[Rd] methods and try() [R-devel]

Byron Ellis byron.ellis at gmail.com
Thu Aug 16 21:53:38 CEST 2007


On 8/16/07, Luke Tierney <luke at stat.uiowa.edu> wrote:
> 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.

I have a sinking feeling that generating a good reduction will also
find my bug. :-) I was mostly wondering if there had been a recent
change in the try() machinery. In any case, I'll keep hunting for the
problem.

>
> 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
>


-- 
Byron Ellis (byron.ellis at gmail.com)
"Oook" -- The Librarian



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