Generic Join on Arrays

Hi,
I'm currently on retrieving meta infromation about db-schemas.

As I found out, pg_proc relation provides me with data about defined stored
procedures. Togehter with other relations as pg_type I can retrieve readable
information, like:
select proname, pd.description FROM pg_proc pp left outer join
pg_description pd on pp.oid=pd.objoid

BUT, how about arrays of type "oidvector" (int4-array) containing foreign
keys (to be joined) as pg_proc's column "proargtypes"

Is there a way to make some kind of indetermine number of JOINs on the
single array items?
I want to retrieve a list of argument type names, not plain numbers.
I want to avoid doing several resolutions oid->name