From murdoch at stats.uwo.ca  Thu Jul 27 14:34:10 2006
From: murdoch at stats.uwo.ca (Duncan Murdoch)
Date: Thu, 27 Jul 2006 08:34:10 -0400
Subject: [Rd] how to start local scope?
In-Reply-To: <20060727121613.GA4594@pu100877.student.princeton.edu>
References: <20060727121613.GA4594@pu100877.student.princeton.edu>
Message-ID: <44C8B2C2.5010104@stats.uwo.ca>

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



[Rd] how to start local scope?
Duncan Murdoch