It has some limit. I create a sandbox to try to load the module first, if any ambiguity is found, it will raise an error and drop the sandbox.
And you can not call or write anything out of module during the require stage (If you do , the reload will raise an error, too),
but refer the variable out of sandbox is allowed. For example :
local othermod = require "othermod" -- Is allowed
local something = othermod.something -- Is allowed
othermod.something = 1 -- Raise an error
GLOBAL = 1 -- Raise an error
local tinsert = table.insert -- Is allowed
table.insert({}, 1) -- Raise an error
And it will merge the same tables in the module are both in old and new version. Reloading would not remove object not exist in the new version.
