constraint definition on an array column?

Hi:

Is it possible to define a constraint that checks all elements of an array type column?

Example...

create table foo (asset text, owner_uids text[]);

I also have a plperlu function that checks to see if a given uid is valid (returns a 0/1). It's called validate_uid(text), This function could be modified to handle a list of uids if that was needed.

I want something like...

constraint validate_all_owner_uids check (select validate_uid(owner_uid) = 1)

...but owner_uid is an array, not any one distinct value.

1) Is there a way to pass in a list for the plperlu to evaluate (return 0 if any uid is invalid)?
2) Is there some sort of syntactical support for defining constraints on array columns?

Thanks in Advance!