[ADD] Rust LSP to emacs config

.emacs

@@ -29,7 +29,6 @@
 (column-number-mode 1)
 (show-paren-mode 1)
 (electric-pair-mode 1)
-(global-font-lock-mode 0)
 (global-display-line-numbers-mode 1)
 (setq display-line-numbers-type 'relative)
 (set-face-attribute 'default nil :height 200)
@@ -44,6 +43,77 @@
 (setq-default display-fill-column-indicator-column 79)  ; 80 column indicator - Emacs columns are 0-based...
 (global-display-fill-column-indicator-mode 1)
 
+(unless (package-installed-p 'lsp-mode)
+  (package-install 'lsp-mode))
+
+(use-package lsp-mode
+  :init
+  :config
+  (add-hook 'lsp-mode-hook 'lsp-ui-mode)
+  :custom
+  ;; what to use when checking on-save. "check" is default, I prefer clippy
+  (lsp-rust-analyzer-cargo-watch-command "clippy")
+  (lsp-eldoc-render-all t)
+  (lsp-idle-delay 0.6)
+  ;; enable / disable the hints as you prefer:
+  (lsp-inlay-hint-enable t)
+  ;; These are optional configurations. See https://emacs-lsp.github.io/lsp-mode/page/lsp-rust-analyzer/#lsp-rust-analyzer-display-chaining-hints for a full list
+  (lsp-rust-analyzer-display-lifetime-elision-hints-enable "skip_trivial")
+  (lsp-rust-analyzer-display-chaining-hints t)
+  (lsp-rust-analyzer-display-lifetime-elision-hints-use-parameter-names nil)
+  (lsp-rust-analyzer-display-closure-return-type-hints t)
+  (lsp-rust-analyzer-display-reborrow-hints nil)
+  :hook (;; replace XXX-mode with concrete major-mode(e. g. python-mode)
+         (c-mode . lsp)
+         (python-mode . lsp))
+  :commands lsp)
+
+;;https://robert.kra.hn/posts/rust-emacs-setup/
+(use-package rustic
+  :ensure
+  :bind (:map rustic-mode-map
+              ("M-j" . lsp-ui-imenu)
+              ("M-?" . lsp-find-references)
+              ("C-c C-c l" . flycheck-list-errors)
+              ("C-c C-c a" . lsp-execute-code-action)
+              ("C-c C-c r" . lsp-rename)
+              ("C-c C-c q" . lsp-workspace-restart)
+              ("C-c C-c Q" . lsp-workspace-shutdown)
+              ("C-c C-c s" . lsp-rust-analyzer-status))
+  :config
+  ;; uncomment for less flashiness
+  ;; (setq lsp-eldoc-hook nil)
+  ;; (setq lsp-enable-symbol-highlighting nil)
+  ;; (setq lsp-signature-auto-activate nil)
+
+  ;; comment to disable rustfmt on save
+  (setq rustic-format-on-save t)
+  (add-hook 'rustic-mode-hook 'rk/rustic-mode-hook))
+
+(defun rk/rustic-mode-hook ()
+  ;; so that run C-c C-c C-r works without having to confirm, but don't try to
+  ;; save rust buffers that are not file visiting. Once
+  ;; https://github.com/brotzeit/rustic/issues/253 has been resolved this should
+  ;; no longer be necessary.
+  (when buffer-file-name
+    (setq-local buffer-save-without-query t))
+  (add-hook 'before-save-hook 'lsp-format-buffer nil t))
+
+;; company
+(unless (package-installed-p 'company)
+	(package-install 'company))
+
+(use-package company
+  :after lsp-mode
+  :hook (prog-mode . company-mode)
+  :bind (:map company-active-map
+         ("<tab>" . company-complete-selection))
+        (:map lsp-mode-map
+         ("<tab>" . company-indent-or-complete-common))
+  :custom
+  (company-minimum-prefix-length 1)
+  (company-idle-delay 0.0))
+
 (setq neo-theme (if (display-graphic-p) 'icons))
 
 ;; Use keybindings
@@ -80,6 +150,10 @@
 (unless (package-installed-p 'exwm)
   (package-install 'exwm))
 
+(require 'exwm)
+(require 'exwm-config)
+;;(exwm-config-example)
+
 (defun my-untabify-all-lines ()
   "Select all lines in the buffer and run 'untabify' on them."
   (interactive)