Message-ID: <Pine.LNX.4.64.0708160742020.2550@itasca2.wildberry.org>
Date: 2007-08-16T12:47:44Z
From: Luke Tierney
Subject: methods and try() [R-devel]
In-Reply-To: <7098abec0708152232s6d9fbb2ewb76cfa2cd4d7b1b2@mail.gmail.com>
On Wed, 15 Aug 2007, Byron Ellis wrote:
> Hi all, I'm having a problem with some sort of interaction with try()
> and methods, I think.
>
> The setup is as follows, I have an S4 class that holds an environment
> and I would like to evaluate the right hand side of a function inside
> that environment. No problem there.
>
> However, if the formula involves a symbol that doesn't exist, which
> may or may not happen, it fails as it should and reports and error
> "blah blah does not exist." As it should.
>
> When I wrap that same call in a try() statement, the error becomes "no
> function to return from, jumping to top level," bypassing the try
> statement and generally wreaking havoc. Any clues what might be
> causing this?
Yes. There is no context on the stack that corresponds to the
environment to which a jump is to be made. Why that is the case is
impossible to tell without a simple reproducible example.
Best,
luke
--
Luke Tierney
Chair, Statistics and Actuarial Science
Ralph E. Wareham Professor of Mathematical Sciences
University of Iowa Phone: 319-335-3386
Department of Statistics and Fax: 319-335-3017
Actuarial Science
241 Schaeffer Hall email: luke at stat.uiowa.edu
Iowa City, IA 52242 WWW: http://www.stat.uiowa.edu