Implementing pg_dump_sort.c topological sorting in sql/plpgsql/plperl?

Hi hackers,

The project I'm currently working with fsnapshot[1], is written in
plain plpgsql and I need to sort all the oids in their
creatable/droppable order.
This has already been properly implemented in pg_dump_sort.c using
Knuth's algorithm for topological sorting, with some special magic to
find and break dependency loops.

It's not possible to use a plain recursive query to do the trick (due
to 'i' bidirectional dependencies and dependency loops).

I need a general approach, only making use of pg_depend.

The function should take no input arguments and the output argument
should be oid[], containing a list of the oids in a
creatable/droppable or order.
It doesn't matter if it is left-to-right, least number of edges first.
Any valid topological sort will do.

I'm sure it's possible to implement it in plpgsql or plperl, but I
wanted to check first if anyone has already made such a function to
hopefully save some time?

Thanks a lot!

[1] https://github.com/gluefinance/fsnapshot

--
Best regards,

Joel Jacobson
Glue Finance