Re: table question

[William Roper <lacutis@...>]

The problem is that you are expecting c to be nil. c is a table that
you are putting an item at index 1 with the value "test" in it.
Setting t[1] to nil makes the item 1 in table t not link to your new
table object o, that is also referenced to by c.

Thats pretty confusing now that I reread it.

To put it in C terms.

you create a new object (o), and assign the pointer c to it.
so c holds the address of o. While creating it, you set one of the
elements of an array (t) also to point at the o address.

By then setting t[1] to null, c still points at it, and it won't be
garbage collected.

You need to:
t[1] = nil
c = nil

Then the table will garbage collect.

Hope that helps.

Ryan

On Mon, 26 Jul 2004 09:53:11 -0500, Michael Cumming <mike@4831.com> wrote:
> I am using Lua 4 and LuaCom.  I would like to maintain a "master" table of all open objects.  I have been playing around with some Lua code to see how tables are handled.  The code below is a quick and dirty test of creating an object which is returned to the caller and also stored in a master table.  I would like to be able to "destroy" the object by iterating the master table.  But if I set an the object in the master table to to nil, the table returned to the caller still exists.  Is there a way around this?
> 
> t = {}   -- master list of open objects
> 
> function newobject ()
>   local o
>   o = {"test"}  -- normally would be "creatobject"
>   tinsert (t,o)
>   return o
> end
> 
> c = newobject ()
> 
> print (c)
> print (t [1])
> 
> t [1] = nil
> 
> print (c)
> print (t [1])
> 
> OUTPUT
> 
> table: 0157B360
> table: 0157B360
> table: 0157B360
> nil
> 
> Thanks,
> 
> Mike
> 
> 
> 
>