From kevin.hendricks at sympatico.ca  Fri Jun  2 20:03:20 2006
From: kevin.hendricks at sympatico.ca (Kevin B. Hendricks)
Date: Fri, 2 Jun 2006 14:03:20 -0400
Subject: [Rd] Helping out - simple bugs to help familiarize with R
	design, source, etc
Message-ID: <021EB023-B2CD-4C07-85C7-45E0AA9DFEB0@sympatico.ca>

Hi Thomas,

> A key fact here is that NAMED(object) is 0 if the object is not  
> (part of) an R variable, 1 if it is (part of) exactly one R  
> variable, 2 if it is part of more than one R variable.


> The point is that NAMED=0 or 1 objects can be safely modified, but  
> NAMED=2 have to be copied first (with the duplicate() function).

I am not sure if this question makes much sense since I am unsure of  
what you mean by "object" here (is that a object oriented programming  
idea of "object" or a more general term for  some structure)
but ...

Can an "object" be an extended "structure" comprised of other  
"objects" and if so do each of the substructure objects have their  
own NAMED() attribute?  If so, then if any of those sub objects  
actually is part of another variable, does that force the NAMED()  
attribute of the parent (or enclosing) object to have a value of 2  
(forcing duplication before modification) for the entire thing?

If so, perhaps the NAMED() attribute of the enclosing object is  
simply not being properly updated to be the maximum of all of the  
NAMED() attributes of the sub objects?  Isn't this what the Note: in  
the bug report was talking about?

This might be fun to look at.  But don't hold your breath for any  
quick fixes!  I still have a very steep learning curve to climb  
before I can be of much use for anything other than build time issues.


Thanks,

Kevin



[Rd] Helping out - simple bugs to help familiarize with R design, source, etc
Kevin B. Hendricks