On 30/06/2008 10:56 AM, Luke Tierney wrote:
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.
On the other hand, what Gabor sees in e is what he would see inside f:
f <- function(...) { ls(all=T) }
f(a=1, b=2)
[1] "..."
I don't think we should distinguish between user level in .GlobalEnv and
what a user sees inside a function he writes. Stopping a user from
seeing ... inside a function would break all sorts of things.
Duncan Murdoch
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