Guarantee that port-type specifies standard operations.

diff --git a/v7/src/runtime/port.scm b/v7/src/runtime/port.scm
index 4acce0dc895e06fe7451187804e16de0f49baf5f..fd1e31430897f8a9176269941fba84ff708316d1 100644 (file)
--- a/v7/src/runtime/port.scm
+++ b/v7/src/runtime/port.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: port.scm,v 1.18 1999/02/25 18:23:06 cph Exp $
+$Id: port.scm,v 1.19 1999/02/25 18:23:55 cph Exp $
 
 Copyright (c) 1991-1999 Massachusetts Institute of Technology
 
@@ -396,7 +396,8 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
             (or (assq 'WRITE-CHAR operations)
                 (assq 'WRITE-SUBSTRING operations))))
        (if (not (or input? output?))
-           (error "No standard operations specified:" operations))
+           (error "Port type must implement one of the following operations:"
+                  '(READ-CHAR WRITE-CHAR WRITE-SUBSTRING)))
        (install-operations! type input?
                             input-operation-names
                             input-operation-modifiers