bkgm

Bkgm is a versatile Rust crate designed to facilitate Backgammon-related operations, such as move generation, position parsing, conversion between standards, and the implementation of the perfect hash for bearoff and hypergammon databases. It supports both traditional Backgammon and 3-checker Hypergammon and provides the foundation for building Backgammon engines or APIs.

Example Position

Here's a visual representation of the starting position in Backgammon:

Position ID: 4HPwATDgc/ABMA
┌13─14─15─16─17─18─┬───┬19─20─21─22─23─24─┬───┐
│ X           O    │   │ O              X │   │
│ X           O    │   │ O              X │   │
│ X           O    │   │ O                │   │
│ X                │   │ O                │   │
│ X                │   │ O                │   │
│                  │BAR│                  │OFF│
│ O                │   │ X                │   │
│ O                │   │ X                │   │
│ O           X    │   │ X                │   │
│ O           X    │   │ X              O │   │
│ O           X    │   │ X              O │   │
└12─11─10──9──8──7─┴───┴─6──5──4──3──2──1─┴───┘

Features

• Support for the Gnubg position id format.
• Ability to generate possible positions.
• Macros to create Backgammon and Hypergammon positions.
• State trait implemented for both Backgammon and Hypergammon.

TODO

• Move generation (next possible position generation is already implemented).
• Move parsing (e.g., 24/23*/22*/21*).
• Improve test coverage.
• Add a game trait, enabling Mat files.
• Addition of optional rules
• Improve macros to work with bar and off

References

• Bkgm Documentation
• Backgammon Wikipedia
• Wildbg by Carsten Wenderdel
• Enumerating Backgammon Positions: The Perfect Hash (1997) by A. T. Benjamin and A. M. Ross