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. Both libraries have similar base features to handle the chessboard – editing the position & making moves – as well as fast move generation. eschac distinguishes itself with a focus on performance for standard chess, a more compact board representation and its use of the borrow checker. shakmaty on the other hand has a more complex interface that handles chess960 and other variants, and offers more features such as PGN parsing, Zobrist hashing, Syzygy endgame tablebases, and more.

Feature flags

• alloc: Enables interfaces requiring the alloc crate (e.g. Moves::sort_by).
• std: Implies alloc. Enabled by default and must be disabled for no_std environments.

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.