From luke at stat.uiowa.edu  Mon Jun 30 16:56:00 2008
From: luke at stat.uiowa.edu (Luke Tierney)
Date: Mon, 30 Jun 2008 09:56:00 -0500 (CDT)
Subject: [Rd] get ...
In-Reply-To: <4866A174.4050706@biostat.ku.dk>
References: <971536df0806281246o75249479gaab3a059952e0f85@mail.gmail.com>
	<4866A174.4050706@biostat.ku.dk>
Message-ID: <alpine.LFD.1.10.0806300950510.2815@nokomis.stat.uiowa.edu>

On Sat, 28 Jun 2008, Peter Dalgaard wrote:

> Gabor Grothendieck wrote:
>> Suppose we do this:
>>
>> 
>>> f <- function(...) environment()
>>> e <- f(a = 1, b = 2)
>>> ls(e, all = TRUE)
>>> 
>> [1] "..."
>> 
>>> e$...
>>> 
>> <...>
>> 
>>> class(e$...)
>>> 
>> [1] "..."
>> 
>> Is there any way of getting a and b given e without
>> modifying f?
>> 
>> evalq(list(...),e)
> $a
> [1] 1
>
> $b
> [1] 2
>
>

I'm wondering though whether we should allow the internal DOTSXP value
of "..." to escape to the user level.  Might be more appropriate for
get(e,"..."), e$... (and as.list.environment and maybe a few other
things) to give the "Error: '...' used in an incorrect context" error
if the value is a DOTSXP.

luke

-- 
Luke Tierney
Chair, Statistics and Actuarial Science
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa                  Phone:             319-335-3386
Department of Statistics and        Fax:               319-335-3017
    Actuarial Science
241 Schaeffer Hall                  email:      luke at stat.uiowa.edu
Iowa City, IA 52242                 WWW:  http://www.stat.uiowa.edu



[Rd] get ...
Luke Tierney