R devel - Jun 2013 - Question about writing portable packages

Dear R-devel list,

I am creating an R package that includes C++ code. I tried to install it
both in Linux and Windows and it worked. I load the C code via the
NAMESPACE file using useDynLib.

Now I am revising once again whether everything is ready before
submitting the package to CRAN and I have read in
http://cran.r-project.org/doc/manuals/R-exts.html#Writing-portable-packages
that ?It is not portable to call compiled code in R or other packages
via .Internal, .C, .Fortran, .Call or .External, since such interfaces
are subject to change without notice and will probably result in your
code terminating the R process?.

However, the R function of my package that calls the C++ code uses the
Call function. 

Does it mean that I cannot submit my package to CRAN because the
portability is not guaranteed?. Then, how could I to call C++ code so
that my package were portable?.

I hope you can clarify my doubts. I have seen the collection of prior
postings to the list, but I have not found a specifical answer to my doubts .

Thank you very much in advance.

Best regards,

Guillermo

I think the key word here is _other_ packages. It's entirely okay to call
your package's own compiled code through the .Call interface (and the code
you write may link to other packages; the obvious example being Rcpp code
you write); however, it is not portable to use .Call to call compiled code
from another package directly. This is because package authors are not
required to maintain a consistent .Call interface to their compiled code;
rather, they just have to make sure the direct user-facing R exported
functions retain a stable interface over different versions (or, if
changed, are done so with prior warning etc.)

Ultimately, if your package passes 'R CMD check' with no errors,
warnings
or notes, you should be okay for CRAN submission.

-Kevin


On Thu, Jun 6, 2013 at 6:54 AM, <Guillermo.Vinue@uv.es> wrote:
> Dear R-devel list,
>
> I am creating an R package that includes C++ code. I tried to install it
> both in Linux and Windows and it worked. I load the C code via the
> NAMESPACE file using useDynLib.
>
> Now I am revising once again whether everything is ready before
> submitting the package to CRAN and I have read in
> http://cran.r-project.org/doc/manuals/R-exts.html#Writing-portable-packages
> that “It is not portable to call compiled code in R or other packages
> via .Internal, .C, .Fortran, .Call or .External, since such interfaces
> are subject to change without notice and will probably result in your
> code terminating the R process”.
>
> However, the R function of my package that calls the C++ code uses the
> Call function.
>
> Does it mean that I cannot submit my package to CRAN because the
> portability is not guaranteed?. Then, how could I to call C++ code so
> that my package were portable?.
>
> I hope you can clarify my doubts. I have seen the collection of prior
> postings to the list, but I have not found a specifical answer to my
> doubts .
>
> Thank you very much in advance.
>
> Best regards,
>
> Guillermo
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>


-- 
-Kevin

	[[alternative HTML version deleted]]

Guillermo,

That phrase is referring to using .Call in your package to call a C
function that shipped with a DIFFERENT package or is part of R itself
(defined in the R source code).

As long as you are only calling C functions you define in the C++ code that
ships with your package you are fine.

~G


On Thu, Jun 6, 2013 at 6:54 AM, <Guillermo.Vinue@uv.es> wrote:
> Dear R-devel list,
>
> I am creating an R package that includes C++ code. I tried to install it
> both in Linux and Windows and it worked. I load the C code via the
> NAMESPACE file using useDynLib.
>
> Now I am revising once again whether everything is ready before
> submitting the package to CRAN and I have read in
> http://cran.r-project.org/doc/manuals/R-exts.html#Writing-portable-packages
> that “It is not portable to call compiled code in R or other packages
> via .Internal, .C, .Fortran, .Call or .External, since such interfaces
> are subject to change without notice and will probably result in your
> code terminating the R process”.
>
> However, the R function of my package that calls the C++ code uses the
> Call function.
>
> Does it mean that I cannot submit my package to CRAN because the
> portability is not guaranteed?. Then, how could I to call C++ code so
> that my package were portable?.
>
> I hope you can clarify my doubts. I have seen the collection of prior
> postings to the list, but I have not found a specifical answer to my
> doubts .
>
> Thank you very much in advance.
>
> Best regards,
>
> Guillermo
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>


-- 
Gabriel Becker
Graduate Student
Statistics Department
University of California, Davis

	[[alternative HTML version deleted]]