Chess games, positions, movetext and notation. More...

Namespaces
namespace	gamepos
	Named board positions commonly used as game starting points.

namespace	move_predicates
	Stateless helpers used by Position move validation.

namespace	pgn
	PGN import, export and movetext traversal helpers.

Classes
class	DString
	Legacy growable string builder. More...

struct	EventInfo
	Event-level metadata for a game. More...

class	FullMove
	Compact value type for encoded moves. More...

class	Game
	A mutable chess game made of header metadata, an optional start position, and a recursive movetext tree. More...

class	GameCursor
	A read-only cursor over a game's mainline and recursive variations. More...

struct	GameHeader
	The structured header of a chess game. More...

class	HashVal
	Zobrist hash table for piece/square occupancy. More...

struct	Move
	A played move in a mainline or variation. More...

struct	MoveAction
	Position-resolved, reversible move action. More...

class	MoveList
	Fixed-capacity container for generated moves. More...

struct	MoveMetadata
	Annotation metadata attached to a move. More...

struct	MoveSequence
	An ordered sequence of moves. More...

struct	MoveSpec
	Describes a requested move before it is resolved against a position. More...

struct	Movetext
	The playable move tree of a game. More...

class	MovetextCursor
	A mutable cursor over a game's mainline and recursive variations. More...

class	MovetextLocation
	A restorable cursor position inside a game's movetext tree. More...

class	PieceFromByte
	Compile-time byte-to-piece lookup for FEN and legacy board strings. More...

struct	Player
	A chess player as recorded in a game header. More...

class	Position
	Complete chess position with move generation, validation, and notation. More...

struct	Rating
	A player's rating and the rating system it belongs to. More...

struct	ScoredMove
	MoveAction plus an ordering score used by search and move pickers. More...

class	SquareList
	Fixed-capacity list of squares. More...

class	SquareSet
	64-bit set of on-board squares. More...

struct	Variation
	A recursive annotation variation. More...

Typedefs
typedef uint32_t	dateT
	Packed date value used by games, indexes, and statistics.

typedef unsigned short	errorT
	Status code returned by legacy Scid APIs.

using	TagPair = std::pair< std::string, std::string >
	A PGN tag pair that is not represented by one of the typed header fields.

typedef byte	resultT
	Game result code used by Game and database statistics.

using	sanStringT = char[SAN_STRING_SIZE]
	Legacy fixed-size SAN buffer type.

using	sanFlagT = byte
	Controls whether generated SAN includes check and mate suffix testing.

typedef uint	genMovesT
	Move-generation filter flags.

typedef unsigned char	byte
	8-bit unsigned scalar used by legacy file formats and board tables.

typedef std::uint16_t	ushort
	16-bit unsigned scalar used by counters and compact encodings.

typedef std::uint32_t	uint
	32-bit unsigned scalar used by hashes, sizes, and database fields.

typedef std::int32_t	sint
	32-bit signed scalar used by scores and signed counters.

typedef byte	pieceT
	Piece code.

typedef byte	colorT
	Colour code: WHITE, BLACK, or NOCOLOR.

typedef byte	squareT
	Square code: A1..H8, COLOR_SQUARE, or NULL_SQUARE.

typedef byte	rankT
	Rank code: RANK_1..RANK_8 or NO_RANK.

typedef byte	fyleT
	File code.

typedef byte	directionT
	Direction code used as an index into movement tables.

typedef byte	leftDiagT
	A1-H8 diagonal index.

typedef byte	rightDiagT
	H1-A8 diagonal index.

typedef byte	castleDirT
	Castling side code: QSIDE or KSIDE.

using	ratingT = ushort
	Numeric player rating value.

using	ratingTypeT = byte
	Identifier for the rating system stored with a player rating.

Enumerations
enum class	Nag : std::uint8_t { None = 0 , GoodMove = 1 , PoorMove = 2 , ExcellentMove = 3 , Blunder = 4 , InterestingMove = 5 , DubiousMove = 6 , OnlyMove = 8 , Equal = 10 , Unclear = 13 , WhiteSlight = 14 , BlackSlight = 15 , WhiteClear = 16 , BlackClear = 17 , WhiteDecisive = 18 , BlackDecisive = 19 , WhiteCrushing = 20 , BlackCrushing = 21 , ZugZwang = 22 , BlackZugZwang = 23 , MoreRoom = 26 , DevelopmentAdvantage = 35 , WithInitiative = 36 , WithAttack = 40 , WithBlackAttack = 41 , Compensation = 44 , SlightCentre = 48 , Centre = 50 , SlightKingSide = 54 , ModerateKingSide = 56 , KingSide = 58 , SlightQueenSide = 60 , ModerateQueenSide = 62 , QueenSide = 64 , SlightCounterPlay = 130 , BlackSlightCounterPlay = 131 , CounterPlay = 132 , BlackCounterPlay = 133 , DecisiveCounterPlay = 134 , BlackDecisiveCounterPlay = 135 , TimeLimit = 136 , WithIdea = 140 , BetterIs = 142 , VariousMoves = 144 , Comment = 145 , Novelty = 146 , WeakPoint = 147 , Ending = 148 , File = 149 , Diagonal = 150 , BishopPair = 151 , OppositeBishops = 153 , SameBishops = 154 , Etc = 190 , DoublePawns = 191 , SeparatedPawns = 192 , UnitedPawns = 193 , Diagram = 201 , See = 210 , Mate = 211 , PassedPawn = 212 , MorePawns = 213 , With = 214 , Without = 215 }
	Numeric annotation glyph values used in PGN movetext. More...

