Emacs ess auto-complete

Question

I am a R user, I want to use R in emacs. But, I am in trouble with customizing ess in emacs. I have installed the auto-complete packages and the latest ess in my emacs. But

Answer 1

I got the same problem and the following code worked for me:

(require 'package)
(add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/") t)
(package-initialize)  ;load and activate packages, including auto-complete
(ac-config-default)
(setq ess-use-auto-complete 'script-only)
;;if not working, use the following instead of (setq ess-use-auto-complete 'script-only)
;;(global-auto-complete-mode t)

Answer 2

I recently started using ESS on Windows, and struggled with the same issue. I don't know all of the ins and outs but recent versions of ESS suggest using company-mode rather than auto-complete-mode. This minimal setup seems to have autocomplete working quite well for me on the following setup:

• Windows 10 x64
• R 3.4.3 x64
• Emacs 25 x64 installed normally
• MELPA repo enabled in init.el
• package-install [RET] company
• package-install [RET] ess
• open a new R file in some directory
• M-x company-mode to enable company-mode in the current buffer
• `C-c C-z' to start an inferior R process

At this point, with the init.el file shown below, R completion is working, completing function calls, and package members. I think more configuration is needed to tailor it to your liking, but getting to this point took me long enough I consider it a success

init.el:

(require 'package)
(let* ((no-ssl (and (memq system-type '(windows-nt ms-dos))
                    (not (gnutls-available-p))))
       (proto (if no-ssl "http" "https")))
  (add-to-list 'package-archives (cons "melpa" (concat proto "://melpa.org/packages/")) t)
  )
(package-initialize)

;; emacs controlled settings
(custom-set-variables
 '(package-selected-packages (quote (company ess)))
 '(show-paren-mode t)
 '(tool-bar-mode nil))
(custom-set-faces
 '(default ((t (:family "Consolas" :foundry "outline" :slant normal :weight normal :height 113 :width normal)))))

(require 'company)

Answer 3

Auto-complete works for me with this setting

(setq ess-use-auto-complete t)