Wish there were a "strict mode" for R interpreter. What

I think the right thing to so is to introduce the students to the
basics of scoping, early in the process of learning R.

I know the basics of scoping perfectly well, but that doesn't stop me from occasionally misspelling a variable name that only causes an error much later.

OTOH, I think with Perl you can start declaring your variables "local" and keep the interpreter happy. But in R's context you then have to also start declaring what you expect to inherit from parent environments, and pretty soon the code is so encrusted with annotation barnacles that it loses the simplicity that  makes R so nice in the interactive mode. 

What would be really nice is if we had a smart R editor/IDE that would "DWIM" and put a red underline under a misspelled name, but leave it alone when, as Duncan said, it's in the environment. 

Davor