shakmaty

A Rust library for chess move generation

Features

• Generate legal moves:

  ```rust use shakmaty::{Chess, Position};

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

• Play moves:

  ```rust 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

• 0.13.1
  • 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

Shakmaty is licensed under the GPL-3.0 (or any later version at your option). See the COPYING file for the full license text.