private IEnumerable<Move> GetMoves(Bitboard b, int offsetFrom)
{
foreach (var to in b.Squares)
{
Square from = to - offsetFrom;
b = b.Except(to);
if (to >= 56)
{
yield return new Move(from, to, MoveTypes.PawnToQueenPromotion);
yield return new Move(from, to, MoveTypes.PawnToRookPromotion);
yield return new Move(from, to, MoveTypes.PawnToBishopPromotion);
yield return new Move(from, to, MoveTypes.PawnToKnightPromotion);
}
else
{
yield return new Move(from, to);
}
}
}
