[Rd] Re: [R] further on ESS/XEmacs for Windows

John Fox jfox@mcmaster.ca
Wed Nov 27 14:06:15 2002

Dear Brian

At 07:43 AM 11/27/2002 +0000, ripley@stats.ox.ac.uk wrote:
>[Moved to R-devel, as this is going to get technical and is already a
>minority interest.]
>On 26 Nov 2002, A.J. Rossini wrote:
> > >>>>> "john" == John Fox <jfox@mcmaster.ca> writes:
> >
> >
> >     john> (2) I spent a good part of the day today trying XEmacs and 
> ESS on a
> >     john> variety of Windows systems -- with and without my configuration
> >     john> files. I noticed a number of intermittent problems with 
> GUI-related
> >     john> commands, such as attempts to open dialog boxes causing the R 
> process
> >     john> to freeze. I'll try to track down the source of these problems.
> >
> > I'm not sure what the status of these is -- I do know that some people
> > I trust have wondered how the heck R even works under (X)Emacs on
> > Windows (issues arising with systems interfacing, blocking calls, and
> > similar "stuff").
>That's right!  rterm used directly uses a separate thread for input to
>avoid it blocking (not processing Windows events) whilst waiting for
>input.  rterm used by ESS is effectively used in batch mode: it was never
>the intention that the GUI interactions should work.

Thanks for the explanation -- I figured that you'd know what's going on here.

>Guido and I once (in 2000) discussed a way out using a supervisor thread,
>and Guido implemented it (although I never saw the code),  He said it
>worked under NT but not Win98.  That's the real problem -- supporting
>low-end versions of Windows which do not behave as documented, when the
>developers (then) were only using NT/2000.  On Unix one uses select() and
>since we have since made that work to support url/socket connections it
>would be possible to try to use that.  However, it would be a lot of work
>to provide something that the main developers would never use, and we
>remain desperately short of contributions by users of R on Windows.

If I had the knowledge to make this kind of contribution, I'd volunteer to 
do it. I expect that this is generally the source of the problem: that is, 
Windows users probably tend to have a lower level of programming expertise.

If Guido's code still exists, would it be possible to incorporate it, 
providing a solution for Windows NT, 2000, and XP? Applications such as 
mine could adapt their behaviour depending upon the Windows version (and 
eventually Windows 9x systems will disappear).

Thanks again,
John Fox
Department of Sociology
McMaster University
Hamilton, Ontario, Canada L8S 4M4
email: jfox@mcmaster.ca
phone: 905-525-9140x23604
web: www.socsci.mcmaster.ca/jfox