need help for array appending & deleting

Hi all,

Unless it exists, I'd like to implement code for the array manipulations
above for Postgresql. and I need some help for it. I have already run
through the sources concerned but I need to be pointed to the right
direction on where to start and what kind of functions I should use. I'd
also like to have a bit more detailed info on array structure (or at
least where I can find a good doc. I've been looking for it in
'array.h', 'arrayutils.c' and 'arrayfuncs.c').

Thanks so much, in advance,
Peter Blazso