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Fixed more bugs when reading PGN
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@jean-bovet
jean-bovet committed May 8, 2021
1 parent 69d1b4a commit 318c466
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Showing 4 changed files with 64 additions and 58 deletions.
18 changes: 17 additions & 1 deletion BChessTests/OpeningsTests.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -41,8 +41,12 @@ class OpeningsTests: public ::testing::Test {
}

void initializeDefaultOpenings() {
loadOpenings("Openings.pgn");
}

void loadOpenings(std::string name) {
auto path = UnitTestHelper::pathToResources;
auto pathToFile = path + "/Openings.pgn";
auto pathToFile = path + "/" + name;

auto pgn = readFromFile(pathToFile);
ASSERT_FALSE(pgn.empty());
Expand Down Expand Up @@ -135,3 +139,15 @@ TEST_F(OpeningsTests, BestMove) {
});
ASSERT_TRUE(result);
}

TEST_F(OpeningsTests, e4NYStyle) {
loadOpenings("e4NYStyle.pgn");
}

TEST_F(OpeningsTests, MultipleWhiteVariations) {
ASSERT_TRUE(openings.load("1.e4 e5 2.Nf3 ( 2.Nc3 ) ( 2.d4 ) *"));
}

TEST_F(OpeningsTests, MultipleBlackVariations) {
ASSERT_TRUE(openings.load("1.e4 e5 ( 1...Nf6 ) ( 1...c6 ) *"));
}
12 changes: 12 additions & 0 deletions BChessTests/PGNTests.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -309,3 +309,15 @@ TEST_F(PGN, LineFromCursor) {
auto line = FPGN::getGame(game, FPGN::Formatting::line, 2);
ASSERT_EQ("Nf3 Nc6 Bb5 a6", line);
}

TEST_F(PGN, MoveWithNumberInFront) {
std::string pgn = "1.e4 1... e5 2.Nf3 2... Nc6 *";

ChessGame game;
ASSERT_TRUE(FPGN::setGame(pgn, game));

ASSERT_EQ(4, game.getNumberOfMoves());

auto pgnAgain = FPGN::getGame(game);
ASSERT_EQ("1. e4 e5 2. Nf3 Nc6 *", pgnAgain);
}
88 changes: 33 additions & 55 deletions Shared/Engine/Helpers/FPGN.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -17,26 +17,7 @@
#include <iostream>
#include <vector>

/**
[Event "F/S Return Match"]
[Site "Belgrade, Serbia JUG"]
[Date "1992.11.04"]
[Round "29"]
[White "Fischer, Robert J."]
[Black "Spassky, Boris V."]
[Result "1/2-1/2"]
1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 {This opening is called the Ruy Lopez.}
4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 Nb8 10. d4 Nbd7
11. c4 c6 12. cxb5 axb5 13. Nc3 Bb7 14. Bg5 b4 15. Nb1 h6 16. Bh4 c5 17. dxe5
Nxe4 18. Bxe7 Qxe7 19. exd6 Qf6 20. Nbd2 Nxd6 21. Nc4 Nxc4 22. Bxc4 Nb6
23. Ne5 Rae8 24. Bxf7+ Rxf7 25. Nxf7 Rxe1+ 26. Qxe1 Kxf7 27. Qe3 Qg5 28. Qxg5
hxg5 29. b3 Ke6 30. a3 Kd6 31. axb4 cxb4 32. Ra5 Nd5 33. f3 Bc8 34. Kf2 Bf5
35. Ra7 g6 36. Ra6+ Kc5 37. Ke1 Nf4 38. g3 Nxh3 39. Kd2 Kb5 40. Rd6 Kc5 41. Ra6
Nf2 42. g4 Bd3 43. Re6 1/2-1/2
*/

#define REMEMBER unsigned savedCursor = cursor;
#define PARSE_BEGIN unsigned savedCursor = cursor; eatWhiteSpaces();

