[Rcpp-devel] inline with classes

[Dirk Eddelbuettel]

On 5 October 2010 at 13:21, Whit Armstrong wrote:
| aha, thanks for correcting me. on the inline/Rcpp division of labor.
| 
| So, what you are suggesting should have been obvious to me.
| 
| I pass the class def in the include statement of the inline function?
| Is that it?
| 
| I'll ping back after I try this.
| 
| If this really works, then I think WinBUGS can finally die.

It works over here, chances are you may get lucky too. 

Here, I took a simple templated class square from one of the unit tests and
wrapped it in (fairly verbose) example:


edd at max:~$ cat /tmp/whit.r 
#!/usr/bin/r -ti

suppressMessages(library(inline))
suppressMessages(library(Rcpp))

inc <- 'template <typename T>
	class square : public std::unary_function<T,T> {
	public:
	    T operator()( T t) const { return t*t ;}
	};
       '

src <- '
       double x = Rcpp::as<double>(xs);
       int i = Rcpp::as<int>(is);
       square<double> sqdbl;
       square<int> sqint;
       return Rcpp::List::create(Rcpp::Named("x", sqdbl(x)),
                                 Rcpp::Named("i", sqint(i)));
       '
fun <- cxxfunction(signature(xs="numeric", is="integer"), body=src, include=inc, plugin="Rcpp")

print(fun(2.0, 3L))
edd at max:~$ chmod 0755 /tmp/whit.r 
edd at max:~$ /tmp/whit.r 
$x
[1] 4

$i
[1] 9

edd at max:~$ 


All good?  Send my condolences to the family of WinBUGS.

Dirk



 
| -Whit
| 
| 
| 2010/10/5 Dirk Eddelbuettel <edd at debian.org>:
| >
| > Hi Whit,
| >
| > On 5 October 2010 at 12:25, Whit Armstrong wrote:
| > | I just reviewed the Rcpp documentation.
| >
| > Great. Now tell us how to make it sticky so that we get you to contribute :)
| >
| > | I see plenty of cfunction/cxxfunction examples, but I'm curious
| > | whether one can provide a class definition inline in an R script and
| > | then initialize an instance of the class and call a method on the
| > | class.  all inline in R.
| > |
| > | Is this feature something you all would consider adding to Rcpp?
| >
| > a) A change would be an inline feature, not an Rcpp feature.
| >
| > b) But we already do :) support this, and even use it in numerous cases in
| >   the unit tests; this uses the   include=   argument to cxxfunction et al.
| >
| > So you can supply your templated logic in an R string to include= and then
| > use the code in an R string to to src= and pass it all through cxxfunction()
| > for a quick test.
| >
| > See e.g. runit.macros.R or or runit.Module.R.  I think we also have blog
| > posts and / or vignette examples that use it.
| >
| > Hth, Dirk
| >
| > --
| > Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com
| >

-- 
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com