- Add chessfriend_core::Color::NUM
- All the library getters can be const.
- Use the constants from the core library to define the length of the slices in
the Library struct.
- Order the values of Direction in a clockwise fashion
- Implement Direction::opposite() to return the opposing direction
- Make some small changes to the macros in this file to improve readability, maybe.
Add a field to MoveSet called special that flags special moves that should be
generated in the iter() method. This field is a u8. It only tracks castles in
the first and second bits (kingside and queenside, respectively). The move iterator
chains two maps over Option<()> that produce the kingside and queenside castle
moves.
With that done, finish the implementation of Position::player_can_castle by
adding checks for whether the squares between the rook and king are clear, and
that the king would not pass through a check. This is done with BitBoards!
Finally, implement some logic in PositionBuilder that updates the position's
castling flags based on the positions of king and rooks.
Supporting changes:
- Add Color:ALL and iterate on that slice
- Add Castle::ALL and iterator on that slice
- Add a CastlingParameters struct that contains BitBoard properties that describe
squares that should be clear of pieces and squares that should not be attacked.
