From: Chris Hanson <org/chris-hanson/cph>
Date: Thu, 12 Feb 1998 06:03:15 +0000 (+0000)
Subject: Eliminate "system" datatype.  Replace it by a simpler "subsystem
X-Git-Tag: 20090517-FFI~4861
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=e326777b380dfd508606f4147700d6cca22e84a6;p=mit-scheme.git

Eliminate "system" datatype.  Replace it by a simpler "subsystem
identification" mechanism.
---

diff --git a/v7/src/runtime/system.scm b/v7/src/runtime/system.scm
index 2b1c8c9a1..0851ef9c4 100644
--- a/v7/src/runtime/system.scm
+++ b/v7/src/runtime/system.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: system.scm,v 14.10 1998/02/12 05:56:48 cph Exp $
+$Id: system.scm,v 14.11 1998/02/12 06:03:15 cph Exp $
 
 Copyright (c) 1988-98 Massachusetts Institute of Technology
 
@@ -57,10 +57,16 @@ MIT in each case. |#
 		     (error "Illegal subsystem version:"
 			    version))))
 	    version))))
-    (remove-subsystem-identification! name)
-    (set! subsystem-identifications
-	  (append! subsystem-identifications (list (cons name version)))))
-  unspecific)
+    (let ((entry (find-entry name)))
+      (if entry
+	  (begin
+	    (set-car! entry name)
+	    (set-cdr! entry version))
+	  (begin
+	    (set! subsystem-identifications
+		  (append! subsystem-identifications
+			   (list (cons name version))))
+	    unspecific)))))
 
 (define (remove-subsystem-identification! name)
   (let loop ((previous #f) (entries subsystem-identifications))