[ESS] Emacs finding "R" on Windows {was "Release of ESS 5.3.5"}

[Phillip Lord]

>>>>> "RS" == Rodney Sparapani <rsparapa at mcw.edu> writes:

  RS> Phillip Lord wrote:
  >>>>>>> "SE" == Stephen Eglen <S.J.Eglen at damtp.cam.ac.uk> writes:

  RS> Well, I was not able to see the attachment (tbird shows that there is a
  RS> MIME part there, but it wouldn't let me open it).  It's just as well
  RS> since I don't have a Windows machine handy to try it on.  But, here's my
  RS> take on the registry.  It is fragile.  Somebody may have moved the R
  RS> executable.  Something that we do all the time on Unix and Mac, so I
  RS> suspect it is common on Windows as well.  And, the executables are fine
  RS> thereafter, however, I suspect the registry will be wrong then.  Is my
  RS> supposition correct?


If you move the R executable on windows it doesn't work any more, at least not
as far as I can tell. In general, it's a bad thing to do. If you want to move
R, uninstall, reinstall. 

I'm not suggesting, incidentally, that this is the only check. You need a set
of heuristics to cope with windows calamitous package management. And the fact
that people who use R and Emacs are, lets be honest, the sort of people who
may have fiddled with the defaults. 

My suggestion was this order:

Do what ever the user has configured explicitly.
Do what the registry says (assuming R.exe exists).
Look in (getenv "ProgramFiles"), using the version number in the directory to
identify the latest. 
Look in path, using who comes first to identify latest. 
Give up.