pl/pgsql list as parameter.

Hi,
I have a couple questions, I am tryingto write a function that takes as
input a list (size being dynamic) of primaryIDKeys, along with a userdefined
type and returns a set of rows containing those keys. Furthermore the rows
are exactly (columns) like the table that contains the keys, but has an
extra field.((so I define my own tupe)

CREATE FUNCTION somefunc(<how do I declare a list of
ints>,my_predef_type ) RETURNS SETOF tp_lm_object AS '
DECLARE

..........

How do you take in a list of int? And how would one loop through that?

Much thanks in advance.

-assad