[R] testing for emptyenv

[Vadim Ogranovich]

Dear R-users,

Is there a way to test whether a particular environment e is equal to emtyenv(), or for that sake whether two environments e1 and e2 are equal?

I tried a couple of ways to compare environments, but neither seem to work:

> e1 <- new.env()
> e2 <- new.env()
> e1 == e2
Error in e1 == e2 :
  comparison (1) is possible only for atomic and list types
> all.equal(e1, e2)
[1] TRUE
> all.equal(e1, emptyenv())
[1] TRUE

My ultimate goal is to make a list of all variables in the lexical scope (enclosure?) of a function FUN. So I thought I'd start with environment(FUN) and apply parent.env() until I reach emptyenv(). But for this to work I need to be able to detect that I reached emptyenv().

Thank you,
Vadim


> version
               _
platform       i386-pc-mingw32
arch           i386
os             mingw32
system         i386, mingw32
status
major          2
minor          9.1
year           2009
month          06
day            26
svn rev        48839
language       R
version.string R version 2.9.1 (2009-06-26)

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