I was recently bitten by this, and it's not clear to me (and others) if this is correct Perl behavior or not. If you have a user defined function 'func' that returns a list and you'd like to sort that return value it's reasonable to try: sort(func(@list)); but apparently Perl interprets this as: sort func @list; thereby using 'func' as an ordering function instead of first processing '@list' with 'func' then sorting. Now I've read the stuff on page 1 of PERLFUNC(1) about parenthesis and whitespace being optional, but still this just strikes me as wrong. No?
