0.6.12.64:

[sbcl.git] / src / pcl / combin.lisp

diff --git a/src/pcl/combin.lisp b/src/pcl/combin.lisp
index 1c600ff..a28a1e4 100644 (file)
--- a/src/pcl/combin.lisp
+++ b/src/pcl/combin.lisp
@@ -306,15 +306,30 @@
        (primary ())
        (after ())
        (around ()))
-    (dolist (m applicable-methods)
-      (let ((qualifiers (if (listp m)
-                           (early-method-qualifiers m)
-                           (method-qualifiers m))))
-       (cond ((member ':before qualifiers)  (push m before))
-             ((member ':after  qualifiers)  (push m after))
-             ((member ':around  qualifiers) (push m around))
-             (t
-              (push m primary)))))
+    (flet ((lose (method why)
+             (invalid-method-error
+              method
+              "The method ~S ~A.~%~
+               Standard method combination requires all methods to have one~%~
+               of the single qualifiers :AROUND, :BEFORE and :AFTER or to~%~
+               have no qualifier at all."
+              method why)))
+      (dolist (m applicable-methods)
+        (let ((qualifiers (if (listp m)
+                            (early-method-qualifiers m)
+                            (method-qualifiers m))))
+          (cond
+            ((null qualifiers) (push m primary))
+            ((cdr qualifiers)
+              (lose m "has more than one qualifier"))
+            ((eq (car qualifiers) :around)
+              (push m around))
+            ((eq (car qualifiers) :before)
+              (push m before))
+            ((eq (car qualifiers) :after)
+              (push m after))
+            (t
+              (lose m "has an illegal qualifier"))))))
     (setq before  (reverse before)
          after   (reverse after)
          primary (reverse primary)
@@ -359,7 +374,7 @@
                                     applicable-methods))
 
 (defun invalid-method-error (method format-control &rest format-arguments)
-  (error "~@<invalid method error for ~2I_~S ~I~_method: ~2I~_~?~:>"
+  (error "~@<invalid method error for ~2I~_~S ~I~_method: ~2I~_~?~:>"
         method
         format-control
         format-arguments))