use cursor in a function

This is a repost of a question which still confuses me.

I wish to write a function that returns NUM_ROWS for a particular
condition AND a subset of those rows (eg by using LIMIT and OFFSET).

I imagine having function b that returns a reference to a cursor and
NUMROWS. In function a I use the cursor to effectively do the LIMIT and
OFFSET, and append the NUM_ROWS column to all of the results.

Is this sensible, efficient, feasible? I have not used cursors before.

Or should I simply do 2 separate functions, 1 for NUM_ROWS, the
other for the result set I want?

Help much appreciated!
Rory
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Rory Campbell-Lange
<rory(at)campbell-lange(dot)net>
<www.campbell-lange.net>