Module shakmaty::fen

source ·
Expand description

Parse and write Forsyth-Edwards-Notation.

§Parsing

The parser is relaxed:

  • Supports X-FEN and Shredder-FEN for castling right notation.
    • Ignores repeated castling rights.
    • Allows castling rights in any order.
    • Allows castling rights without matching rooks (treating Q and K as A and H respectively).
  • Supports [q] and /q styles for Crazyhouse pockets.
  • Supports 3+3 and +0+0 for remaining checks in Three-Check.
  • Accepts missing FEN fields (except the board) and fills them with default values of 8/8/8/8/8/8/8/8 w - - 0 1.
  • Accepts multiple spaces and underscores (_) as separators between FEN fields.
  • Accepts 0 as fulllmove number and uses 1 instead.

Fen and Epd implement FromStr:

use shakmaty::{fen::Fen, CastlingMode, Chess, Position};

let fen: Fen = "r1bqkbnr/ppp2Qpp/2np4/4p3/2B1P3/8/PPPP1PPP/RNB1K1NR b KQkq - 0 4".parse()?;
let pos: Chess = fen.into_position(CastlingMode::Standard)?;
assert!(pos.is_checkmate());

§Writing

Writes X-FEN with [q] style for Crazyhouse pockets and 3+3 style for remainig checks in Three-Check.

Fen and Epd implement Display:

use shakmaty::{fen::Epd, EnPassantMode, Chess, Position};

let pos = Chess::default();

assert_eq!(Epd::from_position(pos, EnPassantMode::Legal).to_string(),
           "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -");

Structs§

  • BoardFen
    Displays a board with notation like rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR.
  • Epd
    An EPD like rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq -.
  • Fen
    A FEN like rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1.

Enums§