R is a pretty cool little language, but it has a long way to go. It would be nice to have support for floating-point arithmetic, strings, structures with named fields, dynamic memory allocation, various built-in abstract data types, type checking and other error checking, exception handling, etc., etc. Not to mention object-oriented programming. It would be nice to have the option to use high-level irreversible operations, and have the compiler deal intelligently with the garbage data.
But anyway, here is revision 0.0, ready for feedback.