Use forget-all in forget-vocab

core/generic/generic.factor

@@ -14,6 +14,15 @@ M: generic definition drop f ;
 
 GENERIC: perform-combination ( word combination -- quot )
 
+M: object perform-combination
+    #! We delay the invalid method combination error for a
+    #! reason. If we call forget-vocab on a vocabulary which
+    #! defines a method combination, a generic using this
+    #! method combination, and a method on the generic, and the
+    #! method combination is forgotten first, then forgetting
+    #! the method will throw an error. We don't want that.
+    nip [ "Invalid method combination" throw ] curry ;
+
 : make-generic ( word -- )
     dup
     dup "combination" word-prop perform-combination

core/vocabs/vocabs.factor

@@ -76,7 +76,7 @@ SYMBOL: load-vocab-hook
     [ ] subset ;
 
 : forget-vocab ( vocab -- )
-    dup vocab-words [ nip forget ] assoc-each
+    dup vocab-words values forget-all
     vocab-name dictionary get delete-at ;
 
 : child-vocab? ( prefix name -- ? )