Why Go
- Case Studies
  
  Common problems companies solve with Go
- Use Cases
  
  Stories about how and why companies use Go
- Security
  
  How Go can help keep you secure by default
Learn
Docs
- Effective Go
  
  Tips for writing clear, performant, and idiomatic Go code
- Go User Manual
  
  A complete introduction to building software with Go
- Standard library
  
  Reference documentation for Go's standard library
- Release Notes
  
  Learn what's new in each Go release
Packages
Community
- Recorded Talks
  
  Videos from prior events
- Meetups
  
  Meet other local Go developers
- Conferences
  
  Learn and network with Go developers from around the world
- Go blog
  
  The Go project's official blog.
- Go project
  
  Get help and stay informed from Go
- Get connected

chess

package module

Go to main page

Versions in this module

v0

v0.2.1

Jun 10, 2025

Changes in this version

+ var ErrInvalidCommand = func(pos int) error

+ var ErrInvalidPiece = func(pos int) error

+ var ErrInvalidRank = func(pos int) error

+ var ErrInvalidSquare = func(pos int) error

+ var ErrNoGameFound = errors.New("no game found in PGN data")

+ var ErrUnterminatedComment = func(pos int) error

+ var ErrUnterminatedQuote = func(pos int) error

+ func GetPolyglotHashBytes(index int) []byte

+ func GetPolyglotHashes() []string

+ func MoveToPolyglot(m Move) uint16

+ func ZobristHashToUint64(hash string) uint64

+ type BookSource interface

+ Read func(p []byte) (n int, err error)

+ Size func() (int64, error)

+ type BytesBookSource struct

+ func NewBytesBookSource(data []byte) *BytesBookSource

+ func (b *BytesBookSource) Read(p []byte) (n int, err error)

+ func (b *BytesBookSource) Size() (int64, error)

type Color

+ func ColorFromString(s string) Color

type File

+ func (f File) Byte() byte

+ type FileBookSource struct

type Game

+ func (g *Game) AddVariation(parent *Move, newMove *Move)

+ func (g *Game) CurrentPosition() *Position

+ func (g *Game) GetRootMove() *Move

+ func (g *Game) GoBack() bool

+ func (g *Game) GoForward() bool

+ func (g *Game) IsAtEnd() bool

+ func (g *Game) IsAtStart() bool

+ func (g *Game) NavigateToMainLine()

+ func (g *Game) PushMove(algebraicMove string, options *PushMoveOptions) error

+ func (g *Game) PushNotationMove(moveStr string, notation Notation, options *PushMoveOptions) error

+ func (g *Game) Variations(move *Move) []*Move

+ type GameScanned struct

+ Raw string

+ type Hash []byte

+ type Lexer struct

+ func NewLexer(input string) *Lexer

+ func (l *Lexer) NextToken() Token

type Move

+ func (m *Move) AddComment(comment string)

+ func (m *Move) AddTag(tag MoveTag)

+ func (m *Move) Children() []*Move

+ func (m *Move) Comments() string

+ func (m *Move) GetCommand(key string) (string, bool)

+ func (m *Move) NAG() string

+ func (m *Move) Number() int

+ func (m *Move) Parent() *Move

+ func (m *Move) Position() *Position

+ func (m *Move) SetCommand(key, value string)

+ func (m *Move) SetComment(comment string)

+ func (m *Move) SetNAG(nag string)

+ type MoveWithWeight struct

+ Move Move

+ Weight uint16

+ type PGNError struct

+ func (e *PGNError) Error() string

+ func (e *PGNError) Is(target error) bool

+ type Parser struct

+ func NewParser(tokens []Token) *Parser

+ func (p *Parser) Parse() (*Game, error)

