Error message during debug (PR#6804)

On Tue, 20 Apr 2004 13:48:43 -0400 (EDT), "Gabor Grothendieck"
<ggrothendieck@myway.com> wrote :

In R 1.9.0 on Windows XP Pro I get an error if I try to
debug the identity function f shown:

f <- function(x)x
debug(f)
f(1)

debugging in: f(1)
Error in f(1) : Unimplemented feature in eval

R.version.string

[1] "R version 1.9.0, 2004-04-12"

Without debuggging its ok.

Confirmed.  It's not new in 1.9.0, it appears in 1.8.1 as well.  It
seems that a function body consisting of a single token triggers it.
I get a crash from this variation:

f <- function(x) 4

Maybe the system is trying to tell us that functions this simple don't
need debugging? ;-)

I'm sending this message to r-bugs to get it into the bug list (but I
won't have time to look at it until at least the weekend, if someone
else wants to fix it).

Duncan Murdoch