Userdata Environments

["Wesley Smith" <wesley.hoke@...>]

I've been looking at the UserDataRefinement wiki example
(http://lua-users.org/wiki/UserDataRefinement) to try and understand
how environments work with userdata.  What I don't understand from
this example is the process by which a method gets overridden in a
script and how the environment tables gets manipulated in this
process.  I'm looking mostly at Udr Code Snippet Three
(http://lua-users.org/wiki/UdrCodeSnippetThree).  Where would I place
these functions in my userdata C code?  I don't want to modify liblua
as is suggested later in the page.  Any hints?

If I have userdata U with function do_it() defined in C consider the
following code:

U:do_it = function() print("new function") end
U:do_it()  --how does the environment table for the userdata
                --come in to play here based on the Udr example?

thanks,
wes