Re: multiple global contexts

[Peter Shook <pshook@...>]

Dylan Cuthbert wrote:
> Of course now I have a massive overhead on all uses of "=" to variables
> within object :-( 

Hi Dylan,

Note that the overhead is only when *new* keys are assigned to the 
table.  So unfortunately if you assign another value to willy3 it won't 
work the way you want it to.  Try this:

  object.nadgers.willy3 = function() bum = 90 end
  object.nadgers.willy3 = function() bum = 90 end

You can also use nicer syntax in Lua 5.0:
  function object.nadgers.willy3() bum = 90 end


A Lua function will have the same environment as where it was defined,
so I recommend implementing some kind of package system (See the list 
archive, I posted some references not long ago).
This will also help you protect the default globals.

Try something like:

local function cache(tab, name)
  local value = _G[name]
  rawset(tab, name, value)  -- cache value
  return value
end

function loadpkg(filename)
  local P = {}
  setmetatable(P, {__index = cache})
  -- setmetatable(P, {__index = _G}) -- if you don't want cache
  local f = assert(loadfile(filename))
  setfenv(f, P)
  return P, f()
end

- Peter Shook