[ESS] Finding 64-bit R versions on Windows

[Kevin Coombes]

Hi,

I've been (mildly) unhappy for some time because, when ESS is finding 
the "latest" R on a 64-bit version of Windows, it always manages to find 
and start the 32-bit version.

And while I know that I can type "M-x R [tab]" and then click on the 
correct version, that always seems like too much work.

So, I wrote the function below (which I am sure someone else could make 
work much more elegantly and reliably) to always select the latest 
64-bit version. Now I sill have to type "M-x R64" but I'm more-or-less 
willing to do that.

Having offered up my solution to this problem, here's my request: Is it 
possible to make something like this a standard part of ESS? Better yet, 
would it be possible to define a new configuration variable so that the 
user could specify whether to invoke the latest 32-bit or latest 64-bit 
version when calling "M-x R"?

Best,
   Kevin


;; the ESS "latest" code always picks the 32-bit version of R on windows.
;; This hack finds the latest 64-bit version.
(defun R64 (&optional start-args)
   "Call the latest 64-bit version of R"
   (interactive "P")
   ;; sweep through the list of R-version commands
   ;; to find the 64-bit ones
   (defun m64 (target)
     "remove string '-64bit' from target"
     (if (string-match "-64bit" target)
     (replace-match "" t t target)
       ))
    (setq nobits (delq nil (mapcar 'm64 ess-r-versions-created)))
    ;; now use the newest version that matches a 64-bit version
    (defun krc-in-newest (source)
      (if source
      (if (string-match source ess-newest-R)
          (concat source "-64bit")
        nil)
        nil))
    (setq pending (delq nil (mapcar 'krc-in-newest nobits)))
    ;; take the first one
    (setq myname (car pending))
    ;; convert from string to symbol
    (setq mysym (intern-soft myname))
    ;; look up the function from the symbol
    (setq myfun (symbol-function mysym))
    ;; invoke it
    (funcall myfun start-args)
)