returning array from function or "structured error"

I've a plpgsql function that execute some tests on data and it has to
return which test failed.

It would be handy to return an array... but an array is returned as a
serialised object and I'd like to avoid to un-serialise it from php.

Building up a temp table and returning a "setof record" or
building up a bitmap look awful.

Any elegant idea?

thx

--
Ivan Sergio Borgonovo
http://www.webthatworks.it