#include "music-list.hh"
#include "request-chord-iterator.hh"
+/*
+ Invariant for the data structure.
+
+
+ if (gh_pair_p (cursor_))
+ iter_p_->music_l_ == unsmob_music (gh_car (cursor_))
+ else
+ iter_p_ == 0;
+
+ The length of musiclist from start to up to cursor_ (cursor_ not
+ including), is summed
+
+ here_mom_ = sum (length (musiclist [start ... cursor> )) %)
+
+ */
+
+
Sequential_music_iterator::Sequential_music_iterator ()
{
- cursor_ = 0;
- here_mom_ = 0;
+ cursor_ = SCM_EOL;
+ here_mom_ = Moment (0);
+
iter_p_ =0;
}
{
cursor_ = src.cursor_;
here_mom_ = src.here_mom_;
- iter_p_ = src.iter_p_->clone ();
+ if (src.iter_p_)
+ iter_p_ = src.iter_p_->clone ();
+ else
+ iter_p_ = 0;
}
Sequential_music_iterator::~Sequential_music_iterator()
{
- if (iter_p_)
- {
- /* if (iter_p_->ok () )
- music_l_->origin ()->warning (_ ("Must stop before this music ends"));
- */
- delete iter_p_;
- iter_p_ = 0;
- }
+ delete iter_p_;
}
-
void
Sequential_music_iterator::construct_children()
{
cursor_ = dynamic_cast<Music_sequence const*> (music_l_)->music_list ();
-
- while (gh_pair_p (cursor_ ))
+
+ iter_p_ = gh_pair_p (cursor_) ? get_iterator_p (unsmob_music (gh_car (cursor_))) : 0;
+ while (iter_p_ && !iter_p_->ok ())
{
- start_next_element();
- if (!iter_p_->ok())
- {
- leave_element();
- }
- else
- {
- set_sequential_music_translator();
- break;
- }
+ next_element ();
}
-}
-void
-Sequential_music_iterator::leave_element()
-{
- delete iter_p_;
- iter_p_ =0;
- Moment elt_time = unsmob_music (gh_car (cursor_))->length_mom ();
- here_mom_ += elt_time;
- cursor_ =gh_cdr (cursor_);
+ /*
+ iter_p_->ok () is tautology, but what the heck.
+ */
+ if (iter_p_ && iter_p_->ok())
+ descend_to_child ();
+
}
+
+/*
+ maintain invariants: change cursor, iter and here_mom_ in one fell
+ swoop.
+*/
void
-Sequential_music_iterator::start_next_element()
+Sequential_music_iterator::next_element ()
{
- assert (!iter_p_);
- iter_p_ = get_iterator_p (unsmob_music (gh_car (cursor_)));
+ here_mom_ += iter_p_->music_length_mom ();
+ delete iter_p_;
+ cursor_ = gh_cdr (cursor_);
+
+ if (gh_pair_p (cursor_))
+ iter_p_ = get_iterator_p (unsmob_music (gh_car (cursor_)));
+ else
+ iter_p_ = 0;
}
+/*
+ move to context of child iterator if it is deeper down in the
+ hierarchy.
+ */
+
void
-Sequential_music_iterator::set_sequential_music_translator()
+Sequential_music_iterator::descend_to_child ()
{
Translator_group * child_report = child_report = iter_p_->report_to_l ();
if (dynamic_cast<Grace_iterator*> (iter_p_))
set_translator (child_report);
}
-void
-Sequential_music_iterator::skip (Moment until)
-{
- while (1)
- {
- SCM nm = iter_p_->get_music (until - here_mom_);
-
- Moment m = 0;
- for (SCM i = nm; gh_pair_p(i); i = gh_cdr (i))
- m = m >? unsmob_music (gh_car (i))->length_mom ();
-
- delete iter_p_;
-
- cursor_ = gh_cdr (cursor_);
-
- iter_p_ = 0;
- if (gh_pair_p (cursor_))
- iter_p_ = get_iterator_p (unsmob_music (gh_car (cursor_)));
- else
- return;
-
- if (m > Moment (0))
- return;
- }
-}
/*
- [todo: translate]
+ Retrieve all music (starting at HERE), until a music with length L >
+ 0 is found. From the precondition, we know that UNTIL is later than
+ the earliest event. Hence we know
- Hier staat in feite: haal alle muziek op (startend op tijd HERE) tot
- je iets met lengte L > 0 tegenkomt. Aangezien de preconditie is dat
- UNTIL het eerstvolgende event is, weet je (per definitie)
-
L >= (UNTIL - HERE)
- en iets wat hierna komt (op tijd T) komt dus na tijd
+ so something that comes after this thing with L > 0 happens after
HERE + L >= HERE + (UNTIL - HERE) = UNTIL
- Dus als je een L>0 tegenkomt, wil je de rest niet meer. Aangezien
- alles wat tot nu toe hebt gespaard op HERE begint, is dat precies wat
- je nodig hebt.