Functions
bool	piece_IsKing (pieceT p)
	Returns true when `p` has king as its uncoloured type.

bool	piece_IsSlider (pieceT p)
	Returns true when `p` is a queen, rook, or bishop type.

pieceT	piece_FromChar (int x)
	Converts a SAN piece designator to an uncoloured piece type.

leftDiagT	square_LeftDiag (squareT sq)
	Returns the A1-H8 diagonal index for `sq`.

rightDiagT	square_RightDiag (squareT sq)
	Returns the H1-A8 diagonal index for `sq`.

colorT	square_Color (squareT sq)
	Returns WHITE for a light square and BLACK for a dark square.

squareT	square_FlipFyle (squareT sq)
	Returns `sq` with its file mirrored, for example A1 becomes H1.

squareT	square_FlipRank (squareT sq)
	Returns `sq` with its rank mirrored, for example A1 becomes A8.

squareT	square_FlipDiag (squareT sq)
	Returns `sq` reflected across the A1-H8 diagonal.

uint	square_Distance (squareT from, squareT to)
	Returns the distance in king moves between two on-board squares.

squareT	square_NearestCorner (squareT sq)
	Returns the nearest corner square, choosing the lower-file/lower-rank corner on ties.

bool	square_IsCornerSquare (squareT sq)
	Returns true when `sq` is A1, H1, A8, or H8.

bool	square_IsEdgeSquare (squareT sq)
	Returns true when `sq` is on the board edge.

int	square_EdgeDistance (squareT sq)
	Returns the distance from `sq` to the nearest board edge.

bool	square_IsKnightHop (squareT from, squareT to)
	Returns true when `from` and `to` form a knight move.

char	square_FyleChar (squareT sq)
	Returns the file character for `sq`.

char	square_RankChar (squareT sq)
	Returns the rank character for `sq`.

directionT	direction_Opposite (directionT d)
	Returns the opposite direction for `d`.

bool	direction_IsDiagonal (directionT dir)
	Returns true when `dir` is one of the four diagonal directions.

int	direction_Delta (directionT dir)
	Returns the board-array delta for `dir`.

bool	square_Adjacent (squareT from, squareT to)
	Returns true when two squares are king-adjacent, including equality.

uint32_t	date_GetYear (dateT date)
	Returns the year field, or 0 when unknown.

uint32_t	date_GetMonth (dateT date)
	Returns the month field, or 0 when unknown.

uint32_t	date_GetDay (dateT date)
	Returns the day field, or 0 when unknown.

bool	date_isPartial (dateT date)
	Returns true when the year, month, or day field is unknown.

void	date_DecodeToString (dateT date, char *str)
	Writes a PGN date tag value into `str`.

dateT	date_EncodeFromString (const char *str)
	Parses a dotted date string into dateT.

dateT	date_parsePGNTag (const char *str, size_t len)
	Parses a PGN Date tag value.

dateT	date_parsePGNTag (std::pair< const char , const char > str)
	Parses a PGN Date tag value described by a pointer pair.

constexpr std::uint8_t	nagCode (Nag nag)
	Returns the PGN numeric code for `nag`.

constexpr Nag	nagFromCode (std::uint8_t value)
	Builds a Nag value from a numeric PGN code.

std::string	nagToString (Nag nag, bool asSymbol)
	Formats `nag` as a symbolic annotation when possible, or `$n`.

std::string_view	nagToSymbol (Nag nag)
	Returns the symbolic form for `nag`, or an empty view if none is known.

