From pburns at pburns.seanet.com  Wed Sep 22 19:30:10 2004
From: pburns at pburns.seanet.com (Patrick Burns)
Date: Wed Sep 22 19:30:18 2004
Subject: [Rd] attaching to position 1
Message-ID: <4151B6A2.7080103@pburns.seanet.com>

If an attempt is made to attach to position 1, it appears to work
(not even a warning) but in fact it doesn't work as many would
expect.  "search" thinks that it gets placed in position 2, but nothing
is actually there (according to "ls").

This is guaranteed to be confusing (and annoying) to people who
are used to attaching to position 1 in S-PLUS.

I'm not clear on all of the implications of changing this, but my
first inclination would be to make it an error to attach to position 1.
The help file says that you can't do it.

At the very least there should be a warning .  My guess is that it is
rare for someone to attach to position 1 and not attempt to modify
what is being attached.

 > attach('foo.RData')
 > search()
 [1] ".GlobalEnv"        "file:foo.RData"    "package:methods" 
 [4] "package:stats"     "package:graphics"  "package:grDevices"
 [7] "package:utils"     "package:datasets"  "Autoloads"       
[10] "package:base"    
 > ls(2)
[1] "jj"
 > jj
[1] 1 2 3 4 5 6 7 8 9
 > detach()
 > search()
[1] ".GlobalEnv"        "package:methods"   "package:stats"   
[4] "package:graphics"  "package:grDevices" "package:utils"   
[7] "package:datasets"  "Autoloads"         "package:base"    
 > attach('foo.RData', pos=1)
 > search()
 [1] ".GlobalEnv"        "file:foo.RData"    "package:methods" 
 [4] "package:stats"     "package:graphics"  "package:grDevices"
 [7] "package:utils"     "package:datasets"  "Autoloads"       
[10] "package:base"    
 > ls(2)
character(0)

         _                          
platform i386-pc-mingw32            
arch     i386                       
os       mingw32                    
system   i386, mingw32              
status   Under development (unstable)
major    2                          
minor    0.0                        
year     2004                       
month    09                         
day      17                         
language R 


Pat


[Rd] attaching to position 1
Patrick Burns