[Fix #547] Fix character literal regexp (#560)

Author: yuhan0

CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ### Bugs fixed
 
+* [#547](https://github.com/clojure-emacs/clojure-mode/issues/547): Fix font-lock regex for character literals for uppercase chars and other symbols.
 * [#556](https://github.com/clojure-emacs/clojure-mode/issues/556): Fix renaming of ns aliases containing regex characters.
 * [#555](https://github.com/clojure-emacs/clojure-mode/issues/555): Fix ns detection for ns forms with complex metadata.
 * [#550](https://github.com/clojure-emacs/clojure-mode/issues/550): Fix `outline-regexp` so `outline-insert-heading` behaves correctly.

clojure-mode.el

@@ -868,7 +868,13 @@ any number of matches of `clojure--sym-forbidden-rest-chars'."))
          "\\>")
        0 font-lock-constant-face)
       ;; Character literals - \1, \a, \newline, \u0000
-      ("\\\\\\([[:punct:]]\\|[a-z0-9]+\\>\\)" 0 'clojure-character-face)
+      (,(rx "\\" (or any
+                    "newline" "space" "tab" "formfeed" "backspace"
+                    "return"
+                    (: "u" (= 4 (char "0-9a-fA-F")))
+                    (: "o" (repeat 1 3 (char "0-7"))))
+            word-boundary)
+       0 'clojure-character-face)
 
       ;; namespace definitions: (ns foo.bar)
       (,(concat "(\\<ns\\>[ \r\n\t]*"

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

@@ -884,15 +884,30 @@ DESCRIPTION is the description of the spec."
     ("\\a"
      (1 2 clojure-character-face))
 
+    ("\\A"
+     (1 2 clojure-character-face))
+
     ("\\newline"
      (1 8 clojure-character-face))
 
+    ("\\abc"
+     (1 4 nil))
+
+    ("\\newlin"
+     (1 7 nil))
+
+    ("\\newlinex"
+     (1 9 nil))
+
     ("\\1"
      (1 2 clojure-character-face))
 
     ("\\u0032"
      (1 6 clojure-character-face))
 
+    ("\\o127"
+     (1 4 clojure-character-face))
+
     ("\\+"
      (1 2 clojure-character-face))
 
@@ -903,6 +918,12 @@ DESCRIPTION is the description of the spec."
      (1 2 clojure-character-face))
 
     ("\\;"
+     (1 2 clojure-character-face))
+
+    ("\\Ω"
+     (1 2 clojure-character-face))
+
+    ("\\ク"
      (1 2 clojure-character-face)))
 
   (when-fontifying-it "should handle referred vars"