Nag	nagFromString (std::string_view text)
	Parses symbolic, bare numeric, or `$n` NAG text.

colorT	color_Flip (colorT c)
	Returns the opposite real colour.

char	color_Char (colorT c)
	Returns the legacy printable colour character for `c`.

colorT	piece_Color (pieceT p)
	Returns the colour of a coloured piece, or NOCOLOR for EMPTY.

colorT	piece_Color_NotEmpty (pieceT p)
	Faster colour extraction when `p` is known not to be EMPTY.

pieceT	piece_Type (pieceT p)
	Returns the uncoloured piece type encoded in `p`.

pieceT	piece_Make (colorT c, pieceT p)
	Builds a coloured piece code from a real colour and an uncoloured type.

char	piece_Char (pieceT p)
	Returns the piece-type character for `p`.

rankT	rank_FromChar (char c)
	Converts `'1'`..`'8'` to a rank, or NO_RANK for invalid input.

fyleT	fyle_FromChar (char c)
	Converts `'a'`..`'h'` to a file, or NO_FYLE for invalid input.

constexpr squareT	square_Make (fyleT f, rankT r)
	Builds a square from file and rank codes.

constexpr fyleT	square_Fyle (squareT sq)
	Returns the file of `sq`.

constexpr rankT	square_Rank (squareT sq)
	Returns the rank of `sq`.

constexpr squareT	square_Relative (colorT c, squareT sq)
	Returns `sq` from White's perspective for WHITE, Black's for BLACK.

constexpr rankT	rank_Relative (colorT c, rankT r)
	Returns `r` from White's perspective for WHITE, Black's for BLACK.

constexpr squareT	square_Move (squareT sq, directionT dir)
	Returns the one-step destination from `sq` in `dir`, or NS off-board.

constexpr squareT	square_Last (squareT sq, directionT dir)
	Returns the last on-board square on the ray from `sq` in `dir`.

Variables
const squareT	knightAttacks [66][9]
	Knight attack targets for each square, terminated by NULL_SQUARE.

const squareT	kingAttacks [66][9]
	King attack targets for each square, excluding castling, terminated by NULL_SQUARE.

const pieceT	WM = 16
	White minor-piece aggregate marker used by material-only searches.

const pieceT	BM = 17
	Black minor-piece aggregate marker used by material-only searches.

const uint	MAX_PIECE_TYPES = 18
	Number of piece-like codes covered by board lookup tables.

const pieceT	PIECE_FLIP [MAX_PIECE_TYPES]
	Maps each piece code to the same piece with colour reversed.

const bool	PIECE_IS_SLIDER [8]
	True for uncoloured piece types that slide along rays.

const uint	rankFyleDist [64]
	Chebyshev distance lookup by rank or file.

const int	edgeDist [66]
	Distance of each square from the closest edge, with -1 for sentinels.

const directionT	NULL_DIR = 0
	No direction or no aligned ray.

const directionT	UP = 1
	One rank toward Black's home rank.

const directionT	DOWN = 2
	One rank toward White's home rank.

const directionT	LEFT = 4
	One file toward A-file.

const directionT	RIGHT = 8
	One file toward H-file.

const directionT	UP_LEFT = (UP \| LEFT)
	Diagonal toward A8.

const directionT	UP_RIGHT = (UP \| RIGHT)
	Diagonal toward H8.

const directionT	DOWN_LEFT = (DOWN \| LEFT)
	Diagonal toward A1.

const directionT	DOWN_RIGHT = (DOWN \| RIGHT)
	Diagonal toward H1.

const directionT	dirOpposite [11]
	Direction-opposite lookup table indexed by directionT values.

const bool	dirIsDiagonal [11]
	Diagonal-direction lookup table indexed by directionT values.

const int	dirDelta [11]
	Board-array delta for a one-square step in each direction.

const pieceT	START_BOARD [66]
	Standard starting board, including COLOR_SQUARE and NULL_SQUARE sentinels.

const colorT	BOARD_SQUARECOLOR [66]
	Standard board square colours, with NOCOLOR for sentinels.

const dateT	ZERO_DATE = 0
	Unknown date.

const uint32_t	YEAR_SHIFT = 9
	Bit shift of the year field.

const uint32_t	MONTH_SHIFT = 5
	Bit shift of the month field.

const uint32_t	DAY_SHIFT = 0
	Bit shift of the day field.

const uint32_t	YEAR_MAX = 2047
	Maximum representable year.

const errorT	OK = 0
	Shared status and error-code values.

const errorT	ERROR = 1
	Unclassified failure.

const errorT	ERROR_UserCancel = 2
	Operation was cancelled by the user or progress callback.

const errorT	ERROR_BadArg = 3
	Invalid argument or unsupported argument combination.

const errorT	ERROR_FileOpen = 101
	File could not be opened.

const errorT	ERROR_FileWrite = 102
	File write failed.

const errorT	ERROR_FileRead = 103
	File read failed.

const errorT	ERROR_FileSeek = 104
	File seek failed.

const errorT	ERROR_BadMagic = 105
	File signature or magic bytes did not match the expected format.

const errorT	ERROR_FileNotOpen = 106
	Operation requires an open file but none is open.

const errorT	ERROR_FileInUse = 107
	File is already in use.

const errorT	ERROR_FileMode = 108
	File was opened in a mode incompatible with the requested operation.

const errorT	ERROR_FileVersion = 109
	File format version is not supported by this code.

const errorT	ERROR_OldScidVersion = 110
	File requires an older Scid compatibility path.

const errorT	ERROR_FileReadOnly = 111
	Operation would modify a read-only file.

