lua - How can I change every index into a table using a metatable? -

i'm trying write metatable indexes table shifted 1 position (i.e. t[i] should return t[i+1]). need because table defined using index 1 first element, have interface program uses index 0 first element. since reading programming in lua, think can accomplish want proxy table, can't seem working. far, have this:

t = {"foo", "bar"}   local _t = t   t = {}   local mt = {       __index =   function(t, i)                       return _t[i+1]                   end   } setmetatable(t, mt) 

however, not create expected result. in fact, doesn't return values @ (every lookup nil). there better way this, or missing something?

t = {"foo", "bar"}   local _t = t   t = {}   local mt = {       __index =   function(t, i)                       return _t[i+1]                   end   } setmetatable(t, mt)  print(t[0]) 

outputs "foo" me when run here: http://www.lua.org/cgi-bin/demo