R help - Jan 2014 - Porting Legacy R Code to Different Language

Hi,

I'm trying to port a quite big piece of legacy R code to a different
language ( Java or C# ).
The package I'm trying to port is quite large but I'm only interested
in one function in the 
package. 

I was just wondering if there's any tools that would allow me to get a
trace of all the code
that a R function executes when evaluating a given input : 

Example :

g 
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