chess 3.2.0

This is a fast chess move generator. It has a very good set of documentation, so you should take advantage of that. It (now) generates all lookup tabels with a build.rs file, which means that very little pseudo-legal move generation requires branching. There are some convenience functions that are exposed to, for example, find all the squares between two squares. This uses a copy-on-make style structure, and the Board structure is as slimmed down as possible to reduce the cost of copying the board. There are places to improve perft-test performance further, but I instead opt to be more feature-complete to make it useful in real applications. For example, I generate both a hash of the board and a pawn-hash of the board for use in evaluation lookup tables (using Zobrist hashing). There are two ways to generate moves, one is faster, the other has more features that will be useful if making a chess engine. See the documentation for more details.
Documentation 
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use crate::bitboard::{BitBoard, EMPTY};
use crate::piece::Piece;
use crate::square::{Square, ALL_SQUARES};
use std::fs::File;
use std::io::Write;

// Given a square and a piece type (rook or bishop only), what are the squares they
// would attack if no pieces were on the board?
// This will be generated here, and then put into the magic_gen.rs as a const array.
static mut RAYS: [[BitBoard; 64]; 2] = [[EMPTY; 64]; 2];

// For each square, generate the RAYS for the bishop.
pub fn gen_bishop_rays() {
    for src in ALL_SQUARES.iter() {
        unsafe {
            RAYS[1][src.to_index()] = ALL_SQUARES
                .iter()
                .filter(|dest| {
                    let src_rank = src.get_rank().to_index() as i8;
                    let src_file = src.get_file().to_index() as i8;
                    let dest_rank = dest.get_rank().to_index() as i8;
                    let dest_file = dest.get_file().to_index() as i8;

                    (src_rank - dest_rank).abs() == (src_file - dest_file).abs() && *src != **dest
                })
                .fold(EMPTY, |b, s| b | BitBoard::from_square(*s));
        }
    }
}

// For each square, generate the RAYS for the rook.
pub fn gen_rook_rays() {
    for src in ALL_SQUARES.iter() {
        unsafe {
            RAYS[0][src.to_index()] = ALL_SQUARES
                .iter()
                .filter(|dest| {
                    let src_rank = src.get_rank().to_index();
                    let src_file = src.get_file().to_index();
                    let dest_rank = dest.get_rank().to_index();
                    let dest_file = dest.get_file().to_index();

                    (src_rank == dest_rank || src_file == dest_file) && *src != **dest
                })
                .fold(EMPTY, |b, s| b | BitBoard::from_square(*s));
        }
    }
}

pub fn get_rays(sq: Square, piece: Piece) -> BitBoard {
    unsafe { RAYS[if piece == Piece::Rook { 0 } else { 1 }][sq.to_index()] }
}

// Write the RAYS array to the specified file.
pub fn write_rays(f: &mut File) {
    write!(f, "const ROOK: usize = {};\n", 0).unwrap();
    write!(f, "const BISHOP: usize = {};\n", 1).unwrap();
    write!(f, "const RAYS: [[BitBoard; 64]; 2] = [[\n").unwrap();
    for i in 0..2 {
        for j in 0..64 {
            unsafe { write!(f, "    BitBoard({}),\n", RAYS[i][j].0).unwrap() };
        }
        if i != 1 {
            write!(f, "  ], [\n").unwrap();
        }
    }
    write!(f, "]];\n").unwrap();
}