State of ESS+eglot

Recently, I decided to give ESS+eglot another go and was quite surprised by how much better it is than 2 years ago. It mostly just works if I call 'eglot' when working on an R file, and the linting is great (for the most part). There are two things missing, though: * Automatic file name completion (I can trigger it manually, but it's annoying) * Variable name completion after $, this one does not seem to work at all Does anyone know how to fix this?

I was wondering, is there no conflict between ess and eglot?

Other than those two points, non that I can see. So far I'm happy.

If you are using company-mode, you can easily get variable name completion by wrting a custom company-backend and add it to your company-backends. Here is what I did ([https://github.com/zhenhua-wang/emacs.d/blob/a045e49faf8f80e1447721726fc1b17b0744051f/lisp/zw-company.el#L94](https://github.com/zhenhua-wang/emacs.d/blob/a045e49faf8f80e1447721726fc1b17b0744051f/lisp/zw-company.el#L94)) For file name completion, you can simply add company-file to your company-backends

And make sure your ess-r process is running.

when I call eglot, it overwrites the backends and only show company-capf, how do I change this?

Ah, that's where I don't like Eglot. You may add hooks to eglot--managed-mode-hook to set up your backends. Or you just use lsp-mode

I should have googled `(setq eglot-stay-out-of '(company))` solves it. Thanks for the capf-with-r-objects, it works great!

Glad it helped!

I use [eglot with corfu](https://github.com/minad/corfu/wiki#configuring-corfu-for-eglot) and [configure additional completion-at-point-functions](https://github.com/minad/corfu/wiki#using-cape-to-tweak-and-combine-capfs), such as cape-file, to give great in-buffer file completion. I also enjoy adding current buffer dabbrev results to completion too.

if you are using cape (together with corfu and corfu-terminal) which can merge different completion at point functions, you can make capf provided sources from both eglot and ESS. You can `C-h v completion-at-point-functions` to see what is the capf backend provided by eglot and merge them together. Here is my config to do the similar thing: https://github.com/milanglacier/.emacs.d/blob/1627d629af4b569974c4928d7d37611607d1cd77/config.el#L586

Is there any guide to get ess and eglot for R up and running? I'm more than happy to drop rstudio for good

This is the relevant part of my .emacs.d/init.el: ``` (use-package eglot :defer t :commands (eglot eglot-ensure) :hook ((c-mode . eglot-ensure) (c++-mode . eglot-ensure) (ess-mode . eglot-ensure)) :config (setq eglot-stay-out-of '(company)) (add-to-list 'eglot-server-programs '((c-mode c++-mode) "clangd-10")) ) (defun company-R-objects--prefix () (unless (ess-inside-string-or-comment-p) (let ((start (ess-symbol-start))) (when start (buffer-substring-no-properties start (point)))))) (defun company-R-objects--candidates (arg) (let ((proc (ess-get-next-available-process))) (when proc (with-current-buffer (process-buffer proc) (all-completions arg (ess--get-cached-completions arg)))))) (defun company-capf-with-R-objects--check-prefix (prefix) (cl-search "$" prefix)) (defun company-capf-with-R-objects (command &optional arg &rest ignored) (interactive (list 'interactive)) (cl-case command (interactive (company-begin-backend 'company-R-objects)) (prefix (company-R-objects--prefix)) (candidates (if (company-capf-with-R-objects--check-prefix arg) (company-R-objects--candidates arg) (company-capf command arg))) (annotation (if (company-capf-with-R-objects--check-prefix arg) "R-object" (company-capf command arg))) (kind (if (company-capf-with-R-objects--check-prefix arg) 'field (company-capf command arg))) (doc-buffer (company-capf command arg)))) (use-package ess :ensure nil :defer t :commands (list R julia) :load-path ("/home/matias/Programas/ESS/lisp") :bind (:map ess-mode-map ("<C-tab>" . company-files) ("<M-tab>" . company-complete-common) ("M-P" . my/add-pipe) ("M-h" . company-show-doc-buffer)) :init (require 'ess-site) (setq ess-nuke-trailing-whitespace-p t ess-toggle-underscore nil ess-toggle-S-assign nil ess-disable-underscore-assign t ;; ess-use-flymake nil ) (company-posframe-mode 0) (add-hook 'ess-mode-hook (lambda() (make-local-variable 'company-backends) (setq company-backends '(company-files company-capf-with-R-objects)))) :config (progn (defalias 'ess-smart-S-assign 'self-insert-command))) (defun my/add-pipe () "Adds a pipe operator %>% with one space to the left and right" (interactive) (just-one-space 1) (insert "%>%") (just-one-space 1)) ```

I like it more than rstudio for two reasons. First, I have all my keybindings. Second, I always thought that rstudio has a lot of wasted screen space in the plot section and the objects section, idk, never felt well structured.

Which version of emacs are you using? I am using 28.1 and I get this error: `Error (use-package): ess/:init: Wrong number of arguments: (3 . 4), 2` Any idea where to start looking for the issue? (new to emacs and elisp)

Which Ess version do you have? The latest version works out of the box with eglot.

ESS 18.10.2 I haven't been able to get it working with 28.1.

Try the devel version, it is working fine for me with 28.1. You might need to compile [ESS from source](https://ess.r-project.org/Manual/ess.html#Installing-from-source). Also, share the relevant config for ESS+R in your init.

I'll try the dev version. I added the ESS/R segment of what you posted above to my init.el....I didn't have anything else related to ESS or R. I'll try stripping other packages. Thanks!