_key()
- << "\npawn key: " << pos.get_pawn_key() << endl;
+ else if (token == "eval")
+ {
+ read_evaluation_uci_options(pos.side_to_move());
+ cout << trace_evaluate(pos) << endl;
+ }
- else if (token == "uci")
- cout << "id name " << engine_name()
- << "\nid author " << engine_authors()
- << "\n" << Options.print_all()
- << "\nuciok" << endl;
- else
- cout << "Unknown command: " << cmd << endl;
+ else if (token == "key")
+ cout << "key: " << hex << pos.get_key()
+ << "\nmaterial key: " << pos.get_material_key()
+ << "\npawn key: " << pos.get_pawn_key() << endl;
- return true;
+ else if (token == "uci")
+ cout << "id name " << engine_name()
+ << "\nid author " << engine_authors()
+ << "\n" << Options.print_all()
+ << "\nuciok" << endl;
+ else
+ cout << "Unknown command: " << cmd << endl;
+ }
}
// fen string ("fen") or the starting position ("startpos") and then
// makes the moves given in the following move list ("moves").
- void set_position(Position& pos, UCIParser& up) {
+ void set_position(Position& pos, istringstream& is) {
+ Move m;
string token, fen;
- up >> token; // operator>>() skips any whitespace
+ is >> token;
if (token == "startpos")
{
- pos.from_fen(StartPositionFEN, false);
- up >> token; // Consume "moves" token if any
+ fen = StarFEN;
+ is >> token; // Consume "moves" token if any
}
else if (token == "fen")
- {
- while (up >> token && token != "moves")
+ while (is >> token && token != "moves")
fen += token + " ";
+ else
+ return;
- pos.from_fen(fen, Options["UCI_Chess960"].value<bool>());
- }
- else return;
+ pos.from_fen(fen, Options["UCI_Chess960"].value<bool>());
// Parse move list (if any)
- while (up >> token)
- pos.do_setup_move(move_from_uci(pos, token));
+ while (is >> token && (m = move_from_uci(pos, token)) != MOVE_NONE)
+ {
+ pos.do_move(m, *SetupState);
+
+ // Increment pointer to StateRingBuf circular buffer
+ if (++SetupState - StateRingBuf >= 102)
+ SetupState = StateRingBuf;
+ }
}
// command. The function updates the corresponding UCI option ("name")
// to the given value ("value").
- void set_option(UCIParser& up) {
+ void set_option(istringstream& is) {
- string token, name;
- string value = "true"; // UCI buttons don't have a "value" field
+ string token, name, value;
- up >> token; // Consume "name" token
- up >> name; // Read option name
+ is >> token; // Consume "name" token
- // Handle names with included spaces
- while (up >> token && token != "value")
- name += " " + token;
+ // Read option name (can contain spaces)
+ while (is >> token && token != "value")
+ name += string(" ", !name.empty()) + token;
- up >> value; // Read option value
-
- // Handle values with included spaces
- while (up >> token)
- value += " " + token;
+ // Read option value (can contain spaces)
+ while (is >> token)
+ value += string(" ", !value.empty()) + token;
if (Options.find(name) != Options.end())
- Options[name].set_value(value);
+ Options[name].set_value(value.empty() ? "true" : value); // UCI buttons don't have "value"
else
cout << "No such option: " << name << endl;
}
// string, and then calls think(). Returns false if a quit command
// is received while thinking, true otherwise.
- bool go(Position& pos, UCIParser& up) {
+ bool go(Position& pos, istringstream& is) {
string token;
SearchLimits limits;
- Move searchMoves[MAX_MOVES] = { MOVE_NONE };
- Move* cur = searchMoves;
+ std::vector<Move> searchMoves;
int time[] = { 0, 0 }, inc[] = { 0, 0 };
- while (up >> token)
+ while (is >> token)
{
if (token == "infinite")
limits.infinite = true;
else if (token == "ponder")
limits.ponder = true;
else if (token == "wtime")
- up >> time[WHITE];
+ is >> time[WHITE];
else if (token == "btime")
- up >> time[BLACK];
+ is >> time[BLACK];
else if (token == "winc")
- up >> inc[WHITE];
+ is >> inc[WHITE];
else if (token == "binc")
- up >> inc[BLACK];
+ is >> inc[BLACK];
else if (token == "movestogo")
- up >> limits.movesToGo;
+ is >> limits.movesToGo;
else if (token == "depth")
- up >> limits.maxDepth;
+ is >> limits.maxDepth;
else if (token == "nodes")
- up >> limits.maxNodes;
+ is >> limits.maxNodes;
else if (token == "movetime")
- up >> limits.maxTime;
+ is >> limits.maxTime;
else if (token == "searchmoves")
- {
- while (up >> token)
- *cur++ = move_from_uci(pos, token);
-
- *cur = MOVE_NONE;
- }
+ while (is >> token)
+ searchMoves.push_back(move_from_uci(pos, token));
}
- assert(pos.is_ok());
-
+ searchMoves.push_back(MOVE_NONE);
limits.time = time[pos.side_to_move()];
limits.increment = inc[pos.side_to_move()];
- return think(pos, limits, searchMoves);
+ return think(pos, limits, &searchMoves[0]);
}
// perft() is called when engine receives the "perft" command.
// The function calls perft() passing the required search depth
- // then prints counted nodes and elapsed time.
+ // then prints counted leaf nodes and elapsed time.
- void perft(Position& pos, UCIParser& up) {
+ void perft(Position& pos, istringstream& is) {
int depth, time;
int64_t n;
- if (!(up >> depth))
+ if (!(is >> depth))
return;
time = get_system_time();