void BitAnd(out Expression exp)
{
Expression second;
BitShift(out exp);
while (la.kind == 37) {
Get();
Token tok = t;
BitShift(out second);
if (!ExpectInt(exp, tok, false)) { return; }
if (!ExpectInt(second, tok, true)) { return; }
exp = new BitwiseAnd((TypedExpression<int>)exp, (TypedExpression<int>)second);
}
}