From 7c71a12cacb6bb6c42a939764c4dccb18ec7aba5 Mon Sep 17 00:00:00 2001
From: Ralf Zerres <ralf.zerres@networkx.de>
Date: Sun, 25 Jul 2021 12:58:53 +0200
Subject: [PATCH] 401-rust: update rustic bindings and dependencies

* adapt lsp-ui handling
* update lsp handling
* update comany completion handling
* update yasnippet code snippet expansion

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>
---
 site-start.d/401-rust.el | 120 ++++++++++++++++++++++++++++++++-------
 1 file changed, 100 insertions(+), 20 deletions(-)

diff --git a/site-start.d/401-rust.el b/site-start.d/401-rust.el
index 83dc145..c521bb1 100644
--- a/site-start.d/401-rust.el
+++ b/site-start.d/401-rust.el
@@ -8,41 +8,94 @@
 
 ;; load rustic -> IDE like for rust
 ;; it superseeds rust-mode
+;; reference: https://robert.kra.hn/posts/2021-02-07_rust-with-emacs/
 (use-package rustic
   :ensure t
+  :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))
   :custom
-  (linum-on)
-  (linum-relative-mode 1)
+  (global-linum-mode)
   (rustic-lsp-server 'rust-analyzer)
-  (setq-default indent-tabs-mode nil)
   (rustic-lsp-format t)
- ;;(linum-relative-toggle)
+  (setq rustic-format-on-save t)
+  ;;(linum-relative-mode 0)
+  ;;(linum-relative-toggle)
   ;;(hs-minor-mode t)
   ;;(lsp-origami-try-enable)
   ;;(linum-relative-mode 1)
   ;;(setq-default indent-tabs-mode nil)
-  ;;(rustic-lsp-server 'rust-analyzer)
-  ;;(rustic-lsp-format t)
 
   :config
   ;; recommended: use spaces instead of tabs
   (add-hook 'rust-mode-hook
-            (lambda () (setq indent-tabs-mode nil)))
-  (add-hook 'rustic-mode-hook
-            (lambda () (setq indent-tabs-mode nil)))
-  ;; enable code folding und line numbering rust buffers
+	    (lambda () (setq indent-tabs-mode nil)))
+    ;; enable code folding und line numbering rust buffers
   (add-hook 'prog-mode-hook
-            ;;'lsp-origami-mode
-            'hs-minor-mode
-            'linum-relative-mode)
-  ;;(remove-hook 'rustic-mode-hook 'flycheck-mode)
+	    ;;'lsp-origami-mode
+	    'hs-minor-mode
+	    ;;'linum-relative-mode
+	    'tmp/rustic-mode-hook)
+  ;; (remove-hook 'rustic-mode-hook 'flycheck-mode)
+  ;; (setq lsp-eldoc-hook nil)
+  ;; (setq lsp-enable-symbol-highlighting nil)
+  ;; (setq lsp-signature-auto-activate nil)
 
-  ;; use the lsp UI package
+  (defun tmp/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)))
+
+  ;; use the lsp package
   ;; https://emacs-lsp.github.io/lsp-mode
+  (use-package lsp-mode
+    :ensure
+    :commands lsp
+    :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)
+    (lsp-rust-analyzer-server-display-inlay-hints t)
+    :config
+    (add-hook 'lsp-mode-hook 'lsp-ui-mode))
+
   (use-package lsp-ivy
     :ensure t)
+
   (use-package lsp-ui
-    :ensure t)
+    :ensure t
+    :commands lsp-ui-mode
+    :custom
+    (lsp-ui-peek-always-show t)
+    (lsp-ui-sideline-show-hover t)
+    (lsp-ui-doc-enable nil))
+
+  ;; use the company package
+  ;; a completion framework for emacs
+  (use-package company
+    :ensure
+    :custom
+    (company-idle-delay 2.5) ;; how long to wait until popup
+    ;; (company-begin-commands nil) ;; uncomment to disable popup
+    :bind
+    (:map company-active-map
+	  ("C-n". company-select-next)
+	  ("C-p". company-select-previous)
+	  ("M-<". company-select-first)
+	  ("M->". company-select-last))
+    (:map company-mode-map
+	  ("<tab>". tab-indent-or-complete)
+	  ("TAB". tab-indent-or-complete)))
 
   ;; use the yasnippet
   (use-package yasnippet
@@ -54,11 +107,38 @@
     (yas-reload-all))
 
   ;; company-capf.el from load-path
-  (use-package linum-relative
-    :config
-    (setq linum-relative-backend 'display-line-numbers-mode))
+  ;;(use-package linum-relative
+  ;;  :config
+  ;;  (setq linum-relative-backend 'display-line-numbers-mode))
 
-)
+  ) ;; end use-package rustic
+
+(defun company-yasnippet-or-completion ()
+  (interactive)
+  (or (do-yas-expand)
+      (company-complete-common)))
+
+(defun check-expansion ()
+  (save-excursion
+    (if (looking-at "\\_>") t
+      (backward-char 1)
+      (if (looking-at "\\.") t
+	(backward-char 1)
+	(if (looking-at "::") t nil)))))
+
+(defun do-yas-expand ()
+  (let ((yas/fallback-behavior 'return-nil))
+    (yas/expand)))
+
+(defun tab-indent-or-complete ()
+  (interactive)
+  (if (minibufferp)
+      (minibuffer-complete)
+    (if (or (not yas/minor-mode)
+	    (null (do-yas-expand)))
+	(if (check-expansion)
+	    (company-complete-common)
+	  (indent-for-tab-command)))))
 
 (provide '401-rust)
 ;; Local Variables: