On Fri, 4 Jan 2002 J.C.Rougier@durham.ac.uk wrote:
Hi everyone,
I encountered unexpected behaviour when calling "missing" within a
"local" environment, namely
fred <- function(x, y)
{
x <- as.vector(x)
local({
dontwantme <- 1:100
if (missing(y)) print("No \"y\" today")
})
x
}
whereupon I get
fred(1:10)
Error in eval(expr, envir, enclos) : "missing" illegal use of missing I think it is reasonable to expect missing to work in this context (I suspect the problem relates to lazy evaluation): if not, it might be helpful to amend the help file.
Why do you think it reasonable? You've take a function from
Evaluate an R expression in a specified environment.
and evaluated it somewhere where missing() is not defined. If you had
used eval() explicitly, would you think it reasonable? I doubt it.
Which help file did you have in mind?
Brian D. Ripley, ripley@stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- 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 _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._