Add clojure-discard-face

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## master (unreleased)
 
+* [#688](https://github.com/clojure-emacs/clojure-mode/issues/688): Add `clojure-discard-face` to allow for font-locking expressions discarded with the #_ form differently than comments. Maintains default by inheriting from `font-lock-comment-face`.
+
 ## 5.20.0 (2025-05-27)
 
 ### New features

README.md

@@ -388,6 +388,34 @@ instructed how to handle the docstrings and highlighting. Here's an example:
 >
 > The `clojure-doc-string-elt` attribute is processed by the function `clojure-font-lock-syntactic-face-function`.
 
+### Custom Faces
+
+`clojure-mode` defines several custom faces that you can customize to adjust the
+appearance of Clojure-specific syntax elements:
+
+- `clojure-keyword-face` - Used to highlight Clojure keywords (e.g.,
+  `:something`, `:keyword-name`). By default, this face inherits from
+  `font-lock-constant-face`.
+
+- `clojure-character-face` - Used to highlight Clojure character literals (e.g.,
+  `\a`, `\newline`, `\u00ff`). By default, this face inherits from
+  `font-lock-string-face`.
+
+- `clojure-discard-face` - Used to highlight forms that are discarded by
+  Clojure's `#_` reader macro. By default, this face inherits from
+  `font-lock-comment-face`, which visually indicates that the discarded form is
+  ignored by the reader.
+
+You can customize these faces using Emacs's customization interface
+(<kbd>M-x</kbd> `customize-face`) or by setting face attributes directly in your
+configuration. For example, to make keywords stand out with a bold blue color:
+
+```el
+(set-face-attribute 'clojure-keyword-face nil
+                    :foreground "blue"
+                    :weight 'bold)
+```
+
 ## Refactoring support
 
 The available refactorings were originally created and maintained by the

clojure-mode.el

@@ -93,6 +93,11 @@
   "Face used to font-lock Clojure keywords (:something)."
   :package-version '(clojure-mode . "3.0.0"))
 
+(defface clojure-discard-face
+  '((t (:inherit font-lock-comment-face)))
+  "Face used to font-lock forms discarded by Clojure's #_ reader macro."
+  :package-version '(clojure-mode . "5.21.0"))
+
 (defface clojure-character-face
   '((t (:inherit font-lock-string-face)))
   "Face used to font-lock Clojure character literals."
@@ -1145,7 +1150,7 @@ any number of matches of `clojure--sym-forbidden-rest-chars'."))
        (1 nil))
 
       ;; #_ and (comment ...) macros.
-      (clojure--search-comment-macro 1 font-lock-comment-face t)
+      (clojure--search-comment-macro 1 'clojure-discard-face t)
       ;; Highlight `code` marks, just like `elisp'.
       (,(rx "`" (group-n 1 (optional "#'")
                          (+ (or (syntax symbol) (syntax word)))) "`")

test/clojure-mode-font-lock-test.el

@@ -138,19 +138,19 @@ DESCRIPTION is the description of the spec."
      (1 2 nil))
 
     ("#_#_"
-     (3 2 font-lock-comment-face))
+     (3 2 clojure-discard-face))
 
     ("#_ #_"
      (1 3 nil))
 
     ("#_ #_"
-     (4 2 font-lock-comment-face))
+     (4 2 clojure-discard-face))
 
     ("#_ \n;; some crap\n (lala 0101\n lao\n\n 0 0i)"
      (1 2 nil))
 
     ("#_ \n;; some crap\n (lala 0101\n lao\n\n 0 0i)"
-     (5 41 font-lock-comment-face))
+     (5 41 clojure-discard-face))
 
     ("#_#_ \n;; some crap\n (lala 0101\n lao\n\n 0 0i)\n;; more crap\n (foobar tnseriao)"
      (1 4 nil))
@@ -159,10 +159,10 @@ DESCRIPTION is the description of the spec."
      (1 5 nil))
 
     ("#_#_ \n;; some crap\n (lala 0101\n lao\n\n 0 0i)\n;; more crap\n (foobar tnseriao)"
-     (7 75 font-lock-comment-face))
+     (7 75 clojure-discard-face))
 
     ("#_ #_ \n;; some crap\n (lala 0101\n lao\n\n 0 0i)\n;; more crap\n (foobar tnseriao)"
-     (8 75 font-lock-comment-face)))
+     (8 75 clojure-discard-face)))
 
   (when-fontifying-it "should handle namespace declarations"
     ("(ns .validns)"