One more option for pg_dump...

Hi all,
On the 6th of february, there's been a thread about adding new options to
pg_dump, but it is now too late for me to add comments to this thread, since
all that was said wouldn't be readable at this time, so I add an new thread
here.
I haven't found any option to dump any user-defined function stored in a
database, unless doing a pg_dump -D -s database, but so far one would get the
definitions of the tables, the permissions, the triggers, and so on, so when
you have a big schema, it is not much user friendly to do a full dump to
change one or two lines of code in a function.
Could there be an option to pg_dump (let's say --function [func_name]) to be
abble to dump the complete source code of a function in a separate file, or
on the terminal ?
I've found that when in  psql, one can type \df+ func_name to have many
informations about the so named func_name, but it is not well readeable.
Do you think it could be a good thing ?
Are there workarounds to have the same comportement that I'm not aware of ?
Thanks for your ideas about this.