const errorT	ERROR_CompactRemove = 121
	Compaction failed while removing or replacing old database files.

const errorT	ERROR_MallocFailed = 151
	Memory allocation failed.

const errorT	ERROR_CorruptData = 152
	Data is structurally corrupt or cannot be trusted.

const errorT	ERROR_Corrupt = 152
	Alias for `ERROR_CorruptData`.

const errorT	ERROR_Full = 201
	Container or database has reached capacity.

const errorT	ERROR_NameNotFound = 202
	Requested name entry was not found.

const errorT	ERROR_NotFound = 202
	Alias for `ERROR_NameNotFound`.

const errorT	ERROR_NameExists = 203
	Requested name entry already exists.

const errorT	ERROR_Exists = 203
	Alias for `ERROR_NameExists`.

const errorT	ERROR_NameBaseEmpty = 204
	Name table is empty.

const errorT	ERROR_Empty = 204
	Alias for `ERROR_NameBaseEmpty`.

const errorT	ERROR_NoMatchFound = 205
	Search or lookup completed without a match.

const errorT	ERROR_NameDataLoss = 206
	Some name data was lost or could not be recovered while loading.

const errorT	ERROR_NameTooLong = 207
	Name exceeds the format limit.

const errorT	ERROR_NameLimit = 208
	Name table has reached its entry limit.

const errorT	ERROR_OffsetLimit = 209
	Encoded offset exceeds the format limit.

const errorT	ERROR_GameLengthLimit = 210
	Encoded game data exceeds the format limit.

const errorT	ERROR_NumGamesLimit = 211
	Database has reached its game-count limit.

const errorT	ERROR_InvalidFEN = 301
	FEN text could not be parsed as a valid position.

const errorT	ERROR_InvalidMove = 302
	Move text could not be parsed or applied legally.

const errorT	ERROR_PieceCount = 303
	Position has an invalid piece count or material arrangement.

const errorT	ERROR_Game = 400
	Generic game or movetext failure.

const errorT	ERROR_EndOfMoveList = 401
	Cursor or decoder reached the end of a move list.

const errorT	ERROR_StartOfMoveList = 402
	Cursor is already at the start of a move list.

const errorT	ERROR_NoVariation = 403
	Requested variation does not exist.

const errorT	ERROR_EmptyVariation = 404
	Requested variation exists but contains no moves.

const errorT	ERROR_VariationLimit = 405
	Variation nesting or count limit was exceeded.

const errorT	ERROR_Decode = 406
	Encoded game or tag data could not be decoded.

const errorT	ERROR_GameFull = 407
	Game movetext has reached its storage limit.

const errorT	ERROR_BufferFull = 601
	Output buffer has no space for the requested write.

const errorT	ERROR_BufferRead = 602
	Input buffer did not contain enough data for the requested read.

const errorT	ERROR_CodecUnsupFeat = 701
	Codec does not support the requested feature.

const errorT	ERROR_CodecChess960 = 702
	Codec cannot represent a Chess960-specific feature.

const uint	NUM_RESULT_TYPES = 4
	Number of result codes, including unknown/unfinished games.

const resultT	RESULT_None = 0
	Unknown, unfinished, or no-result game.

const resultT	RESULT_White = 1
	White win.

const resultT	RESULT_Black = 2
	Black win.

const resultT	RESULT_Draw = 3
	Draw.

const uint	RESULT_SCORE [4] = {1, 2, 0, 1}
	Half-point scores from White's perspective: win=2, draw=1, loss=0.

const char	RESULT_CHAR [4] = {'*', '1', '0', '='}
	Compact one-character result markers.

const char	RESULT_STR [4][4] = {"*", "1-0", "0-1", "=-="}
	Short result strings used by legacy displays.

const char	RESULT_LONGSTR [4][8] = {"*", "1-0", "0-1", "1/2-1/2"}
	PGN result strings.

const resultT	RESULT_OPPOSITE [4]
	Result from the opposite player's perspective.

constexpr auto	HASH = HashVal()
	Shared Zobrist helper used to add piece/square contributions.

auto const &	UNHASH = HASH
	Alias for `HASH` used when removing piece/square contributions.

constexpr unsigned	stdStartPawnHash
	Pawn hash of the standard chess starting position.

constexpr unsigned	stdStartHash
	Full-piece hash of the standard chess starting position.

const uint	MAX_LEGAL_MOVES = 256
	Maximum number of legal moves held by a MoveList.

constexpr std::uint8_t	maxNagCode = nagCode(Nag::Without)
	Largest named Nag code currently recognised by libscid.

constexpr std::size_t	SAN_STRING_SIZE = 10
	Maximum storage size for legacy fixed-size SAN buffers.

constexpr sanFlagT	SAN_NO_CHECKTEST = 0
	Generate SAN without checking for check or mate suffixes.

constexpr sanFlagT	SAN_CHECKTEST = 1
	Generate SAN with check suffix testing.

