Re: Environment variables

["Peter Hill" <corwin@...>]

Szabolcs Szasz:
> I need to support a simple config file written
> consisting purely of
>     variable = "value"
(snip)
> I thought of using a tagmethod for setglobal, but
> that did not seem to be allowed. Also, the globals
> table is of not much help now (I guess).

Globals table should be fine in Lua4 (it's Lua5 that has a new way of doing
things that may take a bit of thinking).

I would expect the following would work fine:

  function f(configfile)
    -- as locals these become immune to changing the global table.
    local dofile = dofile
    local globals = globals

    -- New empty global table (store old globals in glob).
    local glob = globals({}) 

    -- Load the new globals with the config data.
    dofile(configfile)

    -- Reset to the old globals, the new data is safe in glob.
    glob = globals(glob)

    -- Return the config data.
    return glob
  end

*cheers*
Peter Hill.