[HACKERS] an aggregate array function

[Merlin Moncure]

Dear hackers,   Do you think there would be any use for an aggregate which returns an array of the aggregated (usually simple) type?  Has this already been done by anyone?  I looked at the source and noticed that for each inserted item, the array utility functions perform a deep copy of the entire array (plus a reallocation).  Normally, this is no big deal, but if executed in the query stage, it could be kind of slow.  I also noticed that null values inside is an item on the todo list.  Is anybody currently working on this?   Merlin