 (defun zk-file-mtime (file)
   "Retrieve modified time of FILE from cache."
   (gethash file zk-hash-mtimes))
+
+(defun zk-file-title (file)
+  "Retrieve title of FILE from cache."
+  (gethash file zk-hash-titles))
 
 (defun zk-file-summary (file)
   "Retrieve summary of FILE from cache."

  "Initialize hash tables for caching files."
  (setq zk-hash-contents (make-hash-table :test 'equal))
  (setq zk-hash-mtimes (make-hash-table :test 'equal))
  (setq zk-hash-summaries (make-hash-table :test 'equal)))

(defun zk-cache-update-all ()

  "Face for Zk filter string when regexp is invalid."
  :group 'zk-faces)

(defface zk-title-face
  '((t :inherit font-lock-function-name-face :bold t))
  "Face for Zk file titles."
  :group 'zk-faces)

(defface zk-separator-face
  '((t :inherit font-lock-comment-delimiter-face))
  "Face for Zk separator string."
  :group 'zk-faces)

(defface zk-summary-face
