From: Chris Hanson <org/chris-hanson/cph>
Date: Mon, 11 Oct 1993 11:37:49 +0000 (+0000)
Subject: Implement SAVE-EXCURSION.
X-Git-Tag: 20090517-FFI~7782
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=99c50bebb576d8e45484e0b106b8e592f60a15a6;p=mit-scheme.git

Implement SAVE-EXCURSION.
---

diff --git a/v7/src/edwin/curren.scm b/v7/src/edwin/curren.scm
index 3180e7f1d..db970fe49 100644
--- a/v7/src/edwin/curren.scm
+++ b/v7/src/edwin/curren.scm
@@ -1,6 +1,6 @@
 ;;; -*-Scheme-*-
 ;;;
-;;;	$Id: curren.scm,v 1.109 1993/08/16 08:04:34 cph Exp $
+;;;	$Id: curren.scm,v 1.110 1993/10/11 11:37:49 cph Exp $
 ;;;
 ;;;	Copyright (c) 1986, 1989-93 Massachusetts Institute of Technology
 ;;;
@@ -506,6 +506,16 @@ The buffer is guaranteed to be selected at that time."
 
 (define (current-column)
   (mark-column (current-point)))
+
+(define (save-excursion thunk)
+  (let ((point (mark-left-inserting-copy (current-point)))
+	(mark (mark-right-inserting-copy (current-mark))))
+    (thunk)
+    (let ((buffer (mark-buffer point)))
+      (if (buffer-alive? buffer)
+	  (begin
+	    (set-buffer-point! buffer point)
+	    (set-buffer-mark! buffer mark))))))
 
 ;;;; Mark and Region