-/// pawn_attack_span() takes a color and a square as input, and returns a bitboard
-/// representing all squares that can be attacked by a pawn of the given color
-/// when it moves along its file starting from the given square. Definition is:
-/// PawnAttackSpan[c][s] = in_front_bb(c, s) & adjacent_files_bb(s);
+/// forward_file_bb() returns a bitboard representing all the squares along the line
+/// in front of the given one, from the point of view of the given color:
+/// ForwardFileBB[c][s] = forward_ranks_bb(c, s) & file_bb(s)
+
+inline Bitboard forward_file_bb(Color c, Square s) {
+ return ForwardFileBB[c][s];
+}
+
+
+/// pawn_attack_span() returns a bitboard representing all the squares that can be
+/// attacked by a pawn of the given color when it moves along its file, starting
+/// from the given square:
+/// PawnAttackSpan[c][s] = forward_ranks_bb(c, s) & adjacent_files_bb(file_of(s));