[Rcpp-devel] Rcpp: accessing non exported function in a given namespace

Le 22/07/11 16:10, Renaud a ?crit :

Hi,

I am using Rcpp in a package and I need to get a non exported function
in some other namespace.
I do something like the following but it seems to work only for exported
functions (or I guess any R variables):

Environment ns = Environment("package:stats");
Function fun = ns[".asSparse"];

This throws an error: "cannot convert to function".
I am running:
- R-2.13.0 on Ubuntu 10.04
- Rcpp 0.9.5

Actually, I would like to access any type of non-exported R variable,
but I imagine it would work the same and changing the left-side class
should do the trick.

I am sure there is an easy way to do this in Rcpp. Any suggestion?
Thank you.

Bests,
Renaud

Yes. You need Environment::namespace_env to get the namespace and not 
the package environment.

Something like this:

fx <- cxxfunction( , '
     Environment ns = Environment::namespace_env( "stats" ) ;
     return ns[".asSparse"] ;
', plugin = "Rcpp" )
fx()

Romain

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Great.
I knew it had to be possible... and as easy as this.
Thank you.

Renaud

Le 22/07/11 16:10, Renaud a ?crit :

Hi,

I am using Rcpp in a package and I need to get a non exported function
in some other namespace.
I do something like the following but it seems to work only for exported
functions (or I guess any R variables):

Environment ns = Environment("package:stats");
Function fun = ns[".asSparse"];

This throws an error: "cannot convert to function".
I am running:
- R-2.13.0 on Ubuntu 10.04
- Rcpp 0.9.5

Actually, I would like to access any type of non-exported R variable,
but I imagine it would work the same and changing the left-side class
should do the trick.

I am sure there is an easy way to do this in Rcpp. Any suggestion?
Thank you.

Bests,
Renaud

Yes. You need Environment::namespace_env to get the namespace and not 
the package environment.

Something like this:

fx <- cxxfunction( , '
    Environment ns = Environment::namespace_env( "stats" ) ;
    return ns[".asSparse"] ;
', plugin = "Rcpp" )
fx()

Romain

| Great.
| I knew it had to be possible... and as easy as this.

Nice trick indeed. I just added it as a unit test so that I can look it up
another time :)

Dirk

| Thank you.
| 
| Renaud
|

| > Le 22/07/11 16:10, Renaud a ?crit :
| >> Hi,
| >>
| >> I am using Rcpp in a package and I need to get a non exported function
| >> in some other namespace.
| >> I do something like the following but it seems to work only for exported
| >> functions (or I guess any R variables):
| >>
| >> Environment ns = Environment("package:stats");
| >> Function fun = ns[".asSparse"];
| >>
| >> This throws an error: "cannot convert to function".
| >> I am running:
| >> - R-2.13.0 on Ubuntu 10.04
| >> - Rcpp 0.9.5
| >>
| >> Actually, I would like to access any type of non-exported R variable,
| >> but I imagine it would work the same and changing the left-side class
| >> should do the trick.
| >>
| >> I am sure there is an easy way to do this in Rcpp. Any suggestion?
| >> Thank you.
| >>
| >> Bests,
| >> Renaud
| >
| > Yes. You need Environment::namespace_env to get the namespace and not 
| > the package environment.
| >
| > Something like this:
| >
| > fx <- cxxfunction( , '
| >     Environment ns = Environment::namespace_env( "stats" ) ;
| >     return ns[".asSparse"] ;
| > ', plugin = "Rcpp" )
| > fx()
| >
| > Romain
| >
| >
| >
| 
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