Re: event handler for table initialization

[Javier Guerra Giraldez <javier@...>]

On Tue, Sep 21, 2010 at 2:47 AM, Nilson <nilson.brazil@gmail.com> wrote:
> Using function calls and tables arguments to describe structures like
> the example below
>
> Computer{
>        brand = 'XYZ';
>        Motherboard{
>                Processor{type = 'Pentium'};
>        Memory{size = '512MB'}
>    };
>    Harddisk{capacity='120GB'}
> };
>
> will generate function calls in an order completely different of reading order.
> In the example: Processor, Memory, Motherboard, Harddisk, Computer.


when you want to reorder things in time, the usual answer is to pass
around closures.  in your case, the easiest would be to write your
functions as:

local function force_futures (t)
    for k,v in pairs(t) do
        if type(v) == 'function' then
            t[k] = v()
        end
    end
end


function Memory(t)
    return function ()
        -- do some work with 't'
        --......
        force_futures(t)
        return t    -- could be a different object
    end
end

function Motherboard(t)
    return function ()
        -- do some work with 't'
        --......
        force_futures(t)
        return t    -- could be a different object
    end
end


-- 
Javier