Re: C API question

[Ralph Hempel <rhempel@...>]

On 01/07/2011 10:59 AM, Roberto Ierusalimschy wrote:
> > I would be happy to see refs go away because they seem like a sharp,
> > tempting feature that actually doesn't add value.
> >
> > If your userdata object needs to reference other Lua data, you
> > really, really, really want to use the environment mechanism because
> > this works with the GC whereas refs are very prone to creating
> > uncollectable cycles.
> >
> > If your C code needs to reference a Lua value, I tend to recommend
> > using light userdata keys in the registry bearing in mind that this
> > creates anchors for the GC.
>
> Exactly. The archetypal use of references were a full userdata keeping
> references to other Lua values by keeping in its C structure the
> integers returned by luaL_ref. The finalizer for this userdata should be
> responsible to release its references when the userdata was collected.
> This kind of use became obsolete with environments.
>
> Does anyone still use references in real applications? For what?

The IUP source code is full of lua_ref() and friends...

Ralph