Re: how does GC work with complex expressions using metamethods?

["Michael Newberry" <mnewberry@...>]

Well, in my defense, I already have read and re-read that chapter, both in 
the white book and the blue book. And I still did not get the subtle issue 
that lua_newuserdata() has to be left on the stack for return by the 
Cfunction. That is the missing detail. Instead I was returning its value 
(the pointer it allocates). Obviously you know a heck of a lot more about 
userdata than I do, so I don't know if you can appreciate the subtle 
difference when the person at the other end (me) has been going round and 
round for a couple of days. That little nugget of information you gave was 
the key I was missing. So tanks---I really do appreciate your help.

Michael

----- Original Message ----- 
From: "Doug Currie" <doug.currie@gmail.com>
To: "Lua list" <lua@bazar2.conectiva.com.br>
Sent: Sunday, August 16, 2009 4:14 PM
Subject: Re: how does GC work with complex expressions using metamethods?


> On Aug 16, 2009, at 4:57 PM, Michael Newberry wrote:
>
> > It is not true that anyone has told me explicitly to return full 
> > userdata using lua_newuserdata().
>
> Well, in their defense, Sam and David (and maybe others in this  thread) 
> directed you to
> http://www.lua.org/pil/28.1.html
> which is all about lua_newuserdata().
>
> It seemed to me you needed a whack with the keisaku. I'm glad you're  on 
> the right track now.
>
> e