R devel - Nov 2009 - combine UserDefinedDatabase and regular environments

Hello,

Is it possible to have the effect of UserDefinedDatabase outside of 
"attached" environments ? Can I disguise an environment of the 
sys.frames() as a UserDefinedDatabase ?

This seems to suggest that it might be possible :

 > f <- function(){ e <- environment(); class(e) <- 
"UserDefinedDatabase"; ff }
 > f()

  *** caught segfault ***
address (nil), cause 'unknown'

Traceback:
  1: f()

Possible actions:
1: abort (with core dump, if enabled)
2: normal R exit
3: exit R without saving workspace
4: exit R saving workspace


At the moment, it seems to be either lookup using UserDefinedDatabase or 
regular lookup. Has anyone tried to combine both ?


-- 
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
|- http://tr.im/BcPw : celebrating R commit #50000
|- http://tr.im/ztCu : RGG #158:161: examples of package IDPmisc
`- http://tr.im/yw8E : New R package : sos

On Thu, Nov 5, 2009 at 9:58 AM, Romain Francois
<romain.francois@dbmail.com>wrote:
> Hello,
>
> Is it possible to have the effect of UserDefinedDatabase outside of
> "attached" environments ? Can I disguise an environment of the
sys.frames()
> as a UserDefinedDatabase ?
>
> This seems to suggest that it might be possible :
>
> > f <- function(){ e <- environment(); class(e) <-
"UserDefinedDatabase";
> ff }
> > f()
>
>
The UserDefinedDatabase support expects an R_ObjectTable C structure
embedded within an externalptr as the HASHTAB of the environment. So it's
really only possible from C.

>  *** caught segfault ***
> address (nil), cause 'unknown'
>
> Traceback:
>  1: f()
>
> Possible actions:
> 1: abort (with core dump, if enabled)
> 2: normal R exit
> 3: exit R without saving workspace
> 4: exit R saving workspace
>
>
> At the moment, it seems to be either lookup using UserDefinedDatabase or
> regular lookup. Has anyone tried to combine both ?
>
>
> --
> Romain Francois
> Professional R Enthusiast
> +33(0) 6 28 91 30 30
> http://romainfrancois.blog.free.fr
> |- http://tr.im/BcPw : celebrating R commit #50000
> |- http://tr.im/ztCu : RGG #158:161: examples of package IDPmisc
> `- http://tr.im/yw8E : New R package : sos
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
	[[alternative HTML version deleted]]