Fwd: Set-valued function in wrong context

I sent the email below a while ago and haven't seen it appear yet -
apologies for the noise if you've already got it.

-------- Original Message --------
Subject: Set-valued function in wrong context
Date: Thu, 09 Oct 2008 20:04:18 +0100
From: Raymond O'Donnell <rod(at)iol(dot)ie>
Reply-To: rod(at)iol(dot)ie
To: 'PostgreSQL' <pgsql-general(at)postgresql(dot)org>

Hi all,

I've written a function that returns a SETOF TIME WITHOUT TIME ZONE -
code below - which works fine on my development laptop (WinXP, version
8.3.4).

However, when I try it on another machine (8.2.5 on Debian Etch - yes, I
know it's out of date, but it's an installation I only play with from
time to time), I get:

gfc_bookings=# select * from make_time_series('11:00', '14:00', 30);
ERROR: set-valued function called in context that cannot accept a set
CONTEXT: PL/pgSQL function "make_time_series" line 10 at for over
select rows

Now, I know what the error means, and I reckon it's because of the
cast(), but for the life of me I can't see what to do about it. Any help
will be appreciated...

Thanks,

Ray.

-----------------------------

create or replace function make_time_series(
start_time time without time zone,
end_time time without time zone,
mins_delta integer
) returns setof time without time zone
as
$$
declare
TheDiff interval;
TotalMins integer;
ATime time without time zone;
begin
-- Get the total number of minutes covered by the required period.
select end_time - start_time into TheDiff;
TotalMins := extract(hour from TheDiff) * 60 + extract(minute from
TheDiff);

-- Generate the series.
for ATime in
select start_time + s.a
from cast(generate_series(0, TotalMins, mins_delta) || ' minutes' as
interval) as s(a)
loop
return next ATime;
end loop;

return;
end;
$$
language plpgsql immutable;

------------------------------------------------------------------
Raymond O'Donnell, Director of Music, Galway Cathedral, Ireland
rod(at)iol(dot)ie
Galway Cathedral Recitals: http://www.galwaycathedral.org/recitals
------------------------------------------------------------------

--
------------------------------------------------------------------
Raymond O'Donnell, Director of Music, Galway Cathedral, Ireland
rod(at)iol(dot)ie
Galway Cathedral Recitals: http://www.galwaycathedral.org/recitals
------------------------------------------------------------------