+ type ParserError struct

+ Message string

+ Position int

+ TokenType TokenType

+ TokenValue string

+ func (e *ParserError) Error() string

type PieceType

+ func PieceTypeFromByte(b byte) PieceType

+ func PieceTypeFromString(s string) PieceType

+ func (p PieceType) Bytes() []byte

+ func (p PieceType) ToPolyglotPromotionValue() int

+ type PolyglotBook struct

+ func LoadFromBytes(data []byte) (*PolyglotBook, error)

+ func LoadFromReader(reader io.Reader) (*PolyglotBook, error)

+ func LoadFromSource(source BookSource) (*PolyglotBook, error)

+ func NewPolyglotBookFromMap(m map[uint64][]MoveWithWeight) *PolyglotBook

+ func (book *PolyglotBook) AddMove(positionHash uint64, move Move, weight uint16)

+ func (book *PolyglotBook) DeleteMoves(positionHash uint64)

+ func (book *PolyglotBook) FindMoves(positionHash uint64) []PolyglotEntry

+ func (book *PolyglotBook) GetChessMoves(positionHash uint64) ([]Move, error)

+ func (book *PolyglotBook) GetRandomMove(positionHash uint64) *PolyglotEntry

+ func (book *PolyglotBook) ToMoveMap() map[uint64][]MoveWithWeight

+ func (book *PolyglotBook) UpdateMove(positionHash uint64, move Move, newWeight uint16) error

+ type PolyglotEntry struct

+ Key uint64

+ Learn uint32

+ Move uint16

+ Weight uint16

+ type PolyglotMove struct

+ CastlingMove bool

+ FromFile int

+ FromRank int

+ Promotion int

+ ToFile int

+ ToRank int

+ func DecodeMove(move uint16) PolyglotMove

+ func (pm PolyglotMove) Encode() uint16

+ func (pm PolyglotMove) ToMove() Move

type Position

+ func (pos *Position) ChangeTurn() *Position

+ type PushMoveOptions struct

+ ForceMainline bool

type Rank

+ func (r Rank) Byte() byte

+ type ReaderBookSource struct

+ func NewReaderBookSource(reader io.Reader) (*ReaderBookSource, error)

+ func (r *ReaderBookSource) Read(p []byte) (n int, err error)

+ func (r *ReaderBookSource) Size() (int64, error)

type Scanner

+ func (s *Scanner) HasNext() bool

+ func (s *Scanner) ScanGame() (*GameScanned, error)

type Square

+ func (sq Square) Bytes() []byte

+ type Token struct

+ Error error

+ Type TokenType

+ Value string

+ func TokenizeGame(game *GameScanned) ([]Token, error)

+ type TokenType int

+ const CAPTURE

+ const CHECK

+ const CHECKMATE

+ const COMMENT

+ const CommandEnd

+ const CommandName

+ const CommandParam

+ const CommandStart

+ const CommentEnd

+ const CommentStart

+ const DOT

+ const ELLIPSIS

+ const EOF

+ const FILE

+ const KingsideCastle

+ const MoveNumber

+ const NAG

+ const PIECE

+ const PROMOTION

+ const PromotionPiece

+ const QueensideCastle

+ const RANK

+ const RESULT

+ const SQUARE

+ const TagEnd

+ const TagKey

+ const TagStart

+ const TagValue

+ const Undefined

+ const VariationEnd

+ const VariationStart

+ func (t TokenType) String() string

+ type ZobristHasher struct

+ func NewChessHasher() *ZobristHasher

+ func NewZobristHasher() *ZobristHasher

+ func (ch *ZobristHasher) HashPosition(fen string) (string, error)

v0.1.1

Jun 10, 2024

Changes in this version

type Position

+ func (pos *Position) SetHalfMoveClock(hmc int) (p *Position)

v0.1.0

Jun 4, 2024

Changes in this version

+ func FEN(fen string) (func(*Game), error)

+ func IsInCheck(pos *Position) bool

+ func PGN(r io.Reader) (func(*Game), error)

+ func TagPairs(tagPairs []*TagPair) func(*Game)

