[ESS] Aquamacs ESS slow scroll (buffering?)

[Vitalie Spinu]

Hi Paul, 

I have just added an optimization. It should be considerably faster if
you don't use font lock, especially if you already have long comint
buffer.

The main issue is font-lock for me. It drags your example from 9 sec to
unbelievable 500 seconds on my machine. I don't know how to satisfactory
address this. Some time ago I tried to tinker with it by deactivating
during the process output, but nothing came out of it.

  Vitalie


 >>> Paul Johnson on Sun, 24 Nov 2013 14:06:37 -0600 wrote:

 > I've been uninterested in Macs, but I'm trying to be more helpful with
 > student questions by using a MacBook Pro sometimes.  I installed Aquamacs,
 > which has ESS 13.05 built in.

 > I'm encouraging students to Aquamacs because there is some hope of
 > continuity across platforms if they learn Emacs on Windows and Linux.  But
 > it is not as uniform as I would like, since Aquamacs has fiddled the menus
 > and shortcut keys just enough to make this frustrating. Anyway...

 > Yesterday, a student said he preferred to use R.app because Aquamacs is
 > super slow while displaying long vectors of text values. Huh? I thought he
 > must have broken something in his Mac, but I see same.

 > Can you guess if this is a configuration problem, or a Mac OSX problem?

 > My working example, with system.time output at the end.

 > ## Paul Johnson
 > ## 2013-11-23

 > ## Student reports that Macintosh Aquamacs has slow on-screen scrolling
 > ## of large text arrays. So I've created this test

 > set.seed(23456)

 > y <-  lapply(1:50000, function(x) paste0(letters[1:(rpois(1, 10))],
 > collapse=""))

 > system.time(print(y))

 > ## Aquamacs output (ESS 13.05)
 > ## user  system elapsed
 > ##  0.293   0.268  88.735

 > ## R.app output
 > ## user  system elapsed
 > ##  1.552   0.028   1.575

 > Why is elapsed time so grossly in excess of user + system.

 > This reminded me of the problem in MS Command Shell when running C programs
 > compiled with gcc (back in the day). Viewing lots of printf statements was
 > very slow in Windows, not in Linux.

 >> sessionInfo()
 > R version 3.0.2 (2013-09-25)
 > Platform: x86_64-apple-darwin10.8.0 (64-bit)

 > locale:
 > [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

 > attached base packages:
 > [1] stats     graphics  grDevices utils     datasets  methods   base

 > I don't know how to describe the Aquamacs version to you. The file it comes
 > from is on http://aquamacs.org:Aquamacs-Emacs-2.5.dmg
 > In there I find:
 > ESS- 13.05