emacs ess[R] & eglot

;; cribbed from: https://www.reddit.com/r/emacs/comments/yojd70/state_of_esseglot/
;;
;; also see:
;; https://github.com/minad/corfu/wiki#configuring-corfu-for-eglot
;; https://github.com/minad/corfu/wiki#using-cape-to-tweak-and-combine-capfs


(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))