Import guile-1.8 as multiple upstream tarball component

[lilypond.git] / guile18 / ice-9 / history.scm

diff --git a/guile18/ice-9/history.scm b/guile18/ice-9/history.scm
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+;;;;   Copyright (C) 2000, 2001, 2004, 2006 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.
+;;;; 
+;;;; This library is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;;; Lesser General Public License for more details.
+;;;; 
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;;;; 
+\f
+;;;; 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-interface '(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)
+           (module-export! history (list s))
+           (set! count c))))))
+
+(add-hook! before-eval-hook use-value-history)
+(add-hook! before-print-hook save-value-history)