How about the option of declaring variables of a specific type?
If the option is not used Lua continues as it always has; doing a good job of anticipating intent.
When used the declared type will not change and Lua will do what is necessary to comply with the declared type.
I would also hope that the declared types include 64-bit signed and unsigned integers. Industrial communication protocols like Ethernet/IP have such types and life would be much simpler if they were natively supported by plain-vanilla Lua.
Best Regards
Al Pfalzgraf