Chess::Rep::Coverage - Expose chess ply potential energy
use Chess::Rep::Coverage;
my $g = Chess::Rep::Coverage->new();
print $g->board();
$g->set_from_fen('8/8/8/3pr3/4P3/8/8/8 w ---- - 0 1');
$c = $g->coverage(); # Recalculate board status
print $g->board();
This module exposes the "potential energy" of a chess ply by returning a hash reference of the board positions, pieces and their "attack or protection status."
Return a new Chess::Coverage object.
$c = $gcoverage();
Set the cover attribute and return a data structure, keyed on board position, showing
occupant => Human readable piece name color => Color number of the occupant index => The C<Chess::Rep/Position> board position index move => List of positions that are legal moves by this piece protects => List of positions that are protected by this piece threatens => List of positions that are threatened by this piece is_protected_by => List of positions that protect this piece is_threatened_by => List of positions that threaten this piece white_can_move_here => List of white piece positions that can move to this position black_can_move_here => List of black piece positions that can move to this position
print $self->board();
Return an ASCII board layout with threats, protections and move statuses.
Protection and threat is indicated by p/t. White and black movement is indicated by w:b.
For example, the FEN 8/8/8/3pr3/4P3/8/8/8 w ---- - 0 1 is rendered as:
A B C D E F G H
+-----+-----+-----+-----+-----+-----+-----+-----+
1 | | | | | | | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
2 | | | | | | | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
3 | | | | | | | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
4 | | | | 0:1 | 0/2 | | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
5 | | | | 1/1 | 0/0 | 0:1 | 0:1 | 0:1 |
+-----+-----+-----+-----+-----+-----+-----+-----+
6 | | | | | 0:1 | | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
7 | | | | | 0:1 | | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
8 | | | | | 0:1 | | | |
+-----+-----+-----+-----+-----+-----+-----+-----+
This means that, 1) the black pawn at D5 can move to D4 and can capture the white pawn at E4; 2) the white pawn at E4 can capture the pawn at D5 but cannot move; 3) the black rook at E5 protects the black pawn at D5, can capture the white pawn at E4 and can move to F5 through H5 or E6 through E8.
* The code in this distribution examples/ and t/ directories.
