+SCM
+filter_performers (SCM ell)
+{
+ SCM *tail = ℓ
+ for (SCM p = ell; scm_is_pair (p); p = scm_cdr (p))
+ {
+ if (dynamic_cast<Performer *> (unsmob_translator (scm_car (*tail))))
+ *tail = scm_cdr (*tail);
+ else
+ tail = SCM_CDRLOC (*tail);
+ }
+ return ell;
+}
+
+SCM
+filter_engravers (SCM ell)
+{
+ SCM *tail = ℓ
+ for (SCM p = ell; scm_is_pair (p); p = scm_cdr (p))
+ {
+ if (dynamic_cast<Engraver *> (unsmob_translator (scm_car (*tail))))
+ *tail = scm_cdr (*tail);
+ else
+ tail = SCM_CDRLOC (*tail);
+ }
+ return ell;
+}
+
+/*
+ Create a new translator for a newly created child context. Triggered
+ by AnnounceNewContext events.
+ */
+IMPLEMENT_LISTENER (Translator_group, create_child_translator);
+void
+Translator_group::create_child_translator (SCM sev)
+{
+ Stream_event *ev = unsmob_stream_event (sev);
+ // get from AnnounceNewContext
+ SCM cs = ev->get_property ("context");
+ Context *new_context = unsmob_context (cs);
+ Context_def *def = unsmob_context_def (new_context->get_definition ());
+ SCM ops = new_context->get_definition_mods ();
+
+ SCM trans_names = def->get_translator_names (ops);
+
+ Translator_group *g = get_translator_group (def->get_translator_group_type ());
+ SCM trans_list = SCM_EOL;
+
+ for (SCM s = trans_names; scm_is_pair (s); s = scm_cdr (s))
+ {
+ Translator *type = get_translator (scm_car (s));
+ if (!type)
+ warning (_f ("can't find: `%s'", ly_symbol2string (scm_car (s)).c_str ()));
+ else
+ {
+ Translator *tr = type->clone ();
+ SCM str = tr->self_scm ();
+
+ if (tr->must_be_last ())
+ {
+ SCM cons = scm_cons (str, SCM_EOL);
+ if (scm_is_pair (trans_list))
+ scm_set_cdr_x (scm_last_pair (trans_list), cons);
+ else
+ trans_list = cons;
+ }
+ else
+ trans_list = scm_cons (str, trans_list);
+
+ tr->daddy_context_ = new_context;
+ tr->unprotect ();
+ }
+ }
+
+ g->simple_trans_list_ = trans_list;
+
+ /* Filter unwanted translator types. Required to make
+ \with {\consists "..."} work. */
+ if (dynamic_cast<Engraver_group *> (g))
+ g->simple_trans_list_ = filter_performers (g->simple_trans_list_);
+ else if (dynamic_cast<Performer_group *> (g))
+ g->simple_trans_list_ = filter_engravers (g->simple_trans_list_);
+
+ // TODO: scrap Context::implementation
+ new_context->implementation_ = g;
+
+ g->connect_to_context (new_context);
+ g->unprotect ();
+
+ recurse_over_translators (new_context,
+ &Translator::initialize,
+ &Translator_group::initialize,
+ DOWN);
+}
+