R devel - Jul 2006 - how to start local scope?

How can I start a local scope inside an R function?  Eg in
> b
Error: object "b" not found
> f <- function() {
+   {
+     b <- 1
+   }
+   b+2
+ }
> f()
[1] 3

I would like f() to report an error, not finding b.  I am thinking
about something like let in Scheme/Lisp.

Thanks,

Tamas

Try

f <- function() {
	local({
		b <- 1
	})
	b + 2
}


Tamas K Papp wrote:
> How can I start a local scope inside an R function?  Eg in
> 
>> b
> Error: object "b" not found
>> f <- function() {
> +   {
> +     b <- 1
> +   }
> +   b+2
> + }
>> f()
> [1] 3
> 
> I would like f() to report an error, not finding b.  I am thinking
> about something like let in Scheme/Lisp.
> 
> Thanks,
> 
> Tamas
> 
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
> 
-- 
Roger D. Peng  |  http://www.biostat.jhsph.edu/~rpeng/

On 7/27/2006 8:16 AM, Tamas K Papp wrote:
> How can I start a local scope inside an R function?  Eg in
> 
>> b
> Error: object "b" not found
>> f <- function() {
> +   {
> +     b <- 1
> +   }
> +   b+2
> + }
>> f()
> [1] 3
> 
> I would like f() to report an error, not finding b.  I am thinking
> about something like let in Scheme/Lisp.
The local() function does this:

 > f <- function() {
+   local({ b <- 1 })
+   b + 2
+ }
 > f()
Error in f() : object "b" not found