;;;; 	Copyright (C) 2000, 2001 Free Software Foundation, Inc.
;;;; 
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;;;; As a special exception, the Free Software Foundation gives permission
;;;; for additional uses of the text contained in its release of GUILE.
;;;;
;;;; The exception is that, if you link the GUILE library with other files
;;;; to produce an executable, this does not by itself cause the
;;;; resulting executable to be covered by the GNU General Public License.
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;;;; 

;;;; A simple value history support

(define-module (ice-9 history))

(process-define-module '((value-history)))

(define (use-value-history x)
  (module-use! (current-module)
	       (resolve-module '(value-history))))

(define save-value-history
  (let ((count 0)
	(history (resolve-module '(value-history))))
    (lambda (v)
      (if (not (unspecified? v))
	  (let* ((c (1+ count))
		 (s (string->symbol (simple-format #f "$~A" c))))
	    (simple-format #t "~A = " s)
	    (module-define! history s v)
	    (set! count c))))))

(add-hook! before-eval-hook use-value-history)
(add-hook! before-print-hook save-value-history)
