code: protected BigDecimal eval(final Object... _values)
          throws SQLException
      {
          final BigDecimal ret;
  
          if (_values == null || _values.length == 0 || _values[0] == null)  {
              ret = null;
          } else if (_values[0] instanceof String && ((String) _values[0]).length() > 0) {
              try {
                  ret = DecimalType.parseLocalized((String) _values[0]);
              } catch (final EFapsException e) {
                  throw new SQLException(e);
              }
          } else if (_values[0] instanceof BigDecimal) {
              ret = (BigDecimal) _values[0];
          } else if (_values[0] instanceof Number) {
              ret = new BigDecimal(((Number) _values[0]).toString());
          } else  {
              ret = null;
          }
  
          return ret;
      }
docs: Evaluate the value.
  @param _values value to be evaluated
  @return BigDecimal value
  @throws SQLException on error