provide alternative rustic mode that derives from rust-ts-mode

close #475

.github/workflows/test.yml

@@ -11,7 +11,9 @@ jobs:
                 os: [ubuntu-latest]
                 emacs-version:
                     - 27.2
-                    - 28.1
+                    - 28.2
+                    # - snapshot
+
         steps:
             - uses: actions/checkout@v2
 

README.md

@@ -136,6 +136,29 @@ additional [installation
 instructions](https://github.crookster.org/switching-to-straight.el-from-emacs-26-builtin-package.el/)
 for moving your package management from package.el to straight.
 
+## treesitter
+
+You can try the new native treesitter mode `rust-ts-mode` with:
+
+```elisp
+(use-package rustic
+  :init
+  (setq rustic-treesitter-derive t))
+```
+
+In case you want to use treesitter but can't use emacs master, you can
+take a look at
+[tree-sitter](https://github.com/emacs-tree-sitter/elisp-tree-sitter). When
+the dependencies are installed you can activate the feature with:
+
+```elisp
+(use-package tree-sitter
+  :config
+  (require 'tree-sitter-langs)
+  (global-tree-sitter-mode)
+  (add-hook 'tree-sitter-after-on-hook #'tree-sitter-hl-mode))
+```
+
 ## remote
 
 rustfmt and most of the common cargo commands should work remotely.

rustic-rust-mode.el

@@ -0,0 +1,34 @@
+;;; rustic-rust-mode.el --- rust-mode related code -*-lexical-binding: t-*-
+;;; Commentary:
+
+;; Deprecated code related to rust-mode
+
+;;; Code:
+
+(setq rust-load-optional-libraries nil)
+(setq rust-before-save-hook #'rustic-before-save-hook)
+(setq rust-after-save-hook #'rustic-after-save-hook)
+(require 'rust-mode)
+
+;;; Define aliases for removed rustic functions
+
+(defvaralias 'rustic-indent-offset 'rust-indent-offset)
+(defvaralias 'rustic-indent-method-chain 'rust-indent-method-chain)
+(defvaralias 'rustic-indent-where-clause 'rust-indent-where-clause)
+(defvaralias 'rustic-match-angle-brackets 'rust-match-angle-brackets)
+(defvaralias 'rustic-indent-return-type-to-arguments 'rust-indent-return-type-to-arguments)
+(defalias 'rustic-indent-line #'rust-mode-indent-line)
+(defalias 'rustic-end-of-defun #'rust-end-of-defun)
+
+;;;###autoload
+(define-derived-mode rustic-mode rust-mode "Rustic"
+  "Major mode for Rust code.
+
+\\{rustic-mode-map}"
+  :group 'rustic
+
+  (when (bound-and-true-p rustic-cargo-auto-add-missing-dependencies)
+   (add-hook 'lsp-after-diagnostics-hook 'rustic-cargo-add-missing-dependencies-hook nil t)))
+
+(provide 'rustic-rust-mode)
+;;; rustic-rust-mode.el ends here

rustic-ts-mode.el

@@ -0,0 +1,22 @@
+;;; rustic-ts-mode.el --- use native rust-ts-mode -*-lexical-binding: t-*-
+;;; Commentary:
+
+;; Derive from rust-ts-mode instead of rust-mode
+
+;;; Code:
+
+;;;###autoload
+(define-derived-mode rustic-mode rust-ts-mode "Rustic"
+  "Major mode for Rust code.
+
+\\{rustic-mode-map}"
+  :group 'rustic
+
+  (when (bound-and-true-p rustic-cargo-auto-add-missing-dependencies)
+    (add-hook 'lsp-after-diagnostics-hook 'rustic-cargo-add-missing-dependencies-hook nil t))
+
+  (add-hook 'before-save-hook 'rustic-before-save-hook nil t)
+  (add-hook 'after-save-hook 'rustic-after-save-hook nil t))
+
+(provide 'rustic-ts-mode)
+;;; rustic-ts-mode.el ends here

rustic.el

@@ -35,28 +35,13 @@
 
 (require 'dash)
 
-(setq rust-load-optional-libraries nil)
-(setq rust-before-save-hook #'rustic-before-save-hook)
-(setq rust-after-save-hook #'rustic-after-save-hook)
-(require 'rust-mode)
-
 ;;; Customization
 
 (defgroup rustic nil
   "Support for Rust code."
   :link '(url-link "https://www.rustic-lang.org/")
   :group 'languages)
 
-;;; Define aliases for removed rustic functions
-
-(defvaralias 'rustic-indent-offset 'rust-indent-offset)
-(defvaralias 'rustic-indent-method-chain 'rust-indent-method-chain)
-(defvaralias 'rustic-indent-where-clause 'rust-indent-where-clause)
-(defvaralias 'rustic-match-angle-brackets 'rust-match-angle-brackets)
-(defvaralias 'rustic-indent-return-type-to-arguments 'rust-indent-return-type-to-arguments)
-(defalias 'rustic-indent-line #'rust-mode-indent-line)
-(defalias 'rustic-end-of-defun #'rust-end-of-defun)
-
 ;;; Workspace
 
 (defvar-local rustic--buffer-workspace nil
@@ -111,6 +96,13 @@ this variable."
   :type 'function
   :group 'rustic)
 
+(defcustom rustic-treesitter-derive nil
+  "Whether rustic should derive from the new treesitter mode `rust-ts-mode'
+instead of `rust-mode'. This option requires emacs29+."
+  :version "29.1"
+  :type 'boolean
+  :group 'rustic)
+
 ;;; Mode
 
 (defvar rustic-mode-map
@@ -145,24 +137,13 @@ this variable."
     map)
   "Keymap for `rustic-mode'.")
 
-;;;###autoload
-(define-derived-mode rustic-mode rust-mode "Rustic"
-  "Major mode for Rust code.
-
-\\{rustic-mode-map}"
-  :group 'rustic
-
-  (when (bound-and-true-p rustic-cargo-auto-add-missing-dependencies)
-   (add-hook 'lsp-after-diagnostics-hook 'rustic-cargo-add-missing-dependencies-hook nil t)))
+(if (and (version<= "29.1" emacs-version) rustic-treesitter-derive)
+    (require 'rustic-ts-mode)
+  (require 'rustic-rust-mode))
 
 ;;;###autoload
 (add-to-list 'auto-mode-alist '("\\.rs\\'" . rustic-mode))
 
-;; remove rust-mode from `auto-mode-alist'
-(let ((mode '("\\.rs\\'" . rust-mode)))
-  (when (member mode auto-mode-alist)
-    (setq auto-mode-alist (remove mode auto-mode-alist))))
-
 ;;; _
 
 (defun rustic-reload ()