I need to merge two tables, with the contents of the second overwriting contents in the first if a given item is in both. I looked but the standard libraries don\'t seem to
Doug Currie's answer is the simplest for most cases. If you need more robust merging of tables, consider using the merge() method from the Penlight library.
require 'pl'
pretty.dump(tablex.merge({a=1,b=2}, {c=3,d=4}, true))
-- {
-- a = 1,
-- d = 4,
-- c = 3,
-- b = 2
-- }