-
- Misschien kan je deze comment erbij stoppen, en moeten we de
- eigenschappen van het muziek datatype wat formaliseren, zodat deze
- redenering helderder is.
+ Hence all events after the one with L>0 are uninteresting, so we
+ ignore them.
+
*/
-#if 1
SCM
Sequential_music_iterator::get_music (Moment until)const
{
- if (until < pending_moment ())
- return SCM_EOL;
SCM s = SCM_EOL;
- SCM curs = cursor_;
- Music_iterator * iter = iter_p_->clone ();
- while (1)
+ if (until < pending_moment ())
+ return s;
+
+ Sequential_music_iterator * me =
+ dynamic_cast<Sequential_music_iterator*> (clone ());
+ while (me->ok ())
{
- SCM nm = iter->get_music (until - here_mom_);
+ SCM nm = me->iter_p_->get_music (until - me->here_mom_);
s = gh_append2 (nm, s);
Moment m = 0;
for (SCM i = nm; gh_pair_p(i); i = gh_cdr (i))
m = m >? unsmob_music (gh_car (i))->length_mom ();
- delete iter;
-
- curs = gh_cdr (curs);
-
- if (!gh_pair_p (curs) || m > Moment (0))
- return s;
+ if (m > Moment (0))
+ break ;
else
- {
- iter = get_iterator_p (unsmob_music (gh_car (curs)));
- }
+ me->next_element ();
}
+ delete me;
+
return s;
}
-#else
-SCM
-Sequential_music_iterator::get_music (Moment until) const
+/*
+ Skip events till UNTIL. We don't do any other side effects (such as
+ moving descending to child iterator contexts, because they might
+ depend on \context specs and \translator changes being executed
+
+ */
+void
+Sequential_music_iterator::skip (Moment until)
{
- Sequential_music_iterator* i = dynamic_cast<Sequential_music_iterator *> (this->clone ());
- SCM s = SCM_EOL;
- while (1)
- {
- Moment local_until = until - i->here_mom_;
- while (i->iter_p_->ok ())
- {
- Moment here = i->iter_p_->pending_moment ();
- if (here != local_until)
- goto finalise;
-
- s = gh_append2 (i->iter_p_->get_music (local_until), s);
- i->iter_p_->skip (local_until);
- }
-
- if (!i->iter_p_->ok ())
- {
- i->leave_element ();
-
- if (gh_pair_p (i->cursor_))
- i->start_next_element ();
- else
- goto finalise;
- }
- }
- finalise:
- delete i;
- return s;
+ while (ok ())
+ {
+ Moment l =iter_p_->music_length_mom ();
+ if (l >= until - here_mom_)
+ iter_p_->skip (until - here_mom_);
+
+ if (iter_p_->ok ())
+ return ;
+
+ next_element ();
+ }
}
-#endif
-
void
Sequential_music_iterator::process (Moment until)
{
- if (ok ())
+ while (iter_p_)
{
- while (1)
- {
- Moment local_until = until - here_mom_;
- while (iter_p_->ok ())
- {
- Moment here = iter_p_->pending_moment ();
- if (here != local_until)
- return ;
-
- iter_p_->process (local_until);
- }
+ iter_p_->process (until - here_mom_);
+
+ /*
+ if the iter is still OK, there must be events left that have
+
+ TIME > LEFT
- if (!iter_p_->ok ())
- {
- set_sequential_music_translator ();
- leave_element ();
-
- if (gh_pair_p (cursor_))
- start_next_element ();
- else
- return ;
- }
- }
+ */
+ if (iter_p_->ok ())
+ return ;
+
+ descend_to_child ();
+ next_element ();
}
}
projects / lilypond.git / blobdiff