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

[Alex Branham]

On Mon 04 Mar 2019 at 09:35, Samuele Carcagno via ESS-help <ess-help using r-project.org> wrote:

> 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)
> ;;

Hi Sam -

There are a lot of very hard-to-fix design bugs in ESS's implementation
of noweb/sweave. We're encouraging users to switch to polymode.[1] Can
you try that out and see if it fixes your issues?

Thanks,
Alex

Footnotes:
[1]  https://polymode.github.io/installation/