[Rd] R result objects as lists

[Thorsten]

Hello List,
I want to communicate between a minimalistc lisp that has
only numbers, symbols (also used as strings) and lists as datatypes, and R.

It should be no problem to send command strings from the lisp process
to the R childprocess.  

I know, R is mostly implemented in Scheme, and I read recently, that
these special return objects of R are really lists under the
hood. Therefore my questions:

1. When I send a command from a lisp (that iks not elisp) to an R
subprocess, how can I recieve the R result object as a list (and not a
special R object)?

2. Apart from graphics - are all R result objects lists (or numbers or
strings)? That is, is it safe to assume that the result of an R call
will always be either a number, a string or a list (under the hood)?

Cheers
Thorsten