Re: Globals in 5.0 Alpha

[John Belmonte <jvb@...>]

Björn De Meyer wrote:
> I guess if you're willing to change your syntax a little, it'll
> even be possible to do this all in lua itself yet again.
> Something like:
>
> namespace mynamespace
>
> function foo() ... end
>
> endnamespace
>
> Where "namespace" and "endnamespace" are functions that 
> perform the swapping and storing of the functions 
> and the global environment... I'll look into
> this next week at my work if I have the time.

That wouldn't be possible without changing the core.  For one thing, the 
only time ()'s can be omitted from a function call is if there is 
exactly one argument that is a string or table.  Also, since only a 
function scope may have its globals table manipulated, a wrapping 
function must exist to create the namespace.

The best that could be done without changing the core is:

  function namespace(mod_init)
    local G = getglobals()
    local mod_table = { }
    setmetatable(mod_table,{ __index = G })
    setglobals(mod_init, mod_table)
    mod_init()
    return mod_table
  end

and then

  local mod_table = namespace(function()
    local val
    function foo(x) ... end
      .
      .
      .
  end)

...which isn't that bad, but a little obscure for the newcomer.

-John



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