Use nested markdown grammar for highlighting docstrings

This uses the "inline" version of the markdown grammar.

https://github.com/MDeiml/tree-sitter-markdown

see issue #18

clojure-ts-mode.el

@@ -233,6 +233,33 @@ Only intended for use at development time.")
     (rx line-start (or "defprotocol" "definterface") line-end))
   "A regular expression matching a symbol used to define an interface.")
 
+(defun clojure-ts--docstring-query (capture-symbol)
+  "Return a query that captures docstrings with CAPTURE-SYMBOL."
+  `(;; Captures docstrings in def, defonce
+    ((list_lit :anchor (sym_lit) @def_symbol
+               :anchor (sym_lit) ; variable name
+               :anchor (str_lit) ,capture-symbol
+               :anchor (_)) ; the variable's value
+     (:match ,clojure-ts--variable-definition-symbol-regexp @def_symbol))
+    ;; Captures docstrings defn, defmacro, ns, and things like that
+    ((list_lit :anchor (sym_lit) @def_symbol
+               :anchor (sym_lit) ; function_name
+               :anchor (str_lit) ,capture-symbol)
+     (:match ,clojure-ts--definition-symbol-regexp @def_symbol))
+    ;; Captures docstrings in defprotcol, definterface
+    ((list_lit :anchor (sym_lit) @def_symbol
+               (list_lit
+                :anchor (sym_lit) (vec_lit) :*
+                (str_lit) ,capture-symbol :anchor)
+               :*)
+     (:match ,clojure-ts--interface-def-symbol-regexp @def_symbol))))
+
+(defvar clojure-ts--treesit-range-settings
+  (treesit-range-rules
+   :embed 'markdown_inline
+   :host 'clojure
+   (clojure-ts--docstring-query '@capture)))
+
 (defun clojure-ts--font-lock-settings ()
   "Return font lock settings suitable for use in `treesit-font-lock-settings'."
   (treesit-font-lock-rules
@@ -333,29 +360,17 @@ Only intended for use at development time.")
    '((tagged_or_ctor_lit marker: "#" @font-lock-preprocessor-face
                          tag: (sym_lit) @font-lock-preprocessor-face))
 
-   ;; Figure out how to highlight symbols in docstrings.
-   ;; Might require a markdown grammar
    :feature 'doc
    :language 'clojure
    :override t
-   `(;; Captures docstrings in def, defonce
-     ((list_lit :anchor (sym_lit) @def_symbol
-                :anchor (sym_lit) ; variable name
-                :anchor (str_lit) @font-lock-doc-face
-                :anchor (_)) ; the variable's value
-      (:match ,clojure-ts--variable-definition-symbol-regexp @def_symbol))
-     ;; Captures docstrings defn, defmacro, ns, and things like that
-     ((list_lit :anchor (sym_lit) @def_symbol
-                :anchor (sym_lit) ; function_name
-                :anchor (str_lit) @font-lock-doc-face)
-      (:match ,clojure-ts--definition-symbol-regexp @def_symbol))
-     ;; Captures docstrings in defprotcol, definterface
-     ((list_lit :anchor (sym_lit) @def_symbol
-                (list_lit
-                 :anchor (sym_lit) (vec_lit) :*
-                 (str_lit) @font-lock-doc-face :anchor)
-                :*)
-      (:match ,clojure-ts--interface-def-symbol-regexp @def_symbol)))
+   (clojure-ts--docstring-query '@font-lock-doc-face)
+
+   :feature 'markdown-doc
+   :language 'markdown_inline
+   :override t
+   `((inline (code_span
+              (code_span_delimiter) :* @font-lock-delimiter-face)
+             @font-lock-constant-face))
 
    :feature 'quote
    :language 'clojure
@@ -786,6 +801,9 @@ forms like deftype, defrecord, reify, proxy, etc."
   (unless (treesit-language-available-p 'clojure nil)
     (treesit-install-language-grammar 'clojure))
   (setq-local comment-start ";")
+  (when (treesit-ready-p 'markdown_inline 'message)
+    (treesit-parser-create 'markdown_inline)
+    (setq-local treesit-range-settings clojure-ts--treesit-range-settings))
   (when (treesit-ready-p 'clojure)
     (treesit-parser-create 'clojure)
     (setq-local treesit-font-lock-settings (clojure-ts--font-lock-settings)
@@ -798,7 +816,7 @@ forms like deftype, defrecord, reify, proxy, etc."
                 treesit-font-lock-feature-list
                 '((comment definition variable)
                   (keyword string char symbol builtin type)
-                  (constant number quote metadata doc)
+                  (constant number quote metadata doc markdown-doc)
                   (bracket deref function regex tagged-literals)))
     (when (boundp 'treesit-thing-settings) ;; Emacs 30+
       (setq-local treesit-thing-settings clojure-ts--thing-settings))

test/indentation.clj

@@ -1,4 +1,5 @@
 (ns indentation
+  "Docstring `important`. asdf"
   (:require
    [clojure.string :as str])
   (:import