[R] An argument processing puzzle --- solution.
Rolf Turner
r.turner at auckland.ac.nz
Tue Jan 19 01:51:16 CET 2010
Thanks to Berton Gunter and Peter Ehlers who both effectively solved
my problem. Prof. Gunter's solution, slightly more succinct, is:
foo <- function(x)
{
if(is.name(sb <- substitute(x))) deparse(sb)
else eval(sb)
}
(appropriately modified to fit into the ``mv()'' context.
Duncan Murdoch expressed the worry:
> How could you tell what a user intended who typed this?
>
> name1 <- "a"
> name2 <- "b"
> mv(name1, name2)
Well, I guess I couldn't. I am not actually bothered by this
however. I only want mv() to work with the arguments being
either names or expressions which evaluate to explicit text strings.
What ***I*** would intend by mv(name1,name2) in those circumstances
would be in effect:
name2 <- name1
rm(name1)
I.e. I want mv() to apply to the objects ``name1'' and ``name2''.
The fact that these objects consist of text strings which *could*
name other objects is of no importance (to me).
Thanks again to all who responded.
cheers,
Rolf Turner
######################################################################
Attention:\ This e-mail message is privileged and confid...{{dropped:9}}
More information about the R-help
mailing list