#define RETURN_FAILURE_SILENT(error, silent) { \
cursor = savedCursor; \
Expand Down Expand Up @@ -116,7 +97,7 @@ static bool parseUntil(std::string pgn, unsigned &cursor, std::string &comment,
return true;
}

static bool IsCastlingKingSide(Move move) {
static bool isCastlingKingSide(Move move) {
if (!MOVE_IS_CASTLING(move)) return false;

if (MOVE_COLOR(move) == WHITE) {
Expand All @@ -126,7 +107,7 @@ static bool IsCastlingKingSide(Move move) {
}
}

static bool IsCastlingQueenSide(Move move) {
static bool isCastlingQueenSide(Move move) {
if (!MOVE_IS_CASTLING(move)) return false;

if (MOVE_COLOR(move) == WHITE) {
Expand Down Expand Up @@ -175,9 +156,9 @@ std::string FPGN::to_string(Move move, SANType sanType) {
// Non-UCI mode is a bit more complex
std::string pgn = "";

if (IsCastlingKingSide(move)) {
if (isCastlingKingSide(move)) {
pgn += "O-O";
} else if (IsCastlingQueenSide(move)) {
} else if (isCastlingQueenSide(move)) {
pgn += "O-O-O";
} else {
auto isCapture = MOVE_IS_CAPTURE(move);
Expand Down Expand Up @@ -238,6 +219,8 @@ std::string FPGN::to_string(Move move, SANType sanType) {
return pgn;
}

// This function takes a board (which represents a particular board of a chess game)
// as well as a partial description of a move and returns all the moves that fit that description.
std::vector<Move> getMatchingMoves(ChessBoard board, Square to, Piece movingPiece, Piece promotedPiece, File fromFile, Rank fromRank) {
ChessMoveGenerator generator;
auto moveList = generator.generateMoves(board);
Expand Down Expand Up @@ -271,8 +254,7 @@ std::vector<Move> getMatchingMoves(ChessBoard board, Square to, Piece movingPiec
}

bool FPGN::parseMoveNumber(unsigned &moveNumber, bool &isMoveForBlack) {
REMEMBER
eatWhiteSpaces();
PARSE_BEGIN

// Parse the number portion of the move
std::string moveNumberString = "";
Expand Down Expand Up @@ -311,7 +293,6 @@ bool FPGN::parseMoveNumber(unsigned &moveNumber, bool &isMoveForBlack) {
isMoveForBlack = true;
return true;
} else {
// Invalid number of dots
RETURN_FAILURE("Invalid number of dots in move number")
}
}
Expand Down Expand Up @@ -365,8 +346,7 @@ bool FPGN::parsePiece(Piece &piece) {
}

bool FPGN::parseTerminationMarker() {
REMEMBER
eatWhiteSpaces();
PARSE_BEGIN

if (pgn[cursor] == '1' && pgn[cursor+1] == '-' && pgn[cursor+2] == '0') {
// Termination marker: white wins
Expand Down Expand Up @@ -394,9 +374,7 @@ bool FPGN::parseTerminationMarker() {
}

bool FPGN::parseMove(Move &move) {
REMEMBER

eatWhiteSpaces();
PARSE_BEGIN

Piece movingPiece;
if (!parsePiece(movingPiece)) {
Expand Down Expand Up @@ -514,19 +492,14 @@ bool FPGN::parseMove(Move &move) {

// A variation is simply an alternative line to the move that has just been played
bool FPGN::parseVariation() {
REMEMBER

eatWhiteSpaces(); // TODO: should we do this at a high level?
PARSE_BEGIN

if (character() != '(') {
RETURN_FAILURE_SILENT("Unexpected start of variation", true)
} else {
cursor++;
}

// std::cout << "Start variation at " << game.getMoveIndexes().moveCursor << std::endl;
// game.board.print();

// Remember the move indexes so we can restore it once
// we are done parsing the variation.
auto moveIndexes = game.getMoveIndexes();
Expand All @@ -537,17 +510,14 @@ bool FPGN::parseVariation() {
game.setMoveIndexes(moveIndexes);
moveIndexes.moveCursor++;

