hexchess

A library for Gliński's hexagonal chess, and the brain of hexchess.club.

Installation

Run the following Cargo command in your project directory:

cargo add hexchess

Or add hexchess as a dependency to your Cargo.toml file.

Basic usage

The Hexchess struct represents a deserialized version of Forsyth–Edwards Notation. Since castling is not a part of hexchess, that section is omitted. The following is a generalized version of the struct. The board is stored as an array of Option<Piece> values, sorted by FEN index.

{
  board: [
    'b',  'q',  'b',  'k',  'n',  null, 'b',  null, 'n',  'r',
    null, null, null, null, null, 'r',  'p',  'p',  'p',  'p',
    'p',  'p',  'p',  'p',  'p',  null, null, null, null, null,
    null, null, null, null, null, null, null, null, null, null,
    null, 'P',  null, null, null, null, null, null, null, null,
    null, 'P',  null, 'P',  null, null, null, null, null, null,
    null, 'P',  null, 'B',  null, 'P',  null, null, null, null,
    null, 'P',  null, null, 'B',  null, null, 'P',  null, null,
    null, 'P',  'R',  'N',  'Q',  'B',  'K',  'N',  'R',  'P',
    null
  ],
  turn: 'w',
  ep: null,
  halfmove: 0,
  fullmove: 1
}

The following methods are available,

apply

Apply a whitespace separated sequence of moves.

let mut hexchess = Hexchess::init();
let _ = hexchess.apply("g4g5 e7e6 f5f6 e6f6");
    
hexchess.to_string() // b/qbk/n1b1n/r5r/ppp1ppppp/5p5/6P4/4P6/3P1B1P3/2P2B2P2/1PRNQBKNRP1 w - 0 3

apply_move

Apply a single move by San.

let san = San::from("g4g5").unwrap();
let mut hexchess = Hexchess::init();
let _ = hexchess.apply_move(&san);

hexchess.to_string() // b/qbk/n1b1n/r5r/ppppppppp/11/5PP4/4P6/3P1B1P3/2P2B2P2/1PRNQBKNRP1 b - 0 1

apply_move_unsafe

Apply a single by San, regardless of turn or legality.

let san = San::from("b1b6").unwrap();
let mut hexchess = Hexchess::init();
let _ = hexchess.apply_move_unsafe(&san)

hexchess.to_string() // b/qbk/n1b1n/r5r/ppppppppp/1P9/5P5/4P1P4/3P1B1P3/2P2B2P2/2RNQBKNRP1 b - 0 1

current_moves

Get all current legal moves.

let hexchess = Hexchess::init();

for san in hexchess.current_moves() {
    // ...
}

find_king

Find FEN index for king belonging to Color.

let hexchess = Hexchess::init();

hexchess.find_king(Color::Black); // Some(3)
hexchess.find_king(Color::White); // Some(86)

get

Get board value from position name.

let hexchess = Hexchess::init();

hexchess.get("e1") // Some(WhiteQueen)

get_color

Get all board indices occupied by Color pieces.

let hexchess = Hexchess::init();

hexchess.get_color(Black) // [0,  1,  2,  ...]

is_check

Test if the board is in check.

let hexchess = Hexchess::init();

hexchess.is_check() // false

is_checkmate

Test if the game is in checkmate.

let hexchess = Hexchess::init();

hexchess.is_checkmate() // false

is_stalemate

Test if the game is in stalemate.

let hexchess = Hexchess::init();

hexchess.is_stalemate() // false

moves_from

Get all legal moves from a position.

let hexchess = Hexchess::init();

hexchess.moves_from(h!("f5"))  // [San { from: 41, promotion: None, to: 30 }]

moves_from_unsafe

Get all moves from a position, including ones that result in self-check.

let hexchess = Hexchess::parse("1/3/5/7/4r4/5K5/11/11/11/11/11 w - 0 1").unwrap();

hexchess.moves_from_unsafe(h!("f6")) // [San, San, San, ...]

to_string

Serialize Hexchess to string.

let hexchess = Hexchess::init();

hexchess.to_string() // b/qbk/n1b1n/r5r/ppppppppp/11/5P5/4P1P4/3P1B1P3/2P2B2P2/1PRNQBKNRP1 w - 0 1

License

MIT

Copyright (c) 2024-present, Scott Bedard