R devel - Jul 2008 - multiple names to assign

'assign' does not give a warning if 'x' has length
greater than 1 -- it just uses the first element:

assign(c('a1', 'a2'), 1:2)

One way of thinking about this is that people using
'assign' get what they deserve.  The other is that it is
used seldom enough that adding a warning isn't going
to slow things down appreciably.


Patrick Burns
patrick at burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of S Poetry and "A Guide for the Unwilling S User")

Biobase has multiassign.

Kasper

On Jul 13, 2008, at 2:39 AM, Patrick Burns wrote:
> 'assign' does not give a warning if 'x' has length
> greater than 1 -- it just uses the first element:
>
> assign(c('a1', 'a2'), 1:2)
>
> One way of thinking about this is that people using
> 'assign' get what they deserve.  The other is that it is
> used seldom enough that adding a warning isn't going
> to slow things down appreciably.
>
>
> Patrick Burns
> patrick at burns-stat.com
> +44 (0)20 8525 0696
> http://www.burns-stat.com
> (home of S Poetry and "A Guide for the Unwilling S User")
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

Warning does seem sensible (and there is already a test for length > 0), 
so I've added one.

Generally R has followed the Unix philosophy of not chatting and trying to 
make sense of the user's inputs (although it has multiple authors, and 
some advocate more of what others see as nannying).  We do see enough 
'what does this error message mean' about *warnings* on R-help to see
the
downside.

On Sun, 13 Jul 2008, Patrick Burns wrote:
> 'assign' does not give a warning if 'x' has length
> greater than 1 -- it just uses the first element:
>
> assign(c('a1', 'a2'), 1:2)
>
> One way of thinking about this is that people using 'assign' get
what
> they deserve.
Or possibly intend, although as the help page incorrectly suggested that 
a quoted character string was needed, they would have had to have read 
the source code to know what should happen.
> The other is that it is used seldom enough that adding a warning isn't 
> going to slow things down appreciably.
>
> Patrick Burns
> patrick at burns-stat.com
> +44 (0)20 8525 0696
> http://www.burns-stat.com
> (home of S Poetry and "A Guide for the Unwilling S User")
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595