The R interpreter does what it does at run time. The ambiguity is in
reasoning at any time _other than run time_ which environment the returned
value of 'x' is taken from.
This is one reason why R has been profiled to spend a significant amount of
time looking up names (
http://www.cs.purdue.edu/h
When complex assignments are performed, the R interpreter creates, then
removes a special variable *tmp*. However, when byte compiling is enabled,
it seems that a different mechanism for making compound assignments is used.
Would it be possible to eliminate *tmp* from interpreted R code as well? I
