[Rd] Restrict access to variables in parent environment

Hadley Wickham hadley at rice.edu
Fri May 14 16:20:51 CEST 2010


> Hello All,
>
> By default, a reference of a variable in a function cause R to look
> for the variable in the parent environment if it is not available in
> the current environment (without generating any errors or warnings).
> I'm wondering if there is a way to revert this behaviors, such that it
> will not look for the parent environment and will generate an error if
> the variable is not available in the current environment. Is this
> tuning has to be done at the C level?

Try this:
b <- 1
f <- function(a) {
  b
}

environment(f) <- baseenv()
f()

Hadley

-- 
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/



More information about the R-devel mailing list