constexpr sanFlagT	SAN_MATETEST = 2
	Generate SAN with mate suffix testing.

constexpr std::size_t	UCI_MOVE_STRING_SIZE = 6
	Maximum storage size for legacy fixed-size UCI move buffers.

const byte	WQ_CASTLE = 1
	Castling-right bit for White queenside castling.

const byte	WK_CASTLE = 2
	Castling-right bit for White kingside castling.

const byte	BQ_CASTLE = 4
	Castling-right bit for Black queenside castling.

const byte	BK_CASTLE = 8
	Castling-right bit for Black kingside castling.

const genMovesT	GEN_CAPTURES = 1
	Generate capturing moves only.

const genMovesT	GEN_NON_CAPS = 2
	Generate non-capturing moves only.

const genMovesT	GEN_ALL_MOVES = (GEN_CAPTURES \| GEN_NON_CAPS)
	Generate all legal moves.

const castleDirT	QSIDE = 0
	Queenside castling direction.

const castleDirT	KSIDE = 1
	Kingside castling direction.

const unsigned	NUM_COLOR_TYPES = 2
	Number of real chess colours.

const colorT	WHITE = 0
	White side.

const colorT	BLACK = 1
	Black side.

const colorT	NOCOLOR = 2
	Sentinel colour for empty or non-board values.

const char	COLOR_CHAR [3] = {'W', 'B', '_'}
	Printable colour letters used by legacy board strings.

const pieceT	INVALID_PIECE = 0
	Invalid or absent piece type.

const pieceT	KING = 1
	Uncoloured king type.

const pieceT	QUEEN = 2
	Uncoloured queen type.

const pieceT	ROOK = 3
	Uncoloured rook type.

const pieceT	BISHOP = 4
	Uncoloured bishop type.

const pieceT	KNIGHT = 5
	Uncoloured knight type.

const pieceT	PAWN = 6
	Uncoloured pawn type.

const pieceT	EMPTY = 7
	Empty board square marker.

const pieceT	END_OF_BOARD = 0
	Zero terminator for legacy board strings.

const pieceT	WK = 1
	White king.

const pieceT	WQ = 2
	White queen.

const pieceT	WR = 3
	White rook.

const pieceT	WB = 4
	White bishop.

const pieceT	WN = 5
	White knight.

const pieceT	WP = 6
	White pawn.

const pieceT	BK = 9
	Black king.

const pieceT	BQ = 10
	Black queen.

const pieceT	BR = 11
	Black rook.

const pieceT	BB = 12
	Black bishop.

const pieceT	BN = 13
	Black knight.

const pieceT	BP = 14
	Black pawn.

const char	PIECE_CHAR [] = "xKQRBNP.xkqrbnpxMm"
	Piece-code to character table.

constexpr auto	pieceFromByte = PieceFromByte()
	Global byte-to-piece lookup table.

const squareT	A1 = 0
	Board squares in rank-major order, followed by sentinel squares.

const squareT	B1 = 1

const squareT	C1 = 2

const squareT	D1 = 3

const squareT	E1 = 4

const squareT	F1 = 5

const squareT	G1 = 6

const squareT	H1 = 7

const squareT	A2 = 8

const squareT	B2 = 9

const squareT	C2 = 10

const squareT	D2 = 11

const squareT	E2 = 12

const squareT	F2 = 13

const squareT	G2 = 14

const squareT	H2 = 15

const squareT	A3 = 16

const squareT	B3 = 17

const squareT	C3 = 18

const squareT	D3 = 19

const squareT	E3 = 20

const squareT	F3 = 21

const squareT	G3 = 22

const squareT	H3 = 23

const squareT	A4 = 24

const squareT	B4 = 25

const squareT	C4 = 26

const squareT	D4 = 27

const squareT	E4 = 28

const squareT	F4 = 29

const squareT	G4 = 30

const squareT	H4 = 31

const squareT	A5 = 32

const squareT	B5 = 33

const squareT	C5 = 34

const squareT	D5 = 35

const squareT	E5 = 36

const squareT	F5 = 37

const squareT	G5 = 38

const squareT	H5 = 39

const squareT	A6 = 40

const squareT	B6 = 41

const squareT	C6 = 42

const squareT	D6 = 43

const squareT	E6 = 44

const squareT	F6 = 45

const squareT	G6 = 46

const squareT	H6 = 47

const squareT	A7 = 48

const squareT	B7 = 49

const squareT	C7 = 50

const squareT	D7 = 51

const squareT	E7 = 52

const squareT	F7 = 53

const squareT	G7 = 54

const squareT	H7 = 55

const squareT	A8 = 56

const squareT	B8 = 57

const squareT	C8 = 58

const squareT	D8 = 59

const squareT	E8 = 60

const squareT	F8 = 61

const squareT	G8 = 62

const squareT	H8 = 63

const squareT	COLOR_SQUARE = 64

const squareT	NULL_SQUARE = 65

const squareT	NS = 65

const rankT	RANK_1 = 0
	Rank constants and invalid rank sentinel.

