Thanks for all the suggestions. I realize that this isn't the most important
thing in the world -- and as a newcomer to R I gather it's not the way most
people use R anyway.

But I tried to do what looked like the simplest suggestion.

open.account.2 <- function(total) {
       this <- environment()
       list(
         deposit = function(amount) {
           if(amount <= 0)
             stop("Deposits must be positive!\n")
           total <<- total + amount
           cat(amount, "deposited.  Your balance is", this$balance(),
"\n\n")
         },
         withdraw = function(amount) {
           if(amount > total)
             stop("You don't have that much money!\n")
           total <<- total - amount
           cat(amount, "withdrawn.  Your balance is", this$balance(),
"\n\n")
         },
         balance = function() {
           cat("Your balance is", this$total, "\n\n")
         }
       )
     }

When I ran it, this is what happened.

> x <- open.account.2(100)
> x$balance()

Your balance is 100

OK so far. But

> x$deposit(50)
Error in cat(amount, "deposited.  Your balance is", this$balance(), "\n\n")
:
  attempt to apply non-function


Am I doing this the wrong way?

Thanks for your interest.

*-- Russ *



On Sat, Mar 19, 2011 at 6:33 PM, Bert Gunter <gunter.berton@gene.com> wrote:

> See also the proto package, I believe.
>
> -- Bert
>
> On Sat, Mar 19, 2011 at 5:51 PM, Janko Thyson
> <janko.thyson.rstuff@googlemail.com> wrote:
> > You might want to check out Reference Classes (?SetRefClass). The object
> > itself is stored in '.self' and can be referenced that way.
> >
> > HTH,
> > Janko
> >
> > -----Ursprüngliche Nachricht-----
> > Von: r-help-bounces@r-project.org [mailto:r-help-bounces@r-project.org]
> Im
> > Auftrag von Russ Abbott
> > Gesendet: Samstag, 19. März 2011 23:35
> > An: r-help@r-project.org
> > Betreff: [R] Referring to objects themselves
> >
> > Is it possible to refer to an object from within a method, as in *this
> *in
> > Java?  I can't find anything about this in the documentation.  Sorry if I
> > missed it.
> >
> > Thanks.
> >
> > *-- Russ Abbott*
> > *_____________________________________________*
> > ***  Professor, Computer Science*
> > *  California State University, Los Angeles*
> >
> > *  Google voice: 747-*999-5105
> > *  blog: *http://russabbott.blogspot.com/
> >  vita:  http://sites.google.com/site/russabbott/
> > *_____________________________________________*
> >
> >        [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
> > ______________________________________________
> > R-help@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
>
> --
> Bert Gunter
> Genentech Nonclinical Biostatistics
>

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