step-into for hooks

core/generic/standard/standard.factor

@@ -110,6 +110,9 @@ ERROR: no-next-method class generic ;
         \ if ,
     ] [ ] make ;
 
+: single-effective-method ( obj word -- method )
+    [ order [ instance? ] with find-last nip ] keep method ;
+
 TUPLE: standard-combination # ;
 
 C: <standard-combination> standard-combination
@@ -142,8 +145,7 @@ M: standard-combination next-method-quot*
     ] with-standard ;
 
 M: standard-generic effective-method
-    [ dispatch# (picker) call ] keep
-    [ order [ instance? ] with find-last nip ] keep method ;
+    [ dispatch# (picker) call ] keep single-effective-method ;
 
 TUPLE: hook-combination var ;
 
@@ -161,6 +163,10 @@ M: hook-combination dispatch# drop 0 ;
 
 M: hook-generic extra-values drop 1 ;
 
+M: hook-generic effective-method
+    [ "combination" word-prop var>> get ] keep
+    single-effective-method ;
+
 M: hook-combination make-default-method
     [ error-method ] with-hook ;
 

extra/tools/walker/walker.factor

@@ -72,6 +72,7 @@ M: object add-breakpoint ;
     {
         { [ dup "step-into" word-prop ] [ "step-into" word-prop call ] }
         { [ dup standard-generic? ] [ effective-method (step-into-execute) ] }
+        { [ dup hook-generic? ] [ effective-method (step-into-execute) ] }
         { [ dup primitive? ] [ execute break ] }
         { [ t ] [ word-def (step-into-quot) ] }
     } cond ;