[ESS] font color in Sweave file and slowness in inferior mode issues

[Samuele Carcagno]

hello

I'm currently experiencing a couple of issues with ESS:

- when editing code chunks in Sweave (".Rnw") documents sometimes the 
font color of some lines of code suddenly changes. I have the feeling 
that this may be due to using the pipe operator "%>%" because the font 
becomes of the same color as the font color of the pipe operator. Also I 
can't pinpoint exactly when the issue started but probably it was around 
the same time that I started using dplyr

- the second issue is that things like variable name completion via TAB, 
and also navigating lines with the cursor sometimes get very slow in the 
inferior mode after a while. Maybe this is due to the fact that I'm 
processing long Sweave files (e.g. one file with which I've had issues 
recently has ~3000 lines of code, and I have ~500 variables in the 
workspace in total), but if I process the file through R opened up in a 
linux terminal things are not so slow

- I've seen a third issue, but this is really minor: in the latex chunks 
syntax highlighting sometimes becomes active only after I've moved the 
cursor close to the latex chunk

I apologize for the vague report on the issues, but I've found it hard 
to pinpoint exactly when and how they occur. I understand that it's 
difficult to diagnose the issues with only the information I provided, 
but I was hoping to get some pointers to possible causes and ideas to 
try to narrow down the possible causes (e.g. temporarily switching off 
some ESS functionalities to see if the speed issues improve). I've tried 
to search for related issues through google search and in the ESS list 
of open issues on github but I haven't been able to find anything that 
could solve my issues (although this may be partly due to my lack of 
knowledge of ESS and emacs internals).

I'm using ESS version 18.10.2 on Ubuntu Bionic.

My ESS customizations in my .emacs file are the following:

;;
;; Get rid of ESS smart underscore :)
(ess-toggle-underscore nil)
  (defun my-ess-settings ()
     (setq ess-indent-with-fancy-comments nil))
   (add-hook 'ess-mode-hook #'my-ess-settings)
(require 'ess-jags-d)
;;

Best,

Sam