Help finding some code in the R source code

Greg,

I'm trying to write some Python code to check if a string text  
contains a complete R statement.  I'm hoping someone will be able  
to point me to the right place in the R source code, so I can use  
it as a starting point.

What happens internally is that R runs the expression through the  
parser. When the parser returns PARSE_INCOMPLETE then you know that  
the expression is not complete and thus more input is needed. If you  
are directly interfacing R from Python then you can easily do exactly  
the same thing.
However, if you want a solution in pure Python, it may be more  
difficult as it would be equal to re-writing the R parser in  
Python... (or some 'light' version of it..).

Cheers,
Simon