Automatic tree-sitter setup

Install grammars automatically and use tree-sitter modes by default

init.el

@@ -548,6 +548,41 @@
 ;;; Programming tools
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
+(use-package treesit
+  :straight nil
+  :preface
+  (defun dl/setup-install-grammars ()
+    "Install Tree-sitter grammars if they are absent."
+    (interactive)
+    (dolist (grammar
+             '((c "https://github.com/tree-sitter/tree-sitter-c")
+	       (json "https://github.com/tree-sitter/tree-sitter-json")
+	       (python "https://github.com/tree-sitter/tree-sitter-python")
+	       (rust "https://github.com/tree-sitter/tree-sitter-rust")
+	       (toml "https://github.com/tree-sitter/tree-sitter-toml")
+	       (yaml "https://github.com/ikatyang/tree-sitter-yaml")))
+      (add-to-list 'treesit-language-source-alist grammar)
+      ;; Only install `grammar' if we don't already have it
+      ;; installed. However, if you want to *update* a grammar then
+      ;; this obviously prevents that from happening.
+      (unless (treesit-language-available-p (car grammar))
+        (treesit-install-language-grammar (car grammar)))))
+  ;; Optional, but recommended. Tree-sitter enabled major modes are
+  ;; distinct from their ordinary counterparts.
+  ;;
+  ;; You can remap major modes with `major-mode-remap-alist'. Note
+  ;; that this does *not* extend to hooks! Make sure you migrate them
+  ;; also
+  (dolist (mapping '((c-mode . c-ts-mode)
+		     (json-mode . json-ts-mode)
+		     (python-mode . python-ts-mode)
+		     (rust-mode . rust-ts-mode)
+		     (toml-mode . toml-ts-mode)
+                     (yaml-mode . yaml-ts-mode)))
+    (add-to-list 'major-mode-remap-alist mapping))
+  :config
+  (dl/setup-install-grammars))
+
 (use-package expand-region
   :straight t
   :bind ("C-=" . er/expand-region))