[Rcpp-devel] Locating an Instance of a Reference Class in the Environment

[Matthew Supernaw - NOAA Federal]

Hi Dirk,
Thanks for your attention on this. I was able to find a solution that works
for us.
Matthew

https://github.com/NOAA-FIMS/ModularTMBExample/blob/map/src/tmb_objective_function.cpp#L133

On Fri, Mar 24, 2023 at 4:36 PM Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
wrote:

> Well, feel free to ignore my post, but the gist was that anything you have
> access to in R can be passed by your R API code to your Rcpp code. Also,
> due to R's GC you should usually avoid caching references between calls to
> your Rcpp code anyway.
>
> On March 24, 2023 12:40:43 PM PDT, Matthew Supernaw - NOAA Federal <
> matthew.supernaw at noaa.gov> wrote:
> >Hi Jeff,
> >I'm not sure I understand your comment. The code is part of a package.
> >We're just trying to sync the declared object name in the R environment to
> >the object in the Rcpp module programmatically from c++ for internal use.
> I
> >just wondered if there was a way to access the wrapped object in the
> >Rcpp:::PreserveStorage class and Dirk answered that question.
> >Thanks.
> >Matthew
> >
> >
> >On Fri, Mar 24, 2023 at 2:34 PM Jeff Newmiller <jdnewmil at dcn.davis.ca.us>
> >wrote:
> >
> >> Matthew... the normal context for sharing Rcpp code is within a package.
> >> It is a no-brainer to have an R API called by the user that calls
> whatever
> >> Rcpp code it needs to, which is why your objection seems inappropriate
> to
> >> me.
> >>
> >> On March 24, 2023 10:43:34 AM PDT, Dirk Eddelbuettel <edd at debian.org>
> >> wrote:
> >> >
> >> >On 24 March 2023 at 13:08, Matthew Supernaw - NOAA Federal wrote:
> >> >| I'm sure it's possible to do from the R side, however, the
> requirement
> >> is to
> >> >| hide this from the end user and set the reference objects name to the
> >> declared
> >> >| name from the R environment. If I view the environment in RStudio,
> >> there is
> >> >| much more information available. ls() only returns a list of objects
> by
> >> their
> >> >| declared name. I'm wondering how to get more details about elements
> in
> >> the
> >> >| environment.
> >> >
> >> >Thanks for additional color.  That may be a very interesting and
> valuable
> >> >question _for the C API of R_ and youe guess of "maybe Rcpp has a
> helper"
> >> is
> >> >a good one.  Sadly, I fear we may not have anything for you.
> >> >
> >> >Dirk
> >> >
> >> >--
> >> >dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org
> >> >_______________________________________________
> >> >Rcpp-devel mailing list
> >> >Rcpp-devel at lists.r-forge.r-project.org
> >> >
> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
> >> --
> >> Sent from my phone. Please excuse my brevity.
> >>
> >
> >
>
> --
> Sent from my phone. Please excuse my brevity.
>


-- 
Matthew Supernaw
*Scientific Software Developer*
*National Oceanic and Atmospheric Administration*
*Office Of Science and Technology*
*NOAA Fisheries | *U.S. Department of Commerce
Phone 248 - 396 - 7797
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