Simple value history support.

[bpt/guile.git] / ice-9 / history.scm

;;;; 	Copyright (C) 2000 Free Software Foundation, Inc.
;;;; 
;;;; This program is free software; you can redistribute it and/or modify
;;;; it under the terms of the GNU General Public License as published by
;;;; the Free Software Foundation; either version 2, or (at your option)
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;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;;; GNU General Public License for more details.
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;;;; You should have received a copy of the GNU General Public License
;;;; along with this software; see the file COPYING.  If not, write to
;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
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\f
;;;; A simple value history support

(define-module (ice-9 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)