String metatable sandboxing (was: Environment metatable)

["Thiago L." <fakedme@...>]

On 16/04/2014 17:45, Thiago L. wrote:
> How about we have a getmetatable(_ENV).__stringmetatable or something?
> String metatable sandbox and monkeypatching patch at the same time!
Rephrasing: How about we move the string metatable to _ENV's metatable? 
That way modules can do their monkeypatching without affecting other 
ppl's code...

_ENV's metatable would look like this:
setmetatable(_ENV,{
    __stringmt = { -- this is a metafield (like __metatable)
        __index = string
        -- etc
    }
})