Depreciating partial matching

I would think that the ability to hit the Tab key to trigger name

 completion in your R GUI makes partial matching almost useless. The
 avantage of interactive completion in the GUI is that you immediately
 see the result of the partial matching. So you get the best of both
 worlds: no need to type long variable names in full, but no traps when a
 match is not what you would expect.
 
 Doesn't this suit your use case?

 Good point.  This works well at the command line.  However, not when interacting between emacs and R in the way I do.  For reproducability I use and emacs file that is being corrected and massaged with chunks submitted to R; at the end I have a clean record of how the result was obtained.
 

If this is really true (that ESS doesn't complete in R files) then this seems more like a bug (or wish?) report for ESS - other editors correctly support code completion in R documents - after all this is a feature of R, so they don't need to re-invent the wheel.

Cheers,
Simon

If you are running the R process inside ESS then there is matching -- it is R.  Doing 
this, keeping a log file, and then post-hoc cleaning up all the cruft from that file is 
one way to keep documentation.  But since for my analyses the number of models/plots/etc 
that turn out to be detours or dead ends on the way to a solution is larger than the 
worthwhile part (typos alone are lots larger) I prefer to keep the file(s) as their own 
buffers and submit bits of them to an R process either by cut-paste to a separate window 
or ess-submit to an inferior process.  Emacs can't do name completion in that case.  Nor 
could it do so in an Sweave file, unless you were to keep a live R process in hand to 
pre-test chunks as you wrote them.  (One could reasonably argue that when one gets the 
Sweave stage the names should be expanded.)

To summarize: my own interactive mix of emacs/R may be unusual.  For pure interactive 
folks completion does most of the work.  I hadn't tried the newest ESS 
interactive-within-emacs till today, it's slick as well.  The number of people howling 
will be less than my original thought, though not zero.

   Still, this change could cause a lot of grief for saved R scripts.  In our group the 
code + data directory is archived whenever a medical paper is submitted (close to 
500/year), and it is very common to pull one back as is 1-4 years later for further 
exploration.  A very small subset of those are in a legal context where exact 
reproducability is paramount.