const rankT	RANK_2 = 1

const rankT	RANK_3 = 2

const rankT	RANK_4 = 3

const rankT	RANK_5 = 4

const rankT	RANK_6 = 5

const rankT	RANK_7 = 6

const rankT	RANK_8 = 7

const rankT	NO_RANK = 64

const fyleT	A_FYLE = 0
	File constants and invalid file sentinel.

const fyleT	B_FYLE = 1

const fyleT	C_FYLE = 2

const fyleT	D_FYLE = 3

const fyleT	E_FYLE = 4

const fyleT	F_FYLE = 5

const fyleT	G_FYLE = 6

const fyleT	H_FYLE = 7

const fyleT	NO_FYLE = 64

constexpr ratingTypeT	RATING_Elo = 0
	FIDE Elo rating.

constexpr ratingTypeT	RATING_Rating = 1
	Generic rating tag when the original rating system is not more specific.

constexpr ratingTypeT	RATING_Rapid = 2
	Rapid rating.

constexpr ratingTypeT	RATING_ICCF = 3
	International Correspondence Chess Federation rating.

constexpr ratingTypeT	RATING_USCF = 4
	United States Chess Federation rating.

constexpr ratingTypeT	RATING_DWZ = 5
	Deutsche Wertungszahl rating.

constexpr ratingTypeT	RATING_BCF = 6
	British/English Chess Federation rating.

constexpr std::size_t	NUM_RATING_TYPES = 7
	Number of defined rating-system identifiers.

constexpr const char *	ratingTypeNames [NUM_RATING_TYPES+1]
	Null-terminated table of PGN-facing rating-system names.

constexpr uint	MAX_SQUARELIST = 65
	Maximum SquareList capacity: 64 board squares plus NULL_SQUARE.

constexpr squareT	precomputed_sqMove [66][11]
	One-step movement lookup indexed by square and direction.

constexpr squareT	precomputed_sqLast [66][11]
	Ray-end lookup indexed by square and direction.

Detailed Description

Chess games, positions, movetext and notation.

Core is the chess model of libscid. It owns the in-memory representation of a game, the board state needed to validate and replay moves, and the value types that keep chess data portable across storage, PGN, notation and user-facing tools.

Most work in this namespace revolves around two aggregates: scid::core::Game owns complete editable game records, while scid::core::Position owns a board state at one moment in a game. The movetext, cursor, notation and PGN APIs sit around those aggregates as tree, traversal and text-mapping layers.

Typedef Documentation

◆ errorT

typedef unsigned short scid::core::errorT

Status code returned by legacy Scid APIs.

OK is zero and all error values are non-zero, so an errorT can be used in simple boolean checks when only success/failure matters.

◆ fyleT

typedef byte scid::core::fyleT

File code.

Named "fyle" to avoid confusion with disk files.

◆ pieceT

typedef byte scid::core::pieceT

Piece code.

Values may be piece types, coloured pieces, EMPTY, or sentinels.

◆ ratingT

using scid::core::ratingT = typedef ushort

Numeric player rating value.

A value of 0 is commonly used by callers to represent an unknown rating. Database codecs may impose tighter storage limits than the full range of the underlying type.

Enumeration Type Documentation

◆ Nag

enum class scid::core::Nag : std::uint8_t

strong

Numeric annotation glyph values used in PGN movetext.

The enum names cover the annotation values recognised by libscid. Values map directly to PGN $n NAG codes and may also have a symbolic representation such as !, ??, or D.

Function Documentation

◆ color_Flip()

colorT scid::core::color_Flip ( colorT c )

inline

Returns the opposite real colour.

c must be WHITE or BLACK.

◆ date_DecodeToString()

void scid::core::date_DecodeToString	(	dateT	date,
		char *	str
	)

inline

Writes a PGN date tag value into str.

Unknown fields are written as question marks, for example ????.??.?? or 2024.??.??. The destination must have room for at least eleven bytes including the terminator.

◆ date_EncodeFromString()

dateT scid::core::date_EncodeFromString ( const char * str )

inline

Parses a dotted date string into dateT.

This legacy parser accepts numeric fields in yyyy.mm.dd order. Out of range fields stop further precision from being added: an invalid month keeps the parsed year, and an invalid day keeps the parsed year and month.

◆ date_parsePGNTag()

dateT scid::core::date_parsePGNTag	(	const char *	str,
		size_t	len
	)

inline

Parses a PGN Date tag value.

Full YYYY.MM.DD values are accepted, as are partial values with unknown month/day fields. The parser also accepts compact month/day forms such as YYYY.M.D. Invalid or out-of-range fields are treated as unknown.

Parameters

str	memory containing the tag value.
len	number of bytes in `str`.

Returns: the parsed date, or ZERO_DATE when the year is missing or invalid.

