Since RK::Recs is sorted by character order, anonymous defs will be
enumerated like this;
Some records around each gap might be wrapped around along increase or
decrease of records in middle. Then output order of anonymous defs
might be changed.
Numeric sort is expected to prevent such wrap-arounds.
This can be implemented with StringRef::compare_numeric().
Although it would be simpler to change the comparator of Recs as numeric,
I don't do, since;
- I am afraid if numeric comparator is not lightweit.
- It triggers behavior change (mentioned above)