Embed html, yaml and toml in markdown-ts-mode.

* lisp/textmodes/markdown-ts-mode.el (markdown-ts--treesit-settings):
Use @italic on the whole 'block_quote'.
(markdown-ts-outline-predicate): New function.
(markdown-ts--range-settings): Embed 'yaml' in host 'markdown',
embed 'toml' in host 'markdown', embed 'html' in host 'markdown-inline',
and use local 'html_block'.
(markdown-ts-setup): Append html/yaml/toml to treesit-font-lock-settings
and treesit-font-lock-feature-list when their grammars are ready.
(markdown-ts-mode): Set comment-start/comment-end.
Set treesit-outline-predicate to 'markdown-ts-outline-predicate'.

* lisp/textmodes/toml-ts-mode.el
(toml-ts-mode--font-lock-feature-list): New variable.
(toml-ts-mode): Use it.

* lisp/textmodes/yaml-ts-mode.el
(yaml-ts-mode--font-lock-feature-list): New variable.
(yaml-ts-mode): Use it.
(yaml-ts-mode--outline-nodes): New variable.
(yaml-ts-mode--outline-predicate): Use it.

* lisp/treesit-x.el (liquid-generic-ts-mode):
Use 'treesit-ready-p' on optional 'yaml' grammar.
Merge 'yaml-ts-mode--font-lock-feature-list'.

lisp/textmodes/markdown-ts-mode.el

@@ -178,7 +178,8 @@ maps to tree-sitter language `cpp'.")
    :language 'markdown
    :feature 'paragraph
    :override 'prepend
-   '((block_quote_marker) @markdown-ts-delimiter
+   '((block_quote) @italic
+     (block_quote_marker) @markdown-ts-delimiter
      (fenced_code_block_delimiter) @markdown-ts-delimiter
      (fenced_code_block
       (info_string (language) @markdown-ts-language-keyword))
@@ -218,6 +219,12 @@ maps to tree-sitter language `cpp'.")
 	(thread-first (treesit-node-parent node) (treesit-node-text))
       name)))
 
+(defun markdown-ts-outline-predicate (node)
+  "Match a hierarchical section that has a heading."
+  (and (equal (treesit-node-type node) "section")
+       (when-let* ((child (treesit-node-child node 0)))
+         (equal (treesit-node-type child) "atx_heading"))))
+
 ;;; Code blocks
 
 (defvar-local markdown-ts--configured-languages nil
@@ -288,10 +295,26 @@ the same features enabled in MODE."
    :range-fn #'treesit-range-fn-exclude-children
    '((inline) @markdown-inline)
 
+   :embed 'yaml
+   :host 'markdown
+   :local t
+   '((minus_metadata) @yaml)
+
+   :embed 'toml
+   :host 'markdown
+   :local t
+   '((plus_metadata) @toml)
+
    :embed 'html
    :host 'markdown
+   :local t
    '((html_block) @html)
 
+   :embed 'html
+   :host 'markdown-inline
+   :local t
+   '((html_tag) @html)
+
    :embed #'markdown-ts--convert-code-block-language
    :host 'markdown
    :local t
@@ -304,19 +327,61 @@ the same features enabled in MODE."
   "Setup treesit for `markdown-ts-mode'."
   (setq-local treesit-font-lock-settings markdown-ts--treesit-settings)
   (setq-local treesit-range-settings (markdown-ts--range-settings))
+
+  (when (treesit-ready-p 'html t)
+    (require 'html-ts-mode)
+    (defvar html-ts-mode--font-lock-settings)
+    (defvar html-ts-mode--treesit-font-lock-feature-list)
+    (setq-local treesit-font-lock-settings
+                (append treesit-font-lock-settings
+                        html-ts-mode--font-lock-settings))
+    (setq-local treesit-font-lock-feature-list
+                (treesit-merge-font-lock-feature-list
+                 treesit-font-lock-feature-list
+                 html-ts-mode--treesit-font-lock-feature-list)))
+
+  (when (treesit-ready-p 'yaml t)
+    (require 'yaml-ts-mode)
+    (defvar yaml-ts-mode--font-lock-settings)
+    (defvar yaml-ts-mode--font-lock-feature-list)
+    (setq-local treesit-font-lock-settings
+                (append treesit-font-lock-settings
+                        yaml-ts-mode--font-lock-settings))
+    (setq-local treesit-font-lock-feature-list
+                (treesit-merge-font-lock-feature-list
+                 treesit-font-lock-feature-list
+                 yaml-ts-mode--font-lock-feature-list)))
+
+  (when (treesit-ready-p 'toml t)
+    (require 'toml-ts-mode)
+    (defvar toml-ts-mode--font-lock-settings)
+    (defvar toml-ts-mode--font-lock-feature-list)
+    (setq treesit-font-lock-settings
+          (append treesit-font-lock-settings
+                  toml-ts-mode--font-lock-settings))
+    (setq-local treesit-font-lock-feature-list
+                (treesit-merge-font-lock-feature-list
+                 treesit-font-lock-feature-list
+                 toml-ts-mode--font-lock-feature-list)))
+
   (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 comment-start "<!-- ")
+  (setq-local comment-end " -->")
+
   (setq-local font-lock-defaults nil
 	      treesit-font-lock-feature-list '((delimiter heading)
 					       (paragraph)
 					       (paragraph-inline)))
 
