Chess Class

Chees class.

Format

An [R6::R6Class] generator object.

Methods

• new Creating a new instance of Chess class.

• ascii Print the board via console.

• clear Remove all pieces from the board.

• fen Return the actual Forsyth Edwards notation.

• pgn Return Portable Game notation.

• get Return the piece in a spicific square argument.

• history Return a vector containing the moves of the current game. If the argument verbose=TRUE is added the method return a data frame.

• game_over Returns TRUE if the game has ended via checkmate, stalemate, draw, threefold repetition, or insufficient material. Otherwise, returns FALSE.

• in_check Returns true or false if the side to move is in check.

• in_checkmate Returns true or false if the side to move has been checkmated.

• in_draw Returns true or false if the game is drawn 50 move rule or insufficient material.

• in_stalemate Returns true or false if the side to move has been stalemated.

• in_threefold_repetition Returns true or false if the current board position has occurred three or more times.

• insufficient_material Returns true if the game is drawn due to insufficient material (K vs. K, K vs. KB, or K vs. KN); otherwise false.

• move Attempts to make a move on the board, returning a move object if the move was legal, otherwise null. The .move function can be called two ways, by passing a string in Standard Algebraic Notation SAN:

• moves Returns a vector of legals moves from the current position. The function takes an optional parameter which controls the single square move generation and verbosity.

• validate_fen Returns a validation object specifying validity or the errors found within the FEN string.

• load

• load_pgn Load the moves of a game stored in Portable Game Notation.

• put Place a piece on square where piece is an object.

• remove Remove and return the piece on square.

• reset Reset the board to the initial starting position.

• square_color Returns the color of the square (light or dark).

• turn Returns the current side to move.

• undo Takeback the last halfmove, returning a move object if successful.

• header Allows header information to be added to PGN output. Any number of key value pairs can be passed to header().

• get_header Get header of the actual game via list object.

• history_detail Return a detailed version for history(verbose=TRUE).

• summary Print a summary of the object.

• plot Plot the object with chessboard.js or ggplot2.

• print Print the summary ob the Chess object.

Methods

Public methods

• Chess$new()

• Chess$init_ct()

• Chess$ascii()

• Chess$clear()

• Chess$fen()

• Chess$pgn()

• Chess$get()

• Chess$history()

• Chess$game_over()

• Chess$in_check()

• Chess$in_checkmate()

• Chess$in_draw()

• Chess$in_stalemate()

• Chess$in_threefold_repetition()

• Chess$insufficient_material()

• Chess$move()

• Chess$moves()

• Chess$validate_fen()

• Chess$load()

• Chess$load_pgn()

• Chess$put()

• Chess$remove()

• Chess$reset()

• Chess$square_color()

• Chess$turn()

• Chess$undo()

• Chess$header()

• Chess$get_header()

• Chess$history_detail()

• Chess$summary()

• Chess$plot()

• Chess$print()

• Chess$clone()

---

Chess$new()

Create a game from a FEN position.

Usage

Chess$new(fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")

Arguments

fen

A Forsyth-Edwards Notation string.

---

Chess$init_ct()

Initialize the underlying JavaScript chess context.

Usage

Chess$init_ct(fen)

Arguments

fen

A Forsyth-Edwards Notation string.

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Chess$ascii()

Print an ASCII representation of the board.

Usage

Chess$ascii()

---

Chess$clear()

Remove all pieces from the board.

Usage

Chess$clear()

---

Chess$fen()

Return the current FEN position.

Usage

Chess$fen()

---

Chess$pgn()

Return the game in Portable Game Notation.

Usage

Chess$pgn()

---

Chess$get()

Return the piece on a square.

Usage

Chess$get(square)

Arguments

square

A square such as `"e4"`.

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Chess$history()

Return the moves already played.

Usage

Chess$history(verbose = FALSE)

Arguments

verbose

If `TRUE`, return detailed move records as a tibble.

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Chess$game_over()

Test whether the game has ended.

Usage

Chess$game_over()

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Chess$in_check()

Test whether the active player is in check.

Usage

Chess$in_check()

---

Chess$in_checkmate()

Test whether the active player is checkmated.

Usage

Chess$in_checkmate()

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Chess$in_draw()

Test whether the game is drawn.

Usage

Chess$in_draw()

---

Chess$in_stalemate()

Test whether the active player is stalemated.

Usage

Chess$in_stalemate()

---

Chess$in_threefold_repetition()

Test whether the position has repeated three times.

Usage

Chess$in_threefold_repetition()

---

Chess$insufficient_material()

Test whether neither player has mating material.

Usage

Chess$insufficient_material()

---

Chess$move()

Play a legal move.

Usage

Chess$move(move)

Arguments

move

A move in Standard Algebraic Notation.

---

Chess$moves()

Return legal moves from the current position.

Usage

Chess$moves(verbose = FALSE)

Arguments

verbose

If `TRUE`, return detailed move records as a tibble.

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Chess$validate_fen()

Validate a FEN position.

Usage

Chess$validate_fen(fen)

Arguments

fen

A Forsyth-Edwards Notation string.

---

Chess$load()

Replace the current position with a FEN position.

Usage

Chess$load(fen)

Arguments

fen

A Forsyth-Edwards Notation string.

---

Chess$load_pgn()

Load a game from Portable Game Notation.

Usage

Chess$load_pgn(pgn)

Arguments

pgn

A Portable Game Notation string.

---

Chess$put()

Place a piece on a square.

Usage

Chess$put(type, color, square)

Arguments

type

One of `"k"`, `"q"`, `"r"`, `"b"`, `"n"`, or `"p"`.

color

Either `"w"` or `"b"`.

square

A square such as `"e4"`.

---

Chess$remove()

Remove and return the piece on a square.

Usage

Chess$remove(square)

Arguments

square

A square such as `"e4"`.

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Chess$reset()

Reset the game to the standard starting position.

Usage

Chess$reset()

---

Chess$square_color()

Return whether a square is light or dark.

Usage

Chess$square_color(square)

Arguments

square

A square such as `"e4"`.

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Chess$turn()

Return the active color, `"w"` or `"b"`.

Usage

Chess$turn()

---

Chess$undo()

Undo and return the last move.

Usage

Chess$undo()

---

Chess$header()

Add a key-value pair to the PGN header.

Usage

Chess$header(key, value)

Arguments

key

A PGN header name.

value

A value coercible to character.

---

Chess$get_header()

Return the PGN header as a list.

Usage

Chess$get_header()

---

Chess$history_detail()

Return piece-by-piece move history as a tibble.

Usage

Chess$history_detail()

---

Chess$summary()

Print a summary of the game.

Usage

Chess$summary()

---

Chess$plot()

Render the current position.

Usage

Chess$plot(type = "chessboardjs", ...)

Arguments

type

Either `"chessboardjs"` or `"ggplot"`.

...

Additional arguments passed to the renderer.

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Chess$print()

Print the game summary.

Usage

Chess$print()

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Chess$clone()

The objects of this class are cloneable with this method.

Usage

Chess$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.