+ func UseNotation(n Notation) func(*Game)

+ type AlgebraicNotation struct

+ func (AlgebraicNotation) Decode(pos *Position, s string) (*Move, error)

+ func (AlgebraicNotation) Encode(pos *Position, m *Move) string

+ func (AlgebraicNotation) String() string

+ type Board struct

+ func NewBoard(m map[Square]Piece) *Board

+ func (b *Board) Draw() string

+ func (b *Board) Flip(fd FlipDirection) *Board

+ func (b *Board) MarshalBinary() (data []byte, err error)

+ func (b *Board) MarshalText() (text []byte, err error)

+ func (b *Board) Piece(sq Square) Piece

+ func (b *Board) Rotate() *Board

+ func (b *Board) SquareMap() map[Square]Piece

+ func (b *Board) String() string

+ func (b *Board) Transpose() *Board

+ func (b *Board) UnmarshalBinary(data []byte) error

+ func (b *Board) UnmarshalText(text []byte) error

+ type CastleRights string

+ func (cr CastleRights) CanCastle(c Color, side Side) bool

+ func (cr CastleRights) String() string

+ type Color int8

+ const Black

+ const NoColor

+ const White

+ func (c Color) Name() string

+ func (c Color) Other() Color

+ func (c Color) String() string

+ type Decoder interface

+ Decode func(pos *Position, s string) (*Move, error)

+ type Encoder interface

+ Encode func(pos *Position, m *Move) string

+ type File int8

+ const FileA

+ const FileB

+ const FileC

+ const FileD

+ const FileE

+ const FileF

+ const FileG

+ const FileH

+ func (f File) String() string

+ type FlipDirection int

+ const LeftRight

+ const UpDown

+ type Game struct

+ func GamesFromPGN(r io.Reader) ([]*Game, error)

+ func NewGame(options ...func(*Game)) *Game

+ func (g *Game) AddTagPair(k, v string) bool

+ func (g *Game) Clone() *Game

+ func (g *Game) Comments() [][]string

+ func (g *Game) Draw(method Method) error

+ func (g *Game) EligibleDraws() []Method

+ func (g *Game) FEN() string

+ func (g *Game) GetTagPair(k string) *TagPair

+ func (g *Game) MarshalText() (text []byte, err error)

+ func (g *Game) Method() Method

+ func (g *Game) Move(m *Move) error

+ func (g *Game) MoveHistory() []*MoveHistory

+ func (g *Game) MoveStr(s string) error

+ func (g *Game) Moves() []*Move

+ func (g *Game) Outcome() Outcome

+ func (g *Game) Position() *Position

+ func (g *Game) Positions() []*Position

+ func (g *Game) RemoveTagPair(k string) bool

+ func (g *Game) Resign(color Color)

+ func (g *Game) String() string

+ func (g *Game) TagPairs() []*TagPair

+ func (g *Game) UnmarshalText(text []byte) error

+ func (g *Game) ValidMoves() []*Move

+ type LongAlgebraicNotation struct

+ func (LongAlgebraicNotation) Decode(pos *Position, s string) (*Move, error)

