Crate haitaka

Crate haitaka 

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§haitaka ハイタカ   Latest Version Build Status Documentation

§Rust Shogi move generation library

haitaka is a Shogi move generation library written in Rust that aims to support fast move generation. It is inspired by the beautifully designed cozy-chess library written by analog-hors. The layout of the modules and the overall design is largely the same as in cozy-chess. Many low-level functions were copied from cozy-chess, with only trivial modifications, but since there are significant differences between Shogi and International Chess, I also modified some of the higher-level functions and added extra functionality.

§Name

“Haitaka” or “taka” means “sparrowhawk” in Japanese. “Taka” is a haiku kigo (season word) associated with winter.

   鷹の眼​にこぼれて雁のたち騒ぐ
   Taka no me ni koborete kari no tachisawagu

   ​Escaping the hawk’s eye,
   the wild geese
   rise in tumult.
   -— 加賀千代女 (Kaga no Chiyojo)

§Overview

  • no_std compatible
  • Strongly-typed API that makes heavy use of newtypes to avoid errors
  • Efficient bitboard-based board representation
  • Performant legal move generation
  • Incrementally updated zobrist hash for quickly obtaining a hash of a board
  • Supporting both Magic Bitboards and the Qugiy algorithm for slider move generation
  • Support for parsing SFEN strings

§Main differences with cozy-chess

  • BitBoard uses u128 instead of u64 as backing to handle the 9x9 Shogi board
  • Move generation handles both board moves and drops
  • Move generation of sliders also implements the Qugiy algorithm
  • File-major ordering of squares to make move generation faster

§Crate features

  • std: Enable features that require std. Currently only used for the Error trait.

§Installation

Add haitaka to your Cargo.toml:

[dependencies]
haitaka = "0.2.1"   # or use the latest version on crates.io

§Usage

§Basic

use haitaka::*;
// Start position
let board = Board::startpos();
let mut move_list = Vec::new();
board.generate_moves(|moves| {
    // Unpack into move list
    move_list.extend(moves);
    false
});
assert_eq!(move_list.len(), 30);

§Perft

cargo run --release --example perft -- 5

§Testing

This code has been tested on an Apple M2, using the stable-aarch64-apple-darwin toolchain. In GitHub workflows it has also been tested on Ubuntu.

The code has not yet been used in a Shogi engine, so should still be seen as experimental.

To run all tests use:

cargo test

§Contributing

Contributions are very welcome! Please open an issue or submit a pull request on GitHub.

§Acknowledgments

Portions of this library are derived from the cozy-chess project by analog-hors. The cozy-chess project is licensed under the MIT license, and its license text is included in this repository under third_party/cozy-chess/LICENSE.

§References

§Examples

This crate also includes some examples that illustrate the API and can be used as tools. You can find them in the examples directory of the repository:

  • Find Magics Generates magic numbers for slider moves.
  • Perft A perft implementation for Shogi.

To run an example, clone the reposity and use one of the following commands:

cargo run --release --example find_magics -- --verbose
cargo run --release --example perft -- 3

Re-exports§

pub use attacks::*;
pub use board::*;
pub use slider_moves::*;

Modules§

attacks
Pseudo-attacks for non-sliding pieces
board
The Shogi Board representation and move generation functions
slider_moves
Slider

Macros§

bitboard
BitBoard literal macro.

Structs§

BitBoard
A bitboard. A bitboard is an ordered set of squares. The set contains a square if bit 1 << square as usize is set.
BitBoardIter
An iterator over the squares of a bitboard.
BitBoardSubsetIter
An iterator over the subsets of a bitboard.
ColorParseError
The value was not a valid Color.
ColoredPiece
FileParseError
The value was not a valid File.
PieceParseError
The value was not a valid Piece.
RankParseError
The value was not a valid Rank.
SquareParseError
The value was not a valid Square.

Enums§

Color
A side to move.
File
A file (column) on a shogi board.
Move
A Shogi move.
MoveParseError
The value was not a valid Move.
Piece
Shogi piece types.
Rank
A rank (row) on a shogi board.
Square
A square on a Shogi board.

Constants§

BISHOP_TABLE_SIZE
NEG_DIA
Up-slanting diagonals.
POS_DIA
Down-slanting diagonals.
ROOK_TABLE_SIZE
SLIDING_MOVES_TABLE_SIZE

Functions§

bishop_pseudo_attacks
Bishop pseudo-attacks.
drop_zone
Returns a BitBoard representing all squares where a piece may be dropped. This is the inverse of no_fly_zone.
get_between_rays
Get all squares between two squares, if reachable via a ray. The from and to square are not included in the returns BitBoard.
get_bishop_moves_index
get_bishop_moves_slow
get_bishop_relevant_blockers
Get Bishop blocker mask.
get_lance_moves
Return a BitBoard with pseudo-legal lance moves.
get_lance_moves_slow
get_lance_relevant_blockers
Get Lance blocker mask.
get_rook_file_moves
Return a BitBoard of Rook moves on its file, up to the first blocking pieces (if any).
get_rook_moves_index
get_rook_moves_slow
get_rook_rank_moves
Return a BitBoard of Rook moves on its rank, up to the first blocking pieces (if any).
get_rook_relevant_blockers
Returns the Rook blocker mask for the given square.
lance_pseudo_attacks
Lance pseudo-attacks.
line_ray
Get a ray on the board that passes through both squares, if it exists.
must_prom_zone
Returns a BitBoard of all squares where the piece must promote.
no_fly_zone
Get the no-fly-zones for a piece.
prom_zone
Returns a BitBoard representing the promotion zone for the color.
rook_pseudo_attacks
Rook pseudo-attacks from square.