Crate eschac 

eschac - a library for computing chess moves

eschac implements fast legal move generation and a copy-make interface that enforces at compile time that no illegal move is played, with no runtime checks and no potential panics.

Overview

In eschac, a chess position is represented with the Position type. Position::new returns the starting position of a chess game, and arbitrary positions can be built using the Setup type. This type must be validated and converted to Position with Setup::into_position. Legal moves are generated using the Position::legal_moves method or obtained from chess notation like UciMove or San. Moves are represented with the Move<'l> type, which holds a reference to the origin position to ensure that the move is not played on another one. Finally, moves are played with Move::make which returns a new Position, and on it goes.

Example

use eschac::prelude::*;

// read a position from a text record
let setup = Setup::from_text_record("7k/4P1rp/5Q2/5p2/1Pp1bP2/8/r4K1P/6R1 w - -")?;
let position = setup.into_position()?;

// read a move in algebraic notation
let san = "Ke1".parse::<San>()?;
let m = san.to_move(&position)?;

// play the move (note the absence of error handling)
let position = m.make();

// generate all the legal moves on the new position
let moves = position.legal_moves();
for m in moves {
    // print the UCI notation of each move
    println!("{}", m.to_uci());
}

Comparison with shakmaty

shakmaty is another Rust library for chess processing. It is written by Niklas Fiekas, whose work greatly inspired the development of eschac. For most purposes, shakmaty is probably a better option, as eschac comes short of its miriad of features.

Both libraries have the same core features:

• vocabulary to describe the chessboard (squares, pieces, etc.)
• parsing and editing positions
• parsing standard move notations
• fast legal move generation and play

eschac distinguishes itself with:

• a focus on performance
• a more compact board representation
• its use of the borrow checker to guarantee only legal moves are played

shakmaty will be more suitable for a lot of applications, with:

• vocabulary to describe and work with games, not just positions
• insufficient material detection
• PGN parsing
• Zobrist hashing
• Syzygy endgame tablebases
• chess960 and other variants
• etc.

Modules

bitboard

Sets of squares.

board

Chessboard vocabulary.

position

Move generation.

prelude

The eschac prelude.

san

Standard algebraic notation.

setup

Building chess positions.

uci

UCI notation.