Generate appropriate error message when ellipsis appears in template

but not in pattern.

diff --git a/v7/src/runtime/syntax-rules.scm b/v7/src/runtime/syntax-rules.scm
index 86455f0b6b42c39d7696a70f80c6b6626b53a01a..2eef9018afa39f1a7363f32beed8bfbd7a70df8f 100644 (file)
--- a/v7/src/runtime/syntax-rules.scm
+++ b/v7/src/runtime/syntax-rules.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: syntax-rules.scm,v 14.3 2003/01/31 05:00:52 cph Exp $
+$Id: syntax-rules.scm,v 14.4 2003/01/31 06:04:38 cph Exp $
 
 Copyright 1989,1990,1991,2001,2002,2003 Massachusetts Institute of Technology
 
@@ -199,7 +199,8 @@ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
                                                  ellipsis
                                                  (loop (car template)
                                                        (cons ellipsis
-                                                             ellipses))))
+                                                             ellipses))
+                                                 syntax-error))
                             (loop (cddr template) ellipses)))
          ((pair? template)
           (optimized-cons rename compare
@@ -225,22 +226,25 @@ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
            ((pair? ellipses)
             (syntax-error "Extra ellipsis in expansion." #f))))))
 
-(define (generate-ellipsis rename ellipsis body)
+(define (generate-ellipsis rename ellipsis body syntax-error)
   (let ((sids (ellipsis-sids ellipsis)))
-    (let ((name (sid-name (car sids)))
-         (expression (sid-expression (car sids))))
-      (cond ((and (null? (cdr sids))
-                 (eq? body name))
-            expression)
-           ((and (null? (cdr sids))
-                 (pair? body)
-                 (pair? (cdr body))
-                 (eq? (cadr body) name)
-                 (null? (cddr body)))
-            `(,(rename 'MAP) ,(car body) ,expression))
-           (else
-            `(,(rename 'MAP) (,(rename 'LAMBDA) ,(map sid-name sids) ,body)
-                             ,@(map sid-expression sids)))))))
+    (if (pair? sids)
+       (let ((name (sid-name (car sids)))
+             (expression (sid-expression (car sids))))
+         (cond ((and (null? (cdr sids))
+                     (eq? body name))
+                expression)
+               ((and (null? (cdr sids))
+                     (pair? body)
+                     (pair? (cdr body))
+                     (eq? (cadr body) name)
+                     (null? (cddr body)))
+                `(,(rename 'MAP) ,(car body) ,expression))
+               (else
+                `(,(rename 'MAP) (,(rename 'LAMBDA) ,(map sid-name sids)
+                                                    ,body)
+                                 ,@(map sid-expression sids)))))
+       (syntax-error "Missing ellipsis in expansion." #f))))
 \f
 (define (zero-or-more? pattern rename compare)
   (and (pair? pattern)