shakmaty

A Rust library for chess move generation

Features

Generate legal moves:

use shakmaty::{Chess, Position};

let pos = Chess::default();
let legals = pos.legals();
assert_eq!(legals.len(), 20);

Play moves:

use shakmaty::{Square, Move, Role};

// 1. e4
let pos = pos.play(&Move::Normal {
    role: Role::Pawn,
    from: Square::E2,
    to: Square::E4,
    capture: None,
    promotion: None,
})?;

Detect game end conditions: pos.is_checkmate(), pos.is_stalemate(), pos.is_insufficient_material(), pos.outcome().
Read and write FENs, SANs and UCIs.
Supports standard chess, Chess960, Giveaway, Atomic, King Of The Hill, Three-Check, Crazyhouse, Racing Kings and Horde. Provides vocabulary to implement other variants.
Bitboards and compact fixed shift magic attack tables.
Probe Syzygy tablebases with shakmaty-syzygy.

Documentation

Read the documentation

Benchmarks

Simple perft of the initial position. No hashtables. i7-6850K CPU @ 3.60GHz.

perft	4	5
shakmaty	1.4 ms	33.8 ms
jordanbray/chess	1.3 ms	28.7 ms
Stockfish 8 (x86-64-bmi2)	4 ms	33 ms

It should be noted that Stockfish is not optimized for perft speed and also maintains additional data structures for evaluation. Newer versions of Stockfish put even less emphasis on this.