+ func (LongAlgebraicNotation) Encode(pos *Position, m *Move) string

+ func (LongAlgebraicNotation) String() string

+ type Method uint8

+ const Checkmate

+ const DrawOffer

+ const FiftyMoveRule

+ const FivefoldRepetition

+ const InsufficientMaterial

+ const NoMethod

+ const Resignation

+ const SeventyFiveMoveRule

+ const Stalemate

+ const ThreefoldRepetition

+ func (i Method) String() string

+ type Move struct

+ func (m *Move) HasTag(tag MoveTag) bool

+ func (m *Move) Promo() PieceType

+ func (m *Move) S1() Square

+ func (m *Move) S2() Square

+ func (m *Move) String() string

+ type MoveHistory struct

+ Comments []string

+ Move *Move

+ PostPosition *Position

+ PrePosition *Position

+ type MoveTag uint16

+ const Capture

+ const Check

+ const EnPassant

+ const KingSideCastle

+ const QueenSideCastle

+ type Notation interface

+ type Outcome string

+ const BlackWon

+ const Draw

+ const NoOutcome

+ const WhiteWon

+ func (o Outcome) String() string

+ type Piece int8

+ const BlackBishop

+ const BlackKing

+ const BlackKnight

+ const BlackPawn

+ const BlackQueen

+ const BlackRook

+ const NoPiece

+ const WhiteBishop

+ const WhiteKing

+ const WhiteKnight

+ const WhitePawn

+ const WhiteQueen

+ const WhiteRook

+ func NewPiece(t PieceType, c Color) Piece

+ func (p Piece) Color() Color

+ func (p Piece) String() string

+ func (p Piece) Type() PieceType

+ type PieceType int8

+ const Bishop

+ const King

+ const Knight

+ const NoPieceType

+ const Pawn

+ const Queen

+ const Rook

+ func PieceTypes() [6]PieceType

+ func (p PieceType) String() string

+ type Position struct

+ func StartingPosition() *Position

+ func (pos *Position) Board() *Board

+ func (pos *Position) CastleRights() CastleRights

+ func (pos *Position) EnPassantSquare() Square

+ func (pos *Position) HalfMoveClock() int

+ func (pos *Position) Hash() [16]byte

+ func (pos *Position) MarshalBinary() (data []byte, err error)

+ func (pos *Position) MarshalText() (text []byte, err error)

+ func (pos *Position) SetTurn(c Color) (p *Position)

+ func (pos *Position) Status() Method

+ func (pos *Position) String() string

+ func (pos *Position) Turn() Color

+ func (pos *Position) UnmarshalBinary(data []byte) error

+ func (pos *Position) UnmarshalText(text []byte) error

+ func (pos *Position) Update(m *Move) *Position

+ func (pos *Position) ValidMoves() []*Move

+ type Rank int8

+ const Rank1

+ const Rank2

+ const Rank3

+ const Rank4

+ const Rank5

+ const Rank6

+ const Rank7

+ const Rank8

+ func (r Rank) String() string

+ type Scanner struct

+ func NewScanner(r io.Reader) *Scanner

+ func (s *Scanner) Err() error

+ func (s *Scanner) Next() *Game

+ func (s *Scanner) Scan() bool

+ type Side int

+ const KingSide

+ const QueenSide

+ type Square int8

+ const A1

+ const A2

+ const A3

+ const A4

+ const A5

+ const A6

+ const A7

+ const A8

+ const B1

+ const B2

+ const B3

+ const B4

+ const B5

+ const B6

+ const B7

+ const B8

+ const C1

+ const C2

+ const C3

+ const C4

+ const C5

+ const C6

+ const C7

+ const C8

+ const D1

+ const D2

+ const D3

+ const D4

+ const D5

+ const D6

+ const D7

+ const D8

+ const E1

+ const E2

+ const E3

+ const E4

+ const E5

+ const E6

+ const E7

+ const E8

+ const F1

+ const F2

+ const F3

+ const F4

+ const F5

+ const F6

+ const F7

+ const F8

+ const G1

+ const G2

+ const G3

+ const G4

+ const G5

+ const G6

+ const G7

+ const G8

+ const H1

+ const H2

+ const H3

+ const H4

+ const H5

+ const H6

+ const H7

+ const H8

+ const NoSquare

+ func NewSquare(f File, r Rank) Square

+ func (sq Square) File() File

+ func (sq Square) Rank() Rank

+ func (sq Square) String() string

+ type TagPair struct

+ Key string

+ Value string

+ type UCINotation struct

+ func (UCINotation) Decode(pos *Position, s string) (*Move, error)

+ func (UCINotation) Encode(pos *Position, m *Move) string

+ func (UCINotation) String() string