◆ nagFromString()

Nag scid::core::nagFromString ( std::string_view text )

Parses symbolic, bare numeric, or $n NAG text.

Unknown, malformed, or out-of-range text returns Nag::None.

◆ nagToString()

std::string scid::core::nagToString	(	Nag	nag,
		bool	asSymbol
	)

Formats nag as a symbolic annotation when possible, or $n.

Nag::None formats as an empty string. When asSymbol is true but no symbol is known for the code, numeric $n form is used.

◆ piece_FromChar()

pieceT scid::core::piece_FromChar ( int x )

inline

Converts a SAN piece designator to an uncoloured piece type.

Pawns have no SAN designator here, so 'P' and unknown characters return EMPTY.

◆ square_Last()

constexpr squareT scid::core::square_Last	(	squareT	sq,
		directionT	dir
	)

constexpr

Returns the last on-board square on the ray from sq in dir.

For on-board squares and valid directions the result is always on-board. When the ray immediately leaves the board, sq is returned.

Variable Documentation

◆ BOARD_SQUARECOLOR

const colorT scid::core::BOARD_SQUARECOLOR[66]

Initial value:

= {
    BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE,  
    WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK,  
    BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE,  
    WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK,  
    BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE,  
    WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK,  
    BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE,  
    WHITE, BLACK, WHITE, BLACK, WHITE, BLACK, WHITE, BLACK,  
    NOCOLOR, NOCOLOR  
}

Standard board square colours, with NOCOLOR for sentinels.

◆ dirDelta

const int scid::core::dirDelta[11]

Initial value:

Board-array delta for a one-square step in each direction.

◆ dirIsDiagonal

const bool scid::core::dirIsDiagonal[11]

Initial value:

= {
    false,   
    false,   
    false,   
    false,   
    false,   
    true,    
    true,    
    false,   
    false,   
    true,    
    true     
}

Diagonal-direction lookup table indexed by directionT values.

◆ dirOpposite

const directionT scid::core::dirOpposite[11]

Initial value:

= {
    NULL_DIR,
    DOWN,       
    UP,         
    NULL_DIR,
    RIGHT,      
    DOWN_RIGHT, 
    UP_RIGHT,   
    NULL_DIR,
    LEFT,       
    DOWN_LEFT,  
    UP_LEFT     
}

Direction-opposite lookup table indexed by directionT values.

◆ edgeDist

const int scid::core::edgeDist[66]

Initial value:

= {
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 1, 1, 1, 1, 1, 1, 0,
    0, 1, 2, 2, 2, 2, 1, 0,
    0, 1, 2, 3, 3, 2, 1, 0,
    0, 1, 2, 3, 3, 2, 1, 0,
    0, 1, 2, 2, 2, 2, 1, 0,
    0, 1, 1, 1, 1, 1, 1, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    -1, -1
}

Distance of each square from the closest edge, with -1 for sentinels.

◆ OK

const errorT scid::core::OK = 0

Shared status and error-code values.

The numeric ranges are conventional: low values are general errors, 100s are file I/O, 200s are database/name errors, 300s are position errors, 400s are game/movetext errors, 600s are buffer errors, and 700s are codec feature errors. Success.

◆ PIECE_FLIP

const pieceT scid::core::PIECE_FLIP[MAX_PIECE_TYPES]

Initial value:

= {
    END_OF_BOARD,
    BK, BQ, BR, BB, BN, BP,
    EMPTY, EMPTY,
    WK, WQ, WR, WB, WN, WP,
    EMPTY, BM, WM
}

Maps each piece code to the same piece with colour reversed.

◆ PIECE_IS_SLIDER

const bool scid::core::PIECE_IS_SLIDER[8]

Initial value:

= {
    false,
    false, true, true, true, false, false,
    false,
}

True for uncoloured piece types that slide along rays.

◆ precomputed_sqLast

constexpr squareT scid::core::precomputed_sqLast[66][11]

inlineconstexpr

Ray-end lookup indexed by square and direction.

For on-board squares and valid directions, the result is the last on-board square reachable by continuing in that direction. If movement in that direction is immediately off-board, the original square is returned. Sentinel squares map to NS.

◆ precomputed_sqMove

constexpr squareT scid::core::precomputed_sqMove[66][11]

inlineconstexpr

One-step movement lookup indexed by square and direction.

Off-board moves, COLOR_SQUARE, and NULL_SQUARE map to NS.

◆ rankFyleDist

const uint scid::core::rankFyleDist[64]

Initial value:

= {
    0, 1, 2, 3, 4, 5, 6, 7,
    1, 0, 1, 2, 3, 4, 5, 6,
    2, 1, 0, 1, 2, 3, 4, 5,
    3, 2, 1, 0, 1, 2, 3, 4,
    4, 3, 2, 1, 0, 1, 2, 3,
    5, 4, 3, 2, 1, 0, 1, 2,
    6, 5, 4, 3, 2, 1, 0, 1,
    7, 6, 5, 4, 3, 2, 1, 0
}

Chebyshev distance lookup by rank or file.

