Module pleco::core::bitboard

Module containing the BitBoard and associated functions / constants.

A BitBoard is a set of bits, where the index of each bit represents a square on the Board. We use this to mark whether or not something is residing at a certain square. For example, if we are using it to map the positions of the white pawns, and there exists a pawn at square B9, the bit at index 9 will be set to '1'. The lack of a piece is marked with a '0' instead.

Each bit's index of a BitBoard maps to the following squares:

8 | 56 57 58 59 60 61 62 63
7 | 48 49 50 51 52 53 54 55
6 | 40 41 42 43 44 45 46 47
5 | 32 33 34 35 36 37 38 39
4 | 24 25 26 27 28 29 30 31
3 | 16 17 18 19 20 21 22 23
2 | 8  9  10 11 12 13 14 15
1 | 0  1  2  3  4  5  6  7
  -------------------------
     a  b  c  d  e  f  g  h

Structs

BitBoard	A BitBoard is simply a 64 bit long integer where each bit maps to a specific square. Used for mapping occupancy, where '1' represents a piece being at that index's square, and a '0' represents a lack of a piece.
RandBitBoard	BitBoard generating structure.