    '("\\('\\w*'\\)" . font-lock-variable-name-face))
   "Minimal highlighting expressions for ParselTongue mode.")
 
-(defvar psl-indent-width 4
-  "Indent width for ParselTongue mode.")
+(defcustom psl-indent-width 4
+  "Indent width for ParselTongue mode."
+  :group 'psl-mode
+  :type 'integer)
 
 (defvar psl-mode-syntax-table
   (let ((st (make-syntax-table)))


(defvar psl-mode-hook nil
  "Hook for ParselTongue mode.")

(defvar psl-mode-map
  (let ((map (make-sparse-keymap)))

    map)
  "Keymap for ParselTongue mode.")

(defcustom psl-program-name "psl"
  "Path to the ParselTongue interpreter.

Program must accept a ParselTongue program filename as its first
argument."
  :group 'psl-mode
  :type '(file :must-match t))

(defvar psl--keywords
  '("deffun" "defvar" "in" "if" "then" "else" "while" "lambda"))
