internal static T GetField <T>(Triple_Accessor accessor, string fieldName, int field_name_idx)
        {
            uint member_id;
            int  field_divider_idx = fieldName.IndexOf('.', field_name_idx);

            if (-1 != field_divider_idx)
            {
                string member_name_string = fieldName.Substring(field_name_idx, field_divider_idx - field_name_idx);
                if (!FieldLookupTable_Triple.TryGetValue(member_name_string, out member_id))
                {
                    Throw.undefined_field();
                }
                switch (member_id)
                {
                default:
                    Throw.member_access_on_non_struct__field(member_name_string);
                    break;
                }
            }
            fieldName = fieldName.Substring(field_name_idx);
            if (!FieldLookupTable_Triple.TryGetValue(fieldName, out member_id))
            {
                Throw.undefined_field();
            }
            switch (member_id)
            {
            case 0:
                return(TypeConverter <T> .ConvertFrom_string(accessor.Subject));

                break;

            case 1:
                return(TypeConverter <T> .ConvertFrom_string(accessor.Predicate));

                break;

            case 2:
                return(TypeConverter <T> .ConvertFrom_string(accessor.Object));

                break;

            case 3:
                return(TypeConverter <T> .ConvertFrom_string(accessor.Namespace));

                break;
            }
            /* Should not reach here */
            throw new Exception("Internal error T5008");
        }
        internal static void SetField <T>(Triple_Accessor accessor, string fieldName, int field_name_idx, T value)
        {
            uint member_id;
            int  field_divider_idx = fieldName.IndexOf('.', field_name_idx);

            if (-1 != field_divider_idx)
            {
                string member_name_string = fieldName.Substring(field_name_idx, field_divider_idx - field_name_idx);
                if (!FieldLookupTable_Triple.TryGetValue(member_name_string, out member_id))
                {
                    Throw.undefined_field();
                }
                switch (member_id)
                {
                default:
                    Throw.member_access_on_non_struct__field(member_name_string);
                    break;
                }
                return;
            }
            fieldName = fieldName.Substring(field_name_idx);
            if (!FieldLookupTable_Triple.TryGetValue(fieldName, out member_id))
            {
                Throw.undefined_field();
            }
            switch (member_id)
            {
            case 0:
            {
                string conversion_result = TypeConverter <T> .ConvertTo_string(value);

                {
                    accessor.Subject = conversion_result;
                }

                break;
            }

            case 1:
            {
                string conversion_result = TypeConverter <T> .ConvertTo_string(value);

                {
                    accessor.Predicate = conversion_result;
                }

                break;
            }

            case 2:
            {
                string conversion_result = TypeConverter <T> .ConvertTo_string(value);

                {
                    accessor.Object = conversion_result;
                }

                break;
            }

            case 3:
            {
                string conversion_result = TypeConverter <T> .ConvertTo_string(value);

                {
                    accessor.Namespace = conversion_result;
                }

                break;
            }
            }
        }