Changelog

0.15.3
- Follow FICS rules in Atomic castling edge cases.
- Use #[repr(align)] enum and reverse_bits() stabilized in Rust 1.37.
0.15.2
- In Horde chess, allow double pawn moves from the first rank.
- Added {Square,Bitboard}::{flip_anti_diagonal,rotate_90,rotate_180,rotate_270}().
0.15.1
- FEN parser was expecting ~ before promoted pieces, but it should be after.
0.15.0
- Moved Position::from_setup() to a seperate new trait FromSetup.
- Square and file/rank index calculations are now performed with u32 and i32, which is more performant than using the narrower types u8 and i8. The types are still #[repr(u8)].
- Renamed Square::combine() to Square::with_rank_of().
- Added Fen::from_setup().
- Added FenOpts::scid() for Scid/Lichess compatible FEN formatting. Of course the parser also accepts these formats.
- Added variant::Variant and VariantPosition for runtime selected chess variants. Limited to the built in variants.
- Added {Material,MaterialSide}::is_empty().
0.14.1
- TryFrom now available on stable.
0.14.0
- SanPlus::from_move() no longer requires the move to be legal, which was an undocumented requirement. The new SanPlus::from_move_and_play_unchecked() is closest to the previous behavior.
- Added San::disambiguate() and SanSuffix::from_position().
- Implement TryFrom for various types on nightly.
- Implement Add, AddAssign, Sub, SubAssign for Material and MaterialSide.
- Added CastlingSide::from_{king|queen}_side().
- Use u32 for depth argument of perft().
0.13.1
- Performance improvements on nightly (aligned Move enum).
0.13.0
- Replaced SanPlus::check and SanPlus::checkmate with san::Suffix enum.
- Renamed {Rank,File}::rotate() to flip_diagonal().
- Renamed Bitboard::flip() to toggle().
- Added Square::coords().
- Added Bitboard::flip_{vertical,horizontal,diagonal}().
- Added Position::promotion_moves().
- Derive Hash on Board, FenOpts, San, SanPlus, Suffix, Color, Role, Piece, RemainingChecks, CastlingSide, and Uci.
- Minimum Rust version 1.31.0.
0.12.0
- Setup::halfmove_clock() is now Setup::halfmoves().
- New conversions: f32::from(file), f64::from(rank).
- Replaced Pockets and Pocket by more general Material and MaterialSide. Note that their Display and FromStr implementations differ.
- Unified naming of error types.
0.11.2
- Fix Atomic insufficient material: KQN can mate.
0.11.1
- Fix Chess960 should not allow a-side castling over a blocking h-side rook.
0.11.0
- Outcome is now Copy.
- Position::castling_uncovers_rank_attack() is no longer public.
0.10.0
- Added File, Rank. These are now returned by Square::{file, rank}. Square::from_coords(file, rank) takes the new types and is no longer fallible.
- Bitboard is now IntoIterator instead of Iterator itself. Methods Bitboard::{first, last, count, is_empty} remain.
- Bitboard::{add, flip, discard, with, without} are now generic over Into<Bitboard>. Alternative methods *_all have been removed.
- Bitboard::relative_shift(color, shift: u8) now takes u32.
- shakmaty::CarryRippler is now shakmaty::bitboard::CarryRippler.
- Add new methods: Bitboard::{pop_front, pop_back, is_disjoint, is_subset, is_superset}.
- Add Position::has_insufficient_material(color).
0.9.0
- Remove uci, chess960_uci, san and san_plus that were deprecated in 0.8.1.
- Renamed *::from_bytes() to *::from_ascii().
- Take small copy types by value: Piece::char(), CastlingSide::*.
- Added Castles::has(color, side).
- fen::{board_fen, epd, fen} are now shortcuts for formatting with default options.
- Minimum rust version 1.27.0 (i128 conversions again, fused iterators again, Option::filter(), dyn Trait).
- Eliminate many uses of unsafe, including TrustedLen impls, at minor cost.
0.8.1
- Make Role discriminants public.
- Put San, SanPlus and Uci constructors on San, SanPlus and Uci respectively.
0.8.0
- Revert fused iterators and u128. Minimum Rust version back to 1.23.0.
- Changed Role discriminants. Now starting with Pawn = 1.
- Performance improvements (~12% faster perft).
- Switch benchmarks to criterion.rs.
0.7.2
- Add Outcome.winner().
0.7.1
- Minimum Rust version 1.26.0 (fused iterators, u128 conversions).
0.7.0
- Reintroduce the remaining Lichess variants: Crazyhouse, KingOfTheHill, ThreeCheck, Horde, RacingKings.
- Expose Position.castles() and replace Position.is_chess960() with Position.castles().is_chess960().
- Fix insufficient material: KNvK was not given as drawn due to a typo.
- Fix insufficient material in Atomic: Two knights of different colors are not safe.
- Let Pockets.count() and Pocket.count() return usize.
0.6.7
- Giveaway starting position should have no castling rights.
0.6.6
- Fix missing king promotions in Giveaway.
0.6.5
- Validate color of missing king in atomic chess.
- Clear move buffers before generating variant moves.
0.6.4
- Reintroduce Giveaway and Atomic chess variants.
0.6.3
- New method Move.is_zeroing().
0.6.2
- Make unit error types (InvalidSquareName, InvalidUci, InvalidSan) completely public.
- Documentation, coding style and debugging tweaks.
0.6.1
- Expose attacks::bishop_mask and attacks::rook_mask.
- Eliminate almost all unchecked indexing.
0.6.0
- Split impl From<Move> for Uci into uci() and chess960_uci().
- Fix display of pawn drops.
- Move generating methods clear the move buffer (and therefor no longer panic on too full buffers).
- Added Position.is_chess960(), Bitboard.without_all(), Role.upper_char(), Board.stepper().
0.5.1
- Fix Uci::to_move() for en passant moves. Thanks zxqfl.
0.5.0
- Use u64 instead of usize for perft().
- Export error type InvalidSquareName.
- New methods: CastlingSide.is_{queen|king}_side(), San.matches(), Move.is_capture(), Move.is_promotion(), Move.castling_side(), Position.is_check().
- Derive Ord and PartialOrd for Role.
- Support running benchmarks on stable.
0.4.2
- Fix build error on beta due to the new nightly option_filter feature.
- Fix unterminated code block in documentation.
0.4.1
- Fix build error due to the new nightly option_filter feature.
0.4.0
- Rename Color::from_bool() to Color::from_white(), add Color::from_black().
- Add Move::role(), Move::is_en_passant() and Move::is_castle().
- Add Position::en_passant_moves() and Position::capture_moves().
- Implement BitXor<bool> for Color.
- Implement FusedIterator and TrustedLen on Bitboard.
0.3.0
- Switch to #[repr(i8)] for Square. Implement all lossless integer conversions From<Square>.
- Add Square::flip_horizontal(), flip_vertical() and flip_diagonal().
- Efficiently implement CarryRippler::last() by @nvzqz.
- Eliminate some unchecked indexing by @nvzqz.
- Faster ASCII case conversions and tests by @nvzqz.
0.2.0
- Square is now a #[repr(u8)] enum.
- Use bitflags for PositionError.
- Rename RemainingChecks::subtract() to decrement().
- Add Position::swap_turn().
0.1.0
- First release with support for stable Rust.

License