+void
+Folded_repeat_iterator::derived_mark () const
+{
+ if (main_iter_)
+ scm_gc_mark (main_iter_->self_scm ());
+ if (alternative_iter_)
+ scm_gc_mark (alternative_iter_->self_scm ());
+}
+
+void
+Folded_repeat_iterator::derived_substitute (Context *f, Context *t)
+{
+ if (main_iter_)
+ main_iter_->substitute_outlet (f, t);
+ if (alternative_iter_)
+ alternative_iter_->substitute_outlet (f, t);
+}