-;;;; Copyright (C) 2000, 2001, 2004, 2006 Free Software Foundation, Inc.
+;;;; Copyright (C) 2000, 2001, 2004, 2006, 2010 Free Software Foundation, Inc.
;;;;
;;;; This library is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
-;;;; version 2.1 of the License, or (at your option) any later version.
+;;;; version 3 of the License, or (at your option) any later version.
;;;;
;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
\f
;;;; A simple value history support
-(define-module (ice-9 history))
+(define-module (ice-9 history)
+ #:export (value-history-enabled? enable-value-history! disable-value-history!
+ clear-value-history!))
-(process-define-module '((value-history)))
+(define-module* '(value-history))
+
+(define *value-history-enabled?* #f)
+(define (value-history-enabled?)
+ *value-history-enabled?*)
(define (use-value-history x)
(module-use! (current-module)
(module-export! history (list s))
(set! count c))))))
-(add-hook! before-eval-hook use-value-history)
-(add-hook! before-print-hook save-value-history)
+(define (enable-value-history!)
+ (if (not (value-history-enabled?))
+ (begin
+ (add-hook! before-eval-hook use-value-history)
+ (add-hook! before-print-hook save-value-history)
+ (set! *value-history-enabled?* #t))))
+
+(define (disable-value-history!)
+ (if (value-history-enabled?)
+ (begin
+ (remove-hook! before-eval-hook use-value-history)
+ (remove-hook! before-print-hook save-value-history)
+ (set! *value-history-enabled?* #f))))
+
+(define (clear-value-history!)
+ (let ((history (resolve-module '(value-history))))
+ (hash-clear! (module-obarray history))
+ (hash-clear! (module-obarray (module-public-interface history)))))
+
+(enable-value-history!)