Simple value history support.

ice-9/ChangeLog

@@ -1,3 +1,11 @@
+2001-03-17  Keisuke Nishida  <kxn30@po.cwru.edu>
+
+	* boot-9.scm (before-eval-hook, after-eval-hook,
+	before-print-hook, after-print-hook): New hooks.
+	(scm-style-repl): Call these hooks.
+
+	* history.scm: New file.
+
 2001-03-17  Keisuke Nishida  <kxn30@po.cwru.edu>
 
 	* time.scm: New file.

ice-9/boot-9.scm

@@ -2326,6 +2326,10 @@
 
 (define before-read-hook (make-hook))
 (define after-read-hook (make-hook))
+(define before-eval-hook (make-hook 1))
+(define after-eval-hook (make-hook 1))
+(define before-print-hook (make-hook 1))
+(define after-print-hook (make-hook 1))
 
 ;;; The default repl-reader function.  We may override this if we've
 ;;; the readline library.
@@ -2402,13 +2406,17 @@
 
 	   (-eval (lambda (sourc)
 		    (repl-report-start-timing)
-		    (start-stack 'repl-stack
+		    (run-hook before-eval-hook sourc)
-				 ;; If you change this procedure
+		    (let ((val (start-stack 'repl-stack
-				 ;; (primitive-eval), please also
+					    ;; If you change this procedure
-				 ;; modify the repl-stack case in
+					    ;; (primitive-eval), please also
-				 ;; save-stack so that stack cutting
+					    ;; modify the repl-stack case in
-				 ;; continues to work.
+					    ;; save-stack so that stack cutting
-				 (primitive-eval sourc))))
+					    ;; continues to work.
+					    (primitive-eval sourc))))
+		      (run-hook after-eval-hook sourc)
+		      val)))
+		      
 
 	   (-print (let ((maybe-print (lambda (result)
 					(if (or scm-repl-print-unspecified
@@ -2419,7 +2427,9 @@
 		     (lambda (result)
 		       (if (not scm-repl-silent)
 			   (begin
+			     (run-hook before-print-hook result)
 			     (maybe-print result)
+			     (run-hook after-print-hook result)
 			     (if scm-repl-verbose
 				 (repl-report))
 			     (force-output))))))

ice-9/history.scm

@@ -0,0 +1,39 @@
+;;;; 	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)
+;;;; any later version.
+;;;; 
+;;;; This program 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 General Public License for more details.
+;;;; 
+;;;; 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,
+;;;; Boston, MA 02111-1307 USA
+;;;; 
+
+;;;; 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)