Add markdown-ts-mode

* lisp/textmodes/markdown-ts-mode.el: New file.
Ref: https://lists.gnu.org/r/emacs-devel/2024-06/msg01061.html

(cherry picked from commit a102dcebb7d10275cc3818f47cd042ddd27868ff)

diff --git a/lisp/textmodes/markdown-ts-mode.el b/lisp/textmodes/markdown-ts-mode.el
new file mode 100644 (file)
index 0000000..49fe1ba
--- /dev/null
+++ b/lisp/textmodes/markdown-ts-mode.el
@@ -0,0 +1,113 @@
+;;; markdown-ts-mode.el --- tree sitter support for Markdown  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2024 Free Software Foundation, Inc.
+
+;; Author     : Rahul Martim Juliato <rahul.juliato@gmail.com>
+;; Maintainer : Rahul Martim Juliato <rahul.juliato@gmail.com>
+;; Created    : April 2024
+;; Keywords   : markdown md languages tree-sitter
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+
+;;; Code:
+
+(require 'treesit)
+(require 'subr-x)
+
+(declare-function treesit-node-parent "treesit.c")
+(declare-function treesit-node-type "treesit.c")
+(declare-function treesit-parser-create "treesit.c")
+
+(defvar markdown-ts--treesit-settings
+  (treesit-font-lock-rules
+   :language 'markdown
+   :override t
+   :feature 'delimiter
+   '([ "[" "]" "(" ")" ] @shadow)
+
+
+   :language 'markdown
+   :feature 'paragraph
+   '([((setext_heading) @font-lock-keyword-face)
+      ((atx_heading) @font-lock-keyword-face)
+      ((thematic_break) @shadow)
+      ((indented_code_block) @font-lock-string-face)
+      (list_item (list_marker_star) @font-lock-keyword-face)
+      (list_item (list_marker_plus) @font-lock-keyword-face)
+      (list_item (list_marker_minus) @font-lock-keyword-face)
+      (list_item (list_marker_dot) @font-lock-keyword-face)
+      (fenced_code_block (fenced_code_block_delimiter) @font-lock-doc-face)
+      (fenced_code_block (code_fence_content) @font-lock-string-face)
+      ((block_quote_marker) @font-lock-string-face)
+      (block_quote (paragraph) @font-lock-string-face)
+      (block_quote (block_quote_marker) @font-lock-string-face)
+      ])
+
+   :language 'markdown-inline
+   :feature 'paragraph-inline
+   '([
+      ((image_description) @link)
+      ((link_destination) @font-lock-string-face)
+      ((code_span) @font-lock-string-face)
+      ((emphasis) @underline)
+      ((strong_emphasis) @bold)
+      (inline_link (link_text) @link)
+      (inline_link (link_destination) @font-lock-string-face)
+      (shortcut_link (link_text) @link)])))
+
+(defun markdown-ts-imenu-node-p (node)
+  "Check if NODE is a valid entry to imenu."
+  (equal (treesit-node-type (treesit-node-parent node))
+         "atx_heading"))
+
+(defun markdown-ts-imenu-name-function (node)
+  "Return an imenu entry if NODE is a valid header."
+  (let ((name (treesit-node-text node)))
+    (if (markdown-ts-imenu-node-p node)
+       (thread-first (treesit-node-parent node)(treesit-node-text))
+      name)))
+
+(defun markdown-ts-setup ()
+  "Setup treesit for `markdown-ts-mode'."
+  (setq-local treesit-font-lock-settings markdown-ts--treesit-settings)
+  (treesit-major-mode-setup))
+
+;;;###autoload
+(define-derived-mode markdown-ts-mode text-mode "Markdown"
+  "Major mode for editing Markdown using tree-sitter grammar."
+  (setq-local font-lock-defaults nil
+                 treesit-font-lock-feature-list '((delimiter)
+                                                  (paragraph)
+                                                  (paragraph-inline)))
+
+  (setq-local treesit-simple-imenu-settings
+              `(("Headings" markdown-ts-imenu-node-p nil markdown-ts-imenu-name-function)))
+
+  (when (treesit-ready-p 'markdown)
+    (treesit-parser-create 'markdown-inline)
+    (treesit-parser-create 'markdown)
+    (markdown-ts-setup)))
+
+(derived-mode-add-parents 'markdown-ts-mode '(markdown-mode))
+
+(if (treesit-ready-p 'markdown)
+    (add-to-list 'auto-mode-alist '("\\.md\\'" . markdown-ts-mode)))
+
+(provide 'markdown-ts-mode)
+;;; markdown-ts-mode.el ends here