◆ RATING_BCF

constexpr ratingTypeT scid::core::RATING_BCF = 6

inlineconstexpr

British/English Chess Federation rating.

The legacy constant name is kept for compatibility; the public display name in ratingTypeNames is "ECF".

◆ ratingTypeNames

constexpr const char* scid::core::ratingTypeNames[NUM_RATING_TYPES+1]

inlineconstexpr

Initial value:

= {

"Elo", "Rating", "Rapid", "ICCF", "USCF", "DWZ", "ECF", nullptr}

Null-terminated table of PGN-facing rating-system names.

The table is indexed by a ratingTypeT value and has a trailing nullptr sentinel for legacy loops.

◆ RESULT_OPPOSITE

const resultT scid::core::RESULT_OPPOSITE[4]

Initial value:

= {

RESULT_None, RESULT_Black, RESULT_White, RESULT_Draw}

scid::core::RESULT_Draw

const resultT RESULT_Draw

Draw.

Definition game_result.h:22

scid::core::RESULT_None

const resultT RESULT_None

Unknown, unfinished, or no-result game.

Definition game_result.h:16

scid::core::RESULT_Black

const resultT RESULT_Black

Black win.

Definition game_result.h:20

scid::core::RESULT_White

const resultT RESULT_White

White win.

Definition game_result.h:18

Result from the opposite player's perspective.

◆ START_BOARD

const pieceT scid::core::START_BOARD[66]

Initial value:

= {
    WR, WN, WB, WQ, WK, WB, WN, WR,    
    WP, WP, WP, WP, WP, WP, WP, WP,    
    EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY,
    EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY,
    EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY,
    EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY, EMPTY,
    BP, BP, BP, BP, BP, BP, BP, BP,
    BR, BN, BB, BQ, BK, BB, BN, BR,
    EMPTY,        
    END_OF_BOARD  
}

Standard starting board, including COLOR_SQUARE and NULL_SQUARE sentinels.

◆ stdStartHash

constexpr unsigned scid::core::stdStartHash

inlineconstexpr

Initial value:

= [] {
    auto h = stdStartPawnHash;
    HASH (h,WR,A1);  HASH (h,WN,B1);  HASH (h,WB,C1);  HASH (h,WQ,D1);
    HASH (h,WK,E1);  HASH (h,WB,F1);  HASH (h,WN,G1);  HASH (h,WR,H1);
    HASH (h,BR,A8);  HASH (h,BN,B8);  HASH (h,BB,C8);  HASH (h,BQ,D8);
    HASH (h,BK,E8);  HASH (h,BB,F8);  HASH (h,BN,G8);  HASH (h,BR,H8);
    return h;
}()

Full-piece hash of the standard chess starting position.

◆ stdStartPawnHash

constexpr unsigned scid::core::stdStartPawnHash

inlineconstexpr

Initial value:

= [] {
    unsigned h = 0;
    HASH (h,WP,A2);  HASH (h,WP,B2);  HASH (h,WP,C2);  HASH (h,WP,D2);
    HASH (h,WP,E2);  HASH (h,WP,F2);  HASH (h,WP,G2);  HASH (h,WP,H2);
    HASH (h,BP,A7);  HASH (h,BP,B7);  HASH (h,BP,C7);  HASH (h,BP,D7);
    HASH (h,BP,E7);  HASH (h,BP,F7);  HASH (h,BP,G7);  HASH (h,BP,H7);
    return h;
}()

Pawn hash of the standard chess starting position.

◆ UNHASH

auto const& scid::core::UNHASH = HASH

inline

Alias for HASH used when removing piece/square contributions.

Zobrist removal is also an XOR operation, so hashing and unhashing share the same implementation.

Namespaces

Classes

Typedefs

Enumerations

Functions

Variables

Detailed Description

Typedef Documentation

◆ errorT

◆ fyleT

◆ pieceT

◆ ratingT

Enumeration Type Documentation

◆ Nag

Function Documentation

◆ color_Flip()

◆ date_DecodeToString()

◆ date_EncodeFromString()

◆ date_parsePGNTag()

◆ nagFromString()

◆ nagToString()

◆ piece_FromChar()

◆ square_Last()

Variable Documentation

◆ BOARD_SQUARECOLOR

◆ dirDelta

◆ dirIsDiagonal

◆ dirOpposite

◆ edgeDist

◆ OK

◆ PIECE_FLIP

◆ PIECE_IS_SLIDER

◆ precomputed_sqLast

◆ precomputed_sqMove

◆ rankFyleDist

◆ RATING_BCF

◆ ratingTypeNames

◆ RESULT_OPPOSITE

◆ START_BOARD

◆ stdStartHash

◆ stdStartPawnHash

◆ UNHASH