Thank you both for taking the time to respond.

I think the ssandv hit the nail on the head: I did not know "list" meant anything other than the usual data structure in Perl. That perlfaq link makes it clear.

Marshall's advice to trust Perl to do it right is probably also sound. Having worked in C/C++ for several years, I instinctively assume I have to do something clever to make my code efficient, and it is unnerving not to know what is going on under the hood. Perl coding needs a different mindset!