lang/rust: use rustic-mode instead on Emacs 26+

modules/lang/rust/config.el

@@ -1,44 +1,73 @@
 ;;; lang/rust/config.el -*- lexical-binding: t; -*-
 
-(after! rust-mode
+(def-package! rust-mode
-  (set-docsets! 'rust-mode "Rust")
+  :mode ("\\.rs$" . +rust|init)
+  :config
   (setq rust-indent-method-chain t)
 
+  (defun +rust|init ()
+    "Use `rustic-mode' if possible, otherwise fall back to `rust-mode'."
+    (if (and EMACS26+ (require 'rustic nil t))
+        (rustic-mode)
+      (rust-mode)))
+
+  (set-docsets! '(rust-mode rustic-mode) "Rust")
   (when (featurep! +lsp)
     (add-hook 'rust-mode-local-vars-hook #'lsp!))
 
-  (def-package! cargo
+  ;; TODO PR these upstream
-    :defer t
+  (after! dtrt-indent
-    :init
+    (pushnew! dtrt-indent-hook-mapping-list
-    (map! :map rust-mode-map
+              '(rust-mode default rust-indent-offset)
-          :localleader
+              '(rustic-mode default rustic-indent-offset)))
-          (:prefix "b"
+  (when (featurep! :tools editorconfig)
-            :desc "cargo add"    "a" #'cargo-process-add
+    (after! editorconfig
-            :desc "cargo build"  "b" #'cargo-process-build
+      (pushnew! editorconfig-indentation-alist
-            :desc "cargo bench"  "B" #'cargo-process-bench
+                '(rust-mode rust-indent-offset)
-            :desc "cargo check"  "c" #'cargo-process-check
+                '(rustic-mode rustic-indent-offset)))))
-            :desc "cargo clippy" "C" #'cargo-process-clippy
-            :desc "cargo doc"    "d" #'cargo-process-doc
-            :desc "cargo run"    "r" #'cargo-process-run
-            :desc "cargo search" "s" #'cargo-process-search
-            :desc "cargo update" "u" #'cargo-process-update)
-          (:prefix ("t" . "cargo test")
-            :desc "all"          "a" #'cargo-process-test
-            :desc "current file" "f" #'cargo-process-current-file-tests
-            :desc "current test" "t" #'cargo-process-current-test))))
 
 
 (def-package! racer
   :unless (featurep! +lsp)
-  :after rust-mode
+  :hook ((rust-mode rustic-mode) . racer-mode)
   :config
-  (add-hook 'rust-mode-hook #'racer-mode)
   (set-lookup-handlers! 'rust-mode
     :definition '(racer-find-definition :async t)
     :documentation '+rust-racer-lookup-documentation))
 
 
-(def-package! flycheck-rust
+(def-package! rustic
-  :when (featurep! :tools flycheck)
+  :when EMACS26+
   :after rust-mode
-  :config (add-hook 'rust-mode-hook #'flycheck-rust-setup))
+  :config
+  (setq rustic-indent-method-chain rust-indent-method-chain
+        rustic-flycheck-setup-mode-line-p nil
+        rustic-rls-pkg (featurep! +lsp)))
+
+
+;;
+;;; Tools
+
+(def-package! cargo
+  :after rust-mode
+  :config
+  (defvar +rust-keymap
+    (if (boundp 'rustic-mode-map)
+        rustic-mode-map
+      rust-mode-map))
+  (map! :map +rust-keymap
+        :localleader
+        (:prefix "b"
+          :desc "cargo add"    "a" #'cargo-process-add
+          :desc "cargo build"  "b" #'cargo-process-build
+          :desc "cargo bench"  "B" #'cargo-process-bench
+          :desc "cargo check"  "c" #'cargo-process-check
+          :desc "cargo clippy" "C" #'cargo-process-clippy
+          :desc "cargo doc"    "d" #'cargo-process-doc
+          :desc "cargo run"    "r" #'cargo-process-run
+          :desc "cargo search" "s" #'cargo-process-search
+          :desc "cargo update" "u" #'cargo-process-update)
+        (:prefix ("t" . "cargo test")
+          :desc "all"          "a" #'cargo-process-test
+          :desc "current file" "f" #'cargo-process-current-file-tests
+          :desc "current test" "t" #'cargo-process-current-test)))

modules/lang/rust/packages.el

@@ -1,11 +1,13 @@
 ;; -*- no-byte-compile: t; -*-
 ;;; lang/rust/packages.el
 
+(when EMACS26+
+  (package! rustic))
 (package! rust-mode)
-(package! cargo)
-
 (when (featurep! :tools flycheck)
   (package! flycheck-rust))
-
 (unless (featurep! +lsp)
   (package! racer))
+
+;;
+(package! cargo)