[ESS] Telling ess where to look for R

[Stephen Eglen]

> However I do not find the specific code ess-directory-containing-R in
> any place. How is a non-developer to find these variables?


Customize was partly designed to help make user-variables more visible.
Richard Stallman asked me to help "customize" a huge bunch of elisp
files around 1997, so that all the main user variables could be browsed
just by using the customize facility.  Semantically, the information is
all there, but visually I still don't like the look of customize.

In this specific case, ess-directory-containing-R is in the top level,
after you do: M-x customize-group RET ess RET; if you don't see it, that
is a bug:
----------------------------------------------------------------------
Show Value Ess Directory Containing R 
   nil (the default) means the search for all occurences of R Hide
   on the machine will use the default location of the R directory
    (inside "c:/Program Files" in English locale Windows systems).
   Non-nil values mean use the specified location as the
   directory in which "R/" is located.  For example, setting
   `ess-directory-containing-R' to "c:" will tell ESS to search
   for R versions with pathnames of the form "c:/R/R-x.y.z".
   
   Currently only used when `ess-microsoft-p'.

----------------------------------------------------------------------

(By default, the hyphens in variable names are replaced with slash.)

> This is not your problem. This is a problem that I have with emacs
> generally. There are few good complete listings of variables. It's all
> passed word of mouth from one person to another.

I'd disagree; customize should be complete for packages that are in
Emacs.  If you know of variables that aren't visible through customize,
but should be, do let me know.

I do however agree that learning emacs is not easy!  I recommend if you
have been using for more than a couple of years, and really like it, why
not read through this guide: "An Introduction to Programming in Emacs
Lisp" which is in Emacs info (or online).  

Stephen