[Rcpp-devel] S3 methods with cppFunction/sourceCpp

Thu, Dec 27, 2012 1:54 PM #

I just realized that cppFunction can't natively build S3 functions, since
 fun.class isn't valid C++ function name.  I'm wondering if adding and
 S3class argument (default value = FALSE, otherwise class name as
 character) to cppFunction makes sense -- all that's needed is
 appending the class name to the function name, correct?  The downside,
as I see it, is that it's not so simple for sourceCpp/attributes (at
least I don't understand them).

Obviously, this is a minor issue. Is anyone else likely to hit this?

best,
Christian

A man, a plan, a cat, a ham, a yak, a yam, a hat, a canal ? Panama!

JJ Allaire

Thu, Dec 27, 2012 2:06 PM #

Hi Chistian,

With sourceCpp, you can actually specify an exported function name
explicitly in the export declaration. For example:

// [[Rcpp::export("fun.class")]]

So this will work for sourceCpp but alas isn't currently possible for
cppFunction. One way around this for cppFunction would be to pass env
= NULL to cppFunction which will result in the function being returned
rather than added to the calling environment. You could then wrap the
returned function in an appropriately named S3 function.

J.J.

On Thu, Dec 27, 2012 at 4:54 PM, Christian Gunning <xian at unm.edu> wrote: