Re: Possible Lua enhancements (mostly for private data)

["Matthew Wild" <mwild1@...>]

On Thu, Dec 18, 2008 at 2:26 AM, David Manura <dm.lua@math2.org> wrote:
> On Wed, Dec 17, 2008 at 4:33 PM, Mark Hamburg wrote:
>> So, now we can write:
>>        label _angle, _radius
>>        function Point( x, y )
>>                return {
>>                        _angle = math.atan2( y, x ),
>>                        _radius = math.sqrt( y * y + x * x ),
>>                        coordinates = function( self )
>>                                return self._radius * math.cos( self._angle
>> ), self._radius * math.sin( self._angle )
>>                        end
>>                }
>>        end
>
> You can achieve a similar effect with "inside-out objects"[1-2] via
> Lua's support for weak keys.

I'm probably missing something, but why use this method and not
closures? That is, why not define "angle" and "radius" as upvalues,
along with "self"?

Matthew.