Fix single/double quotes in sigils highlighting issue

Author: syohex

elixir-mode.el

@@ -260,12 +260,30 @@ is used to limit the scan."
     (put-text-property beg (1+ beg) 'elixir-interpolation
                        (cons (nth 3 context) (match-data)))))
 
-(defconst elixir-syntax-propertize-function
-  (syntax-propertize-rules
-   ((elixir-rx string-delimiter)
-    (0 (ignore (elixir-syntax-stringify))))
-   ((rx (group "#{" (0+ (not (any "}"))) "}"))
-    (0 (ignore (elixir-syntax-propertize-interpolation))))))
+(defconst elixir-sigil-delimiter-pair
+  '((?\( . ")")
+    (?\{ . "}")
+    (?\< . ">")
+    (?\[ . "]")))
+
+(defun elixir-syntax-replace-property-in-sigil ()
+  (let ((heredoc-p (save-excursion
+                     (goto-char (match-beginning 0))
+                     (looking-at-p "~s\"\"\""))))
+    (unless heredoc-p
+      (forward-char 1)
+      (let* ((start-delim (char-after (1- (point))))
+             (end-delim (or (assoc-default start-delim elixir-sigil-delimiter-pair)
+                            (char-to-string start-delim)))
+             (end (save-excursion
+                    (skip-chars-forward (concat "^" end-delim))
+                    (point)))
+             (word-syntax (string-to-syntax "w")))
+        (when (memq start-delim '(?' ?\"))
+          (setq end (1+ end))
+          (forward-char -1))
+        (while (re-search-forward "[\"']" end t)
+          (put-text-property (1- (point)) (point) 'syntax-table word-syntax))))))
 
 (defun elixir-syntax-propertize-function (start end)
   (let ((case-fold-search nil))
@@ -274,6 +292,8 @@ is used to limit the scan."
      (syntax-propertize-rules
       ((elixir-rx string-delimiter)
        (0 (ignore (elixir-syntax-stringify))))
+      ((elixir-rx sigils)
+       (0 (ignore (elixir-syntax-replace-property-in-sigil))))
       ((rx (group "#{" (0+ (not (any "}"))) "}"))
        (0 (ignore (elixir-syntax-propertize-interpolation)))))
      start end)))