Re: Catch get/set of userdata in table?

["J. Perkins" <jason@...>]

Michael Flad wrote:
> I think somtimes later i may optimize this by adding another type of
> tag method, something like "setuserdata"/"getuserdata". After a
> very quick look at the sources of Lua it seems easy to implement.

I think something like this is the right way to handle it, but I try
to avoid changing "external" sources as much as possible. It does
look easy to implement though so maybe I'll give it a try. Is there
any chance a feature like this could be slipped into 4.1?

Jason




Michael Flad wrote:
> > -----Original Message-----
> > From: owner-lua-l@tecgraf.puc-rio.br
> > [mailto:owner-lua-l@tecgraf.puc-rio.br]On Behalf Of J. Perkins
> > Sent: Thursday, September 06, 2001 23:34
> > To: Multiple recipients of list
> > Subject: Catch get/set of userdata in table?
> >
> >
> > Is there a way to catch a get/set to a userdata object that is stored in 
> > a table? I know how to do it for a global variable, like LHF showed a 
> > while back (see example below) -- is there some way to do an equivalent
> > operation on a table member?
> >
> > (snip)
>
> You could always check if it's a userdata of a type you want to
> handle by yourself and in every other case, call the rawset/rawget
> methods - in this case you could use the tables as usual and you
> only need the special handling for your userdata.
>
> That's the way i do it in a first implementation.
> I think somtimes later i may optimize this by adding another type of
> tag method, something like "setuserdata"/"getuserdata". After a
> very quick look at the sources of Lua it seems easy to implement.
>
> I think for tables, you could insert the required code in 
>
> void luaV_settable (lua_State *L, StkId t, StkId key)
>
> I haven't done any tests right now, but i let you know when i've
> done the changes (don't have the time right now).
>
>
> Regards,
> Michael Flad
>
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