Implement SAVE-EXCURSION.

diff --git a/v7/src/edwin/curren.scm b/v7/src/edwin/curren.scm
index 3180e7f1d2b34939a881f9df0747d45e1b3a893d..db970fe49909dafcf745d777a8622bcd68b08a4b 100644 (file)
--- 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))))))
 \f
 ;;;; Mark and Region