R devel - Sep 1997 - R-alpha: bug in passing of empty (...)

This is too bad (and an old bug at least since 0.49); 
it also breaks some code I have been using in S-plus:
> tst <- function(...) ls(...)
> tst()#--- should really give the same as ls() !!
character(0)
> ls()
  [1] "%in%"                   "As.integer"            
"Dir"
  [4] "Dir0"                   "Fn12"                  
"Slynx"
  ......
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To:
r-devel-request@stat.math.ethz.ch
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Martin Maechler <maechler@stat.math.ethz.ch> writes:
> 
> This is too bad (and an old bug at least since 0.49); 
> it also breaks some code I have been using in S-plus:
> 
> > tst <- function(...) ls(...)
> 
> > tst()#--- should really give the same as ls() !!
> character(0)
> 
> > ls()
>   [1] "%in%"                   "As.integer"            
"Dir"
>   [4] "Dir0"                   "Fn12"                  
"Slynx"
>   ......
I don't know whether it's a bug or a feature, but it has nothing to do
with (...)
> tst<-function()ls()
> tst()
character(0)
> ls()
 [1] "NextMethod" "airquality" "dig"       
"grid"       "l"
 [6] "tst"        "umach"      "x"         
"xmin"       "y"
[11] "z"          "æøå"       
> tst<-function(...){x<-5;ls(...)}  
> tst()
[1] "x"
> tst<-function(){x<-5;ls()}
> tst()
[1] "x"

I'm rather suspecting that pos=-1 in the argument list to ls should
have been pos=1. Anyone have the big picture on pos and envir?

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To:
r-devel-request@stat.math.ethz.ch
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

This is a "feature" of ls().  When invoked with no arguments it
returns
the list of variables \emph{in the environment it is called from}.
This is to make it useful in conjunction with debug() and browser().
It allows you find out what the current local variables are.

To get the same effect as a top level ls(), you must expicitly do
	ls(pos=1)             # may fail if we allow attaching at pos=1
	ls(envir=.GlobalEnv)  # safer

Ross
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To:
r-devel-request@stat.math.ethz.ch
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-