Re: Disconnected

[Han-Wen Nienhuys]

Erik Sandberg schreef:
> On 7/27/06, Han-Wen Nienhuys <address@hidden> wrote:
> > Just send me the patch, I'll see what I can do.
>
> The attached patch converts all try_music functions in *-engraver.cc. The
> conversion is trivial in most cases; there are however a couple of notes:
>
> 0. When a translator only can handle one event each moment, the
> corresponding listen_* method should display a warning on the second
> simultaneous such event. This previously happened with e.g.
> simultaneous lyric events: try_music returned false on the second
> event, which gave a 'junking event' warning. I have implemented this
> behaviour with a macro
> ASSIGN_EVENT_ONCE (event_, ev)
> which corresponds roughly to
> if (!event_) event_=ev; else warning (...);
> The macro isn't used by all translators yet.
>
> IMO, (almost) all occurences of
> event_ = ev
> inside listen_* methods should be changed into
> ASSIGN_EVENT_ONCE (event_, ev)
> because a warning should be displayed if a nonzero event_ is
> overwritten, since information is lost. Do you agree?

Yes.

> 1. some engravers read the 'name property of music and use it to play 
> around
> with strings. I tried a couple of different approaches:
> - dynamic-engraver: name is only used tested for equality, so just test
> against 'class instead.
> - paper-column-engraver: Convert event-class to string on the fly
> - piano-pedal-engraver: Calculate data statically from event-class
> name at program
> init.
>
> I think a more proper solution would be to store e.g. the grob names of
> piano-pedal as immutable properties in stream-events. I don't think it's
> worth the added complexity though, because very few event types will
> use immutable properties.
>
> 2. I discovered that there are abstract engravers (all related to 
> ligatures).
> I chose a simple approach to convert these: the subclasses of abstract
> engravers don't automatically inherit the listeners of the base class.
> I think it's possible to change that, but I don't think it's worth it
> yet (there are too few abstract engravers).

The ligature stuff is kind of strange anyway. Permission given to break it.

> 4. As a part of (3), I needed to make stream events transposable. As a
> part of this, I extracted most of Music::transpose to a new function
> which is useful for stream-events as well. I think it would be nice if
> transposition was reworked to be non-destructive, and the patch is a
> step in that direction; please complain if you don't agree.
>
> 5. We need to eliminate melisma-translator somehow, because it transfers
> information from engravers to iterators. The patch changes the 
> definitions of
> \melisma/\melismaEnd to directly generate PropertySet/Unset music 
> events. An
> alternative would be to keep the ManualMelismaEvent music, as a non-event
> iterated by a softcoded sequential-iterator.

it might even be better to write a \melisma { ... } function which 
changes the lyrics input suitably.

> And a completely unrelated issue:
> The 2.9.13 source tarball contains the files ./configure, ./aclocal.m4,
> lily/out/parser.[cc,hh]
> which shouldn't be there. Something might be missing in an upload script.

it's on purpose. This makes building from source easier.

--

Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen

LilyPond Software Design
 -- Code for Music Notation
http://www.lilypond-design.com