   (setq-local treesit-simple-imenu-settings
-              `(("Headings" markdown-ts-imenu-node-p nil markdown-ts-imenu-name-function)))
-  (setq-local treesit-outline-predicate "section")
+              `(("Headings" ,#'markdown-ts-imenu-node-p
+                 nil ,#'markdown-ts-imenu-name-function)))
+  (setq-local treesit-outline-predicate #'markdown-ts-outline-predicate)
 
   (when (and (treesit-ensure-installed 'markdown)
              (treesit-ensure-installed 'markdown-inline))

lisp/textmodes/toml-ts-mode.el

@@ -114,6 +114,13 @@
    '((ERROR) @font-lock-warning-face))
   "Font-lock settings for TOML.")
 
+(defvar toml-ts-mode--font-lock-feature-list
+  '((comment)
+    (constant number pair string)
+    (escape-sequence)
+    (delimiter error))
+  "Font-lock feature list for TOML.")
+
 (defun toml-ts-mode--defun-name (node)
   "Return the defun name of NODE.
 Return nil if there is no name or if NODE is not a defun node."
@@ -153,11 +160,7 @@ Return nil if there is no name or if NODE is not a defun node."
 
     ;; Font-lock.
     (setq-local treesit-font-lock-settings toml-ts-mode--font-lock-settings)
-    (setq-local treesit-font-lock-feature-list
-                '((comment)
-                  (constant number pair string)
-                  (escape-sequence)
-                  (delimiter error)))
+    (setq-local treesit-font-lock-feature-list toml-ts-mode--font-lock-feature-list)
 
     ;; Imenu.
     (setq-local treesit-simple-imenu-settings

lisp/textmodes/yaml-ts-mode.el

@@ -126,6 +126,13 @@
    '((ERROR) @font-lock-warning-face))
   "Tree-sitter font-lock settings for `yaml-ts-mode'.")
 
+(defvar yaml-ts-mode--font-lock-feature-list
+  '((comment)
+    (string type)
+    (constant escape-sequence number property)
+    (bracket delimiter error misc-punctuation))
+  "Tree-sitter font-lock feature list for `yaml-ts-mode'.")
+
 (defun yaml-ts-mode--fill-paragraph (&optional justify)
   "Fill paragraph.
 Behaves like `fill-paragraph', but respects block node
@@ -158,11 +165,14 @@ Return nil if there is no name or if NODE is not a defun node."
                         node "key")
                        t)))
 
+(defvar yaml-ts-mode--outline-nodes
+  (rx (or "block_mapping_pair" "block_sequence_item"))
+  "Node names for outline headings.")
+
 (defun yaml-ts-mode--outline-predicate (node)
   "Limit outlines to top-level mappings."
-  (let ((regexp (rx (or "block_mapping_pair" "block_sequence_item"))))
-    (when (string-match-p regexp (treesit-node-type node))
-      (not (treesit-node-top-level node regexp)))))
+  (when (string-match-p yaml-ts-mode--outline-nodes (treesit-node-type node))
+    (not (treesit-node-top-level node yaml-ts-mode--outline-nodes))))
 
 ;;;###autoload
 (define-derived-mode yaml-ts-mode text-mode "YAML"
@@ -183,11 +193,7 @@ Return nil if there is no name or if NODE is not a defun node."
 
     ;; Font-lock.
     (setq-local treesit-font-lock-settings yaml-ts-mode--font-lock-settings)
-    (setq-local treesit-font-lock-feature-list
-                '((comment)
-                  (string type)
-                  (constant escape-sequence number property)
-                  (bracket delimiter error misc-punctuation)))
+    (setq-local treesit-font-lock-feature-list yaml-ts-mode--font-lock-feature-list)
 
     (setq-local fill-paragraph-function #'yaml-ts-mode--fill-paragraph)
 

lisp/treesit-x.el

@@ -244,9 +244,10 @@ of `define-treesit-generic-mode'.
                                                "for_loop_statement")
                                        eos)))))
 
-  (when (treesit-ensure-installed 'yaml)
-    (defvar yaml-ts-mode--font-lock-settings)
+  (when (treesit-ready-p 'yaml t)
     (require 'yaml-ts-mode)
+    (defvar yaml-ts-mode--font-lock-settings)
+    (defvar yaml-ts-mode--font-lock-feature-list)
     (setq-local treesit-range-settings
                 (append treesit-range-settings
                         (treesit-range-rules
@@ -256,7 +257,11 @@ of `define-treesit-generic-mode'.
                          '(((front_matter) @cap)))))
     (setq-local treesit-font-lock-settings
                 (append treesit-font-lock-settings
-                        yaml-ts-mode--font-lock-settings))))
+                        yaml-ts-mode--font-lock-settings))
+    (setq-local treesit-font-lock-feature-list
+                (treesit-merge-font-lock-feature-list
+                 treesit-font-lock-feature-list
+                 yaml-ts-mode--font-lock-feature-list))))
 
 (defvar alpinejs-generic-ts-attr-regexp
   (rx bos (or "x-" ":" "@"))