X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fcontext.cc;h=36e506cd7e01d88891b57ac5c68f6817183eafc5;hb=5b4b0d6e9a197e8f9eb085b7c2ad78b8be3e5cfc;hp=f8d84f2d41251e59de4ba22e88618197542d64ae;hpb=5d1ddaf889233f8e5c32a118f9e843e1becca2d2;p=lilypond.git diff --git a/lily/context.cc b/lily/context.cc index f8d84f2d41..36e506cd7e 100644 --- a/lily/context.cc +++ b/lily/context.cc @@ -1,29 +1,31 @@ -/* - context.cc -- implement Context +/* + context.cc -- implement Context source file of the GNU LilyPond music typesetter - (c) 2004--2005 Han-Wen Nienhuys - + (c) 2004--2008 Han-Wen Nienhuys */ #include "context.hh" #include "context-def.hh" +#include "dispatcher.hh" +#include "global-context.hh" +#include "international.hh" #include "ly-smobs.icc" #include "main.hh" #include "output-def.hh" +#include "profile.hh" +#include "program-option.hh" #include "scm-hash.hh" -#include "score-context.hh" #include "translator-group.hh" #include "warn.hh" -#include "lilypond-key.hh" bool Context::is_removable () const { - return context_list_ == SCM_EOL && ! iterator_count_ && - !dynamic_cast (this); + return context_list_ == SCM_EOL && ! iterator_count_ + && !dynamic_cast (daddy_context_); } void @@ -31,19 +33,22 @@ Context::check_removal () { for (SCM p = context_list_; scm_is_pair (p); p = scm_cdr (p)) { - Context *trg = unsmob_context (scm_car (p)); + Context *ctx = unsmob_context (scm_car (p)); - trg->check_removal (); - if (trg->is_removable ()) + ctx->check_removal (); + if (ctx->is_removable ()) { - recurse_over_translators (trg, &Translator::finalize, UP); - remove_context (trg); + recurse_over_translators (ctx, &Translator::finalize, + &Translator_group::finalize, + UP); + send_stream_event (ctx, "RemoveContext", 0, 0); } } } -Context::Context (Context const&) +Context::Context (Context const &src) { + (void) src; assert (false); } @@ -54,233 +59,304 @@ Context::properties_dict () const } void -Context::add_context (Context *t) +Context::add_context (Context *child) { - SCM ts = t->self_scm (); context_list_ = ly_append2 (context_list_, - scm_cons (ts, SCM_EOL)); - - t->daddy_context_ = this; - if (!t->init_) - { - t->init_ = true; + scm_cons (child->self_scm (), SCM_EOL)); - scm_gc_unprotect_object (ts); - Context_def *td = unsmob_context_def (t->definition_); - - /* - this can not move before add_context (), because \override - operations require that we are in the hierarchy. - */ - td->apply_default_property_operations (t); - - recurse_over_translators (t, &Translator::initialize, DOWN); - } + child->daddy_context_ = this; + this->events_below_->register_as_listener (child->events_below_); } -Object_key const* -Context::get_key () const -{ - return key_; -} -Context::Context (Object_key const* key) +Context::Context () { - key_ = key; daddy_context_ = 0; - init_ = false; aliases_ = SCM_EOL; - iterator_count_ = 0; - implementation_ = SCM_EOL; + iterator_count_ = 0; + implementation_ = 0; properties_scm_ = SCM_EOL; accepts_list_ = SCM_EOL; context_list_ = SCM_EOL; definition_ = SCM_EOL; - + definition_mods_ = SCM_EOL; + event_source_ = 0; + events_below_ = 0; + smobify_self (); - properties_scm_ = (new Scheme_hash_table)->self_scm (); - scm_gc_unprotect_object (properties_scm_); - scm_gc_unprotect_object (key_->self_scm ()); + + Scheme_hash_table *tab = new Scheme_hash_table; + properties_scm_ = tab->unprotect (); + event_source_ = new Dispatcher (); + event_source_->unprotect (); + events_below_ = new Dispatcher (); + events_below_->unprotect (); } -/* - TODO: this shares code with find_create_context(). - */ -Context* -Context::create_unique_context (SCM n, SCM operations) +/* TODO: this shares code with find_create_context (). */ +Context * +Context::create_unique_context (SCM name, string id, SCM operations) { /* Don't create multiple score contexts. - */ - if (dynamic_cast (this) - && dynamic_cast (this)->get_score_context ()) - return get_score_context ()->create_unique_context (n, operations); - - /* - TODO: use accepts_list_. - */ - Link_array path - = unsmob_context_def (definition_)->path_to_acceptable_context (n, get_output_def ()); + */ + Global_context *gthis = dynamic_cast (this); + if (gthis && gthis->get_score_context ()) + return gthis->get_score_context ()->create_unique_context (name, id, operations); + vector path = path_to_acceptable_context (name); if (path.size ()) { - Context * current = this; + Context *current = this; - // start at 1. The first one (index 0) will be us. - for (int i = 0; i < path.size (); i++) + // Iterate through the path and create all of the implicit contexts. + for (vsize i = 0; i < path.size (); i++) { - SCM ops = (i == path.size () -1) ? operations : SCM_EOL; - + SCM ops = SCM_EOL; + string id_str = "\\new"; + if (i == path.size () - 1) + { + ops = operations; + id_str = id; + } current = current->create_context (path[i], - "\\new", - ops); + id_str, + ops); } return current; } /* - Don't go up to Global_context, because global goes down to - Score_context - */ + Don't go up to Global_context, because global goes down to the + Score context + */ Context *ret = 0; - if (daddy_context_ && !dynamic_cast (daddy_context_)) - ret = daddy_context_->create_unique_context (n, operations); + if (daddy_context_ && !dynamic_cast (daddy_context_)) + ret = daddy_context_->create_unique_context (name, id, operations); else { - warning (_f ("Cannot find or create new `%s'", - ly_symbol2string (n).to_str0 ())); + warning (_f ("cannot find or create new `%s'", + ly_symbol2string (name).c_str ())); ret = 0; } return ret; } - Context * -Context::find_create_context (SCM n, String id, SCM operations) +Context::find_create_context (SCM n, string id, SCM operations) { /* Don't create multiple score contexts. - */ - if (dynamic_cast (this) - && dynamic_cast (this)->get_score_context ()) - return get_score_context ()->find_create_context (n, id, operations); + */ + Global_context *gthis = dynamic_cast (this); + if (gthis && gthis->get_score_context ()) + return gthis->get_score_context ()->find_create_context (n, id, operations); if (Context *existing = find_context_below (this, n, id)) return existing; if (n == ly_symbol2scm ("Bottom")) { - Context* tg = get_default_interpreter (); + Context *tg = get_default_interpreter (); return tg; } - /* - TODO: use accepts_list_. - */ - Link_array path - = unsmob_context_def (definition_)->path_to_acceptable_context (n, get_output_def ()); + vector path = path_to_acceptable_context (n); if (path.size ()) { - Context * current = this; + Context *current = this; // start at 1. The first one (index 0) will be us. - for (int i = 0; i < path.size (); i++) + for (vsize i = 0; i < path.size (); i++) { SCM ops = (i == path.size () -1) ? operations : SCM_EOL; - String this_id = ""; + string this_id = ""; if (i == path.size () -1) - { - this_id = id; - } - + this_id = id; current = current->create_context (path[i], this_id, - ops); + ops); } return current; } /* - Don't go up to Global_context, because global goes down to - Score_context - */ + Don't go up to Global_context, because global goes down to the + Score context + */ Context *ret = 0; - if (daddy_context_ && !dynamic_cast (daddy_context_)) + if (daddy_context_ && !dynamic_cast (daddy_context_)) ret = daddy_context_->find_create_context (n, id, operations); else { - warning (_f ("Cannot find or create `%s' called `%s'", - ly_symbol2string (n).to_str0 (), id)); + warning (_f ("cannot find or create `%s' called `%s'", + ly_symbol2string (n).c_str (), id)); ret = 0; } return ret; } - -Context* -Context::create_context (Context_def * cdef, - String id, - SCM ops) +IMPLEMENT_LISTENER (Context, acknowledge_infant); +void +Context::acknowledge_infant (SCM sev) { - String type = ly_symbol2string (cdef->get_context_name()); - Object_key const *key = get_context_key (type, id); - Context * new_group - = cdef->instantiate (ops, key); - - new_group->id_string_ = id; - add_context (new_group); - apply_property_operations (new_group, ops); - - return new_group; + infant_event_ = unsmob_stream_event (sev); } +IMPLEMENT_LISTENER (Context, set_property_from_event); +void +Context::set_property_from_event (SCM sev) +{ + Stream_event *ev = unsmob_stream_event (sev); + + SCM sym = ev->get_property ("symbol"); + if (scm_is_symbol (sym)) + { + SCM val = ev->get_property ("value"); + bool ok = true; + if (val != SCM_EOL) + ok = type_check_assignment (sym, val, ly_symbol2scm ("translation-type?")); + if (ok) + set_property (sym, val); + } +} +IMPLEMENT_LISTENER (Context, unset_property_from_event); +void +Context::unset_property_from_event (SCM sev) +{ + Stream_event *ev = unsmob_stream_event (sev); + + SCM sym = ev->get_property ("symbol"); + type_check_assignment (sym, SCM_EOL, ly_symbol2scm ("translation-type?")); + unset_property (sym); +} -Object_key const* -Context::get_context_key (String type, String id) +/* + Creates a new context from a CreateContext event, and sends an + AnnounceNewContext event to this context. +*/ +IMPLEMENT_LISTENER (Context, create_context_from_event); +void +Context::create_context_from_event (SCM sev) { - String now_key = type + "@" + id; + Stream_event *ev = unsmob_stream_event (sev); + + string id = ly_scm2string (ev->get_property ("id")); + SCM ops = ev->get_property ("ops"); + SCM type_scm = ev->get_property ("type"); + string type = ly_symbol2string (type_scm); + + vector path = path_to_acceptable_context (type_scm); - int disambiguation_count = 0; - if (context_counts_.find (now_key) != context_counts_.end ()) + if (path.size () != 1) { - disambiguation_count = context_counts_[now_key]; + programming_error (_f ("Invalid CreateContext event: Cannot create %s context", type.c_str ())); + return; } - - context_counts_[now_key] = disambiguation_count + 1; + Context_def *cdef = path[0]; + Context *new_context = cdef->instantiate (ops); + + new_context->id_string_ = id; - return new Lilypond_context_key (get_key (), - now_mom(), - type, id, - disambiguation_count); + /* Register various listeners: + - Make the new context hear events that universally affect contexts + - connect events_below etc. properly */ + /* We want to be the first ones to hear our own events. Therefore, wait + before registering events_below_ */ + new_context->event_source ()-> + add_listener (GET_LISTENER (new_context->create_context_from_event), + ly_symbol2scm ("CreateContext")); + new_context->event_source ()-> + add_listener (GET_LISTENER (new_context->remove_context), + ly_symbol2scm ("RemoveContext")); + new_context->event_source ()-> + add_listener (GET_LISTENER (new_context->change_parent), + ly_symbol2scm ("ChangeParent")); + new_context->event_source ()-> + add_listener (GET_LISTENER (new_context->set_property_from_event), + ly_symbol2scm ("SetProperty")); + new_context->event_source ()-> + add_listener (GET_LISTENER (new_context->unset_property_from_event), + ly_symbol2scm ("UnsetProperty")); + + new_context->events_below_->register_as_listener (new_context->event_source_); + this->add_context (new_context); + + new_context->unprotect (); + + Context_def *td = unsmob_context_def (new_context->definition_); + + /* This cannot move before add_context (), because \override + operations require that we are in the hierarchy. */ + td->apply_default_property_operations (new_context); + apply_property_operations (new_context, ops); + + send_stream_event (this, "AnnounceNewContext", 0, + ly_symbol2scm ("context"), new_context->self_scm (), + ly_symbol2scm ("creator"), sev); +} + +vector +Context::path_to_acceptable_context (SCM name) const +{ + // The 'accepts elements in definition_mods_ is a list of ('accepts string), + // but the Context_def expects to see elements of the form ('accepts symbol). + SCM accepts = SCM_EOL; + for (SCM s = scm_reverse (definition_mods_); scm_is_pair (s); s = scm_cdr (s)) + if (scm_caar (s) == ly_symbol2scm ("accepts")) + { + SCM elt = scm_list_2 (scm_caar (s), scm_string_to_symbol (scm_cadar (s))); + accepts = scm_cons (elt, accepts); + } + + return unsmob_context_def (definition_)->path_to_acceptable_context (name, + get_output_def (), + accepts); + } -Object_key const* -Context::get_grob_key (String name) +Context * +Context::create_context (Context_def *cdef, + string id, + SCM ops) { - int disambiguation_count = 0; - if (grob_counts_.find (name) != grob_counts_.end ()) + infant_event_ = 0; + /* TODO: This is fairly misplaced. We can fix this when we have taken out all + iterator specific stuff from the Context class */ + event_source_-> + add_listener (GET_LISTENER (acknowledge_infant), + ly_symbol2scm ("AnnounceNewContext")); + /* The CreateContext creates a new context, and sends an announcement of the + new context through another event. That event will be stored in + infant_event_ to create a return value. */ + send_stream_event (this, "CreateContext", 0, + ly_symbol2scm ("ops"), ops, + ly_symbol2scm ("type"), cdef->get_context_name (), + ly_symbol2scm ("id"), ly_string2scm (id)); + event_source_-> + remove_listener (GET_LISTENER (acknowledge_infant), + ly_symbol2scm ("AnnounceNewContext")); + + assert (infant_event_); + SCM infant_scm = infant_event_->get_property ("context"); + Context *infant = unsmob_context (infant_scm); + + if (!infant || infant->get_parent_context () != this) { - disambiguation_count = grob_counts_[name]; + programming_error ("create_context: can't locate newly created context"); + return 0; } - grob_counts_[name] = disambiguation_count + 1; - - Object_key * k = new Lilypond_grob_key (get_key(), - now_mom(), - name, - disambiguation_count); - return k; + return infant; } - - /* Default child context as a SCM string, or something else if there is none. @@ -289,18 +365,17 @@ SCM Context::default_child_context_name () const { return scm_is_pair (accepts_list_) - ? scm_car (scm_last_pair (accepts_list_)) + ? scm_car (accepts_list_) : SCM_EOL; } - bool Context::is_bottom_context () const { return !scm_is_symbol (default_child_context_name ()); } -Context* +Context * Context::get_default_interpreter () { if (!is_bottom_context ()) @@ -308,35 +383,35 @@ Context::get_default_interpreter () SCM nm = default_child_context_name (); SCM st = find_context_def (get_output_def (), nm); - String name = ly_symbol2string (nm); + string name = ly_symbol2string (nm); Context_def *t = unsmob_context_def (st); if (!t) { - warning (_f ("can't find or create: `%s'", name.to_str0 ())); + warning (_f ("cannot find or create: `%s'", name.c_str ())); t = unsmob_context_def (this->definition_); } Context *tg = create_context (t, "", SCM_EOL); - if (!tg->is_bottom_context ()) - return tg->get_default_interpreter (); - else - return tg; + return tg->get_default_interpreter (); } return this; } /* PROPERTIES - */ -Context* -Context::where_defined (SCM sym) const +*/ +Context * +Context::where_defined (SCM sym, SCM *value) const { - if (properties_dict ()->contains (sym)) - { - return (Context*)this; - } +#ifndef NDEBUG + if (profile_property_accesses) + note_property_access (&context_property_lookup_table, sym); +#endif - return (daddy_context_) ? daddy_context_->where_defined (sym) : 0; + if (properties_dict ()->try_retrieve (sym, value)) + return (Context *)this; + + return (daddy_context_) ? daddy_context_->where_defined (sym, value) : 0; } /* @@ -345,16 +420,38 @@ Context::where_defined (SCM sym) const SCM Context::internal_get_property (SCM sym) const { +#ifndef NDEBUG + if (profile_property_accesses) + note_property_access (&context_property_lookup_table, sym); +#endif + SCM val = SCM_EOL; if (properties_dict ()->try_retrieve (sym, &val)) return val; if (daddy_context_) return daddy_context_->internal_get_property (sym); - + return val; } +/* +Called by the send_stream_event macro. props is a 0-terminated array of +properties and corresponding values, interleaved. This method should not +be called from any other place than the send_stream_event macro. +*/ +void +Context::internal_send_stream_event (SCM type, Input *origin, SCM props[]) +{ + Stream_event *e = new Stream_event (type, origin); + for (int i = 0; props[i]; i += 2) + { + e->set_property (props[i], props[i+1]); + } + event_source_->broadcast (e); + e->unprotect (); +} + bool Context::is_alias (SCM sym) const { @@ -363,7 +460,7 @@ Context::is_alias (SCM sym) const return true; if (sym == unsmob_context_def (definition_)->get_context_name ()) return true; - + return scm_c_memq (sym, aliases_) != SCM_BOOL_F; } @@ -373,54 +470,77 @@ Context::add_alias (SCM sym) aliases_ = scm_cons (sym, aliases_); } - +/* we don't (yet) instrument context properties */ +void +Context::instrumented_set_property (SCM sym, SCM val, const char*, int, const char*) +{ + internal_set_property (sym, val); +} void Context::internal_set_property (SCM sym, SCM val) { -#ifndef NDEBUG if (do_internal_type_checking_global) assert (type_check_assignment (sym, val, ly_symbol2scm ("translation-type?"))); -#endif - + properties_dict ()->set (sym, val); } /* - TODO: look up to check whether we have inherited var? - */ + TODO: look up to check whether we have inherited var? +*/ void Context::unset_property (SCM sym) { properties_dict ()->remove (sym); } -/** - Remove a context from the hierarchy. +IMPLEMENT_LISTENER (Context, change_parent); +void +Context::change_parent (SCM sev) +{ + Stream_event *ev = unsmob_stream_event (sev); + Context *to = unsmob_context (ev->get_property ("context")); + + disconnect_from_parent (); + to->add_context (this); +} + +/* + Die. The next GC sweep should take care of the actual death. */ -Context * -Context::remove_context (Context*trans) +IMPLEMENT_LISTENER (Context, remove_context); +void +Context::remove_context (SCM) { - assert (trans); + /* ugh, the translator group should listen to RemoveContext events by itself */ + Translator_group *impl = implementation (); + if (impl) + impl->disconnect_from_context (); + disconnect_from_parent (); +} - context_list_ = scm_delq_x (trans->self_scm (), context_list_); - trans->daddy_context_ = 0; - return trans; +void +Context::disconnect_from_parent () +{ + daddy_context_->events_below_->unregister_as_listener (this->events_below_); + daddy_context_->context_list_ = scm_delq_x (this->self_scm (), daddy_context_->context_list_); + daddy_context_ = 0; } /* ID == "" means accept any ID. - */ +*/ Context * -find_context_below (Context * where, - SCM type, String id) +find_context_below (Context *where, + SCM type, string id) { if (where->is_alias (type)) { if (id == "" || where->id_string () == id) return where; } - + Context *found = 0; for (SCM s = where->children_contexts (); !found && scm_is_pair (s); s = scm_cdr (s)) @@ -430,7 +550,7 @@ find_context_below (Context * where, found = find_context_below (tr, type, id); } - return found; + return found; } SCM @@ -446,18 +566,16 @@ Context::context_name_symbol () const return td->get_context_name (); } -String +string Context::context_name () const { return ly_symbol2string (context_name_symbol ()); } -Score_context* +Context * Context::get_score_context () const { - if (Score_context *sc = dynamic_cast ((Context*) this)) - return sc; - else if (daddy_context_) + if (daddy_context_) return daddy_context_->get_score_context (); else return 0; @@ -471,54 +589,65 @@ Context::get_output_def () const Context::~Context () { - } Moment Context::now_mom () const { - return daddy_context_->now_mom (); + Context const *p = this; + while (p->daddy_context_) + p = p->daddy_context_; + + return p->now_mom (); } int Context::print_smob (SCM s, SCM port, scm_print_state *) { Context *sc = (Context *) SCM_CELL_WORD_1 (s); - + scm_puts ("#<", port); - scm_puts (classname (sc), port); + scm_puts (sc->class_name (), port); if (Context_def *d = unsmob_context_def (sc->definition_)) { scm_puts (" ", port); scm_display (d->get_context_name (), port); } - if (Context *td = dynamic_cast (sc)) + if (!sc->id_string_.empty ()) { scm_puts ("=", port); - scm_puts (td->id_string_.to_str0 (), port); + scm_puts (sc->id_string_.c_str (), port); } - scm_puts (" ", port); scm_display (sc->context_list_, port); scm_puts (" >", port); - + return 1; } SCM Context::mark_smob (SCM sm) { - Context *me = (Context*) SCM_CELL_WORD_1 (sm); - scm_gc_mark (me->key_->self_scm ()); + Context *me = (Context *) SCM_CELL_WORD_1 (sm); + scm_gc_mark (me->context_list_); scm_gc_mark (me->aliases_); - scm_gc_mark (me->definition_); - scm_gc_mark (me->properties_scm_); + scm_gc_mark (me->definition_); + scm_gc_mark (me->definition_mods_); + scm_gc_mark (me->properties_scm_); scm_gc_mark (me->accepts_list_); - scm_gc_mark (me->implementation_); + + if (me->implementation_) + scm_gc_mark (me->implementation_->self_scm ()); + + if (me->event_source_) + scm_gc_mark (me->event_source_->self_scm ()); + + if (me->events_below_) + scm_gc_mark (me->events_below_->self_scm ()); return me->properties_scm_; } @@ -527,53 +656,109 @@ IMPLEMENT_SMOBS (Context); IMPLEMENT_DEFAULT_EQUAL_P (Context); IMPLEMENT_TYPE_P (Context, "ly:context?"); -bool -Context::try_music (Music* m) -{ - Translator* t = implementation (); - if (!t) - return false; - - bool b = t->try_music (m); - if (!b && daddy_context_) - b = daddy_context_->try_music (m); - - return b; -} - - -Global_context* +Global_context * Context::get_global_context () const { - if (dynamic_cast((Context*) this)) - return dynamic_cast ((Context*) this); + if (dynamic_cast ((Context *) this)) + return dynamic_cast ((Context *) this); if (daddy_context_) return daddy_context_->get_global_context (); - programming_error ("No Global context!"); + programming_error ("no Global context"); return 0; } -Context* +Context * Context::get_parent_context () const { return daddy_context_; } -Translator_group* -Context::implementation () const +/* + Ugh. Where to put this? +*/ +Rational +measure_length (Context const *context) +{ + SCM l = context->get_property ("measureLength"); + Rational length (1); + if (unsmob_moment (l)) + length = unsmob_moment (l)->main_part_; + return length; +} + +Moment +measure_position (Context const *context) { - return dynamic_cast (unsmob_translator (implementation_)); + SCM sm = context->get_property ("measurePosition"); + + Moment m = 0; + if (unsmob_moment (sm)) + { + m = *unsmob_moment (sm); + + if (m.main_part_ < Rational (0)) + { + Rational length (measure_length (context)); + while (m.main_part_ < Rational (0)) + m.main_part_ += length; + } + } + + return m; } +/* Finds the measure position after a note of length DUR that + begins at the current measure position. */ +Moment +measure_position (Context const *context, Duration const *dur) +{ + Moment pos = measure_position (context); + Rational dur_length = dur ? dur->get_length () : Rational (0); + + Moment end_pos = pos.grace_part_ < Rational(0) + ? Moment(pos.main_part_, pos.grace_part_ + dur_length) + : Moment(pos.main_part_ + dur_length, 0); + + return end_pos; +} + +int +measure_number (Context const *context) +{ + SCM barnum = context->get_property ("internalBarNumber"); + SCM smp = context->get_property ("measurePosition"); + + int bn = robust_scm2int (barnum, 0); + Moment mp = robust_scm2moment (smp, Moment (0)); + if (mp.main_part_ < Rational (0)) + bn--; + + return bn; +} + + void -Context::clear_key_disambiguations () +set_context_property_on_children (Context *trans, SCM sym, SCM val) { - grob_counts_.clear(); - context_counts_.clear(); - for (SCM s = context_list_; scm_is_pair (s); s = scm_cdr (s)) + trans->set_property (sym, ly_deep_copy (val)); + for (SCM p = trans->children_contexts (); scm_is_pair (p); p = scm_cdr (p)) { - unsmob_context (scm_car (s))->clear_key_disambiguations(); + Context *trg = unsmob_context (scm_car (p)); + set_context_property_on_children (trg, sym, ly_deep_copy (val)); } } + +bool +melisma_busy (Context *tr) +{ + SCM melisma_properties = tr->get_property ("melismaBusyProperties"); + bool busy = false; + + for (; !busy && scm_is_pair (melisma_properties); + melisma_properties = scm_cdr (melisma_properties)) + busy = busy || to_boolean (tr->internal_get_property (scm_car (melisma_properties))); + + return busy; +}