I've lived with this warning for a long time because I didn't really understand
it.
```
warning: `chessfriend_core` (lib) generated 1 warning (run `cargo fix --lib -p chessfriend_core` to apply 1 suggestion)
warning: creating a shared reference to mutable static is discouraged
--> bitboard/src/library.rs:66:9
```
I was able to fix this by creating a new type with a single OnceLock attribute.
The OnceLock acts as a cell, making it mutable, even if self is not. So, you can
declare the MoveLibraryWrapper non-mutable static, but still initialize the
library inside the Cell.
This generator produces moves for slider pieces: bishops, rooks, and queens. All
of these pieces behave identically, though with different sets of rays that
emanate from the origin square. Claude helped me significantly with the
implementation and unit testing. All the unit tests that took advantage of Claude
for implementation are marked as such with an _ai_claude suffix to the test name.
One unique aspect of this move generator that Claude suggested to me was to use
loop { } instead of a recursive call to next() when the internal iterators expire.
I may try to port this to the other move generators in the future.
To support this move generator, implement a Slider enum in core that represents
one of the three slider pieces.
Add Board::bishops(), Board::rooks() and Board::queens() to return BitBoards of
those pieces. These are analogous to the pawns() and knights() methods that return
their corresponding pieces.
Also in the board create, replace the separate sight method implementations with
a macro. These are all the same, but with a different sight method called under
the hood.
Finally, derive Clone and Debug for the bit_scanner types.
Let BitBoard::rank and BitBoard::file take a Rank and File directly, instead of a
u8 by reference. And then make the Rank/File::as_index const and return a value
rather than a reference.
All this allows you to convert between Rank, File, and BitBoard at compile tile
(i.e. as a const method) rather than needing to do runtime stuff.
Add chessfriend_bitboard::IterationDirection
Make BitBoard::occupied_squares() take an IterationDirection and return an iterator
corresponding to the direction.
Do the same for ::first_occupied_square().
Declare the `forward_ref` crate as a dependency (my first external dependency!)
and use it to clean up the infix, assign, and unary op impls. This crate
automatically implements A+&B, &A+B, and &A+&B for me.
It's unused except for the macro, and BitBoard itself can be declared mutable,
and implements Copy and Clone. So, I don't think having a separate Builder type
helps much.
- 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.
- Add allow(dead_code) to LIGHT_SQUARES and DARK_SQUARES. These aren't used yet
but I have a feeling they'll come in handy.
- Add some separators to long numeric literals.
- Lightly reformat BitBoard -> Bitboard in the module documentation
- Implement BitBoard::is_populated(), the opposite of ::is_empty()
- Write a bit of documentation for the BitBoard Library and for some methods on BitBoard
- Mark a few methods as const
Use u64::MIN and u64::MAX to define the empty and full bitboards
Write From<Square> as `1u64 << sq as u32`
Write a doc test for BitBoard::is_single_square()
Make library::RANKS and library::FILES pub(crate) instead of pub(super)
This trait declares ray_to_square() which should return a BitBoard representing
a ray from a Square to another Square. The ray should include the target Square.
PlacedPiece implements this trait.
Add two small BitBoard slices that represent kingside and queenside squares per
color.
Add doc comments to DARK_SQUARES and LIGHT_SQUARES.
Add getters on BitBoard for getting a boardside bitboard.
Clean up imports. Import the whole library module and refer to library things in
BitBoard by path.
This enables a bunch of clean up! Remove the MoveGenerationParameters and MoveList
types from move_generator::pawn.
Implement BitBoard::pawn_pushes to look up pawn pushes by square and color.
