For a number of purposes, it would be very handy if the ordered collections would allow the index to be omitted with the "=" method. An omitted index would be the equivalent of an append operation. Cases where this would be useful:
a = "line1" -- changing the lines don't required
a = "line2" -- indexes to be adjusted
a = "line3"
loop while s~lines() > 0
-- appends the corresponding word to the end of
-- each array
parse value s~linein with a b c