// std::cout << "Backtracking one move for the variation " << game.getMoveIndexes().moveCursor << std::endl;
// game.board.print();

// Parse the variation, which consist of one or more moveText.
// (moveText1 [moveText2]...)
while (parseMoveText()) {
if (!hasMoreCharacters()) {
RETURN_FAILURE("Unexpected end of PGN while parsing a variation")
}
if (character() == ')') {
break;;
break;
}
}

Expand All @@ -558,16 +528,14 @@ bool FPGN::parseVariation() {
RETURN_FAILURE("Unexpected end of variation")
}

// Go past ')'
cursor++;

// Restore the move indexes as it was before the variation
// so the internal game state is properly restored and
// ready to consume the next moves.
game.setMoveIndexes(moveIndexes);

// std::cout << "End variation at " << game.getMoveIndexes().moveCursor << std::endl;
// game.board.print();

return true;
}

Expand All @@ -581,7 +549,7 @@ bool FPGN::parseVariation() {
1. e4 { comment }
*/
bool FPGN::parseMoveText() {
REMEMBER
PARSE_BEGIN

bool isMoveForBlack = false;
unsigned moveNumber;
Expand All @@ -604,7 +572,7 @@ bool FPGN::parseMoveText() {
// game.board.print();

parseComment(); // optional
parseVariation(); // optional
while (parseVariation()) { } // Parse zero or more variations

// Return now if the moveText was actually only for black
if (isMoveForBlack) {
Expand All @@ -622,6 +590,16 @@ bool FPGN::parseMoveText() {
return true;
}

// Sometimes the move number is repeated for the black move
if (isDigit(character())) {
if (parseMoveNumber(moveNumber, isMoveForBlack)) {
assert(isMoveForBlack); // it should always be for black
} else {
RETURN_FAILURE("Invalid black move number")
}
}

// Parse the move itself
Move blackMove = 0;
if (!parseMove(blackMove)) {
RETURN_FAILURE("Invalid black move")
Expand All @@ -632,18 +610,16 @@ bool FPGN::parseMoveText() {
game.move(blackMove, false);

parseComment(); // optional
parseVariation(); // optional
while (parseVariation()) { } // Parse zero or more variations

return true;
}

// Parse comments in the form: { this is a comment }.
// Don't do anything with the comment itself for now.
bool FPGN::parseComment() {
REMEMBER

eatWhiteSpaces();

PARSE_BEGIN

if (character() == '{') {
cursor++;
std::string comment = "";
Expand All @@ -663,8 +639,7 @@ bool FPGN::setGame(std::string pgn, ChessGame &game) {
}

bool FPGN::parseTag(bool lookahead) {
REMEMBER
eatWhiteSpaces();
PARSE_BEGIN

// Expecting a tag opening bracket
if (character() != '[') {
Expand Down Expand Up @@ -731,12 +706,15 @@ bool FPGN::setGame(std::string pgn, ChessGame &game, unsigned & cursor) {
return true;
}

// Parse all the tags
while (fpgn.parseTag()) {
// no-op
}

// Parse the moveText
if (fpgn.parseMoveText()) {
parsedMoveText = true; // remember that we parsed at least one move text section
// Remember that we parsed at least one move text section
parsedMoveText = true;
} else {
return false;
}
Expand Down
4 changes: 2 additions & 2 deletions Shared/Engine/Helpers/FPGN.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -8,14 +8,14 @@

#pragma once

// https://en.wikipedia.org/wiki/Portable_Game_Notation

#include <stdio.h>
#include <string>

#include "ChessGame.hpp"
#include "ChessBoard.hpp"

// This class knows how to parse PGN
// https://en.wikipedia.org/wiki/Portable_Game_Notation
class FPGN {
public:
FPGN(std::string pgn = "") {
Expand Down

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