[Fix #251] Font-lock properly docstrings in the presence of metadata

Author: Bozhidar Batsov

clojure-mode.el

@@ -505,6 +505,45 @@ Called by `imenu--generic-function'."
        (1 'font-lock-regexp-grouping-construct prepend))))
   "Default expressions to highlight in Clojure mode.")
 
+(defun clojure-font-lock-syntactic-face-function (state)
+  (if (nth 3 state)
+      ;; This might be a (doc)string or a |...| symbol.
+      (let ((startpos (nth 8 state)))
+        (if (eq (char-after startpos) ?|)
+            ;; This is not a string, but a |...| symbol.
+            nil
+          (let* ((listbeg (nth 1 state))
+                 (firstsym (and listbeg
+                                (save-excursion
+                                  (goto-char listbeg)
+                                  (and (looking-at "([ \t\n]*\\(\\(\\sw\\|\\s_\\)+\\)")
+                                       (match-string 1)))))
+                 (docelt (and firstsym
+                              (function-get (intern-soft firstsym)
+                                            lisp-doc-string-elt-property))))
+            (if (and docelt
+                     ;; It's a string in a form that can have a docstring.
+                     ;; Check whether it's in docstring position.
+                     (save-excursion
+                       (when (functionp docelt)
+                         (goto-char (match-end 1))
+                         (setq docelt (funcall docelt)))
+                       (goto-char listbeg)
+                       (forward-char 1)
+                       (condition-case nil
+                           (while (and (> docelt 0) (< (point) startpos)
+                                       (progn (forward-sexp 1) t))
+                             ;; ignore metadata and type hints
+                             (unless (looking-at "[ \n\t]*\\(\\^[A-Z:].+\\|\\^?{.+\\)")
+                               (setq docelt (1- docelt))))
+                         (error nil))
+                       (and (zerop docelt) (<= (point) startpos)
+                            (progn (forward-comment (point-max)) t)
+                            (= (point) (nth 8 state)))))
+                font-lock-doc-face
+              font-lock-string-face))))
+    font-lock-comment-face))
+
 (defun clojure-font-lock-setup ()
   "Configures font-lock for editing Clojure code."
   (setq-local font-lock-multiline t)
@@ -517,7 +556,7 @@ Called by `imenu--generic-function'."
           nil
           (font-lock-mark-block-function . mark-defun)
           (font-lock-syntactic-face-function
-           . lisp-font-lock-syntactic-face-function))))
+           . clojure-font-lock-syntactic-face-function))))
 
 (defun clojure-font-lock-def-at-point (point)
   "Range between the top-most def* and the fourth element after POINT.

test.clj

@@ -26,6 +26,23 @@
     (.append buf "x is: ")
     (.append buf (str x))))
 
+;; metadata doesn't break docstrings
+(defn max
+  "Returns the greatest of the nums."
+  {:added "1.0"
+   :inline-arities >1?
+   :inline (nary-inline 'max)}
+  ([x] x)
+  ([x y] (. clojure.lang.Numbers (max x y)))
+  ([x y & more]
+     (reduce1 max (max x y) more)))
+
+(defn ^String reverse
+  "Returns s with its characters reversed."
+  {:added "1.2"}
+  [^CharSequence s]
+  (.toString (.reverse (StringBuilder. s))))
+
 ;; useful for testing docstring filling
 (defn say-hello
   "This is a long doc string to test clojure-fill-docstring. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus sed nunc luctus leo ultricies semper. Nullam id tempor mi. Cras adipiscing scelerisque purus, at semper magna tincidunt ut. Sed eget dolor vitae enim feugiat porttitor. Etiam vulputate pulvinar lacinia. Nam vitae nisl sit amet libero pulvinar pretium nec a dui. Ut luctus elit eu nulla posuere nec feugiat ipsum vehicula. Quisque eu pulvinar neque. Fusce fermentum adipiscing mauris, sit amet accumsan ante dignissim ac. Pellentesque molestie mollis condimentum.