+(defun notmuch-group-disjunctive-query-string (query-string)
+ "Group query if it contains a complex expression.
+
+Enclose QUERY-STRING in parentheses if it matches
+`notmuch-search-disjunctive-regexp'."
+ (if (string-match-p notmuch-search-disjunctive-regexp query-string)
+ (concat "( " query-string " )")
+ query-string))
+