[Rd] Detecting bad lexical scoping

[Gabor Grothendieck]

On Wed, Mar 16, 2011 at 4:14 PM, Ryan King <c.ryan.king at gmail.com> wrote:
> I've recently hunted down a troublesome bug in my own code, and am
> looking for an easy mechanism to detect this kind of error in other R
> code.  The problem was an undefined variable inside of a function.
> Unfortunately, R looked for that variable in the global environment
> and found it since there was variable with that name in my testing
> scripts (note to self: do not name things "x").
>
> Is there an easy way to report all the non-local objects accessed in a
> function?
>
> Is there any easy way around the usual scoping rules?  I want to be
> able to get to base functions, and am willing to namespace:: or :::
> access all of my own functions (it's in a package) if necessary to
> block the standard scoping rules.  The language def section on
> environments made me hurt.
>

One way is discussed in the Feb 27, 2010 news item on the proto home
page: http://r-proto.googlecode.com

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