shakmaty-syzygy

A Rust library to probe Syzygy endgame tablebases, based on shakmaty.

Syzygy tables allow optimal play under the 50-move rule. Tables are available for positions with up to 6 (and experimentally 7) pieces.

Example

```rust use shakmaty::Chess; use shakmaty::fen::Fen; use shakmaty_syzygy::{Tablebase, Wdl, Dtz, Syzygy};

let mut tables = Tablebase::new(); tables.add_directory("tables/regular")?;

let pos: Chess = "8/8/8/8/B7/N7/K2k4/8 b - - 0 1" .parse::()? .position()?;

let wdl = tables.probewdl(&pos)?; asserteq!(wdl, Wdl::Loss);

let dtz = tables.probedtz(&pos)?; asserteq!(dtz, Dtz(-59)); ```

Documentation

Read the documentation

Changelog

• 0.4.5
  • Make better use of positioned-io (cursor, remove RandomAccessFile).
• 0.4.4
  • Remove work around from 0.3.1.
  • Minor internal optimizations and cleanups.
• 0.4.3
  • Fix DTZ off-by-one in some positions when there is mate in 1.
  • Fix DTZ off-by-one in antichess endgames, when there is a threat to force a capture leading to a blessed loss.
  • Add Tablebase::best_move().
• 0.4.2
  • Fix DTZ in en passant positions.
  • Minimum Rust version 1.26.0.
  • Use guaranteed lossless versions from u16 to usize.
  • Provide i128 conversions for Wdl and Dtz.
• 0.4.1
  • Fix debug assertion for Dtz(0).add_plies().
• 0.4.0
  • Update to shakmaty 0.7, which has bugfixes with regard to insufficient material.
• 0.3.1
  • Work around compiler bug in release mode.
• 0.3.0
  • Rename Tablebases to Tablebase.
  • Group file extension and magic as TableType in Syzygy trait.
• 0.2.2
  • Implement support for wide DTZ values. These are required for some long 7 piece endgames.
  • Fix panic on corrupted table.
• 0.2.1
  • Should not panic on corrupted tables (even in debug mode).
  • Switch from fnv to fxhash.
• 0.2.0
  • Replace Wdl::from(dtz) with Wdl::from_dtz_after_zeroing(dtz).
  • Remove isize conversions of Dtz and Wdl.
  • Fix WDL of lone king in atomic chess.
  • Support stable rust.
• 0.1.4
  • Fix ordering of lead pawns.
• 0.1.3
  • Add support for Atomic chess and Giveaway.
• 0.1.2
  • Cosmetic tweak to DTZ in case of mate in 1.
• 0.1.1
  • Optional serde-1 feature.
  • Add Dtz.add_plies().
• 0.1.0
  • First release.

Acknowledgement

Thanks to Ronald de Man for his Syzygy tablebases. The probing code is closely based on his implementation for Stockfish.

License

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